Research On A New Predictive Fault-tolerant Control Strategy For Five Phase PMSM

Permanent magnet synchronous motor(PMSM)has gradually developed into the research hotspot in ship,aerospace,new energy electric vehicle and other related technology fields due to its own characteristics of high power density,high peak power,fast response,simple structure,small size,low noise pollution.The design and control method of permanent magnet synchronous motor has gradually become a hot topic of modern motor scholars.Although the traditional model predictive control has had many advantages,such as convenient modeling,simple control idea and good dynamic control performance,it still has had some problems,such as too many alternative voltage vectors,large amount of calculation,fixed voltage vector direction and amplitude,and lacks its expansion in the control method of five phase permanent magnet synchronous motor.In order to solve the problems of traditional model predictive current control,such as large calculation,too many screening voltage times,non adjustable voltage vector direction amplitude and lack of application in fault-tolerant control of five phase permanent magnet synchronous motor.This paper has taken five phase permanent magnet synchronous motor as the research object,has selected three basic voltage vector combinations from the selected target sectors by using the selection of electric voltage vector sectors.The expected voltage vector could cover all areas of the sector.By substituting the expected voltage vector of 10 sectors of the five-phase space voltage vector as the alternative voltage vector into the value function,the target voltage has been selected to act on the inverter.At the same time,according to the fault-tolerant control strategy of five phase permanent magnet synchronous motor,the new three vector model predictive current fault-tolerant strategy of five phase permanent magnet synchronous motor under single-phase and two-phase fault has been deduced.This method could effectively solve the problem of unbalanced motor output torque under fault mode and large amount of calculation in screening optimization process.In order to verify the effectiveness of the new three vector model predictive current control strategy in improving the steady-state performance of the motor torque output under the fault of the five-phase permanent magnet synchronous motor proposed in this paper,experimental research has been carried out in the MATLAB simulation environment.The experimental results has shown that the new model predictive current control could effectively reduce the calculation amount of the processor and improved the dynamic response of the system under the fault of five phase permanent magnet synchronous motor,so that it also has had stable output torque when it was in the state of phase loss and has improved the safety and stability of the system.