The Study on the Key Hardware Development of Single-Phase Photovoltaic Grid-Connected Inverters

High-efficiency inverter topology design on single-phase photovoltaic grid-connected equipment is the core of bringing considerable benefits to the society and the investors. In order to study the key hardware design of the inverter that meets the leakage current requirement and achieve the maximum efficiency, this paper analyses the H-bridge based topology (H5 and H6) and DPB topology. Firstly, this paper discusses the working principle of these topologies and concludes that the DPB topology involves fewer MOSFETs than the H-bridge based topology. Additional studies of power device analysis and other component losses in these topologies have concluded that DPB topology typically has lower power device losses at different load ratios. For instance, when the load ratio (Po / Pe) is 100, the power device loss of the H5 topology is 77 W, and the loss of the H6 topology is 68.7 W. Under the same conditions, the loss of the power device in the DPB topology is only 53.6 W.