METHOD FOR DIAGNOSING DEGRADATION OF DC/AC INVERTER AND DC/AC RECTIFIER, ESPECIALLY MAXIMIZING FACILITY OPERATION EFFICIENCY

摘要

PURPOSE: A method for diagnosing degradation of a DC/AC inverter and a DC/AC rectifier is provided to judge the amount of degradation and replacement time by measuring electrical characteristics change according to the degradation of a power semiconductor device. CONSTITUTION: According to the method for diagnosing degradation of a DC/AC inverter and a DC/AC rectifier during operation, an input/output voltage and an input/output current of an arm comprising a plurality of power semiconductor devices are measured in a corresponding DC/AC inverter and a corresponding DC/AC rectifier during their operation(S12). A parameter value of an average switch model is calculated by the measurement value as to the input/output voltage and current of the arm(S13). The state of the degradation process of the power semiconductor device is judged according to the variation of the parameter value(S14).