Power converter and control method thereof

Abstract

The invention provides a power converter and a control method thereof, the power converter comprises a capacitor, a power conversion circuit and a controller, the power conversion circuit comprises a positive DC bus and a negative DC bus, and the capacitor is connected between the positive DC bus and the negative DC bus. And the controller is used for reducing the output power of the power converter when the total accumulated self-healing frequency of the capacitor meets a first preset condition. Or the controller is used for controlling the power converter to stop running when the total accumulated self-healing frequency of the capacitor meets a second preset condition. According to the invention, the self-healing probability of the capacitor can be reduced, the capacitance attenuation of the capacitor and the mechanical damage rate can be reduced, and the possibility that the capacitor is in a serious self-healing state is reduced because the self-healing probability of the capacitor is reduced, so that the possibility that the direct-current bus short-circuit fault is triggered is reduced, and the reliability of the direct-current bus short-circuit fault is improved. Therefore, the possibility that the power converter is damaged due to short-circuit fault diffusion can be reduced.

Images