Research On Loss Minimization Control Method Of Permanent Magnet Synchronous Motor

As the development of industry and the innovation of the industrial technique, Permanent Magnet Synchronous Motor(PMSM) with its small size, simple structure, high reliability, strong overload capacity and low loss, the range of PMSM’s application has been expanded. It is widely used in various areas of the long-running industrial production line, electric vehicles, aerospace and oil exploration. Although the performance of permanent magnet synchronous motor is very excellent, the world promote environmental protection and China is advocating energy conservation, the energy consumption of the motor attract the attention of scholars, and it becomes a meaningful research direction.Firstly, this article introduces the research status of PMSM at home and abroad, the future trends and developments, and the purpose and meaning of the research direction. The several types of PMSM, the principle of Vector Control(VC), as well as the control methods is described in this article. At the same time, combining with the basic principles of VC and double close loop control of PMSM, the transfer function model of PMSM system is derived. And the method of computing parameters of the current loop and speed loop controller is given.Secondly, Loss Minimization Control(LMC) based on loss model method is proposed. According the PMSM’s mathematical model and equivalent circuit, a PMSM’s mathematical model with copper loss resistance and iron loss resistance is established. And then the condition which can minimize the controllable electrical loss is derived. Aiming at the problem of iron loss resistance parameter, the method which can search the parameter is also given.Thirdly, LMC based on search method is proposed. In this method, according the computed input power, searching the d-axis current constantly, the d-axis current can be determined when the input power is minimum. In order to shorten the search time, the golden section method is used in this method.Finally, the simulation and experiment are carried out. The simulation shows that according the different operation status, the d-axis current which reduces the PMSM’s loss can be computed. And because of the change of parameters in different operation point, the experiment of loss model method only applies to the low-speed range. The search method can reduce the loss of PMSM in different operation point and verify the correctness of the theory.