전기자동차 급속충전기용 넓은 전압 범위를 갖는 30kW급 SiC MOSFET 기반 고속 스위칭 LLC 컨버터 설계 및 병렬 운전

Abstract

The electrification trend of mobility increases every year due to the development of power semiconductor and battery technology. Accordingly, the development and distribution of fast chargers for electric vehicles (EVs) are in demand. In this study, we propose a design and implementation method of an LLC converter for fast chargers. Two 15 kW LLC converters are configured in parallel to have 30 kW rated output power, and the control algorithm and driving sequence are designed accordingly and verified. In addition, the improved power conversion efficiency is confirmed through zero-voltage switching (ZVS) of the LLC converter and reduction of turn-off loss through snubber capacitors. The implemented 30 kW LLC converters show a wide output voltage range of 200–950 V. Experiments applying various load conditions verify the converter performance.