An IGBT Output Power-Based Diagnosis of Open-Circuit Fault in Inverter

It is of crucial importance for the running and maintenance of subway to diagnose the fault occurred in auxiliary inverter in time,especially,during the running of subway trains both security and reliability of the running can be improve if the fault occurred in auxiliary inverters installed on the train could be detected and diagnosed timely.In allusion to the open-circuit fault in the insulated gate bipolar transistor(IGBT) of the inverter,the flow direction and corresponding power of positive-and negative-half-wave currents of each phase in the inverter under normal and fault conditions are compared,and a method of reflecting output power and working condition of each IGBT by detecting the power corresponding to positive and negative half-wave currents of each phase is proposed to diagnose the open-circuit fault in the IGBT of the inverter.Results of simulation on the platform of Matlab/Simulink,in which a close-loop controlled three-phase inverter model modulated by SPWM is constructed,show that the proposed method can diagnose single and double open-circuit fault occurred in the IGBT accurately and rapidly.