PMSM Sensorless Control on TWR
Contents
1. Kinetis KV31F120M peripherals Jec iN ine Purpose application Group Module Number of modules or channels z Analog ADCO 24 single ended channels four of Three DC bus voltage and motor them in differential pairs channels phase currents sensing 24 single ended channels four of Two ADC1 see f them in differential pairs channels Two modules each has seven Comparators channels DAC One module 7 Two modules six chip select signals Communications SPI on SPIO and four chip select signals One module MOSFET onver configuration for SPI1 UART Three modules One module bree communication LPUART One module C Two modules Timers FlexTimer Eight channels Six channels Generation or SIE cNanneI 9 PWM for motor control Two channels Two channels 7 7 Eight channels 7 PDB Two channels for ADC triggering Two Dnue voltage ang phase channels current sampling initiation Two channels for DAC triggering T z PIT Four channels LPT One module Other eDMA 16 channels 7 2 1 FlexTimer configuration for generating a six 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 signe2. Free MASTER 1 4 Application Installation Since downloading of the FreeMASTER application requires registration it is necessary to create an account before you can log in After logging into the system the license agreement appears User should read the license agreement and then accept the agreement by clicking the I Accept button If using Internet Explorer then a bar asking to authorize the file download appears at the top of the web page Please click on the bar and select Download File A dialog box where the user can choose either Run or Save appears In both cases the installation archive will be stored on user PC PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semiconductor Inc 9 Application operation After selecting Save user has the option to select the preferred location for saving the installation archive otherwise it will be saved to a temporary folder in user system The library installation archive will now be downloaded to user computer To run the installation please click the Run button Follow the instructions on the screen to complete the installation process 4 2 Establishing a connection between the PC and the embedded application The FreeMASTER allows using multiple communication interfaces between the embedded application and the PC UART RS232 CAN Ethernet USB BDM and other For this application the
3. e Voltage FOC e Current FOC e Speed FOC This enables tuning of the application in several steps with each step containing a limited number of unknown parameters that can be adjusted To switch between these modes the MCAT tab Control Struc is used For more information on tuning of the application for any motor see AN49 2 5 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 AN4986 6 PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semiconductor Inc SDK implementation 5 SDK implementation Kinetis SDK KSDK provides a comprehensive software support for Freescale Kinetis devices such as the KV31F120M MCU The KSDK includes all necessary source and header files required by the application as startup code clock configuration and peripherals configuration provided by Hardware Abstraction Layer HAL as low level configuration routines and high level peripherals drivers based on HAL routines This suite provides easy portable basics of applications for the Kinetis family MCUs with no or little code modifications depending on MCU and its periphe
4. CDC Serial Port next to the list box with the available serial port numbers Communication speed of the interface is 19200 Bd PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 10 Freescale Semiconductor Inc Application operation Options Comm MAP Files Pack Dir HTML Pages Demo Mode Views amp Bars Communication Direct RS232 Port OpenSDA OpenSDA CDC Serial Port http www Speed 19200 v Plugin Module v drv 0 ptype 3 pnum 1 devid PE5655478 v IV Save settings to project file Save settings to registry use it as default m 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 5 FreeMASTER communication settings 4 4 Starting stopping the communication and the application 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 Figure 6 F pmsm_foc_kv3x Free MASTER I File Edit View Explorer Project fe oo IS 1 Scalar amp Voltage Control fee Speed Figure 6 Initiating the communication with the embedded side The next step is switching the application to the RUN state Click on th
