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AK-ST7FMC User`s Manual - Digi-Key

1. Page 21 AK ST7FMC Components Figure 2 1 AK ST7FMC Hardware Components 2 2 The Motor Control Board The following figure illustrates the main connectors and functions of the Motor Control board Page 22 AK ST7FMC User s Manual Figure 2 2 Motor Control Board Motor and board input power stage auxiliary power supply and voltage rectification Prototype area RS 232 connector Push buttons and trimmers for standalone operation Hall sensors input Tachometer input for closed loop controlled AC motors Three phases outputs to motor ICC connector to isolation board or directly to inDART STX Page 23 AK ST7FMC Components 9 10 A inverter and level shifter 2 3 The BLDC Motor The motor included in the AK ST7FMC Starter Kit is an AMETEK 5 BLDC Low Voltage 24 V DC Blower For electrical specifications and mechanical dimensions please refer to the AMETEK datasheets present in the SofTec Microsystems AK ST7FMC System Software CD ROM 2 4 The In Circuit Debugger Programmer inDART STX inDART STX is a powerful entry level tool for STMicroelectronics ST7 based systems inDART STX takes advantage of the STMicroelectronics STVD7 STMicroelectronics Visual Debug Integrated Development Environment and the ISP In System Programming feature to program the FLASH memory of the microcontrollers belonging to the ST72F family To
2. Closed Loop Closed Loop requires the use of the speed sensor either a tachometer or an Hall sensor and uses the PI control see real time settings below Pl values must be adjusted depending on load conditions Pl parameters not properly set may lead to unstable behavior especially in case of no load condition Speed Sensor Enable this feature if speed monitoring is required in Open Loop for Feedback efficiency versus slip characterization Page 88 AK ST7FMC User s Manual Parameter Values Description Tachometer Available when the Speed Sensor Feedback option above is Periods per enabled and specifies the number of poles pair of the tachometer Revolution generator if the tachometer has 8 pairs of poles then 8 pulses per revolution will be sent For the SELNI motor this value is fixed to 8 6 4 2 V F Curve Settings Table 6 7 AK ST7FMC Control Panel AC Motor V F Curve Settings Parameter Name Parameter Description Min Voltage Sets the maximum allowed voltage 255 corresponds to full bus voltage for low frequencies This to avoid stator winding saturation ana in turn stator overcurrent Low Frequency Frequency below which voltage cannot go higher than the minimum voltage specified by user High Frequency Frequency above which voltage can go up to the full bus voltage 255 255 6 4 3 Start Up Settings Table 6 8 AK ST7FMC Control Panel AC Motor Start Up Settin
3. Description W13 Present AC motor with tachometer sensor the tachometer signal W14 Lower position is connected to the MCIC input of the ST7FMC W15 Lower position W16 No Jumper J8 All jumpers present AC motor tachometer signal is filtered with capacitors BLDC motor sensorless method other than STMicroelectronics method the four analog inputs MCIA MCIB MCIC and MCVREF are filtered with capacitors BLDC motor Sensor mode hall sensors signals are filtered with capacitors No jumper present BLDC motor STMicroelectronics sensorless method J9 All jumpers present Connects the bus voltage to the AIN1 pin of the microcontroller and the temperature monitoring signal to the AINO pin of the microcontroller No jumper present No monitoring of bus voltage or temperature not recommended The AK ST7FMC Control Panel and the Motor Control library might not work properly if these jumpers are removed real time monitoring of bus voltage and heatsink temperature might read values leading to motor stop J10 All jumpers present May be used for wrapping purposes on ST7FMC Port E 3 0 VO pins J15 All jumpers present Always connected Page 59 Connectors and Functions 5 8 2 Connectors Summary Pinout The following table details the pinout of each of the Motor Control board s connector Table 5 7 Connectors Summary Pinout Reference Description Pinout Optional 15 V DC 0 5 A input
4. When using a BLDC motor the Motor Control board uses by default STMicroelectronics patented three resistor method for BEMF detection This method has the advantage of being implemented with few components but has the drawback of limiting the maximum duty cycle of the PWM signal applied to the power switches If a specific application requires a 100 PWM duty cycle the classical BEMF detection method must be implemented The Alternate Z Sampling daughter board allows to drive a BLDC motor using the classical BEMF detection circuit The daughter board plugs into the J11 connector and into the W14 W15 and W16 jumpers of the Motor Control board Of course motor specific resistors and capacitors must be mounted on the daughter board For detailed information please refer to STMicroelectronics AN1946 Application Note Page 25 AK ST7FMC User s Manual 3 Getting Started for BLDC Motors 3 1 Introduction The Motor Control board is interfaced to a host PC via the inDART STX in circuit debugger programmer control panel application is provided which allows you to change in real time all of the motor s electrical parameters In this way it is possible to learn all of the possibilities offered by the ST7FMC integrated motor control peripheral Caution before supplying the board double check connections make sure that there are no metal parts on below or around the PCB and that there are
5. or any other cause 0 2 Required Skills In order to profitably use the AK ST7FMC Starter Kit you should be acquainted with several skills ranging from hardware design to software design In particular you should possess the following knowledge Electrical motor knowledge Programming knowledge Assembly and C Microcontroller systems SIT architecture knowledge 0 3 Credits The AK ST7FMC Start Kit has been developed by SofTec Microsystems together with STMicroelectronics In particular the Motor Control board has been developed by STMicroelectronics A special thanks goes to the following people for contributing to this project and manual with ideas technical information diagrams Mr Matteo Borini SofTec Microsystems Mr Jean Marie Charreton STMicroelectronics Mr Arnaud Julienne STMicroelectronics Mr Vincent Onde STMicroelectronics Mr Loris Pacquola SofTec Microsystems Mr Eric Payet STMicroelectronics Mr Piero Poletto SofTec Microsystems Page 12 AK ST7FMC User s Manual Mr Jawhar Turki STMicroelectronics Mr Thomas Vicenzotto SofTec Microsystems This manual has been edited by Paolo Xausa SofTec Microsystems Page 13 AK ST7FMC User s Manual 1 Overview 1 1 What is the AK ST7FMC Starter Kit The AK ST7FMC Starter Kit is an integrated system designed to provide the user with a complete ready to use motor control application The Starter Kit is built
6. 13 Using the DataBlaze programming utility you can now program the ST7FMC microcontroller with the generated executable To launch DataBlaze select Start gt Programs gt SofTec Microsystems gt inDART STX gt ST7 gt DataBlaze Programmer 14 From the DataBlaze s main menu select Operations gt Select Device Make sure that the Programming Hardware parameter 1 set to inDART STX and that the Device Code parameter specifies the ST7FMC2N6B microcontroller Click the OK button 15 From the DataBlaze s main menu select File gt Load gt Code Buffer Change the Format parameter to Motorola S Rec and browse for the BLDC_Metrowerks s19 file located under the object Metrowerks subdirectory in your working directory Click the OK button 16 From the DataBlaze s main menu select Edit gt Option Bytes The Option Bytes must be edited as detailed in the table below Table 5 2 Option Bytes Settings for ST7FMC Programming Option Bits Setting FMP_R Read Out Protection Read Out Protection Disabled DIV2 Divider by 2 DIV2 divider enabled RSTC RESET Clock Cycle Selection Reset phase with 4096 CPU cycles VD Voltage Detection Selection LVD and AVD On CKSEL Clock Source Selection PLL clock selected WDG_SW Watchdog Activation Software WDG_HALT Watchdog and Halt Mode Reset in HALT MCO Motor Control Output Options Low PKG Packag
7. 89 6 4 4 Real Time Settings 90 6 4 5 Advanced Settings 91 Electrical Specifications 93 AK ST7FMC User s Manual Index Figure 2 1 Figure 2 2 Figure 3 1 Figure 3 2 Figure 4 1 Figure 5 1 Figure 5 2 Figure 5 3 Figure 5 4 Figure 5 5 Figure 5 6 Figure 5 7 Figure 5 8 Figure 6 1 Figure 6 2 Figure 6 3 Figure 6 4 Figure 6 5 of Figures AK ST7FMC Hardware Components 22 Motor Control Board 23 Motor Type Choice Dialog Box 29 AK ST7FMC Control Panel Main Window for BLDC Motors 30 AK ST7FMC Control Panel Main Window for AC Motors 37 Power Supply Connectors 40 BLDC Motor Closed Loop Parameters Collecting 43 AC Motor Closed Loop Parameters Collecting Ki Kp 47 AC Motor Closed Loop Parameters Collecting Slip Frequency 47 Push Buttons 49 Potentiometers 50 Motor Outputs and Feedback 53 Motor Outputs and Feedback 55 AK ST7FMC Control Panel Main Window for BLDC Motors 70 BLDC Motor Advanced Settings Dialog Box 78 BLDC Motor BEMF Sampling Methods 86 AK ST7FMC Control Panel Main Window for AC Motors 87 AC Motor Advanced Settings Dialog Box 91 AK ST7FMC User s Manual Index of Tables Table 5 1 BLDC Motor Closed Loop Standalone Firmware Defines 44 Table 5 2 Option Bytes Settings for ST7FMC Programming 45 Table 5 3 AC Motor Closed Loop Standalone Firmware Defines 48 Table 5 4 Open and Closed Loop Standalone Controls for a BLDC Motor 51 Table 5 5 Open and Closed Loop Standalone Controls for a
8. Optoisolation Board Supply 40 5 1 3 Power Supply Connectors Summary 40 5 2 Push Buttons and Potentiometer Standalone Mode 41 5 2 1 Introduction 41 5 2 2 Preparing for Standalone Mode General Notes 41 5 2 3 Preparing for Standalone Mode BLDC Motors 42 5 2 4 Preparing for Standalone Mode AC Motors 46 5 2 5 Push Buttons 49 5 2 6 Potentiometers 50 5 2 7 Standalone Mode Driving a BLDC Motor 50 5 2 8 Standalone Mode Driving an AC Motor 51 5 3 BLDC Motor Outputs and Feedback 52 5 3 1 Introduction 52 5 3 2 Sensorless Mode STMicroelectronics Method 53 5 3 3 Sensorless Mode Standard Method 54 5 3 4 Sensor Mode 54 5 4 AC Motor Outputs and Feedback 54 5 4 1 Open Loop 54 5 4 2 Closed Loop 54 5 5 ICC Connector 55 5 6 External Power Stage Connectors 55 5 7 RS 232 Connector 56 5 8 Summary of Jumper and Connector Settings 57 5 8 1 Jumpers Summary 57 5 8 2 Connectors Summary Pinout 60 5 8 3 Jumper Settings for a BLDC Motor Default 64 5 8 4 Jumper Settings for an AC Motor 65 6 AK ST7FMC Control Panel Features 67 6 1 Introduction 67 AK ST7FMC User s Manual 6 2 6 3 6 4 6 1 1 Suggested BLDC Motor Learning Steps 67 6 1 2 Suggested AC Motor Learning Steps 68 Motor Type Choice 69 BLDC Motor Parameters 69 6 3 1 Main Motor Settings 71 6 3 2 Start Up Settings 73 6 3 3 Real Time Settings 76 6 3 4 Advanced Settings 77 AC Motor Parameters 87 6 4 1 Main Motor Settings 88 6 4 2 V F Curve Settings 89 6 4 3 Start Up Settings
9. ST7FMC Control Panel is only one among many different start up methods For some motors it may be necessary to implement a start up strategy different than the one proposed in the AK ST7FMC Control Panel This will require the ST7FMC firmware to be edited directly without using the AK ST7FMC Control Panel The alignment phase consist in rotating the motor in a know position and to stabilize the rotor before starting To achieve this a voltage or current ramp is supplied to the motor increasing current or increasing duty cycle depending on Current or Voltage mode During the alignment phase the motor is polarized with a fixed step configuration T1 T4 T6 no rotating statoric field The acceleration phase is a phase during which synchronous rotation is forced on the motor with a fixed acceleration rate in order to get BEMF information and switch as soon as possible from Forced mode to Autoswitched mode for more information about Forced mode and Autoswitched mode please refer to the ST7FMC microcontroller datasheet Page 73 AK ST7FMC Control Panel Features Table 6 3 AK ST7FMC Control Panel BLDC Motor Start Up Settings Parameter Name Parameter Description Final Current In Current mode sets the final current at the end of the programmed alignment time MCPVH and MCPVL compare registers Final Duty Cycle In Voltage mode sets the final duty cycle at the end of the programmed alignment time MCPUH and MCPUL compare regi
10. and the motor will accelerate 7 Click the STOP button to stop the motor Page 30 AK ST7FMC User s Manual Congratulations You have successfully completed this tutorial You can now continue to experiment with the AK ST7FMC Control Panel on your own Additionally you can develop and debug your own application by installing the inDART STX for ST7 software which includes a complete development toolchain present on the SofTec Microsystems System Software CD ROM Page 31 AK ST7FMC User s Manual 4 Getting Started for AC Motors 4 1 Introduction The Motor Control board is interfaced to a host PC via the inDART STX in circuit debugger programmer A control panel application is provided which allows you to change in real time all of the motor s electrical parameters In this way it is possible to learn all of the possibilities offered by the ST7FMC integrated motor control peripheral A Caution before supplying the board double check proper connections make sure that there are no metal parts on below or around the PCB and that there are no undesired earth ground loops due to measuring equipment such as oscilloscope Caution when the Motor Control board is supplied with voltages greater than 30 V AC DC all of the board and components must be considered hot and any contact with the board must be avoided The operator should stay away from the board as well risk of pro
