Modulation of a Bidirectional Buck-Boost Current-Fed Isolated DC-DC Converter

Abstract

Isolated bi-direction DC-DC converters are frequently used for energy storage systems (ESS) of DC micro grids. There is particular interest in a current-fed isolated bi-directional DC-DC converter (CF-IBDC) because of its advantages, notably the inherently lower current ripple on the battery side. However, the conventional control techniques are not very effective under both light and severe load conditions. This paper suggests a hybrid switching modulation to boost the CF-power IBDC's conversion efficiency under both low and high load circumstances. Depending on the amount of power supplied, separate controls are used to adjust the phase shift angle and the duty cycles of the secondary sides. In order to optimize zero-voltage switching, the control mechanism relies on (ZVS) circumstances and lowers the power converter's circulating current. The suggested control technique uses a single phase-shift modulation (SPSM) Modulation optimization, bidirectional boost-buck conversion, and a current-fed DC-DC converter to provide ZVS capability under all load conditions and to reduce circulating current.