Online Diode Fault Detection in Rotating Rectifier of the Brushless Synchronous Starter Generator

The rotating rectifier in the brushless synchronous starter/generator is more vulnerable than others. Therefore, fault detection of the rotating rectifier is necessary. This article focuses on the identification of the diode failures in the rotating rectifier of the brushless synchronous starter/generator. Traditional approaches based on the analysis from the main exciter field current or main machine output voltage may lose the fault location information. To solve this problem, the fault features based on the rotor current are analyzed. With a simple rotor current restructuring approach, the magnitude ratio of second harmonic to fundamental obtained by bandpass filters on the restructured rotor current is employed to confirm the one diode open-circuit or one diode short-circuit fault. The experimental results verify the feasibility and effectiveness of the proposed method.