An Improved Current-Fed Bidirectional DC-DC Converter for Reconfigurable Split Battery in EVs

• Published in: IEEE transactions on industry applications Vol. 56; no. 6; pp. 6957 - 6967
• Main Authors: Tomar, Pavan Singh, Srivastava, Manaswi, Verma, Arun Kumar
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Batteries; Battery chargers; Battery charging; Charging; Circuits; Converters; DC-DC power converters; dc–dc converter; Direct current; Discharge; Electric potential; electric vehicle (EV); Electric vehicles; High-voltage techniques; Reconfiguration; Switches; Switching; Voltage gain; Zero current switching; zero current switching (ZCS); Zero voltage switching; zero voltage switching (ZVS)
• ISSN: 0093-9994; 1939-9367
• DOI: 10.1109/TIA.2020.3024165

This article is aimed to propose an isolated current-fed bidirectional dc-dc converter (ICFBD<inline-formula><tex-math notation="LaTeX">^{2}</tex-math></inline-formula>C) in reconfigurable split battery (RSB) charging for electric vehicle applications. The proposed CFBD<inline-formula><tex-math notation="LaTeX">^{2}</tex-math></inline-formula>C is capable to counter potential issues of high-frequency CFBD<inline-formula><tex-math notation="LaTeX">^{2}</tex-math></inline-formula>C, such as high voltage spikes across switches, high initial input current, higher switch rating, hard-switched operation, narrow operating range, additional auxiliary circuitry, low charging current, and limited voltage gain. In this article, a CFBD<inline-formula><tex-math notation="LaTeX">^{2}</tex-math></inline-formula>C is proposed to charge RSB voltage sources. The proposed CFBD<inline-formula><tex-math notation="LaTeX">^{2}</tex-math></inline-formula>C comprises three stage gain circuit (synchronous boost converter, voltage doubler, and high frequency transformer) to match two dc voltage level. It operates in two distinguished modes of discharging and charging. In discharging mode, CFBD<inline-formula><tex-math notation="LaTeX">^{2}</tex-math></inline-formula>C offers an 8X voltage gain, and allows discharging of batteries to the grid. Furthermore, in charging mode, RSB is opted to the parallel configuration to inject high current due to high potential difference. In both operating modes, the proposed CFBD<inline-formula><tex-math notation="LaTeX">^{2}</tex-math></inline-formula>C ensures zero voltage switching turn on and zero current switching turn on/off for all the switches and diodes, respectively, during entire battery charging/discharging operation range. The theoretical analysis of the proposed converter is initially validated by SIMULINK9.0, and later on verified by a laboratory prototype of 250 W, validate 145 kHz for charging and 100 kHz for discharging with 94%.