Fault Leg Detection for Open-Circuit Faults in Pwm Voltage-Source Inverters of Renewable Energy via the Fuzzy Logic Diagnostic Method

An inverter is a critical piece of equipment for connecting green energyto a power grid, and whether the inverter equipment works normallywill influence if the electrical energy generated by green energy can besmoothly transmitted to the power grid. This study explores the influenceof a single thyristor and transistor open-circuit faults of an inverter on theoutput current waveform of the inverter. A computer is used to simulatethe fault symptoms of the inverter, and the fault features are discussed, Clarke's transformation is used to transform a three-phase current signal intostationary coordinates in order to observe the distributional characteristics.An expert system is constructed using fuzzy logic to analyse and evaluatethe running state of the inverter, and a testing machine is used in the laboratoryto test the feasibility of the proposed method. The results showthat this method can implement analysis and evaluation of the running stateof an inverter.