Hybrid Modulation Fault-Tolerant Control Of Open-End Windings Linear Vernier Permanent-Magnet Motor With Floating Capacitor Inverter

Rail transit,with its advantages of large passenger capacity and high efficiency,has become the answer to the problem of urban population’s trip and has received extensive attention.Linear motor has become a research hotspot because it omits the transmission device which rotates to the straight line.Among these liner motors,the linear vernier permanent magnet(LVPM)motor has the characteristics of high thrust density and high efficiency which is more suitable for the rail transit field.In this paper,a LVPM motor is used as the control object,and a 180° vector control method is proposed based on dual-power open-end winding(OEW)topology.With the simple structure of this method,the calculation speed is also fast.On the basis of OEW with flying capacitor topology,a hybrid modulation fault-tolerant control algorithm is proposed for the faults of the switching transistors of the inverters.This paper verifies the feasibility and correctness of the algorithm from three aspects: theory,simulation and experiment.The main research contents of this paper are as follows:1.The structure and working principle of LVPM motor are introduced.The electromagnetic simulation of LVPM motor is carried out under the electromagnetic simulation software Ansoft,including its magnetic field distribution,back EMF and so on.On this basis,the mathematical model of the motor in three coordinate systems is established,and the OEW topology and power supply principle are analyzed,which lays the foundation for the following research and simulation analysis.2.Based on the analysis of the space voltage vectors of the traditional two-level inverters,the three-level voltage vector distribution generated by the OEW topology is calculated by using the structure and power supply principle of the OEW topology.On the basis of the simple dual-power OEW topology,a 180° vector control method is proposed.With the simple structure of this method,the calculation speed is also fast.Simulink is used to verify the simulation results and show the simulation results.3.Based on the characteristics of reactive power compensation and high redundancy of OEW with flying capacitor topology,a hybrid modulation fault-tolerant control strategy is proposed to ensure that the motor can continue to operate continuously before and after the one auxiliary inverter switch failure.And make simulation to analyzing it at the same time.4.The experimental platform of the motor drive and control is built.The principle and development process of the hardware and software design in the experimental platform are introduced.On the basis of the experimental platform,experiments are carried out.The experimental results are shown,and the correctness and feasibility of the two algorithms are verified.