AC/DC Side Split Capacitor Power Decoupling Circuit

Abstract

Single-phase inverters have a wide range of applications in many fields, but there are inherent double frequency problems, and double frequency fluctuations can easily cause system instability. This paper proposes a mid-point common-mode injection power decoupling circuit. The advantage of this topology is that there are no additional switching devices and only the original DC side support capacitors and filter capacitors of the H-bridge inverter can be used to buffer the double frequency power. The half-bridge structure of this topology enables the AC side capacitors to operate positively and negatively, which can reduce the selection of the withstand voltage of the decoupling capacitor. Simulation and experimental results prove that the method can effectively suppress the secondary ripple on the DC side. The final data shows that the topology can effectively improve the system efficiency after decoupling.