Design and analysis of isolated and non-isolated bidirectional converter for high voltage applications

Abstract

Purpose A DC-DC converter plays a major role in many applications such as fuel cell, hybrid electric vehicle, renewable energy system, etc. Among these converters, the bidirectional DC-DC fly-back converters are more attractive because of their simple structure and easy control. However, the power devices present in this converter are subjected to high-voltage stresses due to the leakage inductor energy of the transformer. In order to recycle the leakage inductor energy and to minimise the voltage stress on the power devices, the purpose of this paper is to focus on the transformer less bidirectional DC-DC converter with high efficiency. Design/methodology/approach In order to reduce the switching loss, a few passive elements are added. The auxiliary circuit consists of a resonant inductor and resonant capacitors. This auxiliary circuit affords zero voltage switching function and cancels out the ripple component present in the main inductor current irrespective of the power flow direction. Findings In this work three topologies of bidirectional converters for BLDC motor are investigated and are compared in terms of mechanical power output and THD. Originality/value The paper presents enhanced versions of the converters.