Design Of DSEM System For Fault-Tolerant Operation Under Loss Of Excitation

Doubly salient electro-magnetic machine(DSEM)has the advantages of simple structure,good fault tolerance and flexible control of excitation,which has good application prospect in the fields of aero space,new energy power generation and other fields.Excitation fault is an important problem that it must be taken into consideration for the reliability study of the normal operation of the DSEM.It takes a negative impact on the overall performance of the doubly salient electromagnetic machine when the excitation fault occurs.Therefore,it owns important practical significance to research on the fault-tolerant system of excitation-loss.First of all,research status of the DSEM,fault-tolerant techniques and the study of the excitation-loss are introduced in this paper.This paper gives a detailed analysis of the magnetic circuit of the DSEM,and,comprise and analyze the features of the motor's magnetic circuit in different height of stator-yoke,stator-pole,rotor-pole and rotor-yoke as well.The parameters of flux and self inductance of motor under different structural parameters are simulated,and the number of turns of motor is designed to realize the fault tolerant operation of DSEM.Combined with the special structure of DSEM,the paper illustrates the working principle of the motor under the two topologies of full bridge converter and H bridge converter.The working principles contain two conditions of normal excitation and excitation-loss.Then,field-circuit co-simulation models of two kinds of converter are build using the ANSYS software.Two conditions of normal excitation and excitation failure are simulated and analyzed,simulation results verify the feasibility of the proposed fault-tolerant system.Finally,the fault tolerant control strategy is tested on the experimental platform of three phase full bridge and three phase H bridge converter respectively.The results show that the motor can run smoothly when the loss of excitation occurs,and further verify the correctness and effectiveness of the proposed scheme.