1. Drives & Control June 2003 A. Jansen 1 Brushless DC Motor Control with C868 and CAPCOM6

2. Drives & Control June 2003 A. Jansen 2 Agenda  Basics of a BLDC Motor  Topology  BLDC Motor with Hall Sensors  BLDC Motor with Hardware BEMF-Detection  BLDC Motor Sensor less Control  Switching Pattern for Driving a BLDC  How to use the CAPCOM6E for a BLDC  Introduction CAPCOM6E for BLDC purpose  CAPCOM6E & ADC

3. Drives & Control June 2003 A. Jansen 3 Electrical Motor Types Electric Motor types Electric Motor types AC Asynchronous Synchronous Induction Stepper Synchronous PMSM Switched Rel. DC

4. Drives & Control June 2003 A. Jansen 4 BLDC Basics

5. Drives & Control June 2003 A. Jansen 5 Basics of a BLDC Motor  DC Motor with 3 Brushes V W U U V W + -  3-Phase Brush-less DC Motor According to the theory of DC machine, the motor rotational 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 “  ” stands 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 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. N S

6. Drives & Control June 2003 A. Jansen 6 How an Inverter Turns a BLDC (1)

7. Drives & Control June 2003 A. Jansen 7 How an Inverter Turns a BLDC (2)

8. Drives & Control June 2003 A. Jansen 8 How an Inverter Turns a BLDC (3)

9. Drives & Control June 2003 A. Jansen 9 How an Inverter Turns a BLDC (4)

10. Drives & Control June 2003 A. Jansen 10 How an Inverter Turns a BLDC (5)

11. Drives & Control June 2003 A. Jansen 11 How an Inverter Turns a BLDC (6)

12. Drives & Control June 2003 A. Jansen 12 BLDC with Hall Sensors – Switching Pattern  Typical Switching Pattern for a BLDC  Hall Sequence depends on motor construction  Output pattern levels depends on inverter topology

13. Drives & Control June 2003 A. Jansen 13 BLDC with Hall Sensors

14. Drives & Control June 2003 A. Jansen 14 BLDC with Hall Sensors -- Topology  Typical Circuit Block Diagram  Hall Sensors detect the position  Over current protection and control via ADC

15. Drives & Control June 2003 A. Jansen 15 Block Diagram CAPCOM6E for BLDC Usage

16. Drives & Control June 2003 A. Jansen 16 Usage of CAPCOM6E to Control a BLDC (1)  BEMF-Detection/Hall Signals  HW-noise filter on CCPOSx inputs (BEMF-signals)

17. Drives & Control June 2003 A. Jansen 17 Usage of CAPCOM6E to Control a BLDC (2)  BEMF-Detection/Hall Signals  HW-noise filter on CCPOSx inputs (BEMF-signals)  automatic reset of T12 with interrupt  actual speed by capture ch0

18. Drives & Control June 2003 A. Jansen 18 Usage of CAPCOM6E to Control a BLDC (3)  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

19. Drives & Control June 2003 A. Jansen 19 Usage of CAPCOM6E to Control a BLDC (4)  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

20. Drives & Control June 2003 A. Jansen 20 Usage of CAPCOM6E – Hall Sensor Mode (1)  CCPOSx Inputs  for Hallsensor Interface  MCMOUTSH / MCMOUTSL  SW programmable state machine

21. Drives & Control June 2003 A. Jansen 21 Usage of CAPCOM6E – Hall Sensor Mode (2)  CCPOSx Inputs  edge detection triggers Dead Time Counter  MCMOUTSH / MCMOUTSL  compare CCPOSx level with programmed value

22. Drives & Control June 2003 A. Jansen 22 Usage of CAPCOM6E – Hall Sensor Mode (2)  CCPOSx Inputs  MCMOUTSH / MCMOUTSL  switch to next state on valid edge by hardware

23. Drives & Control June 2003 A. Jansen 23 Usage of CAPCOM6E – Hall Sensor Mode (3)  CCPOSx Inputs  wait on edge  MCMOUTSH / MCMOUTSL  prepare next state by software