5. and m1_state_machine h contain the software routines that are executed when the application is in a particular state or state transition freemaster_cfg h configuration file for the FreeMASTER interface pmsm_appconfig h contains constants definitions of the application control processes parameters of the motor and regulators and the constants for other vector control related algorithms When the application is tailored for another motor using the Motor Control Application Tuning Tool MCAT this file is generated by the tool at the end of the tuning process peripherals contains important files for static configuration of the peripherals used in the application FlexTimers ADC PDB SPI PIT Subfolders in the src folder are state_machine contains the application state machine structure definition which handles the switching between the application states and application state transitions control_algorithms contains the structure definitions and subroutines dedicated for performing the the motor control algorithm vector control algorithm position and speed estimation algorithm speed control loop Files in the src CM4_MMCLIB_r1 0 folder are CM4_MMCLIB_IAR a a software library containing motor control general math and filter algorithms Other files in the folder and subfolders are associated header files each one for a particular function of the library ACLIB CM4_ACLIB_F16 a contains th
6. 0M MCU with the debugger or linked to the FreeMASTER communication tool 6 Project file structure The total number of source c and header files in the project exceeds one hundred Therefore only the key project files will be described in detail and the rest will be described in groups The main project folder is divided into three directories e build iar kv3 IVKPMSM_Sensorless_FOC contains configuration files for the LAR compiler as well as the compiler s output executable and object files If the LAR Embedded Workbench for ARM is installed on your computer double clicking the workspace file PMSM_SENSORLESS_FOC eww will launch the IAR IDE PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 14 Freescale Semiconductor Inc Project file structure freemaster PMSM_Sensorless_FOC contains the FreeMASTER configuration file PMSM_Sensorless_FOC pmp and supporting files control page in HTML format and the binary file with addresses of variables src contains the project source and header files and its contents will be described further in the text Files in the src projects kv3 1 PMSM_Sensorless_FOC folder are main c and main h contain basic application initialization enabling interrupts sub routines accessing the MCU peripherals and interrupt service routines The FreeMASTER communication is performed in the background infinite loop m1_state_machine c
7. 2 Sector 4 5 ic g i PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semiconductor Inc 5 MCU peripherals Figure 2 explains the reason why the third current cannot be measured directly in some time instances Case I shows the phase currents at 30 and Case II at 60 o 9 92 9 O N A Q O duty cycle ratios 120 360 angle BOO O29 Sector 1 Sector 2 Sector 3 Sector 4 Sector 5 Sector 6 180 Bottom transistors PWM period PWM period Phase A oven dne Phase B pan PhaseC of ADC sampling point PWM reload Figure 2 Current sensing 2 5 Over current level The over current signal is connected via the TWR Elevator IRQ_A B62 pin to the GPIO_C9 pin of the KV31F120M device This pin is internally connected to the GPIO signal that handles the fault See Figure 3 PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 6 Freescale Semiconductor Inc Interrupts TWR MC LV3PH MC33937 MKV31F512 Over Current Fault Detection R1 0 j 1 65V ref DC Bus Shunt TWR KV31F120M Figure 3 Over current level The over current 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 by turning the trimmer counterclock
8. Freescale Semiconductor Inc Application Note Document Number AN4911 Rev 1 02 2015 PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK by Marek Zeman 1 Introduction This application note represents an addendum to DRM 140 Sensorless PMSM Field Oriented Control It describes the MCU peripherals used in the application the hardware setup and results of the measurement built under the Freescale SDK suite for Kinetis MCUs 2015 Freescale Semiconductor Inc All rights reserved OerXNNMN FWY NF Oo oO Contents lt AMPODUCHON sss eisie sg ela giclee as dso a 8 eg 1 MCU periphe rals 066 esa se ccsaa eneas 2 oo AME TLUP IS ie since Boer he igen Some aialien we ere ae Ruale ss 7 Application operation 0 0 e eee eee 9 SDK implementation 0 04 13 Project file structure 00 cee eee 14 Memory usage and CPU load 16 s Hardware Setup oer sites dhe E secede sence SE 16 s CONCIUSION s cccad Daal Pe VER awa REN 18 References sei att cde he baio E herbelin 18 Acronyms and abbreviated terms 19 Revision history 0 000000 19 P ia y freescale MCU peripherals 2 MCU peripherals Table 1 summarizes the peripherals of the Kinetis KV31F120M MCU and their usage in the PMSM sensorless vector control application Table 1 Kinetis KV31F120M peripherals overview
