Single-phase converter DC bus voltage secondary ripple suppression circuit and method

Abstract

The invention discloses a single-phase converter DC bus voltage secondary ripple suppression circuit and method, and relates to an optimized active power filter (APF) circuit and method, a secondary harmonic auxiliary absorption circuit is built on a converter, the secondary harmonic auxiliary absorption circuit comprises two power switch devices and a switch device control unit, wherein the switching device control unit comprises a sampling circuit, a conditioning circuit, a calculating circuit and a voltage control circuit, and by controlling voltage values at two ends of the filtering capacitor, quadruplicated frequency components on the filtering capacitor and the filtering inductor can be ensured to be very small, and the harmonic requirements of the system are met.

Description

technical field [0001] The invention belongs to the technical field of converter control, and in particular relates to a single-phase converter DC bus voltage secondary ripple suppression circuit and method. Background technique [0002] The existing methods for suppressing double-frequency fluctuations of the DC bus of single-phase converters are divided into passive filtering methods and active filtering (APF) methods, and suppressing the low-order third-order harmonics of grid-connected current caused by DC bus voltage fluctuations through control strategies. category. The traditional passive filtering method directly connects large capacitors or LC resonant circuits at both ends of the DC bus to suppress DC voltage fluctuations. This method requires very large capacitors and inductances, which makes the entire equipment bulky, low power density, and high cost; The active filter (APF) method usually adds two or more fully-controlled power devices on the basis of the orig...

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Problems solved by technology

The traditional passive filtering method directly connects large capacitors or LC resonant circuits at both ends of the DC bus to suppress DC voltage fluctuations. This method requires very large capacitors and inductances, which makes the entire equipment bulky, low power density, and high cost; The active filter (APF) method mostly adds two or more full-control power devices on the basis of the original single-phase PWM circuit, which increases the complexity of the system. The above methods need to be further optimized to reduce costs and improve performance and system stability.

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