The dual PWM control AC-DC-AC voltage source converter is suitable to be used as excitation power supply for AC excited generators（ACEG）. However， The DC-link voltage of the converter will fluctuate when the operational status of ACEG is changing， which may cause instability of the generation system. The reason of DC-link voltage fluctuation is analyzed based on the operational characteristics of ACEG， and an improved dual PWM control strategy based on the rotor-side converter instantaneous power feedback is proposed. The proposed method is validated by experimental results. It will effectively enhance the stability of the DC-link voltage and significantly improve the dynamic response capability and stability of the ACEG system.