Research on Winding Methods of Multi-output Solid-State Transformer Considering the Impact of Power Electronic Converters

Multi-output transformer is a key component in new energy (i.e. photovoltaic) grid-connected power generation. Analysis of insulation voltage withstand requirements of multi-output transformer is an important guarantee for high power density design. The reversal of the current direction is considered to find the maximal voltage between windings. Considering the switching state influence of power electronic converters in different topologies, the opposite dotted terminals are suggested in adjacent windings. Pie structure coil with even number layers can avoid the out-leading wire crossing phenomenon and decrease the maximum electric field strength between adjacent coils. The feasibility of the selected winding method is verified by calculating the distribution of the electric field in the coils under the high frequency square wave excitation.