Insulation improvement scheme of multi-output solid-state-transformer for photovoltaic grid-connected circuit

Solid-state-transformer (SST) with small volume and lightweight has been widely used in renewable energy grid connection. The electric field analysis of the transformer provides accurate insulation design and has significant engineering application value. By analysing the electric field between the adjacent windings of multi-winding transformer, it is determined that the pie winding structure should be selected for single winding and the design of even layers. In combination with the requirements of an LLC resonant circuit for magnetic transformer integration, a shielding ring is set on the plane where the insulating medium intersects the iron core to increase the leakage inductance of the transformer and eliminate the tip effect on the edges and corners of the iron core.