Research On Short-Circuit Fault-Tolerant Control Of Five Phase Fault-Tolerant Permanent-Magnet Vernier Machine

Fault tolerant operations are increasing becoming important in improving reliability and safety of electric drives especially in aerospace and electrical automotive sectors.The paper has done many researches on fault-tolerant control algorithms against to short-circuit fault of a five-phase FT-PMV motor.The main contents are as follows.1.The structural characteristics of FT-PMV motor are analyzed theoretically and verified through simulating the electromagnetic characteristics of motor by finite element simulation software.The mathematical model of motor is established under the natural coordinate system and the rotating coordinate system.And the change matrix between the natural coordinate system and the rotating coordinate system is deduced.2.The minimum copper loss short-circuit fault-tolerant algorithm is researched.The algorithm is based on the basic principle of power conservation.Under the premise of ensuring that no higher harmonics of the current,the Lagrange polynomial of fault-tolerant current is deduced with the minimum copper consumption as the optimal target.This fault-tolerant algorithm is suitable for all kinds of short-circuit fault conditions and is easy to apply.3.The phase-angle structuration short-circuit fault-tolerant algorithm is derived.The algorithm which is also based on the basic principle of power conservation mainly aims at solving the shortcomings of the large number of variables in Lagrange polynomial proposed by minimum copper loss short-circuit fault-tolerant algorithm.The algorithm can reduce the number of variables under the premise of achieving the same torque performance,which greatly simplifies the calculation of fault-tolerant currents.4.The fault-using short-circuit fault-tolerant algorithm is built.The algorithm which is still based on the basic principle of power conservation aims at further simplifying the calculation of fault-tolerant current.Based on the composability of force,the short-circuit fault-tolerant compensation is divided into two parts.One part is to eliminate the torque ripple caused by the short-circuit fault through using the torque of the short-circuit phase.The other part directly compensates for the reduction of the average torque caused by fault through the traditional open-circuit fault-tolerance algorithm.5.The finite element simulation software is used to simulate the operation of motor under normal,fault and fault-tolerant situations.Through the comparison of the simulation results,the correctness and feasibility of these three kinds of short-circuit fault-tolerant control algorithms can be verified.A five phase FT-PMV motor drive system based on DSP is designed.Based on the motor drive system,experiment verification for short-circuit fault-tolerant control algorithms is implemented.Through comparing and analyzing the torque performance of normal and fault-tolerant operation of the motor,the correctness and feasibility of the proposed short-circuit fault-tolerant algorithm are verified.