AN5049 - Freescale Semiconductor
Contents
1. Freescale Semiconductor Application Note Document Number AN5049 Rev 0 12 2014 Three Phase PMSM Sensorless FOC Using the MKV102Z32 with Automated Motor Parameters Identification by Josef Tkadlec 1 Introduction This application note accompanies the Sensorless PMSM Field Oriented Control Design Reference Manual DRM148 1 This application note describes the MCU peripherals used in the PMSM sensorless vector control application the hardware set up and results of the measurement In addition the attached application code contains routines for Automated PMSM parameters identification 2 MCU Peripherals Table 1 summarizes the peripherals on the Kinetis MKV10Z32 MCU 4 and their usage by the PMSM sensorless vector control application 2014 Freescale Semiconductor Inc O l A an A Q N e ph pid amp Contents A A MEU Fern phen E aae T n eters Gra eemeieetn Application Operation cc0 ccccccssseceetseeees Pree rie a OC ein PE U ca termes Hanlware Setanin Measurement Kesis arsina Ba e E A E E A E E nian Fe EEE ANAE A I N PE E EENT Acronyms and Abbreviated Terms V freescale MCU Peripherals Table 1 Kinetis KV10Z32 Peripherals Overview Kinetis KV10 peripherals Number of modules or channels A 11 channels single ended 2 of them differential pairs D S DCO DC1 AC PI 2C Used in the application 2 channels 11 channels single ended 2 o2. CPU Load CPU Clock 75 MHz Algorithm Block CPU Cycles Execution Time usec FOC open loop start up 5 418 RUN state worst case Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 18 Freescale Semiconductor Inc Conclusion 9 Conclusion The results of the execution time measurement show that the Kinetis MK V10Z32 microcontroller can be used to drive the PMSM sensorless vector control algorithm for high dynamic applications The CPU load at 10 kHz FOC calculation frequency is about 72 so there is much room to either to increase the frequency of the fast control loop or to perform additional user s tasks 10 References The following references are available on http www freescale com with the exception of 3 1 Sensorless PMSM Field Oriented Control Document number DRM148 2 Using FlexTimer in ACIM PMSM Motor Control Applications Document number AN3729 3 A New Starting Method of BLDC Motors Without Position Sensor Wook Jin Lee Seung Ki Sul 2006 4 KV10 Sub Family Reference Manual Document number KV10P48M75RM 5 Three Phase Field Effect Transistor Pre driver Data Sheet Document number MC33937 6 Tuning 3 Phase PMSM Sensorless Control Application Using MCAT Tool Document number AN4912 7 Automated PMSM Parameters Identification Document number AN4986 8 TWR MC LV3PH User s Manual Document number TWRMCLV3PHUG 11 Acronyms and Abbr
3. The PDB generates a trigger signal with the same period as the ADC conversion complete interrupt which is also the same as the PWM period If the user places an interrupt in the code this stops execution However the PDB generates a trigger for the next conversion even when the program execution stops The COCO flags are not cleared and the PDB generates a sequence error e Another scenario is when the execution of the ADC conversion complete interrupt when the fast control loop is calculated extends over one period of the PWM This occurs if the user enters additional tasks into the ADC conversion complete interrupt In addition to the generation of PDB sequence error the more serious impact is on the quality of the control process as one of the key assumptions is not met the execution of control algorithms to extend the sampling period The real time control application must be designed in such a way that this situation never occurs 4 Application Operation The application can be operated either with the user button on the TWR KV10Z32 MCU board as mentioned in Ports interrupt or by using the FreeMASTER software which enables visualizing the application variables The FreeMASTER application consists of two parts the PC application used for variables visualization and the set of software drivers running in the embedded application The data between the PC and the embedded application is passed via the RS232 interface 4 1 FreeMASTER instal
4. r ax D aL n mw i TTT esaii a ae x eit a s ETIP ap Ni Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 Freescale Semiconductor Inc 17 Measurement Results The jumper settings for TWR MC LV3PH board are listed and highlighted in the following table See also the user s manual 7 for more details for example the hardware overcurrent threshold setting of the TWR MC LV3PH stage Table 5 Jumper Settings of TWR MC LV3PH Board a E 44 2 y MHH Boo Sitti ee ss j pl ce Ss 8 Measurement Results 8 1 CPU load and the execution time The CPU load is influenced mainly by the execution of the FTMO ISR in which the execution of the application state machine and calculation of the fast current control loop of the PMSM vector control is performed Table 6 shows machine cycle number measured from FTMO ISR routine excluding FreeMASTER recorder function in RUN state for the worst case of RUN STATE that is a transition from open loop startup to close loop speed control The FTMO interrupt is generated periodically with a half frequency as the PWM reload event when the values of the duty cycles are updated In this application the FTMO ISR is generated once per 100us which corresponds to 10 kHz 20 kHz PWM frequency At 75MHz on the Kinetis MK V10Z32 device it consumes up to 72 of CPU performance Table 6
