A Bidirectional DC–DC Converter for an Energy Storage System With Galvanic Isolation

Abstract

This paper addresses a bidirectional dc-dc converter suitable for an energy storage system with an additional function of galvanic isolation. An energy storage device such as an electric double layer capacitor is directly connected to a dc side of the dc-dc converter without any chopper circuit. Nevertheless, the dc-dc converter can continue operating when the voltage across the energy storage device drops along with its discharge. Theoretical calculation and experimental measurement reveal that power loss and peak current impose limitations on a permissible dc-voltage range. This information may be useful in design of the dc-dc converter. Experimental results verify proper charging and discharging operation obtained from a 200-V, 2.6-kJ laboratory model of the energy storage system. Moreover, the dc-dc converter can charge the capacitor bank from zero to the rated voltage without any external precharging circuit.Index Terms-Bidirectional isolated dc-dc converter, electric double layer capacitors, energy storage system, loss analysis, starting procedure.

Implementation of Bidirectional LLC Resonant Converter for RES with Automatic Transition

“…Paper [7], [8] & [9] addresses a bidirectional dc-dc converter suitable for an energy storage system with an additional function of galvanic isolation, usage of transformer and automotive applications. An energy storage device such as an electric double layer capacitor is directly connected to a dc side of the dc-dc converter without any chopper circuit.Paper [10] proposes a bidirectional converter for higher power applications with better performance.…”

Sliding mode observation of capacitor voltage in multilevel power converters

“…The active power flow is controlled by controlling the phase shift between the square-wave voltages across transformer's leakage inductance . The relation between active power flow and phase shift between the voltages is [25]:…”

Reduction of Ripple in the Bidirectional DC-DC Converter with the Coupled Inductor

“…These converters are widely used in applications, such as hybrid electric vehicle energy systems [1]- [4], uninterrupted power supplies [5], [6], fuel-cell hybrid power systems [7]- [10], photovoltaic hybrid power systems [11], [12], and battery chargers [13]- [15]. Many bidirectional DC-DC converters have been researched.…”

“…In order to recycle the leakage inductor energy and to minimize the voltage stress on the power devices, some literature present the energy regeneration techniques to clamp the voltage stress on the power devices and to recycle the leakage inductor energy [18], [19]. Some literatures research the isolated bidirectional DC-DC converters, which include the half-bridge [8], [9], [20], [21] and full-bridge types [13], [22]. These converters can provide high step-up and stepdown voltage gain by adjusting the turns ratio of the transformer.…”