Design and performance of a bidirectional isolated DC-DC converter for a battery energy storage system

• Main Authors: Tan N.M.L., Abe T., Akagi H.
• Other Authors: 24537965000
• Format: Article
• Published: 2023
• Subjects: Bidirectional isolated dc-dc converters; dc-bias currents; energy storage systems; lithium-ion (Li-ion) battery; DC transformers; Energy storage; HVDC power transmission; Lithium alloys; Battery energy storage systems; Battery voltages; Bidirectional isolated dc-dc converter; Converter loss; DC voltage; DC-bias current; Full-bridge; High-voltages; Lithium ions; Low-voltage; DC-DC converters

This paper describes the design and performance of a 6-kW, full-bridge, bidirectional isolated dc-dc converter using a 20-kHz transformer for a 53.2-V, 2-kWh lithium-ion (Li-ion) battery energy storage system. The dc voltage at the high-voltage side is controlled from 305 to 355 V, as the battery voltage at the low-voltage side (LVS) varies from 50 to 59 V. The maximal efficiency of the dc-dc converter is measured to be 96.0 during battery charging, and 96.9 during battery discharging. Moreover, this paper analyzes the effect of unavoidable dc-bias currents on the magnetic-flux saturation of the transformer. Finally, it provides the dc-dc converter loss breakdown with more focus on the LVS converter. � 2011 IEEE.