11. around the STMicroelectronics ST7FMC microcontroller which has a built in dedicated motor control peripheral This peripheral is particularly suited to drive brushless motors either induction or permanent magnet types The Starter Kit demonstrates how effectively the ST7FMC family of microcontrollers can be used in real world motor control applications The Starter Kit is composed of a Motor Control board a three phase permanent magnet brushless DC BLDC motor plus an in circuit debugger board and an Optoisolation board The Motor Control board has a built in power stage and is capable of directly driving both AC and DC motors The Starter Kit can be used in two ways 1 For demonstration purposes Connect your own motor and drive it A graphical user interface AK ST7FMC Control Panel is provided which allows you to change all of the driving parameters 2 For user application development A complete integrated development environment is provided which allows you to write your own software download it to the ST7FMC microcontroller and debug it A Caution The AK ST7FMC Starter Kit should only be used by engineers and technicians who are experienced in power electronics Page 15 Overview 1 2 ST7FMC Family Overview The ST7FMC microcontroller family is designed for mid range applications with a Motor Control dedicated peripheral All devices are based on a common industry standard 8 bit core featuring an enha
12. coefficients sampling time and in the Advanced Settings window software demagnetization and possibly blanking windows event counters needs to be fine tuned This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Note if the desired speed cannot be reached it may be because of the minimum and maximum speed limits set in the Advanced Settings window Please also check that the Switches PWM Minimum Off Time parameter in the Advanced Settings window is not too high only when using the STMicroelectronics patented three resistor BEMF sampling method Duty Cycle This is an Open Loop Voltage Mode parameter It is used to manually control the speed of the motor Note if the desired duty cycle cannot be reached it may be because of the maximum duty cycle set in the Advanced Settings window Please also check that the Switches PWM Minimum Off Time parameter in the Advanced Settings window is not too high only when using the STMicroelectronics patented three resistor BEMF sampling method MCPUH and MCPUL compare registers Current This is an Open Loop Current Mode parameter It is used to manually Reference control the speed of the motor MCPVH and MCPVL compare registers Delay Coefficient Value between 0 and 255 used to compute the delay between the Zero Crossing event Z and the Next Commutation event C Formula Delay Delay Coeffici
13. in Sensorless mode using STMicroelectronics patented three resistor method the W14 W15 and W16 jumpers should select the upper position default factory setting The W13 jumper and all of the J8 jumpers should be removed Additionally the Z Event Sampling Method parameter in the AK ST7FMC Control Panel in the Advanced Settings dialog box should be set to At the end of the PWM low state Page 53 Connectors and Functions 5 3 3 Sensorless Mode Standard Method To drive aBLDC motor in Sensorless mode using classic method dividers and filters on each of the three phases and reconstruction of the motor virtual neutral the Alternate Z Sampling daughter board supplied with the kit should be plugged in on the pins of the W14 W15 and W16 jumpers and on the pins of the J11 connector The W13 jumper must be removed The J8 jumpers can be kept if the provided 2 2 nF filtering capacitors are compatible with the filter needed Of course motor specific resistors and capacitors must be mounted on the daughter board see STMicroelectronics application note AN1946 Additionally the Z Event Sampling Method parameter in the AK ST7FMC Control Panel in the Advanced Settings dialog box should be set to At PWM on with delay once to At PWM on with delay at fscr frequency or to At fscr frequency 5 3 4 Sensor Mode To drive a BLDC motor in Sensor mode the W14 W15 and W16 jumpers shou
14. is related to the fact that the USB driver used by inDART STX is not digitally signed by Microsoft and Windows considers it to be potentially malfunctioning or dangerous for the system However you can safely ignore the warning since every kind of compatibility security test has been carried out by SofTec Microsystems 3 2 4 Tutorial Steps 1 Start the AK ST7FMC Control Panel by selecting Start gt Programs gt SofTec Microsystems gt AK ST7FMC gt AK ST7FMC Control Panel The AK ST7FMC Control Panel application will open 2 You will be asked what motor type you are working with Select the 3 Phase Brushless Permanent Magnet AC or DC Motor Trapezoidal option and click the OK button EE AKST7FMC Control Panel Boe Motor Type Choice 3 Phase Brushless Permanent Magnet AC or DC Motor trapezoidal 3 Phase AC Induction Motor sinewave Figure 3 1 Motor Type Choice Dialog Box Page 29 Getting Started for BLDC Motors 3 Adialog box will appear asking you to check for proper jumpers configuration Click the OK button 4 The AK ST7FMC Control Panel main window will open AK ST7FMC Control Panel EJ File Help A Main Motor Settings Motor Type Poles pairs Detection Mode Driving Speed Regulation AMETEK Motor 3 lt Sensorless Current Open Loop E Other BLPMDC Motor C Sensor 60 Voltage Closed Loop Star
15. no undesired earth ground loops due to measuring equipment such as oscilloscope 3 2 Step by Step Tutorial 3 2 1 Tools Required For this tutorial you need Motor Control board together with the provided BLDC motor The inDART STX debugger programmer Optoisolation board A24V DC 4 power supply not provided with the Starter Kit Page 27 Getting Started for BLDC Motors 3 2 2 Installing the Software Note before to connect the inDART STX board to the PC it is recommended that you install the AK ST7FMC Control Panel application first see below so that the inDART STX USB driver will be automatically found by Windows when you connect the board To install the AK ST7FMC Control Panel insert the SofTec Microsystems System Software CD ROM into your computer s CD ROM drive A startup window will automatically appear Choose Install Instrument Software from the main menu A list of available software will appear Click on the AK ST7FMC Control Panel option Follow the on screen instructions Note if you are installing the AK ST7FMC Control Panel on Windows 2000 or Windows XP you must have logged in as Administrator 3 2 3 Installing the Hardware Connection steps are listed below in the recommended flow order 1 Verify that all of the Motor Control board jumpers are in their default position as detailed in Table 5 8 Jumper Settings Exam
16. to DSO Protects against noise that may be wrongly interpreted as a Zero Crossing event After commutation there is a time window during which a Zero Crossing event cannot physically occur During this time window there should not be Z sampling MZFR register 4 bits from ZWF3 to ZWFO Z Event Counter Filter Protects against Zero Crossing Z spurious information It s possible to detect from 1 to 15 Zero Crossing events before validating the Z event MZFR register 4 bits from ZEF3 to ZEFO Delay Computation Formula Delay Delay Coefficient ZTime 256 When calculating the Delay value see the Delay Coefficient parameter in the Real Time Settings group Ztime is the time between the current Zero Crossing event and the one before or between the previous Zero Crossing event and the one preceding it Usually Current is used Previous can be selected to compensate for asymmetrical step times MCRA register DCB bit Z Event Protection If enabled the Motor Control board verifies that when a Zero Crossing event is detected the state of the BEMF signal was opposite at the previous sampling This is needed to differentiate a BEMF Zero Crossing event from a End of Demagnetization event This feature can be useful when using hardware End of Demagnetization event detection and running the motor at high speed When this parameter is enabled the Z Event Counter Filter parameter is dis
17. transceiver LIN transceiver supplied with the onboard 15 V DC mainly for debugging purposes EXT upper position External voltage is applied to the WUP pin of the L9638 LIN transceiver LIN transceiver supplied with external voltage typically the battery bus in automotive applications W10 Upper position The TDO output of the ST7FMC is directed to the L9638 LIN transceiver Lower position The TDO output of the ST7FMC is directed to ST232 UART transceiver W11 Upper position The RDI input of the ST7FMC comes from the L9638 LIN transceiver Lower position The RDI input of the ST7FMC comes from the ST232 UART transceiver W12 VARIABLE The current reference comes from a PWM generated RC filtered signal generated by the ST7FMC microcontroller Current mode or Voltage mode FIXED The current reference comes from the POT1 potentiometer Voltage mode only W13 Not present BLDC motor sensorless input on the MCIA MCIB W14 Upper position MCIC pins of the ST7FMC rotor position information W15 Upper position comes from motor s three phases W16 Upper position W13 Not present BLDC motor sensor input on the MCIA MCIB MCIC W14 Lower position pins of the ST7FMC rotor position information comes W15 Lower position from J19 W16 Lower position W13 Not present AC motor with no tachometer sensor W14 Lower position W15 Lower position W16 Lower position Page 58 AK ST7FMC User s Manual Selection
18. up to use with an AC motor as explained in Table 5 9 Jumper Settings Example for an AC Motor on page 65 2 The Motor Control board and the provided BLDC motor come assembled together over a metal support To use the AC motor you Page 34 AK ST7FMC User s Manual must first disconnect the BLDC motor cable from the MOTOR connector J12 and from the HALL SENSOR connector 419 Comnect the AC motor phases to the Motor Control board s MOTOR connector J12 with the motor cable provided with the AC motor Connect the AC motor tachometer sensor to the Motor Control board s TACHOMETER connector J16 with the tachometer cable provided with the AC motor The Motor Control board and the Optoisolation board come already connected through an ISP cable Moreover the Optoisolation board s power connector is also already connected to the Motor Control board s J2 connector In this way the Motor Control board automatically supplies the Optoisolation board Verify that both the power cable and the ISP cable are connected as stated above Connect inDART STX to the Optoisolation board with the other ISP cable provided from inDART STX s ISP connector to the Optoisolation board s ICC IN connector Connect inDART STX to the host PC with the USB cable provided The green POWER LED on the instrument will turn on Windows will automatically recognize the instrument and will load the appropriate USB
19. using STMicroelectronics patented three resistor sensorless method unused MCIx input are grounded MSCR register DISS bit BEMF Sampling Method Z Event Sampling Method At end of the PWM low state To be used with STMicroelectronics patented three resistor control method This method uses the default jumper setting of the Motor Control board At PWM on with delay once To be used with sensorless classic control method The Alternate Z Sampling daughter board must be used and jumpers in the Motor Control board must be set accordingly At PWM on with delay at fSCF frequency Classic automotive method The Alternate Z Sampling daughter board must be used and jumpers in the Motor Control board must be set accordingly Page 81 AK ST7FMC Control Panel Features Parameter Name Parameter Values Description At fSCF frequency Pulse Amplitude Modulation method The Motor Control board needs to be significantly modified The figure at the end of this table illustrates these four sampling methods MCRC register SPLG bit and MCONF register 4 bits from DS3 to DSO Delay for Sampling Zero Crossing After D Blanking Window The delay between the PWM signal rising edge and start of BEMF sampling This feature is only applicable to At PWM on with delay once and At PWM on with delay at fSCF frequency Z sampling methods register 4 bits from DS3
20. with the inDART STX in circuit debugger programmer Additional information can be found in the following documents ST7FMC Datasheets STMicroelectronics Motor Control Application Notes AK ST7FMC Schematic Visual Debug Additional Documentation inDART STX for ST7 User s Manual and User s Manual Addendum All of the above documents and many more are present on the AK ST7FMC System Software CD ROM Additionally on the AK ST7FMC System Software CD ROM an interactive tutorial on electric motors is present 1 6 Software Upgrades The latest version of the AK ST7FMC system software is always available free of charge from our website http www softecmicro com When installing the AK ST7FMC system software you have the option to electronically register the product If you register the product you will be automatically notified by e mail every time a new version of the AK ST7FMC system software is available 1 7 Troubleshooting A troubleshooting guide is available online at htip mcu st com faq html Page 18 AK ST7FMC User s Manual 1 8 Getting Technical Support Technical assistance 1 provided free to all customers For technical assistance documentation and information about products and services please refer to your local SofTec Microsystems partner SofTec Microsystems offers its customers a free technical support service at support softecmicro com Before getting in contact with us we ad
