BLDCv学习课程

1、Agenda Basics of a BLDC Motor Topology BLDC Motor with Hall SensorsBLDC Motor with Hardware BEMF-DetectionBLDC Motor Sensor less Control Switching Pattern for Driving a BLDC How to use the CAPCOM6E for a BLDC Introduction CAPCOM6E for BLDC purposeCAPCOM6E & ADC第1页/共55页第一页，编辑于星期五：十二点 二分。Electrica

2、l Motor TypesElectricMotor typesACAsynchronousSynchronousInductionStepperSynchronousPMSMSwitched Rel.DC第2页/共55页第二页，编辑于星期五：十二点 二分。BLDCBasics 第3页/共55页第三页，编辑于星期五：十二点 二分。Basics of a BLDC Motor DC Motor with 3 Brushes VWUUVW+-q 3-Phase Brush-less DC MotorAccording to the theory of DC machine, the motor r

3、otational speed can be written as follows:N = ( Ud - I R ) / (Ke )While,“N” stands for the motor rotational speed“Ud” stands for the DC voltage applied to the motor windings“R” is the pure resistance of the winding while “I” stands for the winding current “Ke” is the magnet coefficient while “ ” sta

4、nds for the motor magnetic flux From the above formula, there are two methods to change the speed of DC motor: One is to change the DC voltage of the motor windings (Ud), the other one is to change the magnetic flux of the motor (). As the BLDC motor has permanent magnet rotor, only the first method

5、 can be used in practical application. The principal of generating variable DC voltage is to use PWM for chopping: change the duty cycle of the PWM voltage, proportionally change the DC voltage. NS第4页/共55页第四页，编辑于星期五：十二点 二分。How an Inverter Turns a BLDC (1)第5页/共55页第五页，编辑于星期五：十二点 二分。How an Inverter Tur

6、ns a BLDC (2)第6页/共55页第六页，编辑于星期五：十二点 二分。How an Inverter Turns a BLDC (3)第7页/共55页第七页，编辑于星期五：十二点 二分。How an Inverter Turns a BLDC (4)第8页/共55页第八页，编辑于星期五：十二点 二分。How an Inverter Turns a BLDC (5)第9页/共55页第九页，编辑于星期五：十二点 二分。How an Inverter Turns a BLDC (6)第10页/共55页第十页，编辑于星期五：十二点 二分。BLDC with Hall Sensors Switc

7、hing Patternq Typical Switching Pattern for a BLDC Hall Sequence depends on motor construction Output pattern levels depends on inverter topology第11页/共55页第十一页，编辑于星期五：十二点 二分。BLDC withHall Sensors第12页/共55页第十二页，编辑于星期五：十二点 二分。BLDC with Hall Sensors - Topologyq Typical Circuit Block Diagram Hall Sensors

8、detect the position Over current protection and control via ADC第13页/共55页第十三页，编辑于星期五：十二点 二分。Block Diagram CAPCOM6E for BLDC Usage第14页/共55页第十四页，编辑于星期五：十二点 二分。Hardware NoiseSuppressionch0 gets capturedvalue for act. speedch1 comparefor phase delaych2 comparefor timeoutCC6xact. speedCC60phase delayCC61t

9、imeoutCC62COUT6y110001CCPOS2CCPOS0111000CCPOS1001111CaptureEventResets T12Usage of CAPCOM6E to Control a BLDC (1)q BEMF-Detection/Hall SignalsHW-noise filter on CCPOSx inputs (BEMF-signals)第15页/共55页第十五页，编辑于星期五：十二点 二分。Hardware NoiseSuppressionch0 gets capturedvalue for act. speedch1 comparefor phase

10、delaych2 comparefor timeoutCC6xact. speedCC60phase delayCC61timeoutCC62COUT6y110001CCPOS2CCPOS0111000CCPOS1001111CaptureEventResets T12Usage of CAPCOM6E to Control a BLDC (2)q BEMF-Detection/Hall SignalsHW-noise filter on CCPOSx inputs (BEMF-signals)automatic reset of T12 with interrupt actual speed

