Development of a High Power, Medium Frequency Transformer for Medium Voltage Applications

This article presents a comprehensive design and analysis for a high power, medium frequency (MF), medium voltage (MV) transformer used in 3-level active neutral point clamped (ANPC) to 2-level dual active bridge (DAB) converter. This MV MF transformer is intended to integrate a 13.8kVac into a 4.16kVac system at 700kVA power level and 20kHz switching frequency. It will be a part of the next-generation grid network structures. In-depth explanations are provided for the transformer's design and analysis phases. The electromagnetics, electrical, and electrostatic components of the transformer design are simulated using the ANSYS Maxwell 3D/Simplorer FEA tool in conjunction with MATLAB/Simulink. Analysis of the core, windings, leakage and magnetizing inductances, flux density, losses, efficiency, and coordination of the insulation are covered. Simulation and experimental results focusing on successful insulation testing are presented.