5. used when the application is running in the Speed FOC control mode Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 Freescale Semiconductor Inc 13 Project File Structure A PMSM_FOC_KV4x FreeMASTER File Edit View Explorer Project Tools Help segs eo 4 ies PMSM FOC Sensorless M3 1 Scalar amp Voltage Control E Speed 3 Phase Currents 8 Position 8 Observer 2 Current Control E Current Controller 8 Phase Currents 8 Observer E Speed k Speed Controller 8 Phase Currents 8 Observer 8 Speed Controller 44 Startup Figure 10 Scopes and recorders used in Speed FOC control mode 4 4 MCAT tool control To run the FreeMASTER application including MCAT tool double click on the MCAT_PMSM_FOC_KV1x pmp file located in the freemaster WPMSM_Sensorless_FOC_MID folder The FreeMASTER application starts and the environment will be automatically created as it is defined in the pmp file The application enables tuning of the PMSM sensorless application to any motor For this purpose the field oriented control can be divided into four modes as follows e Scalar e Voltage FOC e Current FOC e Speed FOC This enables tuning of the application during several steps with each step containing a limited number of unknown parameters that can be adjusted To switch between these modes an MCAT tab Control Stru
6. A4 FIMO CH5 The port settings implemented in the application code reflect the hardware solution built on the Tower System development modules 2 2 FlexTimer2 configuration to generate a slow loop interrupt Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 Freescale Semiconductor Inc 3 p MCU Peripherals The Flex Timer Module 2 FTM2 is configured to generate an independent interrupt that serves to calculate slow loop Speed FOC algorithms The slow loop interrupt is processed with lower priority than the fast loop interrupt Separation of the slow and fast state machine shortens the necessary length of the fast loop interrupt Prescale factor FTM2_SC gt PS is 16 and modulo register FTM2_MOD is set to 75000 16 therefore FTM2 counter overflows and generates the slow loop interrupt with frequency 1kHz 2 3 ADC and PDB modules configuration The on chip ADC module is used to sample feedback signals motor phase currents and DC bus voltage that are necessary to successfully perform the vector control algorithm The Programmable Delay Block closely cooperates with the ADC and triggers the hardware for sampling It is required to perform a self calibrating procedure of the ADC module before it is used in the application to obtain the specified accuracy The calibration process also requires a programmer s intervention that is to generate the plus side and minus
7. _KV1x pmp and supporting files control page in HTML format and the binary file with addresses of the variables It also contains the FreeMASTER project for the Motor Control Application Tuning Tool PMSM_FOC_KV1x_MCAT pmp e src contains the project source and header files and its contents will be described in the following text Files in the sre projects kv10 PMSM_Sensorless_FOC folder e main c and main h contain the basic application initialization enabling interrupts subroutines to access the MCU peripherals and interrupt service routines In the background infinite loop the FreeMASTER communication is performed e state_machine c and state_machine h contain the application state machine structure definition and handles the switching between the application states and application states transitions e motor_structure c and motor_structure h contain the structure definitions and subroutines dedicated to perform the motor control algorithm vector control algorithm position and speed estimation algorithm speed control loop e M1 _ statemachine c and M1_statemachine h contain the software routines that are executed when the application is in the particular state or state transition e freemaster_cfg h configuration file for the Free MASTER interface e PMSM_appconfig h contains the constant definitions of the application control processes parameters of the motor and controllers and the constants for other vector control related alg
