A Single-Phase AC Excitation Method With Phase-Shifting Capacitor for Aircraft Wound Rotor Synchronous Starter/Generator

Wound rotor synchronous starter/generator (WRSSG) faces challenges in excitation during the starting mode. The existing single-phase ac excitation method, though simple to implement, suffers from low output current and excitation efficiency. Conversely, the multiphase ac excitation method achieves higher output current and efficiency but demands a sophisticated excitation control strategy. To address these issues, this article proposes a single-phase ac excitation method with a phase-shifting capacitor. In this approach, the main exciter (ME) is equipped with two field windings: one is connected in series with a capacitor, and both windings are paralleled to a single-phase ac power supply. By optimally selecting the capacitor and excitation power source parameters, the proposed method attains high output current and excitation efficiency. Notably, the ME can maintain an approximately constant output current without active excitation control. The selection principles for the capacitor and excitation power source parameters are analyzed, and the feasibility and superiority of the proposed method are experimentally validated.