Fault Diagnosis of Frequency Control System Based on FFT

A logic judgment method for fault diagnosis of inverters is proposed, which can effectively determine the fault nature of switches and the position of fault. Therefore, it can provide the basis for the subsequent processing. The output voltage waveforms of each state are collected by simulating various faults of the inverter, which the fault characteristics in frequency domain are extracted by FFT spectrum analysis. The spectral components of each order are obtained which reflected the characteristic signals of different fault states in the inverter. The mapping relationship is established to realize fault separation by calculating the spectrum deviation of the characteristic quantity in the state of fault and free-fault. Finally, which build an experimental platform to verify the feasibility of the program.