9. P100M120SF7RM 2 and are package dependent PORT_HAL_SetMuxMode PORTC_BASE 1 kPortMuxAlt4 FTMO CHO PTC1 PORT_HAL_ SetMuxMode PORTC_BASE 2 kPortMuxAlt4 FTMO CH1 PTC2 PORT_HAL_SetMuxMode PORTC_BASE 5 kPortMuxAlt7 FTMO CH2 PTC5 PORT_HAL_SetMuxMode PORTC_BASE 4 kPortMuxAlt4 FTMO CH3 PTC4 PORT_HAL_SetMuxMode PORTD_BASE 4 kPortMuxAlt4 FTMO CH4 PTD4 PORT_HAL_SetMuxMode PORTD_BASE 5 kPortMuxAlt4 FTMO CH5 PTD5 PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semiconductor Inc 3 MCU peripherals The port settings implemented in the application code reflect the hardware solution built on the Tower System board 2 2 Configuring the ADC and PDB modules 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 PDB closely cooperates with the ADC and serves for hardware triggering of sampling It is required to perform a self calibration procedure of the ADC module before it is used in the application in order to obtain specified accuracy The calibration process also requires programmer s intervention to generate the plus side and minus side gain calibration results and store them in the ADC plus side gain and minus side gain registers after the calibration f
10. RS232 was used because the software overhead for the data transfer represents the lowest additional load on the CPU Nowadays the notebooks are not equipped with the COM port so for this purpose the TWR KV31F120M module has a USB to RS232 interface in place CDC Serial Port By connecting the TWR KV31F120M module to a notebook via the USB cable a virtual serial port will be established in the Windows system To run the FreeMASTER application double click the PMSM_FOC_KV31x pmp file located in the freemaster PMSM_Sensorless_FOC_MID folder The FreeMASTER application starts and the environment will be automatically created as defined in the pmp file 4 3 Setting up the communication When the notebook is connected to the TWR KV31F120M board via a USB cable the operating system assigns the number of the COM port to the OpenSDA CDC serial port interface This number is assigned randomly therefore it is necessary to set the right communication port when the connection is established re plugging the USB cable might cause a different port number assignment To set the port number select Project Options from the menu It is necessary to assign a correct port number and or value Add the OpenSDA value to the Port list box and the FreeMASTER automatically assigns a correct communication channel or select COM port from the dropdown listbox menu The correct port number selection is confirmed by the text OpenSDA
11. TWR MC LV3PH with included motor All modules of the Tower System are available to order via the Freescale web page or from distributors so the user can easily build the hardware platform for which the application is targeted PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 16 Freescale Semiconductor Inc Hardware setup 8 1 Hardware setup 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 mini USB connector power supplies and switch Table 4 Jumper settings of the TWR KV31F120M board TT Jumper Settings Jumper Settings J1 1 2 J15 1 2 J2 open J17 1 2 J3 1 2 3 4 J4 open 5 6 J5 1 3 7 8 J8 open J18 open J9 1 2 J20 open J10 open J22 2 3 J11 open J23 2 3 J12 1 2 J25 1 2 J13 1 2 J26 2 3 J14 1 2 J27 open The jumper settings for TWR MC LV3PH board are listed and highlighted in Table 5 See the user s manual TWRMCLV3PHUG 8 for more details for example the hardware over current threshold setting of the TWR MC LV3PH stage PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semicon
12. als FTM_HAL SetChnOutputPolarity FTMO_BASE 0 1 FTM_HAL_ SetChnOutputPolarity FTMO_BASE 2 1 FTM_HAL SetChnOutputPolarity FTMO_BASE 4 1 The duty cycle is changed by adjusting the value of the FlexTimer value registers These registers are double buffered meaning that their values are updated not only by writing the number but it is necessary to confirm the change by setting the Load OK LDOK bit This ensures that all values are updated at the same instance FTM_HAL SetPwmLoadCmd FTMO_BASE true It is necessary to write the LDOK bit every time the value registers are changed 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 As mentioned in Section 2 3 ADC conversion timing currents and voltage sampling hardware triggering of the AD converter is employed in the application The Initialization Trigger signal from the FlexTimer is used as the primary triggering signal and is fed into the Programmable Delay Block that services the timing of the AD conversion initiation FTM_HAL_ SetInitTriggerCmd FTMO_BASE true The output pins of the MCU have to be configured in order to bring the signals out of the chip The assignment of signals to output pins is set in the Pin Control Register while the available signals are listed in the Signal Multiplexing chapter of reference manual KV3
