The Research Of Sensorless Control For BLDCM Based On MKV10

With the advantages of high power density,simple control,no commutator,and good mechanical properties,the BLDCM is more and more used in precision regulator of aviation and home appliances,industrial,medical and other fields.The control strategy of Brushless DC motor rotor position detection method to calculate the rotor position is to use the position sensor,in motor work,but there are some problems such as accuracy decrease,slow response of dynamic caused by vibration,overheating phenomenon.Sensorless control of BLDCM not only reduces the hardware cost,but also overcomes a series of problems brought by the position sensor in the speed control system.So,sensorless control for BLDCM becomes a hot academic research in the field of motor drive.In this paper,making further research on the method of sensorless control which is the breakthrough point.The MKV10Z32VLF7 of Freescale is chosen as the control chip for the BLDCM,the main control chip measures the rotor position signal based on BEMF-crossing-zero detecting,in view of the phase shift problems of the BEMF-crossing-zero detecting,the specific phase compensation algorithm is presented,and the "three stage" starting strategy of the motor is proposed.The speed and current double closed-loop model of BLDCM in Matlab/Simulink have been proposed based on the mathematical model of BLDCM and BEMF-crossing-zero detecting algorithm,the simulation proves the feasibility of the control system.According to the demand of the control system,the hardware and software for a sensorless control system is designed,and details the ways in which software algorithms,specific flow chart and the corresponding hardware circuit,etc.Finally,debugging Brushless DC motor controller through the specific experimental platform,the FreeMASTER was used as system debugging and monitoring tools in order to monitor the working state of the motor in the motor running progress,the efficiency of the control algorithm and the wholesystem debugging was improved a lot.The experimental results show that the design scheme is scientific and reasonable,control system has good dynamic and static performance,the desired requirements is reached.