BLDCv学习教案

1、会计学1BLDCv第一页，编辑于星期五：二十一点 十七分。第1页/共55页第二页，编辑于星期五：二十一点 十七分。ElectricMotor typesACAsynchronousSynchronousInductionStepperSynchronousPMSMSwitched Rel.DC第2页/共55页第三页，编辑于星期五：二十一点 十七分。BLDCBasics 第3页/共55页第四页，编辑于星期五：二十一点 十七分。VWUUVW+-q3-Phase Brush-less DC MotorAccording to the theory of DC machine, the motor r

2、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

3、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

4、 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页第五页，编辑于星期五：二十一点 十七分。第5页/共55页第六页，编辑于星期五：二十一点 十七分。第6页/共55页第七页，编辑于星期五：二十一点 十七分。第7页/共55页第八页，编辑于星期五：

5、二十一点 十七分。第8页/共55页第九页，编辑于星期五：二十一点 十七分。第9页/共55页第十页，编辑于星期五：二十一点 十七分。第10页/共55页第十一页，编辑于星期五：二十一点 十七分。qTypical Switching Pattern for a BLDCHall Sequence depends on motor constructionOutput pattern levels depends on inverter topology第11页/共55页第十二页，编辑于星期五：二十一点 十七分。BLDC withHall Sensors第12页/共55页第十三页，编辑于星期五：二十一

6、点 十七分。qTypical Circuit Block DiagramHall Sensors detect the positionOver current protection and control via ADC第13页/共55页第十四页，编辑于星期五：二十一点 十七分。第14页/共55页第十五页，编辑于星期五：二十一点 十七分。Hardware NoiseSuppressionch0 gets capturedvalue for act. speedch1 comparefor phase delaych2 comparefor timeoutCC6xact. speedCC60p

7、hase delayCC61timeoutCC62COUT6y110001CCPOS2CCPOS0111000CCPOS1001111CaptureEventResets T12qBEMF-Detection/Hall Signals HW-noise filter on CCPOSx inputs (BEMF-signals)第15页/共55页第十六页，编辑于星期五：二十一点 十七分。Hardware NoiseSuppressionch0 gets capturedvalue for act. speedch1 comparefor phase delaych2 comparefor ti

8、meoutCC6xact. speedCC60phase delayCC61timeoutCC62COUT6y110001CCPOS2CCPOS0111000CCPOS1001111CaptureEventResets T12q BEMF-Detection/Hall Signals HW-noise filter on CCPOSx inputs (BEMF-signals) automatic reset of T12 with interrupt actual speed by capture ch0第16页/共55页第十七页，编辑于星期五：二十一点 十七分。Hardware Noise

9、Suppressionch0 gets capturedvalue for act. speedch1 comparefor phase delaych2 comparefor timeoutCC6xact. speedCC60phase delayCC61timeoutCC62COUT6y110001CCPOS2CCPOS0111000CCPOS1001111CaptureEventResets T12q BEMF-Detection/Hall Signals HW-noise filter on CCPOSx inputs (BEMF-signals) automatic reset of

10、 T12 with interrupt actual speed by capture ch0 phase delay function on ch1第17页/共55页第十八页，编辑于星期五：二十一点 十七分。Hardware NoiseSuppressionch0 gets capturedvalue for act. speedch1 comparefor phase delaych2 comparefor timeoutCC6xact. speedCC60phase delayCC61timeoutCC62COUT6y110001CCPOS2CCPOS0111000CCPOS100111

11、1CaptureEventResets T12q BEMF-Detection/Hall Signals HW-noise filter on CCPOSx inputs (BEMF-signals) automatic reset of T12 with interrupt actual speed by capture ch0 phase delay function on ch1 time out function on ch2第18页/共55页第十九页，编辑于星期五：二十一点 十七分。qMCMOUTSH / MCMOUTSLSW programmable state machine第1

12、9页/共55页第二十页，编辑于星期五：二十一点 十七分。qMCMOUTSH / MCMOUTSLcompare CCPOSx level with programmed value 第20页/共55页第二十一页，编辑于星期五：二十一点 十七分。qCCPOSx InputsqMCMOUTSH / MCMOUTSLswitch to next state on valid edge by hardware 第21页/共55页第二十二页，编辑于星期五：二十一点 十七分。qCCPOSx Inputswait on edgeqMCMOUTSH / MCMOUTSLprepare next state b