24. Drives & Control June 2003 A. Jansen 24 Usage of CAPCOM6E – Modulation Control (some Choices)

25. Drives & Control June 2003 A. Jansen 25 Usage of CAPCOM6E – Generate the PWM Pattern for BLDC

26. Drives & Control June 2003 A. Jansen 26 Usage of CAPCOM6E – Generate the PWM Pattern for BLDC

27. Drives & Control June 2003 A. Jansen 27 Usage of CAPCOM6E – Generate the PWM Pattern for BLDC

28. Drives & Control June 2003 A. Jansen 28 Usage of CAPCOM6E – Generate the PWM Pattern for BLDC

29. Drives & Control June 2003 A. Jansen 29 Usage of CAPCOM6E – Generate the PWM Pattern for BLDC

30. Drives & Control June 2003 A. Jansen 30 Usage of CAPCOM6E – Generate the PWM Pattern for BLDC

31. Drives & Control June 2003 A. Jansen 31 Usage of CAPCOM6E – Modulation and Synchronization

32. Drives & Control June 2003 A. Jansen 32 Usage of CAPCOM6E – Modulation and Synchronization

33. Drives & Control June 2003 A. Jansen 33 Usage of CAPCOM6E – Modulation and Synchronization

34. Drives & Control June 2003 A. Jansen 34 Usage of CAPCOM6E – Modulation and Synchronization

35. Drives & Control June 2003 A. Jansen 35 Usage of CAPCOM6E to Control a BLDC (5)

36. Drives & Control June 2003 A. Jansen 36 Usage of CAPCOM6E to Control a BLDC (6)

37. Drives & Control June 2003 A. Jansen 37 Usage of CAPCOM6E to Control a BLDC (7)

38. Drives & Control June 2003 A. Jansen 38 Usage of CAPCOM6E to Control a BLDC (8)

39. Drives & Control June 2003 A. Jansen 39 BLDC Sensor less

40. Drives & Control June 2003 A. Jansen 40 BLDC in Theory – Back Electro Magnetic Force  Theory  U P = (R x i) + (L x di/dt) + e P  where "U P " stands for phase voltage "R" stands for winding resistance "i" stands for actual phase current "L" stands for phase inductance "di/dt"stands for changment of phase current over time "e P "stands for electromagnetic voltage caused by magnet  while i = 0 and di/dt = 0: U P = e P  by measuring U P a position detection is possible

41. Drives & Control June 2003 A. Jansen 41 BLDC in Reality (1) – BEMF vs. Current  Real BEMF Voltage and Current:  shape depends on magnets, motor speed, voltage

42. Drives & Control June 2003 A. Jansen 42 BLDC in Reality (2a) – BEMF vs. Current  Zoom In:  BEMF is only visible at active switching Phase Current BEMF Voltage

43. Drives & Control June 2003 A. Jansen 43 BLDC in Reality (2b) – BEMF vs. Current  Current Commutation in a Coil  Freewheeling diode conducts Phase Current BEMF Voltage

44. Drives & Control June 2003 A. Jansen 44 BLDC in Reality (3) – All Important Signals Phase Current BEMF Voltage

45. Drives & Control June 2003 A. Jansen 45 BLDC Sensor less with Hardware BEMF-Detection  Typical Circuit Block Diagram  Comparators and RC-Filter detect the BEMF zero crossing for position detection

46. Drives & Control June 2003 A. Jansen 46 BLDC Sensor less Using ADC  Typical Circuit Block Diagram  Use simple resistor divider and ADC for position detection

47. Drives & Control June 2003 A. Jansen 47 CAPCOM6E & ADC  Synchronize ADC on T13  T13 period match can trigger the ADC  equidistant sampling of analog signals  exact timing guaranteed by hardware  no timing jitter due to software delays

48. Drives & Control June 2003 A. Jansen 48 CAPCOM6E & ADC  Synchronize T13 on T12  T13 performs delay for stable measurement  T13 period match triggers ADC  Useful for Current Measurement  E.g. induction machine

49. Drives & Control June 2003 A. Jansen 49 CAPCOM6E & ADC  T13PM triggers ADC  Delay between T13PM and high voltage switching event due to driving circuit  Useful for Voltage or Current Measurement  E.g. BEMF detection  Sample shortly before power device is switched off (BEMF is noise free)

50. Drives & Control June 2003 A. Jansen 50 CAPCOM6E & ADC  T13PM triggers ADC  Delay between T13PM and high voltage switching event due to driving circuit  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)

51. Drives & Control June 2003 A. Jansen 51 BLDC Sensor less Using ADC  T13 used for  Modulation  ADC trigger  T12 used for  Phase delay  Software (for 60° sector)  With every T13PM the BEMF voltage is sampled and compared to a BEMF- wave table  When crossing a limit the 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)

52. Drives & Control June 2003 A. Jansen 52 BLDC Sensor less with Current Control  T13 used for  Modulation  ADC trigger  T12 used for  Phase delay  Software (for 60° sector)  With every T13PM the ADC alternatively samples  BEMF voltage  Phase current  The current set value can be controlled by adjusting the PWM duty cycle

53. Drives & Control June 2003 A. Jansen 53 BLDC Sensor less Scope Shots Port pin toggles when BEMF is below limit BEMF Voltage Phase Current

54. Drives & Control June 2003 A. Jansen 54  Application: Line powered Industrial Drives  Power: 750 W  Current: max. 5 A  AC Input Voltage: 110 to 264 VAC  Features:  8-bit MCU: C868 with on-chip 8 kB SRAM, with 8- bit ADC and powerful PWM module  CoolSet: TDA61831G instead of a transformer for 12V supply  6 rugged IGBT DuoPacks  EEPROM: 8 kB to store program + stand alone boot option  Optically Isolated Serial Interface to PC for SW development + boot from PC option  Protection: shut down protection for over current and over temperature  Extension for alternative MCU like XC164 or TC1775  SW environment: Keil Compiler + Debugger or Mini Debugger (free software)  Board can be used for current/torque or speed control  Supports Hall-Effect sensors or sensor-less control High Voltage 3-Phase Brushless DC / Induction Motor Reference Design and Development Kit

55. Drives & Control June 2003 A. Jansen 55 Low Voltage 3-Phase Brushless DC / Induction Motor Reference Design and Development Kit  Application: Industrial & Automotive Drives  Power: 1.2 kW  Current: max. 50 A  Voltage: 12 - 24 V DC  Features:  8-bit MCU: C868 with on-chip 8 kB SRAM, with 8- bit ADC and powerful PWM module  3-Phase Bridge Driver: TLE6280G  6 OptiMOS MOSFETs  EEPROM: 8 kB to store program + stand alone boot option  RS232: Interface to PC for SW development + boot from PC option  Protection: shut down protection for over current and over temperature  Extension for alternative MCU like XC164  SW environment: Keil Compiler + Debugger or Mini Debugger (free software)  Board can be used for current/torque or speed control  Supports Hall-Effect sensors or sensor-less control