Small-signal model of a 5kW high-output voltage capacitive-loaded series-parallel resonant DC-DC converter

Abstract

This paper presents an accurate method, based on first harmonic analysis, to derive the small-signal model of the series-parallel resonant DC-DC converter with capacitive output filter for high-voltage applications. The model provides a fast and reliable way to obtain the desired transfer functions of the system for each operating point. For this reason, the small-signal model simplifies the controller design task for resonant converters by removing the need of complex mathematical analysis and saves the time required for measurements when using trial and error design method. The small-signal model has been verified through simulation and experimental measurements.