Current-Fed High-Frequency AC Distributed Power System for Medium–High-Voltage Gate Driving Applications

A current-fed high-frequency alternating-current (HFAC) distributed power system is presented in this paper for medium- or high-voltage gate driving applications. The distributed gate driving modules (GDMs) at the high-voltage side are isolated from the low-voltage-side current-source power supply through magnetic coupling of current transformers (CTs), which are assembled by a high-voltage cable carrying HFAC and passing through the center of toroid magnetic cores. The centralized high-frequency current-source power supply is designed and composed of a two-stage resonant inverter and a double Γ-CL resonant network. The resonant network is parameterized by considering the tradeoff between the quality factor and component stress. Different magnetic core samples are tested and compared to construct the CTs for improving transmission efficiency. A 400-W prototype was built and experimentally evaluated with two load conditions, including resistive loads and practical GDMs. It showed significant improvements with regard to sinusoidal current output, system stability, and efficiency. Finally, the proposed current-fed HFAC power supply system was successfully applied to a practical solid-state fault current limiter, demonstrating the advantages of multiple outputs (n > 10), high-voltage isolation, low harmonic distortion, high efficiency, easy installation, and flexible extensibility.