21. BRUSHLESS MOTOR CONTROL MICROSYSTEMS Development Tools for the EmbeddedWorld AK ST7FMC Starter Kit for STMicroelectronics ST7FMC Motor Control Device User s Manual Revision 1 0 We want your feedback SofTec Microsystems is always on the look out for new ways to improve its Products and Services For this reason feedback comments suggestions or criticisms however small are always welcome SofTec Microsystems E mail general information info softecmicro com E mail marketing department marketing softecmicro com E mail technical support support softecmicro com Web http www softecmicro com Important SofTec Microsystems reserves the right to make improvements to the AK ST7FMC Starter Kit its documentation and software routines without notice Information in this manual is intended to be accurate and reliable However SofTec Microsystems assumes no responsibility for its use nor for any infringements of rights of third parties which may result from its use SOFTEC MICROSYSTEMS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF PRODUCTS OR INCIDENTAL OR CONSEQUENTIAL DAMAGES EVEN IF ADVISED OF THE POSSIBILITY THEREOF Trademarks STMicroelectronics is a registered trademark of STMicroelectronics Inc Metrowerks and CodeWarrior are trademarks or registered trademarks ot Metrowerks Corp Microsoft and Windows are trademarks or registered trademarks of Microsoft Co
22. FMC Control Panel la File Help Hain Motor Settings Motor Type Poles Pairs Speed Regulation Speed Sensor SELNI Induction Motor LO Open Loop Br Other 3 Phase Induction Motor ce Closed Loop VF Curve Settings Min Voltage 150 xj 255 xi 10 He Start Up Stator Frequency 115 Hz ans 50 E Duration 1800 ms Min rotor frequency to 50 100 150 200 Hz validate closed loop 10 te Real Time Settings Settings Feedback El Closed Loop Parameters Reported Frequency Power Stage Status zizi z 0 Integral Coefficient 50 Hz amp Heatsink Over temperature js 8 Motor Over Current Proportional Coefficient Kp 5 Slip Frequency ho a Do H 8 Bus Over Voltage Sampling Time 10 ms Target rotor 15 aja Motor Status frequency sisi I Reported Voltage Start up Fails Target Slip Frequency 3 2 Hz START 0 255 Motor Stalled Default Settings Advanced Settings Generate Source Files Figure 4 1 AK ST7FMC Control Panel Main Window for AC Motors 5 Click the START button A firmware will be automatically created based on all of the AK ST7FMC Control Panel s parameter and downloaded to the ST7FMC microcontroller in the Motor Control board At the end of the download phase the motor will start to run 6 Change the Target Rotor Frequency parameter to 40 by typing in the new value and pressing the Enter key The new parame
23. Name Parameter Values Description Alternate It is possible to get more reliable End of Hardware Demagnetization event detection by using Software hardware detection together with software detection This consists in extending by software after the hardware detection of D event the total demagnetization time before validating the End of Demagnetization event In both the AK ST7FMC Control Panel and in the ST7FMC firmware this is implemented by multiplying the detected hardware demagnetization time by 1 25 as in the following formula Total demagnetization time Hardware demagnetization time Ked where Ked 1 25 However when editing directly the ST7FMC firmware it is possible to change the Ked value and it is also possible add a fixed time i e Total demagnetization time Hardware demagnetization time Ked Ved where Ved is a time set by the user and which depends on several parameters including motor speed see the All Software below register bit at 1 bit SDM at 1 Page 84 AK ST7FMC User s Manual Parameter Name Parameter Values Description All Software In some situations e g when the Hardware Software option is not safe enough it may be necessary to set a demagnetization time This demagnetization time must always be equal to or higher than the physical demagnetization time of the motor winding In addition since the rotor speed will affect direct
24. Name Parameter Values Description Motor Type AMETEK Motor An 24 V BLDC blower is the default motor included in the AK ST7FMC Starter Kit This motor features 3 Hall sensors but is controlled in Sensorless mode by default It can also be controlled in Sensor mode see below The Default Settings button restores the best performance settings for this motor Other BLDC Any other BLDC motor including compressor Motor with or without sensors can be controlled by the AK ST7FMC Starter Kit Motors including compressors wound to use sinewave mode so called PMAC motors can also be controlled with optimum results in trapezoidal mode Note that all basic and advanced parameters are by default those chosen for the AMETEK motor It is unlikely that these settings will suit your motor The AK ST7FMC Control Panel can help you find these parameters Poles Pair Number of pair poles of the motor connected to the Starter Kit BLDC motors with up to 18 pairs of poles can be used Detection Mode Sensorless The default sensorless control method is the STMicroelectronics patented three resistor method Other standard sensorless methods can be implemented by modifying the Motor Control board hardware and by selecting the appropriate BEMF sampling method All sensorless methods implemented in this Starter Kit use a six step signal driving topology MCRA register bit SR at 0 Sensor 120 To run the motor in Sens
25. a classic three phase stator like that of an induction motor and the rotor has surface mounted permanent magnets In this respect the BLDC motor is equivalent to a reversed DC commutator motor in which the magnet Page 16 AK ST7FMC User s Manual rotates while the conductors remain stationary In the DC commutator motor the current polarity is altered by the commutator and brushes On the contrary in the brushless DC motor the polarity reversal is performed by power transistors switching in synchronization with the rotor position Therefore BLDC motors often incorporate either internal or external position sensors to sense the actual rotor position or the position can be detected without sensors The BLDC motor is driven by rectangular voltage strokes coupled with the given rotor position The generated stator flux interacts with the rotor flux which is generated by a rotor magnet and defines the torque and thus speed of the motor The voltage strokes must be properly applied to the two phases of the three phase winding system so that the angle between the stator flux and the rotor flux is kept close to 90 to get the maximum generated torque Due to this fact the motor requires electronic control for proper operation 1 4 The AC Induction Motor The AC induction motor is a rotating electric machine designed to operate from a three phase source of alternating voltage The stator is a classic three phase stator with the windi
26. ab Current Reference 1 Delay Coefficient 4 gt X DS a D B emf rising edge 20 4 ns en e B em falling edge 20 Main Motor Settings Detection Mode Driving Mode Speed Regulation Sensorless Current Open Loop C Sensor 60 Voltage C Closed Loop Start Up Settings Acceleration phase Mechanical Acceleration Rate 1500 Rpm s 2 Y Current 2 Number of Z events before 2 ya auto switched mode Step number without Z detection 2 Real Time Settings Feedback Electrical Frequency o Default Settings Advanced Settings Values at end of ramp Electrical og Frequency 325 Total Duration 653 ms Power Stage Status e Heatsink Over temperature Motor Over Current e Bus Over Voltage Motor Status amp Start up Fails amp Motor Stalled Generate Source Files Figure 6 1 AK ST7FMC Control Panel Main Window for BLDC Motors Note In the following tables the name of the ST7FMC registers corresponding to the AK ST7FMC Control Panel settings is reported in bold when applicable This is in order to help you establish an easy link between the AK ST7FMC Control Panel and the information available in the microcontroller datasheet Page 70 AK ST7FMC User s Manual 6 3 1 Main Motor Settings Table 6 2 AK ST7FMC Control Panel BLDC Motor Main Settings Parameter
27. abled MCRA register PZ bit Page 82 AK ST7FMC User s Manual Parameter Name Parameter Values Description Threshold Voltage When using the STMicroelectronics patented sensorless BLDC method this parameter sets the voltage of the second comparator input the voltage to be compared to first comparator input being the BEMF A list of pre set values is available When using other BEMF sampling methods requiring the reconstruction of the motor ground the external threshold option Ext Ref value should be selected and the corresponding hardware should be implemented on the Motor Control board MCRC register 3 bits from VR2 to VRO After C Blanking Window Protect against noise that may be wrongly interpreted as an End of Demagnetization D event After commutation there is a time window during which an End of Demagnetization event cannot physically occur During this time window there should not be D sampling MDFR register 4 bits from DWF3 to DWFO D Event Counter Filter Protects against End of Demagnetization D spurious information It s possible to detect from 1 to 15 D events before validating the D event MDFR register 4 bits from DEF3 to DEFO Demagnetization All Hardware The End of Demagnetization event is detected only by hardware register bit at 1 bit SDM at 0 Page 83 AK ST7FMC Control Panel Features Parameter
28. age According to V F Curve In Open Loop and for predictable load systems this option is useful to adjust the speed without taking care of the applied voltage the V F curve has been tuned to fit the load If this option is disabled then the voltage can be set in the Voltage parameter below Voltage Open Loop parameter only For a given stator frequency this is the voltage applied to the stator windings it can be any voltage below the V F limit in other words any voltage within the red area Target Rotor Frequency Closed Loop parameter only The target rotor speed frequency is the expected speed frequency of the rotor The Proportional Integral Pl control will adjust the stator voltage and frequency according to this target frequency the slip frequency and the V F curve This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Target Slip Frequency Closed Loop parameter only The slip value to be entered here should be the slip giving optimum efficiency for the given target rotor frequency and motor characteristics The PI control will adjust the stator voltage and frequency according to this slip frequency the target frequency and the V F curve This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Integral Coefficient Ki Closed Loop parameter For beginning w
29. agnetization option above is enabled Stop Condition Free Wheeling After stop the motor will continue to spin freely DC Current To slow down the motor quickly this feature Braking allows to apply active braking Brake Level Available when the DC Current Braking option above 15 selected Two of the three bridge legs are grounded and a PWM signal with 50 duty cycle maximum is applied on the third leg s high side switch In Voltage mode the duty cycle is loaded in the MCPUH and MCPUL registers In Current mode the current reference is loaded in the MCPVH and MCPVL registers Page 85 AK ST7FMC Control Panel Features Parameter Name Parameter Values Description Brake Time Available when the DC Current Braking option above is selected Time during which active braking is applied and after which the motor is free wheeling The following figures illustrates the options available for the Z Event Sampling Method parameter Sampling at end of the PWM OFF state d 4 4 Programmable delay Fi 4 Sampling at PWM ON with delay once Programmable Sampling delay fscr Sampling Sampling at PWM ON with delay at fscr frequency 9 fscr Sampling at fscr frequency Figure 6 3 BLDC Motor BEMF Sampling Methods Page 86 AK ST7FMC User s Manual 6 4 AC Motor Parameters This set of parameters allows you to control the SELNI three phase induction motor to be ordered s
30. alone Mode AC Motors section on page 46 Page 68 AK ST7FMC User s Manual 6 2 Motor Type Choice When starting the AK ST7FMC Control Panel you must choose which motor type you are working with Table 6 1 AK ST7FMC Control Panel Motor Type Choice Parameter Name Parameter Values Description Motor Type 3 Phase Controls the BLDC blower included in the AK Choice Brushless ST7FMC Starter Kit or any other BLDC Permanent motor compressor including PMAC wound Magnet AC or DC motors in six step mode Motor MDTG write once register bit at 0 Trapezoidal 3 Phase AC Controls the SELNI three phase induction motor Induction Motor not included in the AK ST7FMC Starter Kit or Sinewave any other three phase induction motor compressor in sinewave mode MDTG write once register bit at 1 6 3 BLDC Motor Parameters This set of parameters allows you to control the AMETEK BLDC blower included the kit or any other BLDC motor compressor including PMAC wound motors in six step mode Please ensure that the correct jumper settings have been set on the board Page 69 AK ST7FMC Control Panel Features E AK ST7FMC Control Panel Joy File Help Motor Type Poles pairs AMETEK Motor Other BLPMDC Motor Alignment phase Final Current 2 lo gt Alignment Duration 1250 Current me Time Settings ms lahi l
