Optimal Design of a Multiwinding High-Frequency Transformer Using Reluctance Network Modeling and Particle Swarm Optimization Techniques for the Application of PV-Linked Grid-Connected Modular Multilevel Inverters

This article presents an optimal design procedure and development of a multiwinding high-frequency transformer for application in the cascaded modules of a grid-connected modular multilevel inverter. The transformer should be designed for a certain value of inductances and high efficiency because of its effect on the performance of the entire modular structure. To realize such an accurate design procedure with minimum computation effort and design complexity, a three-stage method including initial design using lumped-parameter modeling, optimal design using particle swarm optimization with reluctance network modeling and finite element method is proposed. An amorphous-based toroidal core transformer is designed, developed, and tested under different load conditions and frequency range to validate the design procedure.