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

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.