Abstract

Power rectifiersare important devices for AC to DC conversion. Many systems are supplied through this electronic powerdevice. These systems include DC electric motors, exciter systems of synchronous machines, secondary circuits in power systems and so on.This paper focuses on monitoring and diagnosis of three-phase bridge rectifier faults. The monitoring and diagnosis is desirable in order to ensure energy quality and improved operational efficiency of rectifiers as the main power supply. This paper presents detection nd simulation of faults in a rectifier in order to diagnose failure of elements. The output voltage and current of the rectifier was compared with simulation signals in order to obtain the difference of these signals. Differences between the simulation of faults and rectifier functioning without faults are observed. Also, the harmonics spectra of output voltage and current of three phase bridge rectifier are analysed in order to achieve information for the detection of faults. We observe current and output voltage differences between “healthy” rectifier and rectifier missingone, two or three diodes in resistive load case. The signals of output voltage and current are analysed by FFT method to diagnose rectifier faults.