SOLID STATE TRANSFORMERS AND WIRELESS POWER TRANSFER ARCHITECTURES FOR EXTREME FAST CHARGING OF ELECTRIC VEHICLES

Abstract

The rapid global shift toward electric vehicles (EVs) has intensified the demand for extreme fast charging (XFC) systems capable of reducing charging duration without compromising grid stability, power quality, or system reliability. Two emerging technologies at the forefront of this transformation are Solid-State Transformers (SSTs) and Wireless Power Transfer (WPT), in both static and dynamic configurations. This work presents a technical analysis of state-of-the-art SST architectures and WPT compensation topologies designed for high-power EV charging applications. Key engineering trade-offs including efficiency, power density, cost, electromagnetic interference (EMI), thermal management, and reliability are examined in detail based on recent high-impact research.

Building on these insights, we propose a hybrid SST–WPT architecture that integrates a medium-voltage SST front-end with adaptive wireless charging pads/tracks, enabling both static and low-speed dynamic charging. A hypothetical 400-kW, 800-V XFC station is simulated using a cascaded H-bridge (CHB) rectifier and Dual Active Bridge (DAB) isolation stage coupled with a magnetically coupled resonant WPT system for pad-based charging. Simulation results indicate ~95–96% efficiency under ideal alignment and ~92% under moderate coil misalignment, fast DC-bus regulation, and controlled EMI behavior under realistic misalignment and parasitic conditions. The study also outlines open research challenges and future directions in coil alignment, MFT optimization, wide-bandgap reliability, EMI shielding, and multi-MW station scalability. The proposed framework demonstrates the technical viability of combining CHB, DAB, and resonant WPT technologies to enable modular, efficient, and grid-aware XFC infrastructure.