8. c is used For more information on tuning the application to any motor see 6 4 4 1 Automated PMSM parameters identification The application code contains routines for a PM synchronous motor parameters identification The algorithm simplifies and speeds up controller constant calculations and settings The identification process is disabled by default in the application and can be enabled from the MCAT control tab Motor Identif For more information on user motor identification see Freescale document AN4986 Automated PMSM Parameter Identification 7 5 Project File Structure The total number of source c and header files h in this project exceeds one hundred Therefore only the key project files will be described in detail and the remainder will be summarized in groups Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 14 Freescale Semiconductor Inc Project File Structure The main project folder is divided into three directories e build iar kv10 PMSM_Sensorless contains the configuration files for the IAR compiler as well as the compiler s output executable and object files If the IAR Embedded Workbench for ARM is installed on your computer double clicking the workspace file PMSM_SAC_SENSORLESS eww located in the directory build iar launches the IAR IDE e freemaster PMSM_Sensorless contains the FreeMASTER configuration file PMSM_FOC
9. calls Speed Ramp Speed PI Controller Slow Control Loop Figure 5 FTM2 ISR flow chart 3 3 Ports interrupt Handling of the user s button on the Kinetis KV10 MCU Tower System controller board is performed in the ISR associated with the Ports interrupt generated whenever the SW2 button is pressed At the beginning the interrupt flag is cleared Pressing the SW2 button enables disables the Demo mode The first pressing of the SW2 button puts the application state into RUN mode and the required speed is changed in several steps according to a predefined profile The subsequent press of the SW2 button returns the application to STOP mode More about the application control is available in Application Operation Using the FreeMASTER control interface enables enhanced control and diagnostic 3 4 PDB error interrupt The PDB error ISR serves to clear the sequence error fault that is generated in situations when PDB initiates the sampling of the AD converter even though the COCO flag in the specific ADCx_SCIn register of the ADC module was not cleared The values from the result registers are not read due to the reasons described as follows Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 Freescale Semiconductor Inc 9 Application Operation e One scenario is when the PDB counter stops working and an interrupt is asserted The ISR in the PDB module is then re initiated
10. cording to Equation 2 on page 6 Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 Freescale Semiconductor Inc Ol MCU Peripherals Sector 1 6 ig ic Sector2 3 ip ij ic Sector4 Siic ip ty Equation 2 Figure 2 illustrates two cases case I at 30 case II at 60 which explain why calculating the third current is necessary O 0O a VARVARA N 7 duty cycle ratios oO D 0 2 Phase B Phase C Lee 0 60 120 18 240 300 360 angle BOSS Sector 1 Sector 2 Sector 3 Sector 4 Sector 5 Sector 6 Bottom transistors PWM period PWM period a a aKa a Phase A open aieu n m Phase B oF close open Phase C dse ai Critical pulse width ADC sampling point PWM reload Figure 2 Current sensing Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 6 Freescale Semiconductor Inc MCU Peripherals 2 6 Overcurrent level The overcurrent signal is connected via the TWR Elevator IRQ_A B62 pin to the GPIO_B2 pin of the MKV10Z32 device This pin is internally connected to the FTMO_FLT1 signal that handles the fault by PWM hardware See Figure 3 The overcurrent level can be set in the range of 0 8 A by the trimmer R37 on the TWR MC LV3PH board The maximum current level can be set by turning the trimmer counterclockwise The user can find the level b
11. correct port number selection is confirmed by the text OpenSDA CDC Serial Port next to the list box with the available serial port numbers f Plugin Module drv 0 ptype 3 pnum 1 devid P 56554 76 W Save settings to project file Save settings to registry use it as default Communication state on startup and on project load C Open port at startup Do not open port at startup C Store port state on exit apply it on startup Store state to project file apply upon its load Advanced Figure 6 FreeMASTER communication settings 4 3 2 Application operation 4 3 2 1 Start Stop the communication When the communication settings are performed the communication between the PC and the embedded application can be initiated Click the STOP button in the FreeMASTER toolbar as shown in following picture Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 Freescale Semiconductor Inc 11 Application Operation Gal MCAT_PMSM_FOC_KV ix FreeMASTER File Edit View Explorer Project Toe TO Figure 7 Initiating the communication with the embedded side 4 3 2 2 Start Stop the application required speed setting The next step is to switch the application to the RUN state In the FreeMASTER window in the Variable Watch grid click on the drop down list next to the Application Switch variable name and select ON as the follo
