Analysis and design of coupled inductor for a new single-phase transformerless photovoltaic inverter topology

The demand for photovoltaic (PV) converters with high efficiency and low cost has supported investigations into new topologies in the last few years. In particular, transformerless topologies are able to achieve the highest efficiency values and the lowest specific costs. In order to support these goals, as well as to obtain a high power density, the functional integration of magnetic components is a known technique. Integrated magnetic components lead to reduced number of magnetic components and are able to achieve application-specific functions. The speaker presents the design of a coupled inductor for a new transformerless buck-boost inverter topology for PV applications. The coupled inductor serves as an energy storage device as well as a transformer in order to transfer the power to the grid. As the basis for the inductor development, the inverter topology is briefly explained. The design procedure, including an analysis of the magnetic components, is presented, as well as a simulation and experimental results.