Switched Capacitor-Based PWM- and Phase Shift-Controlled Multiport Converter With Differential Power Processing Capability for Standalone Photovoltaic Systems Under Partial Shading

Photovoltaic (PV) systems consist of multiple dc–dc converters, such as a front-end converter for a PV panel and a bidirectional converter for battery regulation. In addition, a differential power processing (DPP) converter is desirably installed to preclude partial-shading issues of the significant reduction in energy yield and the occurrence of multiple maximum power points. This article proposes a novel multiport converter (MPC) based on a switched capacitor converter (SCC) with DPP capability to simplify such PV systems by reducing the converter count. The proposed SCC-MPC is derived from the integration of a noninverting PWM buck–boost converter, SCC, and phase shift (PS) SCC with sharing switches. In addition to the reduced converter count, the proposed MPC achieves reduced circuit volume thanks to the SCC and PS-SCC, both of which are a high power-density converter. The proposed SCC-MPC can regulate the load and battery by PS and PWM controls, respectively, while automatically precluding the partial-shading issues by its DPP capability. The experimental verification using a 200-W prototype demonstrated that the load and battery could be independently regulated with preventing the partial-shading issues.