Research On Redundant PMSM And Fault-tolerant Control

As an integral part of automatic control system,the electric servo system plays an important role in the development of modern industry.With the rapid development of aviation,aerospace,military,medical machinery,electric vehicles and other fields,the complexity of the system is increasing,and a hydraulic system is being replaced by electrical drives.Therefore,the improvement of the motor servo system reliability and fault tolerance is especially important for improving the reliability of the system.In order to improve the reliability and fault tolerance of motor servo system,the widely adopted methods at present include Switched Reluctance Motor technology,Dual Redundancy Motor technology and Multi Phase Permanent Magnet FaultTolerant Motor technology.This paper presents a new fault tolerant model of redundant servo system.On the basis of improving the fault capacity of the motor,it also solves the problem of low voltage and high power in servo system and the problem of miniaturization of system.In this paper,the reliability of the motor servo system is studied from a new Angle.First,this paper analyzes the working principle of the redundant servo system,introducing the basic structure of the redundant system.according to the structure,establishing the mathematical model of the system and simplified,the voltage balance equation of the system and the transfer function is derived,analyzing the stability of the system when disturbed.Secondly,the reliability of the system is analyzed in general,the traditional system and redundancy system are compared in theory,proving the importance of redundant motor servo system for improving system reliability.The specific implementation scheme is: the first is the control strategy planning,the hardware circuit of the system is designed according to the control strategy,including the motion control module,encoder module,communication module,motor drive module.Each module coordinates the driver of the system.The magnetic coder is selected to be the sensor.The design and experiment of the composite magnet coder is carried out on the basis of single pair of magnetic coder,and the accuracy of encoder is tested.Secondly,according to the characteristics of high power permanent magnet synchronous motor,the redundant givers rotor motor is designed.the electromagnetic properties of the motor are analyzed,and the motor slot pole,materials,structures and other technical indicators is determined.For the validation of the proposed motor servo system fault tolerance principle,this topic set the redundant degree of permanent magnet synchronous motor servo system experiment platform,control principle of redundancy system is verified.In addition,the consistency of the induction electromotive force coefficient and the moment coefficient of the redundant permanent magnet synchronous motor are experimentally analyzed and verified.Secondly,completed the driving test of current loop and speed loop running,which verified the controllability of the system.Finally,the fault experiment of the system is carried out to prove the high reliability and fault tolerance of the redundant motor servo system.