Design and Simulation of a Bidirectional Isolated DC–DC Converter for a Battery Energy Storage System

Abstract

Photovoltaic(PV) system have been installed in some residential house, schools and buildings without energy
storage systems. Massive penetration of PV systems with the capability of exporting electric power into the grid, but
without energy storage systems can affect the grid due to their intermittent nature. Therefore, integration of energy
storage systems is essential to make the output power of PV systems dispatchable in supply and demand control. Highefficiency power converters are indispensable to charging and discharging of energy storage devices. The main goals
of the project included the implementation of two modes of operation: a battery discharge mode where current is
being fed into the grid and a battery charging mode in which current is pulled from the grid and put into the batteries.
A secondary goal of the design was to ensure that the current being injected into grid was at or near unity power
factor. The three-phase, full-bridge bidirectional isolated dc–dc converter was introduced for high power-density
power conversion systems. This converter works as the interface between the battery pack and the ac grid, which
needs to meet the requirements of bidirectional power flow capability and to ensure high power factor and low THD
as well as to regulate the dc side power regulation. All simulation of energy storage system, bidirectional dc-dc
converter and high frequency transformer are obtained from MATLAB Simulink Environment.