Research On Sensorless Permanent Magnet Synchronous Motor Vector Control With Improved Low-pass Filter Algorithm

As a hot spot of the development of motor control technology,sensorless permanent magnet synchronous motor control system has advantages of simple structure,easy installation and low cost,but it is still a difficult technical problem to perform under low-speed condition at present.It is the key to estimate rotor position angle accurately,which will directly affect the performance of the motor speed regulation system,especially the low speed performance.The forefathers studied the improved low-pass filtering algorithm to improve the stator flux estimation performance of the induction motor direct torque control system,the paper references to the ideas in permanent magnet synchronous motor vector control system,and proposes the rotor position angle estimation method based on a algorithm of the improved low-pass filtering to improve rotor position angle estimation precision and the system control performance under the condition of low speed.The paper analyzes the mechanism of the algorithm to improve the low speed performance of sensorless permanent magnet synchronous motor control system theoretically,and then verifies the effectiveness by simulation and experiment.The sensorless permanent magnet synchronous motor control system based on the improved algorithm still has good performance under the condition of rated motor speed of 3.6%.Compared with the existing research results in the current field(the typical value is about 6.7%),the improved low-pass filtering algorithm has better low-speed dynamic and static performance.In order to improve the speed tracking performance of the system,a sliding mode variable structure control algorithm is adopted to replace the original PI algorithm to further improve the control performance of the system.Theoretical analysis,simulation research and experimental results show that the proposed rotor position estimation method based on improved algorithm is effective,and the improved algorithm has the advantages of simple calculation and easy implementation.Therefore,the improved algorithm has better engineering value and application prospect.