31. anced Settings button in the main AK ST7FMC Control Panel window E AC Advanced Settings y x Switches PWM Frequency 25 KHz Speed Range Minimum Stator Frequency 1 c Hz Maximum Stator Frequency 25 Hz Dead times value 10525 us Stop Condition C Free Wheeling DC Current Braking Brake Level po aj duty cycle Brake Time 3000 ms Cancel Figure 6 5 AC Motor Advanced Settings Dialog Box Page 91 AK ST7FMC Control Panel Features Table 6 10 AK ST7FMC Control Panel AC Motor Advanced Settings Parameter Name Switches PWM Frequency Parameter Values Description Inverter switches IGBT MOSFET PMW output frequency In the firmware the 12 bit timer frequency is set to the desired PWM frequency MCPOL MCPOH and MPCR registers The output polarity MPOL register 6 bits from OP5 to OPO of the six PWM outputs is fixed for the STMicroelectronics drivers and cannot be changed For sources using the opposite polarity please contact STMicroelectronics Minimum Stator Frequency Speed below which you do not want the motor to run This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Maximum Stator Frequency This is a safety value Example for a motor with a specification of 20 000 RPM absolute maximum set the same value if this speed is exceeded the rotor may be explode or bal
32. be observed When the Motor Control board is supplied with voltages greater than 30 V AC DC all of the board and components must be considered hot and any contact with the board must be avoided The operator should stay away from the board as well risk of projection of material in case of components destruction especially when powering the board with high voltages The rotating parts of motors are also a source of danger The AK ST7FMC Starter Kit contains electrostatic sensitive components which may be damaged through improper use 0 1 2 Intended Use The AK ST7FMC Starter Kit is made of components designed for demonstration purposes and must not be included in electrical installations or machinery Instructions about the setup and use of the AK ST7FMC Starter Kit must be strictly observed 0 1 3 Operation After disconnecting the board from the voltage supply several parts and power terminals must not be touched immediately because of possible energized capacitors or hot surfaces Page 11 Before Starting 0 1 4 Important Notice to Users While every effort has been made to ensure the accuracy of all information in this document SofTec Microsystems assumes no liability to any party for any loss or damage caused by errors or omissions or by statements of any kind in this document its updates supplements or special editions whether such errors are omissions or statements resulting from negligence accident
33. cient from 0 to 255 Sets the braking torque from a 0 to 40 PWM duty cycle if the PWM frequency is 12 5 KHz and from 0 to 50 for other PWM frequencies Not used Sets the Kp proportional coefficient from 0 to 255 Not used Not used Not used 5 3 BLDC Motor Outputs and Feedback 5 3 1 Introduction The Motor Control board can be configured to drive a BLDC motor in Sensor Sensorless mode Open Closed Loop mode and an AC motor in Open Closed loop This sections explains how to configure the Motor Control board to drive a BLDC motor while the next section explains how to configure the Motor Control board to drive an AC motor The following figure illustrates where the input sensor connectors the output connector motor phases and related jumper settings selectors are located Page 52 AK ST7FMC User s Manual Figure 5 7 Motor Outputs and Feedback J8 filtering capacitors jumper selection W14 W15 W16 Sensor Sensorless mode jumper selection W13 tachometer jumper selection AC motors only J19 Hall sensors input connector J12 motor phases output connector J16 tachometer input connector na sie 9 IN A BLDC motor can be controlled in Sensorless mode using STMicroelectronics patented three resistor method in Sensorless mode using classic method and in Sensor mode as detailed below 5 3 2 Sensorless Mode STMicroelectronics Method To drive a BLDC motor
34. connector to supply the Motor Control board logic separately from the motor power stage 1 15V DC Power Supply 2 VSS Power 15 V DC output connector to supply the Optoisolation board 1 15V DC Power Supply 2 VSS Power Up to 42 V DC or 30 Veff AC power supply input connector 1 Earth 2 Power Input AC DC 3 Power Input AC DC AC motor power connector when overriding internal power inverter 1 2 3 4 5 6 7 8 MCOO Motor Control Output 0 MCO2 Motor Control Output 2 4 Motor Control Output 4 MCO1 Motor Control Output 1 Motor Control Output 3 MCO5 Motor Control Output 5 MCES Motor Control Emergency Stop Selectable between 5 V and MCES see W8 Jumper 9 Selectable between 5 V and 15 V see W7 Jumper 10 VSS Board Page 60 AK ST7FMC User s Manual Reference Description Pinout LIN output connector 1 BAT LIN Transceiver External Supply Voltage 2 LIN Bidirectional I O 3 VSS Board BLDC motor power connector when overriding internal power inverter MCES Motor Control Emergency Stop VSS Board MCO1 Motor Control Output 1 VSS Board MCOO Motor Control Output 0 VSS Board Motor Control Output 3 VSS Board Motor Control Output 2 VSS Board MCO5 Motor Control Output 5 VSS Board 4 Motor Control Output 4 VSS Board 15 V DC Power Supply VSS Board MCIA Mo
35. driver Make sure that the S1 jumper selects the lt 35V ONLY position then power up the Motor Control board by connecting the output terminals of your DC power supply to the MAINS connector The provided voltage must be 30 V DC and your power supply must be able to provide a current of 4 A Page 35 Getting Started for Motors Note both Windows 2000 and Windows XP may issue a warning the first time inDART STX is connected to the PC This warning is related to the fact that the USB driver used by inDART STX is not digitally signed by Microsoft and Windows considers it to be potentially malfunctioning or dangerous for the system However you can safely ignore the warning since every kind of compatibility security test has been carried out by SofTec Microsystems 4 2 4 Tutorial Steps 1 Start the AK ST7FMC Control Panel by selecting Start gt Programs gt SofTec Microsystems gt AK ST7FMC gt AK ST7FMC Control Panel The AK ST7FMC Control Panel application will open 2 You will be asked what motor type you are working with Select the 3 Phase AC Induction Motor Sinewave option and click the OK button 3 Adialog box will appear asking you to check for proper jumpers configuration Click the OK button 4 The AK ST7FMC Control Panel main window will open Page 36 AK ST7FMC User s Manual AK ST7
36. e Selection SDIP56 17 From the DataBlaze s main menu select Operations gt Auto Make sure that all of the programming steps but Run are enabled Click the START button 18 Now the microcontroller is programmed You can unplug the ISP cable from the Motor Control board and operate the Motor Control board in standalone mode 19 To start running the microcontroller press the RESET push button For details about how to control the motor with the Motor Control Page 45 Connectors and Functions board s push buttons and potentiometers please refer to the Push Buttons Potentiometers and Standalone Mode Driving a BLDC Motor sections later in this chapter 5 2 4 Preparing for Standalone Mode AC Motors 1 2 Set up the Motor Control board as explained in the Installing the Hardware section in the Getting Started for AC Motors chapter Get the latest release of the AK ST7FMC Control Panel system software from SofTec Microsystems website http www softecmicro com uninstall the previous version and install the new one In the Program Files SofTec Microsystems AK ST7FMC Library directory there are various subdirectories each specific for a motor control type Each subdirectory contains a pre made project specific for that motor control type Copy the appropriate subdirectory the subdirectory that corresponds to your motor and control type i
37. e acceleration the BEMF may detection be too low to be detected During these first steps the BEMF detection should be inhibited Page 74 AK ST7FMC User s Manual Parameter Name Parameter Description Electrical Frequency Theoretical projected mechanical speed based on the 64th step duration and acceleration rate Based on the number of pairs of poles and acceleration rate the AK ST7FMC Control Panel will compute the length of all of the elementary 64 electrical steps of the acceleration ramp and therefore provide a projection of the mechanical frequency at the end of the 64 steps this is a theoretical value as it is unlikely that 64 steps are actually needed to start up the motor typically the motor control will be switched to Autoswitched mode within the first 10 steps This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Total Duration Theoretical duration of the acceleration phase if all of the 64 steps are completed Page 75 AK ST7FMC Control Panel Features 6 3 3 Real Time Settings Table 6 4 AK ST7FMC Control Panel BLDC Motor Real Time Settings Parameter Name Parameter Description Target Electrical Closed Loop target speed When running in Closed Loop this is a key Frequency parameter because for a given speed several other parameters in the AK ST7FMC Control Panel main window BEMF coefficients Pl control
38. ent ZTime 256 where ZTime is the time between the current Zero Crossing event and the previous Zero Crossing event or the previous two if this has been set in the Delay Computation parameter in the Advanced Setting window Rising and falling edge detection have been differentiated to compensate the small delay due to the imbalance in step time Imbalance in step time comes from the fact that the Zero Crossing event is not exactly detected at zero but slightly before falling BEMF or after rising BEMF This is caused by threshold voltage and by the asymmetrical BEMF shape on some motors Page 76 AK ST7FMC User s Manual Parameter Name Parameter Description BEMF Rising Sets the coefficient used to compute the delay when the BEMF 1 Edge rising MWGHT register Falling Sets the coefficient used to compute the delay when the BEMF 1 Edge falling MWGHT register Integral Closed Loop parameter For beginning with a new motor it is Coefficient Ki recommended to start from 0 The higher the value the shorter the time necessary to cancel the static error but a value too high will render the system unstable Proportional Coefficient Closed Loop parameter The higher the value the lower will be the static error but a value too high will render the system unstable Sampling Time The time interval between two Pl control samplings The lower the sampling time the bett
39. eparately or any other three phase induction motors compressors in sinewave mode Please ensure that the correct jumper settings has been set on the board AK ST7FMC Control Panel m File Help Main Motor Settings Motor Type Poles Pairs Speed Regulation Speed Sensor SELNI Induction Motor Open Loop vd Other 3 Phase Induction Motor Sd Closed Loop WIR Curve 0 8StaitUp Settings zi Min Voltage 150 xj 255 zi 10 4 Start Up Stator Frequency 115 Hz High Frequency 50 Hz Max Duration 1800 ms Min rotor frequency to 50 100 150 200 Hz validate closed loop te Real Time Settings Settings Feedback E E Closed Loop Parameters Reported Frequency Power Stage Status xix 0 z Integral Coefficient Ki 50 Hz Heatsink Over temperature 8 Motor Over Current Proportional Coefficient 5 Slip Frequency o 0o 8 Bus Over Voltage Sampling Time 10 ms z Target rotor 15 2 2 Hz Motor Status frequency Reported Voltage Start up Fails Target Slip Frequency 3 Hz START 0 1255 Motor Stalled Default Settings Advanced Settings Generate Source Files Figure 6 4 AK ST7FMC Control Panel Main Window for AC Motors Page 87 AK ST7FMC Control Panel Features 6 4 1 Main Motor Settings Table 6 6 AK ST7FMC Control Panel AC Motor Main Settings Parameter Name Pa
40. er will be the regulation bandwith However a value too low will not increase the system dynamic response above a certain point and will consume microcontroller resources Electrical Rotor speed reading Frequency This value can be read in Hz or RPM click the Hz or RPM button next to the value to switch between units Reported Duty Cycle Available in Closed Loop only Displays the duty cycle computed by the PI control which is directly applied on power switches in Voltage mode or used to modulate the current reference in Current mode 6 3 4 Advanced Settings BLDC motor advanced settings are available by clicking the Advanced Settings button in the main AK ST7FMC Control Panel window Page 77 AK ST7FMC Control Panel Features 3 PMDC Advanced Settings Eo PWM Settings B emf Sampling Method Switches PWM Frequency 18 1 KHz Z Event Sampling Method At end of the PWM Low state v Switches PWM Minimum Off Time 25 us El Complementary PWM Signal Disabled Zero Crossing Dead Times After D Blanking window 5 Distribution Z Event Counter Filter 1 After After Delay Computation Previous 11 74 13 12 Z Event Protection Disabled Ti T6 0 o 0 T5T2 0 0 0 Threshold Voltage 02 1376 0 0 0 TeT4 0 0 0 Demagnetization Speed Range After Blanking Window 5 jus t en D Event Counter Filter 1 Y lt en All Hardware Alternate Hardware S
41. esn t allow to set this value in real time the motor needs to be stopped each time However in the actual application the maximum current value can be programmed and modified by software in real time by varying the 8 bit ARTimer or 12 bit PWM duty cycle and connecting the 8 bit ARTimer or 12 bit PWM output to the proper RC circuit this RC circuit being connected to the current comparator input MCPVH and MCPVL compare registers Speed Open Loop No speed regulation no Proportional Integral Regulation regulation is available The motor is controlled directly by the user through duty cycle voltage mode or current reference current mode Useful to fine tune the start up parameters and the BEMF rising and falling edge coefficients Page 72 AK ST7FMC User s Manual Parameter Name Parameter Values Description Closed Loop Proportional Integral regulation is available this is done by software in the MCU The user sets a desired speed based on the Pl values for this speed the MCU defines a duty cycle voltage mode or a current reference current mode Closed Loop mode is used to implement a fine speed response and regulation 6 3 2 Start Up Settings A successful motor start up is a start up that occurs 100 of the times and in a very short time To achieve a successful start up two phases are required the alignment phase and the acceleration phase The start up method implemented in AK
