Research On Control System Of Permanent Magnet Synchronous Motor For Fan

Permanent magnet synchronous motors(PMSM)have been widely used in industry due to simple structure,high operating efficiency,high power density,simpler control system,etc.Especially in the household appliance industry,the fans we used in life is more and more made of Permanent magnet synchronous motors.Therefore,it is important to research on the high efficiency and low cost control method of PMSM.The sensor installed in PMSM reduces the reliability of the system,while increasng the costs of motor and maintenance costs.In order to reduce costs and improve the reliability of system,the sensorless vector control technology is the focus of research in the future.The system of fans is not demanding to the dynamic performance of controller,the sensorless vector control technology is the fiest choice.The sensorless vector control technology is used in PMSM control to reduce the costs in this paper.In this paper the research object is SPMSM which is 200 W.NM1100 which made by xintang is the core of the system.The sensorless vector control system is designed with the sliding mode observer.The main research content of this graduation project is as follows:(1)The vector control of PMSM is reaearched in this paper.Based on the mathematical model of PMSM in three-phase stationary coordinate system,the mathematical model of PMSM in two-phase rotating coordinate system is established by vector control coordinate transformation principle.(2)The starting strategy in the sensorless vector control of PMSM is studied in this paper.The problem that PMSM has low degree of identification at low speed is solved.The pre-positioning method solves the problem of starting position recognition of the motor,and the secondary positioning solves the problem of starting failure.In order to solve the problem that observer can not observe at low speed,the V / F control mothed is used to enhance the motor speed.(3)This paper analyzes the theory of sliding mode variable structure control and verifies its satisfying conditions.Based on the theory of sliding mode variable structure,a sliding mode observer is designed.The position sensor system of permanent magnet synchronous motor based on sliding mode observer is simulated in MATLAB,and the feasibility of the system is verified by the simulation waveform.(4)The hardware circuit of the drive system of PMSM is designed for 200 W fan,and the software algorithm is programmed with NM1100 as the core.The experimental platform of the sensorless vector technology of PMSM is built and the experimental waveform is measured.The reliability of the system is verified by the experimental waveform.