Single-switch single-magnetic PWM converter integrating voltage equalizer for series-connected photovoltaic modules under partial shading

Partial shading on a photovoltaic (PV) string is well known to trigger serious issues, such as reduction in power generation and occurrence of multiple power point maxima. Although various kinds of differential power processing (DPP) converters and voltage equalizers have been proposed to preclude the partial-shading issues, conventional topologies and systems require multiple converters and switches, likely resulting in complex systems and circuitry. A single-switch single-magnetic PWM converter integrating a voltage equalizer is proposed in this paper. Two components (i.e. a converter and equalizer) can be integrated into a single unit without increasing the switch count, realizing not only systemlevel but also circuit-level simplifications. In addition, the single-magnetic circuitry allows a compact design. An experimental test was performed emulating a partially-shaded condition. The proposed integrated converter precluded the occurrence of multiple power point maxima and effectively increased the extractable maximum power, demonstrating the performance and efficacy of the proposed integrated converter.