An integrated four-port full-bridge converter with DMPPT for renewable power system

In order to involve multiple different renewable energy sources and balance power flow, a four-port full-bridge converter (FPFBC) with distributed maximum power point tracking (DMPPT) is proposed for renewable power systems. This converter, featuring two input ports, one bidirectional port and one isolated output port, is derived by integrating two Buck-Boost converters and a full-bridge converter. The switching legs are shared by the Buck/Boost converter and full-bride converter. Hence, single stage conversion between any two of the ports is achieved. As a result, high power density and high efficiency can be guaranteed. DMPPT is realized on the two input ports connecting to different renewable sources, which ensures maximum renewable energy harvest. A pulse-width modulation plus phase angle shift control scheme and a power control strategy are presented for the FPFBC to implement the power management of the four ports. The operation modes and principles of the proposed converter, along with the design considerations, are discussed in detail. Simulation and experimental results verify the feasibility and effectiveness of the proposed converter.