BIAXIAL EXCITATION GENERATOR (BEGA) – 9 PHASES OPERATION IN FAULTY CONDITIONS

This paper presents a biaxial excitation generator for automobiles (BEGA) in generator mode, three three-phase windings (9 phases), and three diode bridge rectifiers DC parallel-connected for full power. BEGA is a synchronous machine with a biaxial excitation: one along the d-axis produced by the DC excitation coils (fed through brushes or contactless) and another along the q-axis produced by the PMs. The experimental demonstration of fault-tolerant characteristics was conducted under various fault conditions, including interrupted phases, short-circuited coils, and missing or short-circuited diodes. The importance of having all three three-phase windings (star-connection) connected in neutral points is highlighted and discussed. A comprehensive analysis of the impact of these faults on the harmonic spectrum is presented using a fast Fourier transform.