On-Line Fault Diagnosis for Rotating Rectifier in Wound-Rotor Synchronous Starter/Generator Using Idle Field Winding

Based on the terminal voltage of the idle field winding of the main exciter, a novel fault diagnosis method for the rotating rectifier of the wound-rotor synchronous starter/generator in the generator mode has been proposed. Instead of complex signal processing, simple calculation is adopted to achieve one diode open-circuit and short-circuit fault detection. To be specific, the terminal voltage of the idle field winding is firstly measured and the maximum voltage and RMS value in one cycle are obtained. Then the ratio is calculated used for fault detection. Experimental results verify the validity and feasibility of the proposed method.

I. Introduction

With the development of the more electric aircraft, the integrated starter/generator has become the development trend. Further, the wound-rotor synchronous generator has been regarded as excellent candidate to be the integrated starter/generator for its mature generator technique and wide application [1]. As illustrated in Fig. 1, the wound-rotor synchronous starter/generator (WRSSG) consists of the pre-exciter (PE), the main exciter (ME), the rotating rectifier and the main machine (MM). The PE is a permanent magnet generator which does not connect to the system in the startup process. The ME is a rotating-armature electrically excited synchronous generator with three-phase field windings. The rotating rectifier is a three- phase full bridge diode rectifier and a wound-rotor synchronous machine serves as the MM.