13、y software 第22页/共55页第二十三页，编辑于星期五：二十一点 十七分。第23页/共55页第二十四页，编辑于星期五：二十一点 十七分。第24页/共55页第二十五页，编辑于星期五：二十一点 十七分。第25页/共55页第二十六页，编辑于星期五：二十一点 十七分。第26页/共55页第二十七页，编辑于星期五：二十一点 十七分。第27页/共55页第二十八页，编辑于星期五：二十一点 十七分。第28页/共55页第二十九页，编辑于星期五：二十一点 十七分。第29页/共55页第三十页，编辑于星期五：二十一点 十七分。第30页/共55页第三十一页，编辑于星期五：二十一点 十七分。第31页/共55页第三

14、十二页，编辑于星期五：二十一点 十七分。第32页/共55页第三十三页，编辑于星期五：二十一点 十七分。第33页/共55页第三十四页，编辑于星期五：二十一点 十七分。第34页/共55页第三十五页，编辑于星期五：二十一点 十七分。第35页/共55页第三十六页，编辑于星期五：二十一点 十七分。第36页/共55页第三十七页，编辑于星期五：二十一点 十七分。第37页/共55页第三十八页，编辑于星期五：二十一点 十七分。BLDCSensor less第38页/共55页第三十九页，编辑于星期五：二十一点 十七分。nwhilei = 0 and di/dt = 0:UP = ePnby measuring U

15、Pa position detectionis possible第39页/共55页第四十页，编辑于星期五：二十一点 十七分。qReal BEMF Voltage and Current: shape depends on magnets, motor speed, voltage第40页/共55页第四十一页，编辑于星期五：二十一点 十七分。qZoom In: BEMF is only visible at active switching PhaseCurrentBEMFVoltage第41页/共55页第四十二页，编辑于星期五：二十一点 十七分。qCurrent Commutation in

16、a CoilFreewheeling diode conductsPhaseCurrentBEMFVoltage第42页/共55页第四十三页，编辑于星期五：二十一点 十七分。PhaseCurrentBEMFVoltage第43页/共55页第四十四页，编辑于星期五：二十一点 十七分。qTypical Circuit Block DiagramComparators and RC-Filter detect the BEMF zero crossing for position detection第44页/共55页第四十五页，编辑于星期五：二十一点 十七分。q Typical Circuit Bl

17、ock Diagram Use simple resistor divider and ADC for position detection第45页/共55页第四十六页，编辑于星期五：二十一点 十七分。qSynchronize ADC on T13T13 period match can trigger the ADCequidistant sampling of analog signalsexact timing guaranteed by hardwareno timing jitter due to software delays第46页/共55页第四十七页，编辑于星期五：二十一点 十

18、七分。qSynchronize T13 on T12T13 performs delay for stable measurementT13 period match triggers ADCqUseful for Current Measurement E.g. induction machine第47页/共55页第四十八页，编辑于星期五：二十一点 十七分。qT13PM triggers ADCDelay between T13PM and high voltage switching event due to driving circuitqUseful for Voltage or Cu

19、rrent Measurement E.g. BEMF detectionSample shortly before power device is switched off (BEMF is noise free)第48页/共55页第四十九页，编辑于星期五：二十一点 十七分。qT13PM triggers ADCDelay between T13PM and high voltage switching event due to driving circuitqUseful for Voltage or Current Measurement E.g. Current in DC link

20、path Sample shortly before power device is switched off (current is noise free)第49页/共55页第五十页，编辑于星期五：二十一点 十七分。qT13 used for Modulation ADC triggerq T12 used for Phase delay q Software (for 60 sector) With every T13PMthe BEMF voltage is sampled and compared to a BEMF-wave table When crossing a limit t

21、he software generates a CHE-event (1) Speed reference is captured and phase delay for T12ch1 is calculated At T12ch1 the pattern for the next sector is switched (2)第50页/共55页第五十一页，编辑于星期五：二十一点 十七分。q T13 used for Modulation ADC triggerq T12 used for Phase delay q Software (for 60 sector) With every T13

22、PM the ADC alternatively samplesBEMF voltagePhase currentThe current set value can be controlled by adjusting the PWM duty cycle第51页/共55页第五十二页，编辑于星期五：二十一点 十七分。Port pin toggles when BEMF is below limitBEMFVoltagePhaseCurrent第52页/共55页第五十三页，编辑于星期五：二十一点 十七分。qApplication: Line powered Industrial DrivesPower: 750 WCurrent: max. 5 AAC Input Voltage: 110 to 264 VACqFeatures:8