Analysis and design of coupled inductor for a new single phase transformer less photovoltaic inverter topology

The demand of photovoltaic (PV) converters with high
efficiency and low cost has supported the investigations in
new topologies in the last years. Especially transformerless
topologies are able to achieve highest efficiency values and
lowest specific costs [1]. In order to support these goals as
well as to obtain a high power density [2] the functional
integration of magnetic components is a known technique.
Integrated magnetic components will lead to reduced number
of magnetic components and are able to achieve application
specific functions [8]. This paper will present the design of a
coupled inductor for a new transformerless buck-boost
inverter topology for photovoltaic applications. The coupled
inductor will serve as energy storage as well as transformer in
order to transfer the power to the grid. As basis for the
inductor development the inverter topology will be briefly
explained. The design procedure including an analysis of the
magnetic components is presented as well as simulation and
experimental results.