Comparison of Different Multi-winding Transformer Models in Multi-port AC-coupled Converter Application

Multi-port AC-coupled converter (MAC) is promising to become the next-generation energy router in future Micro-grid and energy Internet to satisfy the upcoming requirement. As the most critical component of MAC, the multi-winding transformer needs a suitable model to achieve power flow analysis and flexible control. This paper analyzes the multi-winding transformer model suitable for MAC application. Three existing transformer modeling methods have been investigated, i.e. self-/mutual-inductance matrix, extended T model, and extended cantilever model. Their equivalent conversions to the expected model have been derived. A four-port multi-winding transformer is designed for the Multi-Active-Bridge converter. The experiment and simulations are performed to compare the advantages and disadvantages of three transformer models.