Voltage stability analysis for aircraft variable frequency generation system loaded with PWM rectifier

This paper studies the dynamic voltage stability of a typical aircraft power system - variable frequency generation system loaded with PWM rectifier as a constant power load. The L-CCR filter is used for reducing input current harmonics of the rectifier. It establishes the small-signal model of the system. The parameters dominating the system stability were studied based on the eigenvalues of the system state matrix. Larger inductor including the filter inductor and the line equivalent inductor will be destructive to the system stability. Larger output capacitor of the rectifier will be beneficial for the system stability. The system will be stable when the system frequency is 400Hz but be unstable at 800Hz with the same parameters. It implies that higher system frequency will have less ability to take on constant power loads. The results are verified in the Saber simulation environment.