Multiport Smart Transformers: A Review of Architectures, Applications, and Future Trends

Multiport smart transformers (MSTs) are transforming modern power systems as they offer advanced flexibility, improved energy efficiency, fault-tolerant operation, seamless integration of renewable energy sources (RESs), bidirectional power flow, grid support, and intelligent control. These advanced functionalities of MSTs make them a key element of next-generation grids, where adaptability and fault-tolerant operations are crucial. MSTs help balance variable generation and load demands through enabling the seamless integration of RESs. Moreover, the ability of MSTs to support bidirectional power flow plays an important role in modern applications such as electric vehicle (EV) charging, microgrids, and other energy systems. This article provides a review of MST architectures, focusing on design principles, topologies, and the essential control strategies for bidirectional power flow regulation, voltage regulation, and protection. The article also highlights real-world applications and demonstrates how MSTs enable RES integration, improve grid resiliency, and support advanced technologies like vehicle-to-grid (V2G) operation. The article also explores recent advancements in MST technology, such as efficiency improvements and thermal management, while addressing current challenges related to standardization and control complexity.