42. gether with STVD7 inDART STX provides you with everything you need to write compile download in circuit emulate and debug user code Full speed program execution allows you to perform hardware and software testing in real time inDART STX is connected to the host PC through a USB port while the 10 pin probe of the product fits into the target s standard ISP connector A standalone full featured programming utility DataBlaze is also provided with inDART STX inDART STX is required to program and debug in real time the ST7FMC microcontroller present in the Motor Control board For more information on inDART STX please refer to the inDART STX for ST7 User s Manual 2 5 The Optoisolation board The Optoisolation board s purpose is to provide galvanic isolation between the inDART STX debugger programmer board and the Motor Control board The inDART STX ISP cable also called ICP cable in Page 24 AK ST7FMC User s Manual STMicroelectronics terminology plugs into the Optoisolation board while another ISP cable goes from the Optoisolation board to the Motor Control board s ICC connector The Optoisolation board helps to prevent damage to the PC in the event of a catastrophic failure on the Motor Control board This isolation barrier also solves the problem caused by the PC inDART STX and the Motor Control board being at different ground potentials 2 6 The Alternate Z Sampling Daughter Board
43. gs Parameter Name Parameter Description Voltage Slew Open Loop parameter only Time interval between two voltage Rate increments 1 255 Start Up Stator Closed Loop parameter only Inverter output frequency at start up Frequency This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Maximum Closed Loop parameter only Time after which the motor is considered Duration as not started if no speed information has been detected Minimum Rotor This frequency when reached by the rotor will trigger true Closed Frequency to Loop control by exiting the start up phase and entering the Closed Validate Closed Loop routine the start up phase is controlled in Open Loop by default Loop as no speed information is available during this phase This value is always smaller then start up frequency This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Page 89 AK ST7FMC Control Panel Features 6 4 4 Real Time Settings Table 6 9 AK ST7FMC Control Panel AC Motor Real Time Settings Parameter Name Stator Frequency Parameter Description Open Loop parameter only Defines the synchronous speed of the motor Basically it is the inverter output frequency This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Set Volt
44. he motor is supplied to the J3 connector while a separate power for the Motor Control board logic must be supplied to the J1 connector 15 V DC 0 5 A The S1 jumper must be removed Note on the J3 connector polarity of DC or AC input is not important Page 39 Connectors and Functions 5 1 2 Optoisolation Board Supply The Optoisolation board requires a 15 V DC power supply This power is conveniently provided by the Motor Control board s J2 connector Note J7 and J2 connectors are internally connected to the same 15 DC power bus 5 1 3 Power Supply Connectors Summary The following figure illustrates the location of the Motor Control board power supply connectors Figure 5 1 Power Supply Connectors 1 41 connector 15 V DC 0 5 A power supply input used for dual power supply mode 2 J2 connector 15 V DC output to Optoisolation board 3 connector Motor power supply for dual power supply mode or motor plus Motor Control board power supply for single power supply mode Up to 42 V DC or 30 Veff AC Page 40 AK ST7FMC User s Manual 4 51 jumper In single power supply mode selects the motor voltage In dual power supply mode it must be removed 5 2 Push Buttons and Potentiometer Standalone Mode 5 2 1 Introduction Four potentiometer and two push buttons are available on the Motor Control board for standalone operation no PC connection required To operate the M
45. ibution between the switches high side and low side respectively even and odd after each C D and Z event Double click to toggle from 0 to 1 and vice versa For each step it is possible to select on which active switch the PWM signal is applied after the 3 different events C D and Z This is useful to accelerate demagnetization and to reduce the level of reactive current inside the winding Example on step T1 T4 T1 is the high side even and T4 is the low side odd Setting the corresponding After C value to 1 causes the PWM signal to be applied on the odd switch T4 from the event until the event setting the After value to 0 causes the PWM signal to be applied on the even switch T1 from the D event until the Z event setting the After Z value to 1 causes the PWM signal to be applied on the odd switch T4 from the Z event until the next C event register 3 bits from OS2 to OSO Available in Closed Loop only Speed below which you do not want the motor to run This can be useful in Sensorless mode to avoid going below a speed that doesn t allow to generate enough BEMF This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Maximum Mechanical Speed Current Loop Current Blanking Window This is a safety value Example for a motor with a specification of 20 000 RPM absolute maximum set the same value if this
46. ilable in the Motor Control board A Figure 5 5 Push Buttons Page 49 Connectors and Functions 1 ON OFF starts or stops the motor 2 RESET resets the ST7FMC microcontroller 5 2 6 Potentiometers The following figure shows the location of the four potentiometers available in the Motor Control board Figure 5 6 Potentiometers 1 POT1 current reference setting for BLDC motor only 2 RV1 RV2 open loop and closed loop settings 5 2 7 Standalone Mode Driving BLDC Motor A BLDC motor can be driven in Current mode or Voltage mode Depending on the driving mode you must set the W12 jumper accordingly Furthermore in either mode you can drive the motor in Open Loop mode or Closed Loop mode The W12 jumper must be set as follows Ifthe W12 jumper selects the VARIABLE position the current reference comes from a PWM generated RC filtered signal generated by the ST7FMC microcontroller The VARIABLE position may be selected either in Current mode or Voltage mode Note In Voltage Page 50 AK ST7FMC User s Manual mode the maximum current is set in the AK ST7FMC Control Panel before generating the h files fthe W12 jumper select the FIXED position the current reference comes from the POT1 potentiometer The FIXED position can be selected only in Voltage mode The following table summarizes how the pote
47. inverter power stage Not present Disables the onboard inverter when using an external inverter power stage J4 J6 Present Connects the heatsink thermal sensor NTC2 located on the bottom side of the PCB to the AINO pin of the ST7FMC Not present Heatsink thermal sensor not connected to the AINO pin of the ST7FMC Not present ST7FMC internal OpAmp is used to amplify current sensed by the R21 shunt resistor Upper position ST7FMC internal OpAmp not used External OpAmp not used ST7FMC MCCFIO pin comparator input is directly connected to the R21 shunt resistor to sense current Lower position ST7FMC internal OpAmp not used External OpAmp used to amplify the current sensed by the R21 shunt resistor The ST7FMC MCCFIO pin comparator input is connected to the external OpAmp output 15V left position A voltage of 15 V DC is applied on pin 9 of J4 to supply the external inverter and driver Page 57 Connectors and Functions Selection Description 5V right position A voltage of 5 V DC is applied on pin 9 of J4 to supply the external inverter and driver Ws 5V left position A voltage of 5 V DC is applied on pin 8 of J4 Right position The pin 8 of J4 is redirected to the MCES input of the ST7FMC W9 INT lower position Internal voltage is applied to the WUP pin of the L9638 LIN
48. is done during the PWM OFF state but just before the ON state The optimum OFF time should be carefully calculated depending on the PWM switching frequency and on motor behavior mainly the motor stray capacitance MPWME register 4 bits from OT3 to Complementary PWM Signal Only when using MOSFETs instead of the Motor Control board s onboard IGBTs this feature can be enabled to perform synchronous rectification allowing the free wheeling current to pass inside the MOSFETs instead of the body diode reduced power losses The Dead Times parameter see below must be set correctly Compl PWM disabled MDTG write once register bit DTE at 0 Compl PWM enabled MDTG write once register bit DTE at 1 Dead Times Sets the deadtime between the switches high and low side to avoid cross conduction The inverter of the Motor Control board requires a minimum deadtime of 0 625 us to avoid cross conduction problems Values from 0 625 us to 16 us are available in the AK ST7FMC Control Panel However values as low as 0 125 us can be set when editing ST7FMC registers directly This allows to modify the deadtime in case an external inverter power stage is connected to the board MDTG write once register 6 bits from DTG5 to DTGO Page 79 AK ST7FMC Control Panel Features Parameter Name Parameter Values Description PWM Distribution Speed Range Minimum Mechanical Speed Sets PWM signal distr
49. ith a new motor it is recommended to start from 0 The higher the value the shorter the time necessary to cancel the static error but a value too high will render the system unstable Proportional Coefficient Kp Closed Loop parameter The higher the value the lower will be the static error but a value too high will render the system unstable Sampling Time The time interval between two Pl control samplings The lower the sampling time the better will be the regulation bandwith However a value too low will not increase the system dynamic response above a certain point and will consume microcontroller resources Reported Frequency Only valid in Closed Loop or in Open Loop with speed sensor feedback This is the speed frequency of the rotor as read by the speed sensor This value can be read in Hz or RPM click the Hz or RPM button next to the value to switch between units Page 90 AK ST7FMC User s Manual Parameter Name Parameter Description Slip Frequency The slip speed frequency is the stator speed frequency minus the rotor speed frequency This value can be read in Hz or RPM click the Hz or RPM button next to the value to switch between units Reported Voltage Voltage output of the Pl controller in units of the bus voltage full bus voltage being 255 255 6 4 5 Advanced Settings AC motor advanced settings are available by clicking the Adv
50. jection of material in case of components destruction especially when powering the board with high voltages The rotating parts of motors are also a source of danger 4 2 Step by Step Tutorial 4 2 1 Tools Required For this tutorial you need Page 33 Getting Started for Motors Motor Control board three phase SELNI AC motor available as an accessory SofTec Microsystems order code 237 00157 inDART STX in circuit debugger programmer Optoisolation board 4 2 2 Installing the Software Note before to connect the inDART STX board to the PC it is recommended that you install the AK ST7FMC Control Panel application see below so that the inDART STX USB driver will be automatically found by Windows when you connect the board To install the AK ST7FMC Control Panel insert the SofTec Microsystems System Software CD ROM into your computer s CD ROM drive A startup window will automatically appear Choose Install Instrument Software from the main menu A list of available software will appear Click on the AK ST7FMC Control Panel option Follow the on screen instructions Note if you are installing the AK ST7FMC Control Panel on Windows 2000 or Windows XP you must have logged in as Administrator 4 2 3 Installing the Hardware Connection steps are listed below in the recommended flow order 1 Verify that all of the Motor Control board jumpers are set
51. l bearings may get damaged and in turn this may cause major injuries the rotor may be blocked instantaneously causing the whole motor chassis to turn as a reaction Always fix securely the motor on a mechanical bench This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Dead Times Value Sets the deadtime between the switches high and low side to avoid cross conduction The inverter of the Motor Control board requires a minimum deadtime of 0 625 us to avoid cross conduction problems Values from 0 625 us to 16 us are available in the AK ST7FMC Control Panel However values as low as 0 125 us can be set when editing ST7FMC registers directly This allows the deadtime to be modified in case an external inverter power stage is connected to the board MDTG write once register 6 bits from DTG5 to DTGO Stop Condition Free Wheeling After stop the motor will continue to spin freely DC Current Braking To slow down the motor quickly this feature allows to apply active braking Brake Level Available when the DC Current Braking option above is selected Two of the three bridge legs are grounded and a complementary PWM with maximum 50 duty cycle is applied on the switches of the third leg Duty cycle loaded in the MCPUH and MCPUL registers Brake Time Available when the DC Current Braking option above is selected Time du
