Inverter Power Module IGBT Fault Tolerant Control

With the deep reform of electric power industry, it has been an economic goal of all power plants to pursue the low operation cost and the low electric power consumption. In recent years, the modern power electronic technology has promoted the development of adjustable speed motor drive technology. In order to improve the energy-saving effect, the applications of adjustable speed motor drive in the major power plants become increasingly common.However, there are also some problems in the using of adjustable speed motor drives. By doing investigation in some power plants, we find that the faults of adjustable speed motor drive are major in IGBTs of power modules. When the problem occurs, the output line voltage and line current will distort significantly, which will reduce the reliability of the whole induction motor drive systems.On the basis of adjustable speed motor drive principles, this paper builds the power module of cascaded multilevel converter based adjustable speed motor drive, and simulates the voltage variation and current variation of the adjustable speed motor drive when the power module is failure. Besides, this thesis also presents several fault tolerant control methods to improve the fault waveforms. By these methods, the line voltage and line current distortion of induction motor will be minimized and the adverse effects will be reduced.This paper consists of the theoretical analysis of induction motor reliability and adjustable speed motor drive, the introduction of MATLAB/Simulink software and the simulation waveforms of the output voltage and current. At last, through the fault-tolerant control methods, the fault waveform distortion is minimized, which then improves the reliability of the induction motor drive system.