12. etc For this application the RS232 was used because the software overhead for the data transfer represents the lowest additional load on the CPU Nowadays notebooks are not equipped with the COM port so for this purpose the TWR KV10Z32 module has in place a USB to RS232 interface CDC Serial Port By connecting the TWR KV10Z32 module with a notebook via the USB cable a virtual serial port will be established in the Windows system 4 3 Application operation using FreeMASTER Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 10 Freescale Semiconductor Inc Application Operation To run the FreeMASTER application double click on the PMSM_FOC_KV1x pmp file located in the freemaster PMSM_Sensorless_FOC_MID folder The FreeMASTER application starts and the environment will be automatically created as it is defined in the pmp file 4 3 1 Setting up the communication When the notebook is connected via USB cable with the TWR KV10Z32 board the operating system assigns the number of the COM port to the OpenSDA CDC Serial Port This number is assigned randomly therefore it 1s necessary to set the right communication port each time the connection is established re plugging the USB cable might cause a different port number assignment To set the port number click the menu item Project Options Then assign the port number in the Comm tab of the opened window The
13. eviated Terms Table 7 contains abbreviated terms used in this document Table 7 Acronyms and Abbreviated Terms a a Back EMF Back electromotive force a voltage generated by rotating motor PMSM Permanent Magnet Synchronous Motor Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 Freescale Semiconductor Inc 19 How to Reach Us Home Page freescale com Web Support freescale com support Information in this document is provided solely to enable system and software implementers to use Freescale products There are no express or implied copyright licenses granted hereunder to design or fabricate any integrated circuits based on the information in this document Freescale reserves the right to make changes without further notice to any products herein Freescale makes no warranty representation or guarantee regarding the suitability of its products for any particular purpose nor does Freescale assume any liability arising out of the application or use of any product or circuit and specifically disclaims any and all liability including without limitation consequential or incidental damages Typical parameters that may be provided in Freescale data sheets and or specifications can and do vary in different applications and actual performance may vary over time All operating parameters including typicals must be validated for each customer ap
14. f them differential pairs Comparators 2 modules each 7 channels 1 module 4 chip select 1 module signals FlexTimer 6 channels PDB 8 channels for ADC triggering Communications 2 channels Purpose DC bus voltage and motor phase currents sensing MOSFET driver configuration FreeMASTER communication Generation 6 channels PWM for motor control Generation of slow loop interrupt DC bus voltage and phase current sampling initiation 2 1 FlexTimer0 configuration to generate a 6 channel PWM The FlexTimer Module FTM is a two to eight channel timer which supports input capture output compare and the generation of PWM signals to control an electric motor and power management applications The FTM time reference is a 16 bit counter that can be used as an unsigned or signed counter On the Kinetis KV10 MCUs there are three instances of FTM One FTM has 6 channels the other two FTMs have 2 channels The FTMO is clocked from the system clock 75 MHz and the generated PWM has a frequency of 20 kHz period 50 us therefore MODULO must be 3750 CNTIN register 1875 MOD1 1874 There is an interrupt generated every second PWM reload by FTMO period 100 us 10 kHz This interrupt serves to calculate fast loop Current FOC algorithms The procedure of the FlexTimer configuration for generating a center aligned PWM with dead time insertion is described in 2 Because 2 supports an earlier version 1 0 of the F