13. cation variables 96 KB 9 657 B including 4096 B FreeMASTER recorder buffer Table 3 Memory usage values in bytes Algorithm block Program MAR r constants a e FOC fast slow loops 4472 0 FreeMASTER 2950 4365 SAC Sensor and Actuator Components 2696 4 MID Motor Identification 3412 590 Application State Machine 4638 596 The CPU load is influenced mainly by the execution of the ADC1 ISR in which the execution of the application state machine and calculation of the fast current and slow speed control loop of the PMSM vector control is performed The complete ADC1 ISR requires 5506 state machine and fast slow control loop machine cycles in the worst case the total consumed time per interrupt is 45 us The ADC1 interrupt is generated periodically with the same frequency as the PWM re load event when the values of the duty cycles are updated In this application the ADC ISR is generated once per 100 us which corresponds to 10 kHz of the PWM frequency At 120 MHz on the Kinetis KV31F120M MCU it consumes 45 85 of the total CPU performance 8 Hardware setup The Tower System a modular development system is used as a hardware platform for the PMSM sensorless application on Kinetis KV31F120M MCU It consists of the following modules e Tower System elevator modules TWR ELEV e Kinetis KV31F120M Tower System module TWR KV30F120M e Three phase low voltage power module
14. d counter Kinetis KV31F120M has four instances of FTM where two FTMs have eight channels and the other two FTMs have two channels PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semiconductor Inc MCU peripherals The procedure of the FlexTimer configuration for generating a center aligned PWM with dead time insertion is described in the AN3729 application note 1 Since the reference application note supports an earlier version of the FlexTimer 1 0 with respect to the hardware used TWR MC LV3PH there are a few differences needed in the configuration described as follows Enable the system clock for the FlexTimer module by SIM_HAL_ EnableFtmClock SIM_BASE 0 Disable the write protection of some registers before they can be updated FTM_HAL SetWriteProtectionCmd FTMO_BASE false Enable the internal FlexTimer counter to run in the debug mode FTM_HAL SetBdmMode FTMO_BASE 3 While the hardware debugging interface JLink Multilink or other is connected to the MCU it is in the debug mode It is not dependent on whether the running code contains breakpoints or not The PWM signals generated by the FlexTimer are directly connected to the MOSFET driver For safety reasons the input signals for the top transistors on the MOSFET driver used on the TWR MC LV3PH board have inversed polarity Therefore it is also necessary to set the right polarity of the PWM sign
15. d estimation The slow speed control loop is calculated based on the value of software counter that is decremented each time the fast control loop is passed The interrupt flag is cleared by reading the result register of the ADC channel that triggered the interrupt Therefore the results of the AD conversion are read at the beginning of each particular state machine function even when the values are not later used in the program execution The flowchart depicted in Figure 4 provides an overview of the program flow during the execution of the ADC interrupt service routine when the application is in the RUN state and SPIN sub state ADC ISR Start Function call SM_StateMachine Read ADC results Clarke Transformation currents let a formation currents Position and Function calls Park Trans s r Back EMF Observer speed estimation Tracking Observer IIR filter 1 order Fast Control Function calls Loop Update PWM registers ADC channel assignment Function calls Slow Control Speed Ramp J Loop Speed PI Controller Clarke Transformation currents Park Transformation currents D current PI controller Q current controller Limit Calculation incl SQRT Q current PI controller Inverse Park Transformation req voltages DC Bus Ripple Elimination l Space Vector Modulation FreeMASTER Recorder Figure 4 ADC ISR flowchart PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application N
16. de the execution will stop However the PDB will generate triggers for the next conversion even when the program execution stops The COCO flags are not cleared and the PDB generates a sequence error Another reason is that the execution of the ADC conversion complete interrupt where also the fast control loop is calculated would extend over one period of PWM This might happen if the user put additional tasks into the ADC conversion complete interrupt Besides the generation of the PDB sequence error a 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 extends the sampling period The real time control application has to be designed in such a way that this situation never occurs 4 Application operation The application can be operated either via the user button on the TWR KV31F120M MCU board as mentioned in Section 3 2 Ports interrupt or using the FreeMASTER software which enables visualization of 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 transferred via the RS232 interface 4 1 Installing FreeMASTER on a PC The FreeMASTER application for PC can be downloaded from the Freescale webpage freescale com freemaster from the Download tab select