11、 by capture ch0第16页/共55页第十六页，编辑于星期五：十二点 二分。Hardware NoiseSuppressionch0 gets capturedvalue for act. speedch1 comparefor phase delaych2 comparefor timeoutCC6xact. speedCC60phase delayCC61timeoutCC62COUT6y110001CCPOS2CCPOS0111000CCPOS1001111CaptureEventResets T12Usage of CAPCOM6E to Control a BLDC (3)

12、q BEMF-Detection/Hall SignalsHW-noise filter on CCPOSx inputs (BEMF-signals)automatic reset of T12 with interrupt actual speed by capture ch0phase delay function on ch1第17页/共55页第十七页，编辑于星期五：十二点 二分。Hardware NoiseSuppressionch0 gets capturedvalue for act. speedch1 comparefor phase delaych2 comparefor t

13、imeoutCC6xact. speedCC60phase delayCC61timeoutCC62COUT6y110001CCPOS2CCPOS0111000CCPOS1001111CaptureEventResets T12Usage of CAPCOM6E to Control a BLDC (4)q BEMF-Detection/Hall SignalsHW-noise filter on CCPOSx inputs (BEMF-signals)automatic reset of T12 with interruptactual speed by capture ch0phase d

14、elay function on ch1time out function on ch2第18页/共55页第十八页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Hall Sensor Mode (1)CCPOSx Inputsfor Hallsensor Interface q MCMOUTSH / MCMOUTSL SW programmable state machine第19页/共55页第十九页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Hall Sensor Mode (2)CCPOSx Inputsedge detection trigger

15、s Dead Time Counter q MCMOUTSH / MCMOUTSL compare CCPOSx level with programmed value 第20页/共55页第二十页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Hall Sensor Mode (2)q CCPOSx Inputsq MCMOUTSH / MCMOUTSL switch to next state on valid edge by hardware 第21页/共55页第二十一页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Hall Sensor Mode (

16、3)q CCPOSx Inputs wait on edgeq MCMOUTSH / MCMOUTSL prepare next state by software 第22页/共55页第二十二页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Modulation Control (some Choices)第23页/共55页第二十三页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Generate the PWM Pattern for BLDC第24页/共55页第二十四页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Generate t

17、he PWM Pattern for BLDC第25页/共55页第二十五页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Generate the PWM Pattern for BLDC第26页/共55页第二十六页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Generate the PWM Pattern for BLDC第27页/共55页第二十七页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Generate the PWM Pattern for BLDC第28页/共55页第二十八页，编辑于星期五：十二点 二分。Usage of

18、 CAPCOM6E Generate the PWM Pattern for BLDC第29页/共55页第二十九页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Modulation and Synchronization第30页/共55页第三十页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Modulation and Synchronization第31页/共55页第三十一页，编辑于星期五：十二点 二分。Usage of CAPCOM6E Modulation and Synchronization第32页/共55页第三十二页，编辑于星期五：十二点 二

19、分。Usage of CAPCOM6E Modulation and Synchronization第33页/共55页第三十三页，编辑于星期五：十二点 二分。Usage of CAPCOM6E to Control a BLDC (5)第34页/共55页第三十四页，编辑于星期五：十二点 二分。Usage of CAPCOM6E to Control a BLDC (6)第35页/共55页第三十五页，编辑于星期五：十二点 二分。Usage of CAPCOM6E to Control a BLDC (7)第36页/共55页第三十六页，编辑于星期五：十二点 二分。Usage of CAPCOM6E

20、 to Control a BLDC (8)第37页/共55页第三十七页，编辑于星期五：十二点 二分。BLDCSensor less第38页/共55页第三十八页，编辑于星期五：十二点 二分。BLDC in Theory Back Electro Magnetic Force Theory UP = (R x i) + (L x di/dt) + eP whereUP stands for phase voltageR stands for winding resistancei stands for actual phase currentL stands for phase inductan

21、cedi/dtstands for changment of phase current over timeePstands for electromagnetic voltage caused by magnet whilei = 0 and di/dt = 0:UP = eP by measuring UPa position detectionis possible第39页/共55页第三十九页，编辑于星期五：十二点 二分。BLDC in Reality (1) BEMF vs. Currentq Real BEMF Voltage and Current: shape depends o

