Fault Tolerant DTC For Five Phase Permanent Magnet Synchronous Motor With Open Circuit Fault

With the development of materials science and motors becoming more and more mature,the requirements for high-performance control of motors are getting higher and higher.Permanent Magnet Synchronous Motor(PMSM)has gradually become a research hotspot in aerospace,shipbuilding,new energy vehicles and other industries due to its small size and low manufacturing cost.With the deepening of the research on the motor itself,more and more attention has been paid to the research of permanent magnet synchronous motor drive control technology.Motor as the core component of electromechanical energy conversion,if it fails,it will often affect the operation of the whole equipment,resulting in huge losses,which makes the development of permanent magnet synchronous motor fault-tolerant control technology more urgent.Compared with three-phase motor,the PMSM has higher freedom and better fault tolerance performance.Therefore,this thesis proposes a flux correction fault-tolerant direct torque control strategy for the problem of open circuit fault occuring,which is due to the large electromagnetic torque and speed fluctuation in the open circuit fault and the failure of dynamic response.Finally,a Matlab/Simulink simulation experiment platform was built for verification,and the magnetic field,torque,and speed were compared before and after the failure..The results show that the five phase permanent magnet synchronous motor has good torque and speed effect under the fault-tolerant control method in this paper,and the smooth operation of the motor in fault mode is realized.Firstly the research background and significance of FPMSM are reviewed,and the application and development prospects of permanent magnet synchronous motors in many fields are introduced.The research status of fault-tolerant control technology,PWM and SMC technology are respectively described.The model of five phase permanent magnet synchronous motor is analyzed,the motor structure is studied,and the winding equation,inductance equation and flux linkage equation are established.Derive its mathematical expressions in different coordinate systems,and conduct research and analysis on the coordinate transformation of each parameter.Combining the mathematical model in the normal mode to analyze the mathematical model when the motor has two non-adjacent two-phase open circuit and adjacent two-phase open circuit faults.In order to achieve the purpose of fault-tolerant control,the flux linkage is researched and corrected to restore it to a circular state.Introduce SVPWM control technology,and design the switch table according to the faulty motor model.The MATLAB / Simulink simulation platform is built to simulate and compare the running state before and after the fault.The basic principle of SMC is summarized,four common control laws are introduced,and the direct torque control strategy based on second order sliding mode is studied.The flux and torque controller are designed respectively to reduce the system pulsation and noise.Build a MATLAB/Simulink simulation platform to compare the effects of traditional DTC strategy and the control strategy used in this article.Briefly describe the design of the key software and hardware required for the construction of the experimental platform.Focus on the analysis of the main control chip selection,rotor position signal acquisition,current detection module and drive control module.