17. ductor Inc 17 Conclusion Table 5 Jumper settings of the TWR MC LV3PH board Jumper Settings J2 1 2 J3 1 2 E J10 1 2 1 I dee Fe J11 1 2 jE z 5 p J12 1 2 BU a 4 J13 1 2 J14 1 2 9 Conclusion The results of the execution time measurement show that the Kinetis KV31F120M MCU can be used to drive the PMSM sensorless vector control algorithm for high dynamic applications The CPU load at 10 kHz PWM frequency represents only 45 so there is much space to either increase the frequency of the fast control loop or to perform additional user s tasks 10 References The following resources are available on freescale com MK WN DS SND Using FlexTimer in ACIM PMSM Motor Control Applications Document AN3729 KV31F Sub Family Reference Manual Document KV31P100M120SF7RM Three Phase Field Effect Transistor Pre driver Data Sheet Document number MC33937 TWR KV31F120M OOBE Demo User Guide Document TWRKV31F 120M Tuning 3 Phase PMSM Sensorless Control Application Using MCAT Tool Document number AN4912 Automated PMSM Parameters Identification Document number AN4986 Kinetis SDK Demo Applications User s Guide Document KSEDKDEMOUG TWR MC LV3PH User s Manual Document number TWRMCLV3PHUG Kinetis SDK KV31 User s Guide Document number KSDKKV31FUG PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semicond
18. e 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 application 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 SalesTermsandConditions Freescale the Freescale logo and Kinetis are trademarks of Freescale Semiconductor Inc Reg U S Pat amp Tm Off Tower System is a trademark of Freescale Semiconductor Inc All other product or service names are the property of their respective owners ARM and ARM logo are the registered trademarks of ARM Limited 2015 Freescale Semiconductor Inc a ms io pra a a ARM YY y 2 freescale
19. e advanced control algorithms for rotor position and speed estimation back EMF observer and tracking observer Other subdirectories in the src folders are 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 handled via the freemaster_cfg h file located in the src projects kv3 I PMSM_Sensorless_FOC folder sac sensor and actuator components contains routines for accessing 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 sdk startup contains pre compiled start up library ksdk_startup_lib a with clock setting possibilities and pre defined header for clock setup system_KV31F51212 h PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semiconductor Inc 15 Memory usage and CPU load 7 Memory usage and CPU load The following tables show the memory usage of the KV31F120M MCU total available data and RAM memory size of used memory and memory used by individual algorithm blocks Table 2 Memory usage values in bytes Memory Total N kinetis Used by the application Program Flash application code 27 214 B 512 KB Data Flash application constants 1094 B Data RAM appli
20. e drop down list next to the Application Switch variable name in the FreeMASTER window in the Variable Watch grid and select ON as shown in Figure 7 Once the application is switched to the RUN state the required speed can be changed to a non zero value The procedure is similar to the previous step in the Variable Watch grid enter a positive or negative value next to the Speed required variable name PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semiconductor Inc Application operation File Edit View Explorer Project Tools Help SUDE baga ap BI e 0 ia il BEN ig PMSM FOC Sensorless eM 1 Scalar amp Voltage Control E Speed 4 Phase Currents 44 Position control page Variable Watch _ Application State MCAT Control Speed Required Speed Actual __ DCB Voltage Filtered Figure 7 Starting the application 4 5 MCAT tool control To run the FreeMASTER application including the MCAT tool double click on the MCAT_PMSM_FOC_KV3x pmp file located in the freemaster WPMSM_Sensorless_FOC_MID folder The FreeMASTER application starts and the environment will be automatically created as defined in the pmp file The application enables tuning of the PMSM sensorless application for any motor For this purpose the field oriented control can be divided into four modes as follows e Scalar
21. ote Rev 1 02 2015 8 Freescale Semiconductor Inc Application operation 3 2 Ports interrupt Handling of the user s buttons on the KV31F120M Tower System board is performed in the ISR associated with the ports interrupt generated whenever one of the buttons is pressed At the beginning of the ISR a simple logic is executed to evaluate which button was pressed and the interrupt flag is cleared Pressing the SW1 button causes the speed to increase in 10 steps Pressing of the SW2 button causes the speed to decrease in 10 steps and also causes the transition back to STOP state For more information about the application control via the user buttons see TWRKV3 F 120M 4 where the use of the FreeMASTER control interface for enhanced control and diagnostics is described 3 3 PDB error interrupt The PDB error ISR serves for clearing the sequence error fault that is generated in situations when the PDB initiates the sampling of the AD converter but the COCO flag in particular ADCx_SC In register of the ADC module was not cleared the values from result registers were not read due to multiple reasons described below In such case the PDB counter stops working and the interrupt is asserted The PDB module is then re initiated in the ISR The PDB generates trigger signals with the same period as is the period of the ADC conversion complete interrupt and this period is the same as the PWM period If the user places an interrupt in the co
