Research On Fault Tolerant Control System Based On Three-phase Four-Bridge Permanent Magnet Synchronous Motor

In recent years,with the application of permanent magnet synchronous motors in the field of industrial control,the research of high performance permanent magnet synchronous motor controllers has been highly valued by scholars at home and abroad.In some occasions where the redundancy and reliability of the control system are strictly required,the traditional three-phase topology will not be able to maintain the normal operation of the system in the event of a phase failure.Therefore,in these applications where the controller is required to have anti-fault performance,the application field of the conventional controller topology is greatly limited.In this paper,based on the actual engineering requirements of permanent magnet synchronous motor controller with fault tolerance,a space vector algorithm based on three-phase four-bridge control is proposed,which adds one to the traditional three-phase three-bridge arm.The bridge arm connected to the neutral point of the motor adopts three-dimensional voltage space vector modulation(3D-SVPWM)technology,which makes the permanent magnet synchronous motor have good running characteristics and can guarantee in the case of phase loss or single-phase open circuit failure.The motor operates safely and reliably.Firstly,this paper introduces the basic structure of permanent magnet synchronous motor and the topological characteristics of three-phase four-bridge arm.The application status of fault-tolerant system is introduced.In the fault-tolerant main topology with many applications,the main circuit topology suitable for this design is selected.structure.Secondly,this thesis deeply studies the control strategy of three-dimensional space vector fault-tolerant system,and proposes a space vector algorithm based on three-phase four-bridge arm.The mathematical estimation of the current compensation algorithm and the three-dimensional space vector control principle is given.The vector duty cycle is calculated,the modulation order of the bridge arms is arranged.Thirdly,in order to verify the correctness of the above proposed control strategy,Matlab/Simulink software was used to simulate the experiment,and a complete three-phase four-bridge three-dimensional space vector fault-tolerant system was built,and the system design was verified to be correct and effective.Finally,according to the control method proposed in this paper,the test platform is built.The hardware circuit is designed first,including the main circuit,the drive circuit,the current detection circuit and the position detection circuit.After that,the software part of the system is written and the main part is given.The flow chart,the circuit test of the built platform,the test includes start response test,speed burst test,load burst test,fault test test.The experimental results verify that the controller has excellent control performance and control accuracy during normal operation and fault operation.