Dynamic Performance Improvement of Wound Rotor Synchronous Starter/Generator System Based on PWM Rectifier

This article proposes an active field current tracking (AFCT) control strategy for a pulsewidth modulation (PWM) rectifier, which can remarkably enhance the system's dynamic performance of a wound rotor synchronous starter/generator (WRSSG) system when the load changes. The WRSSG system uses a PWM converter in the aero-engine starting process and can reuse the power circuit as a PWM rectifier for high-voltage direct current (HVDC) power generation, thus simplifying the system structure, volume, and weight. The mathematical model of the WRSSG system with the PWM rectifier is introduced. Based on the system model, the proportional-integral (PI) controller of the armature current loop is designed. The nonlinear PI controller of the excitation voltage loop is also illustrated. A 15-kW WRSSG system based on the PWM rectifier is implemented. The AFCT control strategy and its high dynamic performance are verified by experiments. The simple system structure and distinguished dynamic performance of the PWM rectifier with AFCT control can make the WRSSG system more competitive in aircraft applications.