Identification Methods for Rotating Diode Rectifier Open Circuit Failures Without Rotor Position Information in Brushless Exciter Systems of Wound Field Synchronous Machines

In the wound-field synchronous starter-generator (WFSSG) system used in fully or more electric airplanes, the open-circuit (OC) fault of the rotating diode rectifier (RDR) poses a significant threat to the system's safe operation. The probability of this fault mode occurring is particularly high during high-speed operations, making it a critical issue to address. This article introduces a method for identifying OC faults in the RDR of the WFSSG without relying on position information. The proposed approach leverages the physical phenomenon whereby the rotor current vector modulus (CVM) of the three-phase brushless asynchronous excitation system (TBAES) distorts when a fault occurs in the RDR. Additionally, it relies on the mathematical relationship that the TBAES rotor CVM is solely a function of the TBAES stator currents and voltages. This enables the identification of RDR OC faults independent of rotor-position information. The experimental results validate the effectiveness of the proposed method.