Series Resonant Converter-Based Full-Bridge DC–DC Partial Power Converter for Solar PV

Maximum Power Point Tracking (MPPT) in solar photovoltaic (PV) systems is predominantly achieved by full power DC-DC converters (FPC). Alternatively, partial power DC-DC converters (PPCs) process only a portion of the full power to achieve MPPT. Other goals of PPCs are a higher efficiency, a higher power density and a lower overall cost compared to FPCs (e.g. by using lower voltage class and/or lower current semiconductors). The flyback PPC topology shows that efficiency can be improved by 1% in comparison to FPCs. However, the use of transformers with large self-inductance tends to increase the volume. An alternative architecture is proposed in this work based on a series resonant converter (SRC). The addition of this partial power SRC stage pays off in terms of current ripple mitigation, reduced volume and high efficiency. The analysis and design of the proposed converter is presented in detail. The advantage of the proposed PPC architecture is highlighted by volume and loss comparisons. The analyzed efficiency and the practical efficiency measurement results are compared. The concept is experimentally validated using a 1.6kW prototype.