52. ld select the lower position The W13 jumper must be removed The J8 jumpers can be kept to filter the sensor signal 5 4 AC Motor Outputs and Feedback An AC motor can be controlled in open or closed loop as detailed below 5 4 1 Open Loop To drive an AC motor in open loop the W14 and W15 jumpers must select the lower position the W16 jumper must be removed and all of the J8 jumpers must be present 5 4 2 Closed Loop To drive an AC motor in closed loop the W14 and W15 jumpers must select the lower position and the W16 jumper must be removed Additionally the W13 jumper must be present to feed the tachometer signal to the Page 54 AK ST7FMC User s Manual microcontroller s MCIC input This signals needs to be filtered by the C56 capacitor The filtering is done by placing a jumper between pins 7 and 8 in the J8 connector 5 5 ICC Connector The ST7FMC microcontroller can be in circuit programmed via the ICC connector using the inDART STX in circuit debugger programmer 5 6 External Power Stage Connectors Two connectors allow you to override the internal power inverter Figure 5 8 Motor Outputs and Feedback J4 AC motor power connector J6 BLDC motor power connector W3 onboard power inverter current sensor W4 onboard power inverter diagnostic enable W5 onboard power inverter thermal sensor IX 55 Connectors and Functions The W3 and W4 jumper
53. ly the step time itis important for each speed or duty cycle in Open Loop Voltage mode or current reference in Open Loop Current mode to set a corresponding software demagnetization time or duty cycle or current reference If the demagnetization time is too long it will limit the speed that can be reached by the motor What all of this means 15 that when using software demagnetization you should not significantly modify the target speed duty cycle or current reference in the real time settings when the motor is running but you should instead stop the motor change the software demagnetization time and start the motor again register bit at 0 bit SDM at 1 Demagnetization Time Available when the All Software option above is selected This time should be longer than the physical demagnetization time of the motor but short enough not to delay the BEMF detection For each target speed there should be a different software demagnetization time register 8 bits from DN7 to DNO Force Duty Cycle during Demagnetization During demagnetization current circulating in windings where the polarization doesn t change may increase to a level which may damage the motor To avoid this situation a dedicated duty cycle can be applied during demagnetization This feature is available in Sensorless Voltage mode Duty Cycle Available when the Force Duty Cycle during Dem
54. meter Input 417 21 External analog input connected to the AIN9 pin the ST7FMC available to the user 1 Analog Input filtered with 1 KOhm 10 nF RC network 2 VSS Board J18 21 External digital I O connected to the pin of the ST7FMC available to the user 1 Digital Input 47 KOhm pull up resistor to 5 V and 10 nF debouncing capacitor allows to directly connect a push button or switch 2 VSS Board J19 1 Hall sensors input connector MEE 1 Hall Sensor Input 1 2 Hall Sensor Input 2 3 Hall Sensor Input 4 5V DC Power Supply 5 VSS Board P1 RS 232 connector N C RX TX Tied to Pin 6 OV Tied to Pin 4 Tied to Pin 8 Tied to Pin 7 N C son 63 Connectors and Functions 5 8 3 Jumper Settings for BLDC Motor Default Table 5 8 Jumper Settings Example for aBLDC Motor Settings for the Default Settings for a Generic AMETEK 24 V BLDC Motor High Voltage BLDC Motor 1 lt 35V ONLY lt 35V ONLY or HIGH VOLTAGE W3 Present W4 Present W5 Present W6 Not present W7 Not present w8 Not present w9 Not present W10 Lower position W11 Lower position W12 VARIABLE W13 Not present W14 Sensorless mode default all jumpers in upper position W15 3 Sensor mode all jumpers in lower position W16 J8 No jumper present J9 All jumpers present J10 No j
55. n AC Motor 52 Table 5 6 Jumpers Summary 57 Table 5 7 Connectors Summary Pinout 60 Table 5 8 Jumper Settings Example for a BLDC Motor 64 Table 5 9 Jumper Settings Example for an AC Motor 65 Table 6 1 AK ST7FMC Control Panel Motor Type Choice 69 Table 6 2 AK ST7FMC Control Panel BLDC Motor Main Settings 71 Table 6 3 AK ST7FMC Control Panel BLDC Motor Start Up Settings 74 Table 6 4 AK ST7FMC Control Panel BLDC Motor Real Time Settings 76 Table 6 5 AK ST7FMC Control Panel BLDC Motor Advanced Settings 79 Table 6 6 AK ST7FMC Control Panel AC Motor Main Settings 88 Table 6 7 AK ST7FMC Control Panel AC Motor V F Curve Settings 89 Table 6 8 AK ST7FMC Control Panel AC Motor Start Up Settings 89 Table 6 9 AK ST7FMC Control Panel AC Motor Real Time Settings 90 Table 6 10 AK ST7FMC Control Panel AC Motor Advanced Settings 92 Table 7 1 Motor Control Board Electrical Specifications 93 Table 7 2 Optoisolation Board Electrical Specifications 93 AK ST7FMC User s Manual O Before Starting 0 1 Safety Warnings 0 1 1 General In operation the AK ST7FMC Starter Kit has uninsulated wires moving or rotating parts when connected to a motor as well as hot surfaces In case of improper use wrong installation or maloperation there is danger of serious personal injury and damage to property All operations installation and maintenance are to be carried out by skilled technical personnel national accident prevention rules must
56. nDART STX Page 47 Connectors and Functions 10 11 12 13 14 15 From the main menu choose File gt Open Workspace Select the AC_Metrowerks wsp workspace file that is located under your working directory Click Open Only in the case of Closed Loop control some defines in the ACMParam h file must be edited according to the collected parameters The defines to be edited are listed in the following table Table 5 3 AC Motor Closed Loop Standalone Firmware Defines AC Motor Specific Defines to Be Edited define SAMPLING_TIME define PI_PROP_LOWSPD define PI_PROP_HIGHSPD define PI_INT_LOWSPD define PI_INT_HIGHSPD define PI_LOWFREQ_LIMIT define PI_HIGHFREQ_LIMIT define OPT_SLIP_LOWFREQ_LIMIT define OPT_SLIP_HIGHFREQ_LIMIT define OPT_SLIP_LOWFREQ define OPT_SLIP_HIGHFREQ Select the Build command from the Project menu The project will be compiled and built and an executable file will be generated Using the DataBlaze programming utility you can now program the ST7FMC microcontroller with the generated executable To launch DataBlaze select Start gt Programs gt SofTec Microsystems gt inDART STX gt ST7 gt DataBlaze Programmer From the DataBlaze s main menu select Operations gt Select Device Make sure that the Programming Hardware parameter is set to inDART STX and that
57. nced instruction set and are available with FLASH memory The ST7 Motor Controller peripheral MTC can be seen as a three phase pulse width modulator multiplexed on six output channels and a Back Electromotive Force BEMF zero crossing detector for sensorless control of Permanent Magnet Brushless Direct Current BLDC motors The MTC is particularly suited to driving brushless motors either induction or permanent magnet types and supports operating modes like Commutation step control with motor voltage regulation and current limitation Commutation step control with motor current regulation i e direct torque control Position sensor or sensorless motor phase commutation control six step mode BEMF zero crossing detection with high sensitivity The integrated phase voltage comparator is directly referred to the full BEMF voltage without any attenuation A BEMF voltage down to 200 mV can be detected providing high noise immunity and self commutated operation in a large speed range Real time motor winding demagnetization detection for fine tuning the phase voltage masking time to be applied before BEMF monitoring A Automatic and programmable delay between BEMF zero crossing detection and motor phase commutation PWM generation for three phase sinewave or three channel independent PWM signals 1 3 The Brushless DC BLDC Motor A brushless DC BLDC motor is a rotating electric machine where the stator is
58. ng displaced by 120 The most common type of induction motor has a squirrel cage rotor in which aluminum conductors or bars are shorted together at both ends of the rotor by cast aluminum end rings When three currents flow through the three symmetrically placed windings a sinusoidally distributed air gap flux generating the rotor current is produced The interaction of the sinusoidally distributed air gap flux and induced rotor currents produces a torque on the rotor The mechanical angular velocity of the rotor is lower then the angular velocity of the flux wave by so called slip velocity In adjustable speed applications AC motors are powered by inverters The inverter converts DC power to AC power at the required frequency and amplitude The inverter consists of three half bridge units where the upper and lower switches are controlled complimentarily As the power device s turn off time is longer than its turn on time some dead time must be inserted between the turn off of one transistor of the half bridge and turn on of it s complementary device The output voltage is mostly created by a pulse width modulation PWM technique The three phase voltage waves are shifted 120 to each other and thus a three phase motor can be supplied Page 17 Overview 1 5 Recommended Reading This documentation describes how to use the AK ST7FMC Starter Kit and how to set up basic debugging sessions with STMicrolectronics Visual Debug IDE together
59. ng the appropriate header files to be used with the provided Motor Control library in order to generate a firmware to be programmed into the microcontroller This is explained in detail in the Preparing for Standalone Mode BLDC Motors section on page 42 6 1 2 Suggested AC Motor Learning Steps 1 We suggest you to order the SELNI motor and experiment with the AK ST7FMC Control Panel s default settings for this motor to understand the interdependence of the various parameters Then run your own motor in Open Loop mode with a speed sensor this will allow to monitor the speed and ensure that the stator frequency doesn t go below the rotor frequency otherwise reactive current will be generated by the motor causing overvoltage on bulk capacitors and possibly destruction of the board in order to characterize the motor and or to verify that the motor is suitable for the intended load After the V F curve the start up parameters and the advanced settings have been fine tuned the motor can then be run in Closed Loop mode In Closed Loop mode start up parameters must be set again to comply with the closed loop operation It is then possible to run the motor in standalone mode by collecting real time data and generating the appropriate header files to be used with the provided Motor Control library in order to generate a firmware to be programmed into the microcontroller This is explained in detail in the Preparing for Stand
60. ntiometers can be used in Open Loop mode or Closed Loop mode for a BLDC motor Table 5 4 Open and Closed Loop Standalone Controls for a BLDC Motor Potentiometer RV1 Open Loop Sets the duty cycle Voltage mode or the current reference Current mode Closed Loop Sets the target speed frequency RV2 Sets the coefficient to calculate Not used the delay for a rising BEMF RV3 Sets the coefficient to calculate Not used the delay for a falling BEMF POT1 Sets the maximum current allowed Sets the maximum current allowed in the motor Voltage mode only in the motor Voltage mode only Note in Current mode the W12 jumper must always select the VARIABLE position to allow dynamic current control by the ST7FMC microcontroller In Current mode the POT1 potentiometer is inactive 5 2 8 Standalone Mode Driving an AC Motor The following table summarizes how the potentiometers can be used in Open Loop mode or Closed Loop mode for an AC motor Page 51 Connectors and Functions Table 5 5 Open and Closed Loop Standalone Controls for an AC Motor Potentiometer Open Loop Sets the stator frequency from 1 Hz to 256 Hz Closed Loop Set the target speed from 10 Hz to 266 Hz Closed Loop with PI Tuning Set the target speed from 10 Hz to 266 Hz Sets the stator voltage from 0 V to the limit set by the V F curve Not used Sets the Ki integral coeffi
61. nto another location The copied subdirectory will become your working directory Run the AK ST7FMC Control Panel by selecting Start gt Programs gt SofTec Microsystems gt AK ST7FMC gt AK ST7FMC Control Panel You will be asked what motor type you are working with Select the 3 Phase AC Induction Motor Sinewave option and click the OK button The main AK ST7FMC Control Panel window will open To run an AC motor in standalone mode Closed Loop you must choose an optimum sampling time and then characterize two curves a Ki Kp versus stator frequency curve and a slip frequency versus stator frequency curve Both curves must have two points as illustrated below Page 46 AK ST7FMC User s Manual Ki Kp Target Rotor Frequency Figure 5 3 AC Motor Closed Loop Parameters Collecting Ki Kp A Slip Frequency Target Rotor Frequency Figure 5 4 AC Motor Closed Loop Parameters Collecting Slip Frequency To run an AC motor in standalone mode Open Loop it is not necessary to collect any real time settings since all real time parameters are controlled through the potentiometers Click the Generate Source Files button Browse for your working directory and select the source subdirectory Click the OK button The appropriate header files will be generated Run the STVD7 IDE by selecting Start Programs SofTec Microsystems gt inDART STX gt ST7 gt STVD7 for i