22. rals and core equipments used More information about the KSDK can be found in KSDKDEMOUG 7 and on freescale com ksdk Next steps explain how to run a demo application under KSDK with IAR workbench and how to pre build the platform driver library in IAR workbench which is necessary to run the example application 5 1 Building the platform driver library in IAR In the first step it is required to generate the platform library file before building and debugging the demo application This library contains all HAL and peripheral driver functions that are device specific Therefore each device has its own library platform a It should not be necessary to build the library after initially downloading the KSDK because the platform library is already pre built However if this is necessary follow the following directions to rebuild the platform library Open the workspace file by double clicking on pmsm_sensorless_foc eww in IAR located in build iar kv3 1 pmsm_sensorless_foc The IAR workspace launches and contains two projects ksdk_platform_lib and pmsm_sensorless_foc It is needed to build the platform library before the PMSM sensorless project can be used As shown in Figure 8 the workspace contains two projects Right click on ksdk_platform_lib and a drop down menu appears Click on Set as Active and then click on the Make button highlighted by a red rectangle in Figure 8 When the build is complete the librar
23. se current 2 gt ADC1 RA Interrupt ADCLISR ADCLISR ADCLISR ADCLISR AD channel conversion Result Register updated Figure 1 ADC conversion timing 2 4 Current measurement The assignment of the ADC channels to the measured analog signals is closely related to the ADC conversion trigger timing For computation of the fast current control loop of the FOC it is necessary to know the values of all three motor phase currents Since there are only two ADC modules it is possible to sample only two analog quantities at one instance Assuming the motor represents a symmetrical three phase system the sum of all three instantaneous phase currents is zero O igtigtic Eqn 1 Since the phase currents are measured in the instance when the bottom transistors are conducting the time when the current can be measured is too short especially in the case of high duty cycle ratios current value is in the area of the maximum of the sine curve 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 based on the section where 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 can be easily calculated according to Equation 2 Sector 1 6 i g Sector 2 3 ig i ic Eqn
24. t to 19200 Bd 3 Interrupts The application requires minimum number of interrupts because of the MCU s capability to hardware trigger the AD conversion There are three interrupts in the application The ADC1 interrupt serves to execute fast loop current FOC algorithms while the port interrupt handles the user buttons and PDB error interrupt clears the sequence error fault PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semiconductor Inc 7 Interrupts 3 1 ADC1 interrupt This interrupt request is triggered when the conversion of channel A of the ADC1 module is completed and has the highest priority In the time of the interrupt generation there are sampled values of physical quantities ready as follows e in the result register A of the ADCO motor phase current one e in the result register A of the ADC1 module motor phase current two e in the result register B of the ADC1 DC bus voltage The interrupt is always enabled only for one module at a time otherwise there would be two interrupt requests generated at the same time since the triggers for the motor phase currents are generated in the same instance The application state machine function is called in the beginning of the ADC1 ISR execution If the application is in the RUN state then the execution of the fast current control loop of the PMSM vector control algorithm follows including the position and spee
25. the initialization value after overflow This signal is supplied into the PDB which consequently triggers the AD conversion of the voltage and currents with a pre defined delay There are two ADC modules implemented on the Kinetis KV31F120M 120 MHz MCU 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 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 interconnection of modules and the ADC interrupt generation PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 4 Freescale Semiconductor Inc MCU peripherals FTMOVALI 4 fl 7 6 5 FTMO counter FTMOVALO n nn on Cones FCoavensonannea oe Bas omana FTMO Init trig PWM top channel PWM bottom channel PDBO CHO ae ees Aen baeuen DC Bus voltage gt ADC1 RB PDBOCH1 otpe o 22000 0 00 EEEE S bat Phase current1 gt ADCORA gs gs gs PDB1CHO 5 a JO mnnnenvnnnnrnnrecneeneenee a Pha
