PWM Step-Up Converter Integrating Differential Power Processing Converter to Enhance Energy Yield of Partially-Shaded Photovoltaic Panels

Partial shading on a photovoltaic (PV) panel consisting of multiple substrings is known to trigger a significant reduction in power yield and the occurrence of multiple maximum power points (MPPs). Although differential power processing (DPP) converters can preclude the negative influences of partial shading, an additional DPP converter is separately required in addition to an existing step-up converter for panel control, resulting in increased circuit volume and system complexity. This paper proposes a novel integrated converter that realizes system simplification and circuit miniaturization by integrating a PWM step-up converter and a DPP converter. Laboratory and field tests were performed emulating partial shading and characteristic mismatch conditions. A local MPP successfully disappeared, and the extractable maximum power increased while boosting the panel voltage, demonstrating the efficacy of the proposed integrated converter.