62. oftware Current Loop All Software Current Blanking Window 0 5 vips aso a Current Event Counter Filter 1 S j Maximum Allowed Current 3 HA 05 eA si Stop Condition Sampling Parameters 7 DC Current Braking Sampling Clock fSCF 1000 v KHz Unused MClx Input Grounded Cancel Figure 6 2 BLDC Motor Advanced Settings Dialog Box Page 78 AK ST7FMC User s Manual Table 6 5 AK ST7FMC Control Panel BLDC Motor Advanced Settings Parameter Name Switches PWM Frequency Parameter Values Description Inverter switches IGBT MOSFET PWM output frequency In the firmware the frequency is set as follows in Voltage mode the 12 bit timer frequency is set to the desired PWM frequency MCPOL MCPOH and MPCR registers in Current mode the PWM frequency is selected in the MPRSR register 4 bits from to SAO The output polarity MPOL register 6 bits from OP5 to of the six PWM outputs is fixed for the STMicroelectronics drivers and cannot be changed For sources using the opposite polarity please contact STMicroelectronics Switches PWM Minimum Off Time When using the STMicroelectronics patented three resistor method this parameter is required to maintain sufficient PWM OFF state on the high side of the switches to allow for BEMF reading This parameter is enabled only when the At end of PWM low state Z Event sampling method is selected The BEMF sampling
63. or mode you need to properly set jumpers W14 W15 W16 You need to connect sensors and respect sensor wiring MCRA register bit SR at 1 Page 71 AK ST7FMC Control Panel Features Parameter Name Parameter Values Description Sensor 60 To run the motor in Sensor mode you need to properly set jumpers W14 W15 W16 For the AMETEK motor the wiring of sensors provided is compatible with the firmware to control the motor in Sensor mode For other motors you need to connect sensors and respect sensor wiring and modify jumper settings accordingly MCRA register bit SR at 1 Driving Mode Current Mode In this mode a current reference is set either by the user in Open Loop mode or by the Pl Proportional Integral regulator to reach or maintain target speed in Closed Loop mode The ST7FMC motor control peripheral automatically adapts the PWM duty cycle to maintain the current in the motor at the level of the current reference MCRA register bit VOC1 at 1 Voltage Mode Voltage mode is preferred in applications requiring high torque at start up and applications with significant load variations In this mode a PWM duty cycle 1 set by the user in Open Loop mode or by the Pl Proportional Integral regulator to reach or maintain target speed in Closed Loop mode MCRA register bit VOC1 at 0 Current When using Voltage mode a programmable current limitation can be Limitation set The AK ST7FMC Control Panel do
64. otor Control board in standalone mode several steps must be completed to ensure compatibility between the ST7FMC firmware and the push buttons and potentiometers 5 2 2 Preparing for Standalone Mode General Notes The steps below must be followed to generate the correct firmware to use the Motor Control board in standalone mode Please note that the firmware is motor specific After generating and downloading to the ST7FMC microcontroller the appropriate firmware for the type of motor and the type of control you want to use the push buttons and potentiometers are available for use in standalone mode as explained later Note the following steps require that the inDART STX for ST7 System Software be installed To install the inDART STX for ST7 System Software insert the SofTec Microsystems System Software CD ROM into your computer s CD ROM drive A startup window will automatically appear Choose Install Instrument Software from the main menu A list of available software will appear Click on the inDART STX for ST7 option Follow the on screen instructions Page 41 Connectors and Functions Note in order to compile a project linked to the STMicroelectronics Motor Control library you must have a full version of either the Metrowerks or Cosmic C compiler Due to the size ofthe STMicroelectronics Motor Control library and the code size limit of the evaluation versions of these compilers any attempt
65. ple for a BLDC Motor on page 64 2 Motor Control board and the provided BLDC motor come assembled together over a metal support Verify that the motor cable is correctly connected between the Motor Control board s MOTOR connector J12 and the motor terminal connector 3 Motor Control board and the Optoisolation board come already connected through an ISP cable Moreover the Optoisolation board s power connector is also already connected to the Motor Control board s J2 connector In this way the Motor Control board automatically supplies the Optoisolation board Verify that both the power cable and the ISP cable are connected as stated above Page 28 AK ST7FMC User s Manual 4 Connect inDART STX to the Optoisolation board with the other ISP cable provided from inDART STX s ISP connector to the Optoisolation board s ICC IN connector 5 Connect inDART STX to the host PC with the USB cable provided The green POWER LED on the instrument will turn on Windows will automatically recognize the instrument and will load the appropriate USB driver 6 Power up the Motor Control board by connecting the output terminals of your DC power supply to the MAINS connector The provided voltage must be 24 V DC and your power supply must be able to provide a current of 4 A Note both Windows 2000 and Windows XP may issue a warning the first time inDART STX is connected to the PC This warning
66. ption and click the OK button The main AK ST7FMC Control Panel window will open 6 Torun a BLDC motor in standalone mode Closed Loop you must choose an optimum sampling time and collect for each of four critical Page 42 AK ST7FMC User s Manual 10 speeds a set of real time parameters rising BEMF delay falling BEMF delay Ki and These parameters must be fine tuned for the minimum and maximum motor speed the same speeds specified in the Advanced Settings window plus two other intermediate speeds of your choice During operation the ST7FMC firmware will make a linear extrapolation of real time parameters in between the four specified speeds to ensure smooth operation for more information about parameter collecting refer to the STMicroelectronics Application Note AN1905 A Rising B EMF Delay Falling B EMF Delay Ki Kp Maximum speed Target Mechanical Minimum speed Speed gt Figure 5 2 BLDC Motor Closed Loop Parameters Collecting To run a BLDC motor in standalone mode Open Loop it is not necessary to collect any real time settings since all real time parameters are controlled through the potentiometers Click the Generate Source Files button Browse for your working directory and select the source subdirectory Click the OK button The appropriate header files will be generated and saved in the source subdirectory as h files All parameters se
67. rameter Values Description Motor Type SELNI Induction The SELNI motor is an 800 W 190 V three Motor phase induction motor It features a tachometer generator for speed monitoring Due to its size and weight it is not included in the AK ST7FMC Starter Kit but can be ordered separately Beginners to three phase induction motor control are strongly recommended to first use the SELNI motor as a learning phase The Default Settings button restores the best performance settings for driving this motor when the Motor Control board is supplied with an input voltage of 42 V DC Other 3 Phase Any three phase induction motor with or without Induction Motor sensor tachometer encoder Hall sensor Poles Pair Number of pair of poles of the motor connected to the Starter Kit Induction motors with up to 2 pairs of poles can be used Setting the correct number of pairs of poles is important as this defines the relationship between speed and stator frequency Speed Open Loop Open Loop can be selected for operating the Regulation motor with no sensors and predictable load Open Loop can also be used to drive the motor over the full Voltage Frequency range When selecting Open Loop no Proportional Integer control is available but speed monitoring is possible with the speed sensor When characterizing the efficiency versus the slip of the motor the speed sensor must be used Beware of motor breakdown and reactive current
68. ring which active braking is applied and after which the motor is free wheeling Page 92 AK ST7FMC User s Manual 7 Electrical Specifications Table 7 1 Motor Control Board Electrical Specifications Parameter Maximum Ratings lt Three Phase BLDC Three Phase Main Input Voltage 43 42 V DC or 30 Veff AC Auxiliary Input Voltage J1 15V DC 0 5A Auxiliary Output Voltage J2 15V DC 0 5A Maximum Output Current on Motor Phases J12 10A Analog Input Voltage J17 5VDC Digital Input Output Voltage J18 5VDC Table 7 2 Optoisolation Board Electrical Specifications Parameter Maximum Ratings Input Voltage J3 15V DC 0 3A ICC IN Connector I O Lines Voltage J1 5V DC ICC OUT Connector Lines Voltage J2 5 V DC Page 93
69. rporation PC is a registered trademark of International Business Machines Corporation Other products and company names listed are trademarks or trade names of their respective companies AK ST7FMC User s Manual Contents 0 Before Starting 11 0 1 0 2 0 3 Safety Warnings 11 0 1 1 General 11 0 1 2 Intended Use 11 0 1 3 Operation 11 0 1 4 Important Notice to Users 12 Required Skills 12 Credits 12 1 Overview 15 What is the AK ST7FMC Starter Kit 15 ST7FMC Family Overview 16 The Brushless DC BLDC Motor 16 The AC Induction Motor 17 Recommended Reading 18 Software Upgrades 18 Troubleshooting 18 Getting Technical Support 19 2 AK ST7FMC Components 21 Package Checklist 21 The Motor Control Board 22 The BLDC Motor 24 The In Circuit Debugger Programmer inDART STX 24 The Optoisolation board 24 The Alternate Z Sampling Daughter Board 25 3 Getting Started for BLDC Motors 27 3 1 3 2 Introduction 27 Step by Step Tutorial 27 3 2 1 Tools Required 27 3 2 2 Installing the Software 28 3 2 3 Installing the Hardware 28 3 2 4 Tutorial Steps 29 Contents 4 Getting Started for AC Motors 33 4 1 Introduction 33 4 2 Step by Step Tutorial 33 4 2 1 Tools Required 33 4 2 2 Installing the Software 34 4 2 3 Installing the Hardware 34 4 2 4 Tutorial Steps 36 5 Connectors and Functions 39 5 1 Power Supply 39 5 1 1 Introduction 39 5 1 2
70. s should be removed when using an external power inverter The W5 jumper should be present if no thermal monitoring is available on the external power inverter otherwise the thermal sensor must be connected to pin 1 ofthe W5 jumper 5 7 RS 232 Connector An optoisolated RS 232 connector allows the Motor Control board to be connected to a PC for displaying information about using a terminal utility like HyperTerminal By default AC motor real time values such as speed voltage stator frequency etc are sent to the PC see STMicroelectronics Application Note AN1904 Page 56 AK ST7FMC User s Manual 5 8 Summary of Jumper and Connector Settings 5 8 1 Jumpers Summary Selection HIGH VOLTAGE Table 5 6 Jumpers Summary Description Motor supply is greater than 35 V DC or 25 Veff AC lt 35V ONLY Motor supply is less than 35 V DC or 25 Veff AC Not present Motor supply is separated from Motor Control board The Motor Control board must be supplied with 15 V DC 0 5 on J1 Present Connects the R21 shunt resistor to external Operational OpAmp circuitry and to the ST7FMC internal OpAmp Not present Disconnects the R21 shunt resistor from the external Operational OpAmp circuitry and to the ST7FMC internal OpAmp when using an external power stage through J4 or J6 Present Connects the diagnostic output of the L6386 driver to the MCES pin of the ST7FMC and enables the onboard
71. speed is exceeded the rotor may be explode or ball bearings may get damaged and in turn this may cause major injuries the rotor may be blocked instantaneously causing the whole motor chassis to turn as a reaction Always fix securely the motor on a mechanical bench This value can be set in Hz or RPM click the Hz or RPM button next to the edit box to switch between units Used to prevent the Current Loop from stopping on a current spike after PWM ON This spike is usually caused by the recovery current from the half bridge free wheeling diode and can be further increased by the discharge of the motor winding stray capacitance The blanking window starts after each PWM ON event and during this blanking window no reading of current is done This blanking window can also be disabled MCFR register 3 bits from CFW2 to CFWO Current Event Counter Filter Number of consecutive current comparator samples at 1 MHz required to switch the PWM signal to OFF MCFR register 3 bits from CFF2 to CFFO Page 80 AK ST7FMC User s Manual Parameter Name Maximum Allowed Current Parameter Values Description In Current mode to avoid damaging the motor the user can set maximum current acceptable for the motor This value cannot be exceeded by the PI control in Closed Loop and by the current reference real time setting in Open Loop However this value can be exceeded during the start up phase Alignmen
72. start up and or run In this case separate fine tuning of the ST7FMC firmware is needed for optimum start up algorithm and maximum speed 6 1 1 Suggested BLDC Motor Learning Steps 1 the provided AMETEK motor and use the AK ST7FMC Control Panel default settings to understand the interdependence of the various parameters 2 Then run your own motor in Sensorless Open Loop mode in order to find the correct start up sequence setting Preferably select Voltage mode this allows the motor to take as much current as needed within the maximum current limit acceptable by the motor and ensures a successful start up 3 Set the correct alignment parameters and acceleration phase parameters In the Real Time Settings parameter group set a duty cycle at least equal to the acceleration phase s Click the START Page 67 AK ST7FMC Control Panel Features button and in case the motor fails to start adjust start up settings and or advanced settings When the motor starts adjust the delay coefficients for a given duty cycle speed to get the best motor efficiency After the Open Loop mode start up parameters and advanced settings have been fine tuned the motor can then be run in Closed Loop mode based on these parameters In Closed Loop mode start up parameters must be set again to comply with the closed loop operation It is then possible to run the motor in standalone mode by collecting real time data and generati