15. he PDB and the ADC use the Bus Clock and the FTM uses the System Clock 2 4 ADC conversion timing currents and voltage sampling FlexTimer0 is configured to trigger an internal hardware signal when its counter is reset after overflow to the initialization value This signal is fed into the Programmable Delay Block PDB that consequently triggers the AD conversion of the voltage and currents with a predefined delay On the Kinetis KV10 75 MHz MCU two ADC modules are implemented Each ADC module associates to one channel of the PDB module Each ADC module has two result registers two channels and they correspond to two programmable pre trigger delays of the PDB channels So it is possible to perform four AD conversions without requesting an interrupt with respect that the DMA is not used for data transfer In this application only three conversions need to be triggered without CPU intervention two motor phase currents and the DC Bus voltage Figure 1 shows the module interconnections and the ADC interrupt generation Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 4 Freescale Semiconductor Inc n MCU Peripherals SL E E a EE N SEEE CO EEEE P EE Ce T SEE PREE FIMO counter FIMO varo ere EENE fae een TEE A ee O FIMO Inittrig PWM top channel PWM bottom channel PDBO CHO wae zal e ee DC Bus voltage gt ADC RB PDBO CH1 Phase c
16. l Fast State i sM FastStateMachine Machine Read ADC results Position and Function calls Clarke Transformation currents imati Sin speed estimation z Park Transformation currents Park Transformation voltages Back EMF Observer Tracking Observer IIR filter 1 order Fast Control Function cals Q Clarke Transformation currents Park Transformation currents Loop D current PI controller Q current controller Limit Calculation incl SART Q current PI controller Update PATTI registers Inverse Park Transformation req voltages DC Bus Ripple Elimination Space Vector Modulation i ADC channel assignment FreeMASTER Recorder Figure 4 FTMO ISR flow chart Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 8 Freescale Semiconductor Inc Interrupts 3 2 FTM2 interrupt This interrupt request executes slow loop state machine and is triggered when FTM2 overflows therefore it is independent on FTMO interrupt Speed control functions are called in this interrupt The interrupt flag is cleared by writing 0 to TOF bit in FTM2 gt SC register The flow chart depicted in Figure 5 provides an overview of the program flow during execution of the FT M2 interrupt service routine when the application is in the Run state and the Spin sub state FI M2 ISR Start Function call Slow State Machine SM SlowStateMachine Function
17. lation on the PC or notebook The FreeMASTER PC application can be downloaded from the Freescale webpage http www freescale com freemaster from the Download tab select FreeMASTER 1 4 Application Installation Because downloading the FreeMmASTER application requires registration it is necessary to create an account before you can log in After you log into the system the license agreement appears You should read the license agreement and then you have to accept the agreement by clicking the I Accept button If you are using Internet Explorer then at the top of the web page you will see a bar asking to authorize the file download Click on the bar and select Download File A dialog box appears where you can choose to either Run or Save In both cases the installation archive will be stored on your machine By selecting the Save you have the option to select your preferred location for saving the installation archive otherwise it will be saved to a Temporary folder created by your system The library installation archive will be now downloaded to your computer To run the installation click the Run button Follow the instructions on the screen to complete the installation process 4 2 Establishing the connection between the PC and the embedded application The FreeMASTER allows using multiple communication interfaces between the embedded application and the PC or notebook UART RS232 CAN Ethernet USB BDM
18. lexTimer and with regards to the hardware used TWR MC LV3PH there are a few differences in the configuration as follows e It is necessary to enable the system clock for the FlexTimer module in the Clock Gating Control register SIM SCGC6 l SIM_SCGC6_FTM0O_MASK e It is necessary to disable the write protection of some registers before they can be updated Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 Freescale Semiconductor Inc MCU Peripherals FTM0 gt MODE l FTM_MODE_WPDIS_MASK e It is recommended to enable the internal FlexTimer counter to run in the debug mode FTM0 gt CONF l FTM_CONF_BDMMODE 3 e When the HW debugging interface Link Multilink is connected to the microcontroller the MCU is in debug mode This is not dependent on running code containing breakpoints e The PWM signals generated by the FlexTimer0 are directly connected to the MOSFET driver Because of safety reasons the input signals for the top transistors on the MOSFET driver used on the Freescale Tower System development board low voltage power stage have inverse polarity Therefore it is also necessary to set the right polarity of the PWM signals FTM0 gt POL FTM_POL_POLO_MASK FTM_POL_POL2_MASK FTM_POL_POL4_MASK e The duty cycle is changed by changing the value of the FlexTimer Value registers These registers are double buffered meaning that their values a
