一种基于开关电容的太阳能光伏与电池接口双输入变换器

Standalone renewable energy systems with rechargeable batteries typically rely on multiple converters to regulate the DC bus voltage and manage power flow from solar PV and batteries to the DC load. However, this multi-converter approach increases size and system complexity. Three-port DC-DC converters (TPCs) address these challenges by integrating multiple sources, but existing circuit topologies suffer from limited voltage gain and complex control schemes due to distinct dynamic model across various modes. To address this, a new transformerless TPC with a bidirectional port for battery integration is explored in this article. The proposed converter offers high voltage gain and reduced device stress without imposing voltage constraints between the PV and battery ports. Additionally, it regulates the solar PV current and output voltage with two degrees of freedom employing a simplified control strategy. Unlike existing non-isolated TPCs, the proposed circuit topology features a consistent small-signal model across both battery charging and discharging modes, eliminating the need for complex mode selectors and control structures. The paper presents a comprehensive analysis of the converter’s steady-state operation in different modes and controller design for mode transition. Experimental results from a 200 Watts laboratory fabricated prototype validate the feasibility and effectiveness of the proposed TPC.