73. sters Alignment The alignment duration is the duration of the alignment phase Duration MCOMP data and MPRSR clock registers Mechanical The acceleration phase is a phase during which synchronous rotation Acceleration is forced on the motor with a fixed acceleration rate in order to get Rate information and switch from the forced mode to the autoswitched mode as soon as possible Forced mode MCRA register SWA bit at 0 Autoswitched mode MCRA register SWA bit at 1 To achieve mechanical acceleration a 64 step acceleration ramp is built based on this parameter 64 steps are usually more than enough to safely reach Autoswitched mode If Autoswitched mode cannot be reach by the end of the acceleration ramp the motor will stop and the Start Up Fails or Motor Stalled if rotor blocked red icon turns on This value can be set in Hz s or RPM s click the Hz or RPM button next to the edit box to switch between units Duty Cycle Constant duty cycle applied during the acceleration phase MCPUH and MCPUL compare registers Current Constant current reference applied during the acceleration phase MCPVH and MCPVL compare registers Number of Z Number of consecutive Z events that must be detected to switch to Events Before Autoswitched mode Autoswitched Mode Step Number Number of first steps of the ramp which are blanked no BEMF without Z reading During the very first steps of th
74. t Phase and Acceleration Phase The AK ST7FMC Control Panel the maximum current value is clamped to 8 7 A to suit the starter kit hardware Maximum Allowed Duty Cycle In Voltage mode the user can specify a maximum PWM duty cycle that the application can t exceed This value cannot be exceeded by the PI control in Closed Loop and by the duty cycle real time setting in Open Loop However this value can be exceeded during the start up phase Alignment Phase and Acceleration Phase When using the STMicroelectronics patented three resistor control method Z Event Sampling Method parameter set to At the end of the PWM low state the maximum PWM duty cycle is clamped to a value calculated by the AK ST7FMC Control Panel which is based on the programmed PWM signal frequency and on the minimum off time Clamping the maximum PWM signal duty cycle to this value allows for sufficient time for BEMF reading during the PWM OFF state D and Z Sampling Parameters Sampling Clock fSCF Sampling frequency used for detecting D events The same sampling frequency is used for detecting Zero Crossing events when the Z Event Sampling Method parameter is set to At PWM On with delay at fSCF frequency or to At fSCF frequency MSCR register 2 bits from SCF1 to SCFO Unused MCIx Input Sets the state of the two phases that at any given time are not sampled while the third phase is being sampled When
75. t Up Settings Alignment phase Acceleration phase Final Current 2 HA Mechanical Acceleration Rate 1500 Rpm s EZ Alignment Duration 1250 ms Values at end of ramp Current 2 Current ud Number ofZ events before 2 auto switched mode h Step number without Z detection 2 Time lo Electrical Frequency 32 5 Hz lo lab Total Duration 653 ms Real Time Settings Settings Feedback N tage Stat Electrical Frequency Hn Heatsink Over temperature 0 Motor Over Current Current Reference 1 isla Bus Over Voltage Delay Coefficient n Nx Motor Status B emf rising edge 2256 O ee START B emf falling edge 20 256 3 Motor Stalled Default Settings Advanced Settings Generate Source Files Figure 3 2 AK ST7FMC Control Panel Window for BLDC Motors 5 Change the Speed Regulation parameter to Closed Loop and click the START button A firmware will be automatically created based on all of the AK ST7FMC Control Panel s parameter and downloaded to the ST7FMC microcontroller in the Motor Control board At the end of the download phase the motor will start to run 6 Change the Target Mechanical Speed parameter to 5000 by typing in the new value and pressing the Enter key The new parameter will be downloaded to the ST7FMC microcontroller in real time
76. t in the AK ST7FMC Control Panel other than the real time parameters listed in point 6 are saved automatically in the h files Run the STVD7 IDE by selecting Start gt Programs gt SofTec Microsystems gt inDART STX gt ST7 gt STVD7 for inDART STX From the main menu choose File gt Open Workspace Select the BLDC_Sensorless_Metrowerks wsp or BLDC Page 43 Connectors and Functions _Sensor_Metrowerks wsp workspace file that is located under your working directory Click Open 11 Only in the case of Closed Loop control some defines in the mtc h file must be edited according to the collected parameters The defines to be edited are listed in the following table Table 5 1 BLDC Motor Closed Loop Standalone Firmware Defines BLDC Motor Specific Defines to Be Edited define SAMPLING_TIME define Rising_Fmin define Falling_Fmin define Ki_Fmin define Kp_Fmin define F_1 define Rising_F_1 define Falling_F_1 define Ki_F_1 define Kp_F_1 define F_2 define Rising_F_2 define Falling_F_2 define Ki_F_2 define Kp_F_2 define Rising_Fmax define Falling_Fmax define Ki_Fmax define Kp_Fmax 12 Select the Build command from the Project menu The project will be compiled and built and an executable file will be generated Page 44 AK ST7FMC User s Manual
77. ter will be downloaded to the ST7FMC microcontroller in real time and the motor will accelerate 7 Click the STOP button to stop the motor Congratulations You have successfully completed this tutorial You can now continue to experiment with the AK ST7FMC Control Panel on your own Page 37 Getting Started for Motors Additionally you can develop and debug your own application by installing the inDART STX for ST7 software which includes a complete development toolchain present on the SofTec Microsystems System Software CD ROM Page 38 AK ST7FMC User s Manual 5 Connectors and Functions 5 1 Power Supply 5 1 1 Introduction The Motor Control board can be supplied in two ways Single power supply for motors requiring a voltage greater than 18 V Power is supplied to the J3 connector Power supply voltage must not be higher than 42 V DC or 30 Veff AC This power supplies both the motor and the Motor Control board A 15 V DC voltage is automatically generated for the Motor Control board logic However depending on the voltage supplied to the J3 connector two cases are possible 1 If the supplied voltage is greater than 35 V DC the S1 jumper must select the HIGH VOLTAGE position 2 Ifthe supplied voltage is between 18 V and 35 V DC the S1 jumper must select the lt 35V ONLY position Dual power supply for motors requiring a voltage less than 18 V Power for t
78. the Device Code parameter specifies the ST7FMC2N6B microcontroller Click the OK button From the DataBlaze s main menu select File gt Load gt Code Buffer Change the Format parameter to Motorola S Rec and browse for Page 48 AK ST7FMC User s Manual 16 17 18 19 the AC_Metrowerks s19 file located under the object Metrowerks subdirectory in your working directory Click the OK button From the DataBlaze s main menu select Edit gt Option Bytes The Option Bytes must be edited as detailed in Table 5 2 Option Bytes Settings for ST7FMC ProgrammingTable 5 2 Option Bytes Settings for ST7FMC ProgrammingTable 5 2 Option Bytes Settings for ST7FMC Programming on page 45 From the DataBlaze s main menu select Operations gt Auto Make sure that all of the programming steps but Run are enabled Click the START button Now the microcontroller is programmed You can unplug the ISP cable from the Motor Control board and use the Motor Control board in standalone mode To start running the microcontroller press the RESET push button For details about how to control the motor with the Motor Control board s push buttons and potentiometers please refer to the Push Buttons Potentiometers and Standalone Mode Driving an AC Motor sections here below 5 2 5 Push Buttons The following figure shows the location of the two push buttons ava
79. to compile a project linked to the Motor Control library will not succeed unless you have the full version of the above compilers Note the following steps illustrate how to use the Metrowerks C compiler to compile a project based on the STMicroelectronics Motor Control library Similar procedures apply for the Cosmic C compiler 5 2 3 Preparing for Standalone Mode BLDC Motors 1 Setup the Motor Control board as explained in the Installing the Hardware section in the Getting Started for BLDC Motors chapter 2 Get the latest release of the AK ST7FMC Control Panel system software from SofTec Microsystems website http www softecmicro com uninstall the previous version and install the new one 3 Inthe Program Files SofTec Microsystems AK ST7FMC Library directory there are various subdirectories each specific for a motor control type e g BLDC Sensorless Each subdirectory contains a pre made project specific for that motor control type Copy the appropriate subdirectory the subdirectory that corresponds to your motor and control type into another location The copied subdirectory will become your working directory 4 the AK ST7FMC Control Panel by selecting Start gt Programs gt SofTec Microsystems gt AK ST7FMC gt AK ST7FMC Control Panel 5 You will be asked what motor type you are working with Select the Phase Brushless Permanent Magnet AC or DC Motor Trapezoidal o
80. tor Control Input A VSS Board MCIB Motor Control Input VSS Board Motor Control Input VSS Board Operational Amplifier Input VSS Board 5 V DC Power Supply VSS Board Co E 0 gt a Io 9 0 61 Connectors and Functions Reference Description Pinout LIN control connector WUP LIN Wake Up Input INH LIN Inhibit Output EN LIN Enable Input 2 2 KOhm Pull Up Resistor to 5 V enables the LIN transceiver when adding a jumper between pin 3 and pin 4 Motor phases and additional monitor signals Also used to connect the Alternate Z Sampling daughter board for classic sensorless control method Motor Phase VSS Board Motor Phase B VSS Board Motor Phase A VSS Board MCVREF Motor Control Voltage Reference Motor three phases output Motor Phase Motor Phase A Motor Phase B DC Bus Middle Point may be used for bi phase motors 5 Earth ICC connector to be used with inDART STX to download debug code VSS Board CCDATA VSS Board ICCCLK VSS Board RESET 5VDC Power Supply VPP N C 0 VSS Board 4 2 3 4 5 6 7 8 9 1 Page 62 AK ST7FMC User s Manual Reference Description Pinout J16 2 Tachometer input connector for motor speed loop control 1 Tachometer Bias 0 6 V 2 Tacho
81. umper present J15 All jumpers present Page 64 AK ST7FMC User s Manual 5 8 4 Jumper Settings for an AC Motor Table 5 9 Jumper Settings Example for an AC Motor Jumper Settings for a Generic AC Motor Onboard Inverter Power Stage Tachometer Feedback 1 lt 35V ONLY or HIGH VOLTAGE W3 Present W4 Present W5 Present W6 Not present W7 Not present W8 Not present W9 Not present W10 Lower position W11 Lower position W12 VARIABLE W13 Present W14 Lower position W15 Lower position W16 Not present J8 All jumpers present J9 All jumpers present J10 No jumper present J15 All jumpers present Page 65 AK ST7FMC User s Manual 6 AK ST7FMC Control Panel Features 6 1 Introduction Note the AK ST7FMC Control Panel doesn t reflect the full capabilities of the ST7FMC microcontroller and uses only partially ts built in resources To take full advantage of the ST7FMC capabilities it may be necessary to bypass the AK ST7FMC Control Panel and edit directly the ST7FMC firmware For instance sinewave control of PMAC motors with sensors is not implemented in the AK ST7FMC Control Panel at the time of printing and requires a separate firmware It can be the case that for a specific motor e g PMAC or BLDC compressor with load condition the AK ST7FMC Control Panel doesn t provide enough flexibility to be used for motor driving
82. vise you to check that you are working with the latest version of the AK ST7FMC system software upgrades are available free of charge at http www softecmicro com Additional online support is available on the STMicroelectronics MCU Support Site http mcu st com For ST7FMC product information datasheets tools application notes etc please go to http mcu st com devicedocs ST7MC2N6 15 html Knowledge base FAQ is available at http mcu st com faq html To subscribe to automatic Motor Control updates please go to http mcu st com modules php name Subscription STMicroelectronics also hosts a Motor Control forum at htip mcu st com forums html Page 19 AK ST7FMC User s Manual 2 AK ST7FMC Components 2 1 Package Checklist The AK ST7FMC package includes the following items Motor Control board 1 ABLDC motor a 24 V DC AMETEK blower 2 Anin circuit debugger programmer inDART STX 3 Optoisolation board code 237 00156 4 Alternate Z Sampling daughter board to use optionally with BLDC motors code 237 00158 5 Cables motor cable 6 Optoisolation board s power supply cable 7 USB Cable 8 ISP Cables also called ICP cables in STMicroelectronics terminology 9 SofTec Microsystems AK ST7FMC System Software CD ROM A QuickStart Tutorial color poster TheinDART STX for ST7 user s manual This user s manual

AK-ST7FMC User`s Manual - Digi-Key

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