19. ol Block Diagram ce A anne VTL ie hy wy Faults Status Required Speed DC Bus Under Voltage Speed Selector DC Bus Over Voltage Load Over speed Over MC33937 Faul an Faults indicators i Speed selector for quickly Freescale Semiconduct igned by Motor Control Team Microcont setting the required speed Figure 9 FreeMASTER control page 4 3 2 4 Scopes and Recorders One of the main benefits of the FreeMASTER application is to visualize the values of the variables in real time For this purpose there are two possibilities The user can select between the Scope and the Recorder While the Scope feature downloads a stream of the data continuously in real time the Recorder stores the data in a buffer located in the RAM of the embedded MCU and after a trigger condition is met the data is transferred in blocks via the communication interface and visualized in the FreeMASTER window The sampling period of the Scope is limited by the speed of the communication interface and therefore is used for slowly changing quantities such as the speed The sampling period of the oscilloscope like Recorder is in the microseconds range enabling visualization of quickly changing quantities such as the phase currents or the duty cycles In this application the recorder buffer is updated each time the fast control loop is executed that 1s every 100 us The following picture shows the Recorders and Scopes that can be
20. orithms When the application 1s tailored for another motor using the Motor Control Application Tuning Tool this file is generated by the tool at the end of the tuning process e peripherals folder contains the important files for static configuration of the peripherals used in the application FlexTimers ADC PDB SPI Subdirectories in the src folder e common and cpu folders containing CPU initialization routines e cpul isr h an important file with definitions of the peripherals interrupt service routines assigned to the interrupt vectors In this file the user can add the definition of an ISR for an additional peripheral interrupt e drivers files in the subdirectories contain generic source and header files for UART and watchdog configuration as well as the CPU clock settings routines e platforms tower h contains the Tower System development board definitions for Kinetis CPU speed and UART parameters e platforms MKV10Z7 h is the header file containing macro definitions of all the MCU registers and register bits Files in the src MMCLIB folder e CM0 _MMCLIB_IAR a software library containing motor control general math and filter algorithms Additional files in the folder and subfolders are associated header files each one for a particular function of the library e ACLIB CM0 _ACLIB_JIAR_r0 2 a contains the advanced control algorithms for rotor position and speed estimation Back EMF observer and Tracking observe
21. plication by customer s technical experts Freescale does not convey any license under its patent rights nor the rights of others Freescale sells products pursuant to standard terms and conditions of sale which can be found at the following address freescale com Sales TermsandConditions Freescale the Freescale logo and Kinetis are trademarks of Freescale Semiconductor Inc Reg U S Pat amp Tm Off Tower is a trademark of Freescale Semiconductor Inc All other product or service names are the property of their respective owners ARM and the ARM Powered logo are registered trademarks of ARM Limited or its subsidiaries in the EU and or elsewhere 2014 Freescale Semiconductor Inc Document Number AN5049 Revision 0 12 2014 Lp freescale
22. r Other subdirectories in the src folders Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 Freescale Semiconductor Inc 15 Memory Usage e FreeMASTER contains all source files of the FreeMASTER application it is not necessary to access it or change anything inside The interface to the programmer is only via freemaster_cfg h file located in src projects kv 1O PMSM_ Sensorless folder e SAC folder Sensor and Actuator Components contains routines to access peripherals used by the motor control algorithm to sense input feedback physical quantities currents voltage speed position and to set the actuators based on calculated output variables FlexTimer MOSFET pre driver 6 Memory Usage Table 2 summarizes the chip memories usage Table 2 Total Memory Usage Memory Type Total Memory Available on the Used by the Application Bytes Kinetis MKV10Z32 Program Flash application code 32KB 22 970 Data Flash application constants 1 650 Data RAM application variables 6 614 1 Including 4096 bytes of FreeMASTER recorder buffer Table 3 summarizes the chip memories usage for selected algorithm blocks Table 3 Algorithm Blocks Memory Usage Algorithm Block Program Memory Code Constants Data Memory Bytes Bytes eee esa Aik re ae 7 Hardware Setup The Tower System development board platform is used as the hardware platform fo
