Research On Control System Of BLDCM Based On Sensorless Control Technology

BLDCM has many advantages such as simple structure,wide speed range,good performance and no excitation loss.It is widely used in the modern industrial equipment and household appliances fields.The smooth operation of BLDCM usually depends on drive control strategy that can be adjusted quickly and accurately according to the rotor magnetic field position information.The selection of control scheme according to the presence or not of the position sensor is the core meanings of the drive control strategy of BLDCM.In view of the miniaturization and low cost requirements,the position sensorless control technology has become a research hotspot in the current drive control of the BLDCM.In this paper,the development and application prospect about BLDCM are briefly described.the operation mechanism and control system principle of BLDCM are comprehensively analyzed,the non position detection control and speed regulation technology based on back EMF method are described in detail,and the fuzzy control PI control model and algorithm of non position control are established in this paper.Finally,the control system of BLDCM based on STM32F051R8T6 is designed and built,and the corresponding physical prototype is set up to verify the control model and algorithm.In this paper,the sensorless control system of BLDCM is taken as the research object,and the improved three-stage-motor-starting method is adopted.Based on the zero-crossing-time sequence control strategy of back EMF,the fuzzy PI algorithm is used to realize the speed control technology.The experimental results show that the method can provide accurate motor commutation signal.When the sensorless control is adpoted,the performance of the BLDCM shows relatively high control accuracy,fast response speed and better speed regulation performance.