Design Analysis And Fault Tolerant Control Of Five Phase Induction Motor

Induction motor has the advantages of excellent mechanical performance,high working stability,simple structure and so on.Nowadays,with the rapid development of modern control and drive technology,and the outstanding power electronic devices,and for the motor driven by frequency conversion,the motor phase number is no longer the constraint of the traditional motor.With the increase of motor phase number,the development prospect of polyphase induction motor with more degrees of freedom and phase number redundancy becomes more and more bright.Therefore,it is of great significance to study the performance analysis and fault-tolerant control strategy of multiphase induction motor for the stable operation of motor system in harsh working environment.Firstly,taking a Y160L-4,15 kW induction motor as the control prototype,this paper designs the five phase winding by using the space-time phase congruence method and slot electromotive force star diagram method.According to the design method and modified formula of induction motor,the basic size of the motor is determined.The equivalent circuit,magnetic field distribution,mechanical characteristics,starting characteristics,loss and efficiency of the five phase induction motor are analyzed.Compared with the prototype machine,each phase characteristic parameter is more excellent,which verifies the correctness and rationality of the design of five phase induction motor.Secondly,the basic mathematical model of five phase induction motor is established,and the spatial decoupling mathematical model of five phase induction motor is obtained by spatial decoupling transformation.In this paper,the most common fault of multi-phase induction motor is listed.The mechanical performance,electromagnetic torque ripple,copper loss of stator and rotor,and mechanical efficiency of five phase induction motor under phase failure are compared and analyzed.Finally,two control strategies based on the principle of equal total magnetomotive force and minimum copper consumption of stator are proposed by matlab/simulink.Both fault-tolerant control strategies can eliminate and recover torque ripple and speed fluctuation.The speed and torque can return to normal operation data,and can run smoothly for a long time with excellent effect.The difference is that the fault-tolerant control scheme based on the principle of total magnetomotive force invariance has less current fluctuation,but it will produce higher stator copper consumption.The optimal current control strategy based on the principle of minimum copper consumption of stator has some advantages in loss and efficiency,but it has a large fluctuation in current.