Fault Diagnosis of a Rotating Rectifier in a Wound-Rotor Synchronous Starter/Generator in the Generation Mode

Accurate and timely fault diagnosis of the rotating rectifier for a wound-rotor synchronous starter/generator is of great importance to improve system reliability. In the generation mode of the system, there is one idle stator winding of the main exciter. The terminal voltage characteristic of the idle stator winding is analyzed, and a novel fault diagnosis method for the rotating rectifier in the generation mode of the system is proposed. In this method, two feature voltages, namely the maximum peak voltage and any other peak voltage of the idle stator winding terminal voltage, are extracted through voltage sequence reconstruction to calculate the feature ratio for fault detection. The corresponding rotor position obtained by an inherent position sensor where the maximum peak voltage occurs is collected to determine the faulty diode location. The experimental results verify the feasibility and effectiveness of the proposed fault diagnosis method.

I. Introduction

The rapid development of more electric aircraft (MEA) has led to great demand for large-capacity and high-reliability integrated starter/generator systems. The wound-rotor synchronous starter/generator (WRSSG) has become a research focus due to its high reliability, mature generator technique, and large-scale on-board applications [1], [2]. As shown in Fig. 1, the WRSSG comprises a pre-exciter (PE), a main exciter (ME), a rotating rectifier, and a main machine (MM). The PE is a permanent magnet synchronous machine, and the ME is a rotating-armature electrically excited generator with three-phase stator windings. The rotating rectifier, mounted on the rotor shaft, is a three-phase full-bridge diode rectifier, and a wound-rotor synchronous machine serves as the MM. Fig. 1.

Structure of the WRSSG.