Design Of BLDCM Controlling System Based On FPGA

During the micro-electronics technology and automation technology is in fastdevelopment, MPU is used in motor control system more and more to make it come true thatmany complex and available control arithmetic is used in real applications fleetly. However,generic SCM deal with signal too slow to exert some motor’s capabilities. Generic SCM’scapabilities restrict the deep research of motor control system, many design ideas and controlarithmetic can not work.In this paper it analyses the development, structure, work theory and control method ofBLDCM and designs a BLDCM control system based on FPGA. In this paper it contrastssome main BLDCM control manners, chooses blocking control method and validates theholistic control system.The BLDCM control system’s hardware circuit was designed and implemented such asFPGA periphery circuit, drive circuit, current detecting circuit and so on. And the controlarithmetic of current loop, position loop and speed loop were designed and the closed loopcontrol of BLDCM control system in hardware was achieved.The BLDCM control system adopts PWM way to control BLDCM. The signal of PWMthat is produced by FPGA passes push-pull amplifier circuit first and drives three-phasebridge-type inverter circuit to make motor stator to commutate. The feedback signal-positiondetection signal and current detection signal-that is sent back to system’s fore-end acts onmotor system with input signal. As the paper adopts non-position sensor motor, locationparameter is detected by dedicated detection circuit and is caught by FPGA’s bank. Currentfeedback signal is got through detecting the voltage between the ends of sample resistance.The position signal is used to control commutation, the feedback speed that is figured outthrough position parameter compared with given speed parameter to get a deviation which isused as current reference quantity, the current reference quantity compares with currentfeedback to get a deviation to control PWM signal’s duty, this achieves BLDC motor’s speedand current control.The speed adjustment is based on the adjustment of PWM’s duty cycle. Throughout thesampling resistance’s voltage can calculate the current. Position control used the EMF zerodetecting method that is a comparatively mature method in BLDDM control system.Through debugged, the BLDCM is in stabilization work state whether in no-load or loadinstance.