Study Of The Key Technologies Of High Performance PMSM Servo System

Due to good control performance, small volume, high efficiency and a series ofadvantages, Permanent magnet synchronous motor (PMSM) has been widely used inservo drive system of tool machines. How to improve its performance, especially howto improve the output torque in high speed and the stability in low speed to meet theneed of servo system of high performance tool machines deserves further researchwork. The research situation of permanent magnetic servo system was summarizedand the frontiers and hot issues in this field were discussed in this paper, in addition,which focused much on the following aspects:Comparing and analyzing four kinds of stator current control strategies ofpermanent magnet synchronous motor and the flux weakening operation to deduce anew composite stator current control strategy which can increase the torque duringhigh speed running with performance assurance at low speed;Proposing a method which can extend the rang of running speed of PMSMthrough winding series-parallel switching. The possible influence of the ways and theprocess of switching on the running status of the motor was studied which proved thearmature winding series-parallel switching is one of the effective ways to extendpermanent magnet synchronous motor speed in tool machines under availablecondition;Analyzing the effect of structure parameters on air-gap magnetic field of thesurface permanent magnet synchronous motor. On this basis motor optimization wasstudied with Taguchi orthogonal method, pattern search method and genetic algorithm;The results show two kinds of novel complex algorithms applied in optimizationdesign of the motor structure can improve the air-gap magnetic field and theperformance of the motor.Applying a kind of new Halbach structure in permanent magnet synchronousmotor and comparing the air-gap waveform of ordinary surface permanent magnetsynchronous motor with that of several structural forms Halbach motor. Severaloptimization algorithms was applied to improve the performance of the motor inoptimization of the structure of Halbach magnet with partition between poles.