평면형 변압기를 사용한 병렬 LLC 공진형 컨버터의 간단한 교차제어기 설계 및 구현

Abstract

The design and implementation of a simple interleaved controller for LLC resonant converters with a planar transformer is presented. The interleaved operation of a power converter is used to reduce the size of the passive components. It is, however, difficult to achieve the interleaved control of the LLC resonant converter because the frequency control is generally applied to resonant-type converters. A digital control method using a digital signal processor (DSP) is mostly used for the interleaved control. However, it is still complex to implement because of the additional processing for the analog feedback signals. The size, cost and power consumption of a DSP and peripheral devices are also practical issues. This paper describes the design and implementation of the interleaved LLC resonant converter using a commercial analog resonant controller. The interleaved gate pulse generation and over current protection circuits are proposed using this controller. The analysis for the current unbalancing due to the parameter deviations of the resonant circuit components are also provided. The two-phase interleaved LLC resonant converter with a power rating of 1.5kW is implemented to verify the validity of the proposed controller.