Diagnosis with Analytic Model of a Rectifier for Faults of the Rectifier Control


The diagnosis of the electric systems is an actual item for the specialists in domain. Due to the variety of the measurements and multiplicity of faults which can be analyzed, the approach is motivating. The model reproduces the behavior of a system both in normal operation and fault occurrence. The procedure which uses the analytic models compares the system evolution in normal and fault conditions operation. The faults which affect the normal system operation can occur on the supplying side (grid faults), in the rectifier itself (one or more switches in fault), on the load side or in the control circuit of the rectifier. Authors had previously studied different faults within a controlled rectifier-DC motor system. The supplying side faults (broken phase, phase to ground and two phases short-circuit faults), interrupted or short-circuited switch within the rectifier and excitation disappearance were investigated. The paper deals with the analysis of different faults of the control circuit. The considered faults were the firing pulses lack for one switch or for the two switches on the same arm (phase). The effects on the rectifier operation (waveforms, major values) and on the load behavior are highlighted. As it is shown, the effects on the output waveforms of the two studied faults are quite different. images