A reduced-order dynamical model of a phase-shift-controlled DAB resonant CLLLC converter

Identifier:  imarina:9671712

Handle: https://hdl.handle.net/20.500.11797/imarina9671712

Authors:  Vidal-Idiarte E; Lopez-Santos O; Haroun R; Castillon RG; Calvente J

Abstract:
This paper presents a reduced-order dynamical model of a phase-shift controlled dc/dc converter with a CLLLC resonant tank and applies it to a battery charger. The reduced second-order resonant tank model is based on the time-varying phasor technique and is described by a first-order differential equation in the complex domain. Its equivalent circuit representation using d-q components consists of two inductors with equal inductance. The proposed model accurately predicts the steady-state operating point, transient behavior associated with the beat frequency, and interactions with the input and output filters. Due to its reduced complexity, it enables the derivation of simpler transfer functions and significantly speeds up circuit simulations. The model is validated through comparisons with more accurate models and is finally applied to the design of the damping resistors and the control of the battery current in a 2-kW experimental prototype. The main discrepancies between the model and the experimental results arise when the soft-switching transition times, which are not included in the model, become comparable to the phase-shift delays. However, these discrepancies result in a larger stability margin in the experiments than that predicted by the model.