23. r the PMSM sensorless on Kinetis MKV10Z32 It consists of the following modules e Tower System elevator modules TWR ELEV e Kinetis MKV10Z32 Tower System module TWR KV10Z32 e Three phase low voltage power module TWR MC LV3PH with included motor All modules of the Tower System development platform are available for order via the Freescale web page or from distributors so the user can easily build the hardware platform for which the application is targeted Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 16 Freescale Semiconductor Inc Hardware Setup 7 1 Hardware set up and jumpers configuration Building the system using the modules of the Tower System is not difficult The peripheral modules and the MCU module are plugged into the elevator connectors while the white stripe on the side of the module boards determines the orientation to the Functional elevator the elevator with the mini USB connector power supplies and the switch It is necessary to configure jumpers on both the TWR KV10Z32 module and the TWR MC LV3PH module The jumper settings for TWR KV10Z32 board are listed and highlighted in the following table Table 4 Jumper Settings of TWR KV10Z32 Board a 424 PRIMARY gry TWR KVIOZ32 2013 FREESCALE RE FFFFFFRFRFFF errr nh re hn en mn S s ne Eo e rs a Fass Es x i IOF E Ja D ss 5 ia fe w E z wE E A r r
24. re updated not only by writing the number but also by confirming the change by setting the Load Enable LDOK bit This ensures that all values are updated at the same instance FTMO gt PWMLOAD FTM_PWMLOAD_LDOK_MASK It is necessary to write the LDOK bit every time the value registers are changed so not only at the stage of loading them with initial values but with every update after the duty cycle value is computed in the vector control algorithm e Within the application hardware triggering of the AD converter is employed The Initialization Trigger signal from the FlexTimer is used as the primary triggering signal which is fed into the Programmable Delay Block that services the timing of the AD conversion initiation FTM0O gt EXTTRIG l FTM_EXTTRIG_INITTRIGEN_MASK e FTMO interrupt is generated on every second PWM reload FTMO gt SC l FTM_SC_TOIE_MASK FTMO0 gt CONEF l FTM_CONF_NUMTOF 1 e Finally the output pins of the MCU must be configured to bring out the signals from the chip The assignment of signals to output pins is set in the Pin Control Register The available signals are listed in the Signal Multiplexing chapter of 3 and are package dependent PORTC gt PCR 1 PORT_PCR_MUX 4 FTMO CHO PORTE gt PCR 25 PORT_PCR_MUX 3 FTMO CH1 PORTC gt PCR 3 PORT_PCR_MUX A4 FIMO CH2 PORTC gt PCR 4 PORT_PCR_MUX 4 FTMO CH3 PORTD gt PCR 4 PORT_PCR_MUX 4 FTMO CH4 PORTD gt PCR 5 PORT_PCR_MUX
25. side gain calibration results and store them in the ADC plus side and minus side gain registers after the calibration function completes The calibration must be performed for both ADC modules After calibration the ADC modules are configured to a 12 bit accuracy The CPU frequency is set to 75 MHz so by using available prescaler values the input clock to the ADC module is set to 12 5 MHz That setting yields a conversion time of 2 64 us 33 ADC clock cycles Finally the hardware trigger must be enabled in the Status and Control Register 2 The Programmable Delay Block PDB provides controllable delays from either an internal or an external trigger or a programmable interval tick to the hardware trigger inputs of the ADCs so that a precise timing between ADC conversions is achieved The PDB module has an internal counter that overflows on a modulo value Because the input trigger periodically comes from FTMO the value of the modulo register can be set to its reset value The values in the channel delay registers are set to generate triggers to start sampling the DC bus voltage and the motor phase AD conversions The PDB module on the KV10 MCU allows 15 different input trigger sources They are listed in the Chip configuration chapter in section PDB Configuration in 4 Similarly as for FTMO the LDOK bit must be set to acknowledge the changes in the delay registers On the KV10 MCU the clock source for the PDB is different than the FTM that is t
26. the Tower System development boards the UART1 is used The communication speed is set to 19200 Bd and is limited by use of the OpenSDA CDC serial communication driver The use of direct RS232 connection between the PC and the embedded side enables an increase of the communication speed to 115200 Bd Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 Freescale Semiconductor Inc 7 Interrupts 3 Interrupts In the application there are 4 interrupts in total FTMO interrupt serves to execute fast loop Current FOC algorithms FTM2 serves to execute slow loop Speed FOC algorithms ports interrupt handles user buttons and PDB error interrupt clears the sequence error fault 3 1 FTMO interrupt This interrupt request executes fast loop state machine and is triggered every second PWM reload In the beginning of the FTMO ISR execution an application state machine function is called If the application is in the Run state then it is followed by the execution of the fast current control loop of the PMSM vector control algorithm including the position and speed estimation The interrupt flag is cleared by writing 0 to TOF bit in FTMO gt SC register The flow chart depicted on the Figure 4 provides an overview of the program flow during execution of the FTMO interrupt service routine when the application is in Run state and Spin sub state FIMO ISR Start 3 Function cal
