Fault Diagnosis of Rotating Rectifier Based on Waveform Distortion and Polarity of Current

In this paper, a rotating rectifier fault detection method is proposed and tested, by using the differences between the total harmonic distortion (THD) and polarity of asynchronous exciter armature current, when the rotating rectifier works in various conditions. To describe these differences, the conception of THD, residual and sum are used, and corresponding functions are defined. With the THD, residual and sum functions, the fault can be confirmed. Considering the influence of interference and the error of measurement, a pre-set value is employed and compared with the values of residual, THD, and sum functions. Then, the fault diagnosis table is given. The experimental results verify the feasibility and effectiveness of the proposed method both in the stationary state and rotating state.