26. uctor Inc Acronyms and abbreviated terms 11 Acronyms and abbreviated terms Table 6 contains abbreviated terms used in this document Table 6 Acronyms and abbreviated terms Term Meaning ADC Analog to digital converter Back EMF _ Back electromotive force a voltage generated by a rotating motor FOC Field oriented control PMSM Permanent magnet synchronous motor PWM Pulse width modulation SVM Space vector modulation the algorithm used for generation of signals for PWM output SDK Software development kit 12 Rev ision history Table 7 Revision history Revision number Date Substantial changes 0 04 2014 Initial release 1 02 2015 Updated sections 4 and 5 Kinetis SDK compatible PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semiconductor Inc 19 How to Reach Us Home Page freescale com Web Support freescale com support Document Number AN4911 Rev 1 02 2015 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 th
27. unction completes The calibration has to be performed for both ADC modules After the calibration the ADC modules are configured for a 12 bit accuracy The CPU frequency is set to 120 MHz so by using the available pre scaler values the input clock to the ADC module is set to 15 MHz That setting yields a conversion time of 2 2 us 33 ADC clock cycles Finally the hardware trigger has to be enabled in the Status and Control Register 2 The PDB provides controllable delays from either an internal or 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 Since the input trigger comes periodically from the 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 KV31F120M MCU allows for 15 different input trigger sources They are listed in the Chip configuration chapter in the PDB Configuration section of the device reference manual KV31PI100M120SF7RM 2 For FTMO the LDOK bit has to be set in order to acknowledge the changes in the delay registers 2 3 ADC conversion timing currents and voltage sampling The FTMO is configured to trigger an internal hardware signal when its counter is reset to
28. wise while the motor is running until the red LED is lit It is recommended to set the trimmer to a somewhat higher level so the motor can operate at maximum speed 2 6 SPI configuration The SPI interface is used in the application for communication between the intelligent MOSFET gate driver MC33937 and the KV31F120M 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 has to be performed mainly in setting the dead time While the motor is running there is also a periodic checking of the status register of the driver in order 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 be used The exact timing of the SPI signals is listed in the Three Phase Field Effect Transistor Pre driver Data Sheet 3 2 7 SCI UART configuration The SCI is used in the application for communication between the master system and the embedded application The master system is the PC where the FreeMASTER software is installed in order to control the application and visualize its state On the Kinetis KV31F120M there are three UART modules implemented Due to the hardware solution being based on the Tower System modules the UARTO is used The communication speed is se
29. y ksdk_platform_lib a is generated in the output directory according to the build target and can be located depending on the build target e Debug lt ksdk_install_dir gt Nib ksdk_platform_lib lt toolchain gt lt device_name gt output Debug e Release lt ksdk_install_dir gt Nib ksdk_platform_lib lt toolchain gt lt device_name gt output Release PMSM Sensorless Control on TWR KV31F120M Using Kinetis SDK Application Note Rev 1 02 2015 Freescale Semiconductor Inc 13 Project file structure File Edit View Project Tools Window Help iD Ugl al Belo 7VY UuERP Ow AD o pmsm_sensorless_foc Debug x Files n B lpmsm_sensorless_foc Stop Build Add Remove Rename Version Control System Open Containing Folder File Properties Figure 8 Platform driver library build 5 2 Building the PMSM project in IAR After the platform library build is complete the PMSM sensorless project can be generated As mentioned in Section 5 1 Building the platform driver library in IAR and as shown in Figure 8 the workspace contains two projects It is required to activate the pmsm_sensorless_foc project by right clicking the project name and then selecting Set as Active The PMSM project is activated and can be built by clicking the Make button After the output file pmsm_sensorless_foc out is generated in the output directory it can be loaded into the KV31F12
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