27. urrent 1 gt ADCO RA PDB1 CHO Phase current 2 gt ADC1 RA ADCI COCO FIMO ISR ADC1 COCO ADCI COCO FIMO ISR ADCI COCO Interrupt AD channel conversion Result Register updated Figure 1 ADC conversion timing diagram 2 5 Current measurement Closely related to the ADC conversion trigger timing is the assignment of the ADC channels to the measured analog signals For computation of the fast current control loop of the FOC it is necessary to know the values of all three motor phase currents Because there are only two ADC modules it is possible to sample only two analog quantities in one instance Assuming the motor represents a symmetrical three phase system the sum of all three instantaneous phase currents is zero 0 Lytiptic Equation 1 Because the phase currents are measured the instance when the bottom transistors are conducting in the case of high duty cycle ratios current value is in the area of the maximum of the sine curve the time when the current can be measured is too short The bottom transistor must be switched on at least for a critical pulse width to get a stabilized current shunt resistor voltage drop The selection of the channels is determined based on the section when the space vector of the stator current is generated This assignment is performed at the end of the ADC1 interrupt service routine Therefore it is enough to sample only two phase currents while the third is easily calculated ac
28. wing picture illustrates H MCAT_PMSM_FOC_KV ix FreeMASTE File Edit View Explorer Projet Tools Help fay PMSM FOC Sensorless HME 1 Scalar amp Voltage Control E Speed 4 Phase Currents A Dacitinn Variable Watch Value OFF 0 Eil STOP i EED_FOC 3 f Name Application Switch Application State MCAT Control Speed Required Speed Actual DCE Voltage Filtered 0 0 Figure 8 Start the application Once the application is set to the RUN state the required speed can be changed to some non zero value The procedure is similar as in the previous step in the Variable Watch grid enter a positive or negative value next to the Speed Required variable name 4 3 2 3 Operation of the application from the control page The application can also be operated from the control page see the description in Figure 9 Three Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters Identification Rev 0 12 2014 12 Freescale Semiconductor Inc Application Operation 2 freescale Required speed can be changed by clicking in the green Application Switch Speed Control aias area Stop Application Status Demo Mode aa Start Stop switch iad MLE Wes _ Start Stop Demo mode the Required speed will be changed Freeh ASTER Communication E in the predefined profile DC Bus Current PMSM Sensorless Vector Control on Kinetis Application Contr
29. y turning the trimmer counterclockwise while the motor is running until the red LED is lit It is recommended to set the trimmer to a somewhat higher level so that the motor can operate at maximum speed TWR MC LV3PH MC33937 MKV102Z32 R10 DC Bus Shunt 1 65V ref TWR KV10232 Figure 3 Overcurrent level 2 7 SPI configuration The SPI interface is used in the application for communication between the intelligent MOSFET gate driver MC33937 and the KV10 MCU The MC33937 gate driver is placed on the Tower System low voltage power module and serves for driving the high side and low side MOSFET transistors of the three phase inverter In the application the initialization of the MC33937 must be performed primarily to set dead time During the motor operation there is also periodic checking of the status register of the driver to provide information on the latched faults The MC33937 driver requires precise timing of the SPI signals The default setting of the SPI module on the MCU is not possible to use The exact timing of the SPI signals is listed in 5 2 8 SCI UART configuration The SCI is used in the application for the communication between the master system and the embedded application A master system is the notebook or the PC where the FreeMASTER software is installed to control the application and visualization of its state On the Kinetis KV10 there are two UART modules implemented Because the hardware solution is based on
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