22、n magnets, motor speed, voltage第40页/共55页第四十页，编辑于星期五：十二点 二分。BLDC in Reality (2a) BEMF vs. Currentq Zoom In: BEMF is only visible at active switching PhaseCurrentBEMFVoltage第41页/共55页第四十一页，编辑于星期五：十二点 二分。BLDC in Reality (2b) BEMF vs. Currentq Current Commutation in a Coil Freewheeling diode conductsPhas

23、eCurrentBEMFVoltage第42页/共55页第四十二页，编辑于星期五：十二点 二分。BLDC in Reality (3) All Important SignalsPhaseCurrentBEMFVoltage第43页/共55页第四十三页，编辑于星期五：十二点 二分。BLDC Sensor less with Hardware BEMF-Detectionq Typical Circuit Block Diagram Comparators and RC-Filter detect the BEMF zero crossing for position detection第44页

24、/共55页第四十四页，编辑于星期五：十二点 二分。BLDC Sensor less Using ADCq Typical Circuit Block Diagram Use simple resistor divider and ADC for position detection第45页/共55页第四十五页，编辑于星期五：十二点 二分。CAPCOM6E & ADCq Synchronize ADC on T13 T13 period match can trigger the ADC equidistant sampling of analog signals exact timin

25、g guaranteed by hardware no timing jitter due to software delays第46页/共55页第四十六页，编辑于星期五：十二点 二分。CAPCOM6E & ADCq Synchronize T13 on T12 T13 performs delay for stable measurement T13 period match triggers ADCq Useful for Current Measurement E.g. induction machine第47页/共55页第四十七页，编辑于星期五：十二点 二分。CAPCOM6E

26、& ADCq T13PM triggers ADC Delay between T13PM and high voltage switching event due to driving circuitq Useful for Voltage or Current Measurement E.g. BEMF detection Sample shortly before power device is switched off (BEMF is noise free)第48页/共55页第四十八页，编辑于星期五：十二点 二分。CAPCOM6E & ADCq T13PM trigg

27、ers ADC Delay between T13PM and high voltage switching event due to driving circuitq Useful for Voltage or Current Measurement E.g. Current in DC link path Sample shortly before power device is switched off (current is noise free)第49页/共55页第四十九页，编辑于星期五：十二点 二分。BLDC Sensor less Using ADCq T13 used for

28、ModulationADC triggerq T12 used for Phase delay q Software (for 60 sector) With every T13PMthe BEMF voltage is sampled and compared to a BEMF-wave tableWhen crossing a limit the software generates a CHE-event (1) Speed reference is captured and phase delay for T12ch1 is calculated At T12ch1 the patt

29、ern for the next sector is switched (2)第50页/共55页第五十页，编辑于星期五：十二点 二分。BLDC Sensor less with Current Controlq T13 used forModulationADC triggerq T12 used for Phase delay q Software (for 60 sector) With every T13PM the ADC alternatively samplesBEMF voltagePhase currentThe current set value can be control

30、led by adjusting the PWM duty cycle第51页/共55页第五十一页，编辑于星期五：十二点 二分。BLDC Sensor less Scope ShotsPort pin toggles when BEMF is below limitBEMFVoltagePhaseCurrent第52页/共55页第五十二页，编辑于星期五：十二点 二分。qApplication: Line powered Industrial Drives Power: 750 WCurrent: max. 5 AAC Input Voltage: 110 to 264 VACqFeatures

31、: 8-bit MCU: C868 with on-chip 8 kB SRAM, with 8-bit ADC and powerful PWM moduleCoolSet: TDA61831G instead of a transformer for 12V supply 6 rugged IGBT DuoPacksEEPROM: 8 kB to store program + stand alone boot optionOptically Isolated Serial Interface to PC for SW development + boot from PC optionProtection: shut down protection for over current and over temperature Extension for alternative MCU like XC164 or TC1775 SW environment: Keil Compiler + De