Research on Parameter Design in Realization of LLC Resonant Converter Soft-switching

Abstract

The soft-switching performance of LLC resonant converter is closely related to the design parameters. The core contradiction lies in the strong coupling characteristics between the parameters of the resonant cavity and the spatial dislocation between the soft-switching range and the optimal efficiency. In this paper, a multi-objective collaborative design framework based on particle swarm optimization algorithm is proposed to solve the problem of performance mutual exclusion caused by parameter coupling, and the global optimal solution of key parameters is searched by building a fitness function of joint optimization of efficiency, gain bandwidth and soft switching range. In order to solve the problem of limited soft switching range under light load and wide input voltage conditions, an improved genetic algorithm is introduced to establish a gradient search mechanism for soft switching boundary constraints, which can expand the operating range of zero voltage switching while maintaining the efficiency balance. The research results reveal the inherent relationship between the static parameter system and the adaptability of dynamic conditions, and provide a systematic design paradigm for the engineering realization of high reliability LLC converters.