Gain scheduling control of a bidirectional dc–dc converter with large dead‐time

Abstract

This study investigates the impact of the dead‐time of the semiconductor switches on the operation of a dc–dc converter used in a bidirectional storage system for a hybrid electric vehicle. The dead‐time of the switches of the dc–dc converter under investigation is exaggerated to clearly illustrate the effects of the non‐linear dependency of the current on the duty cycle. The resulting current response makes it impossible for a simple proportional–integral‐controller to regulate the current in a satisfactory way. In this study, the mechanism behind the highly non‐linear behaviour is investigated. The results of the analysis are used to develop a control scheme that employs gain‐scheduling and duty cycle presetting to cope with the non‐linear response of the converter current to changes in the duty cycle. Experimental results are presented based on the implementation of the proposed control algorithm on a two‐phase interleaved bidirectional boost converter to prove the viability of the concept.