TY - JOUR
T1 - A Cell-to-Cell Battery Equalizer With Zero-Current Switching and Zero-Voltage Gap Based on Quasi-Resonant LC Converter and Boost Converter
AU - Shang, Yunlong
AU - Zhang, Chenghui
AU - Cui, Naxin
AU - Guerrero, Josep M.
PY - 2015/7
Y1 - 2015/7
N2 - In conventional equalizers, the facts of bulky size and high cost are widespread. Particularly, the zero switching loss and zero-voltage gap (ZVG) between cells are difficult to implement due to the high-frequency hard switching and the voltage drop across power devices. To overcome these difficulties, an innovative direct cell-to-cell battery equalizer based on quasi-resonant LC converter (QRLCC) and boost DC-DC converter (BDDC) is proposed. The QRLCC is employed to gain zero-current switching (ZCS), leading to a reduction of power losses. The BDDC is employed to enhance the equalization voltage gap for large balancing current and ZVG between cells. Instead of a dedicated equalizer for each cell, only one balancing converter is employed and shared by all cells, reducing the size and implementation cost. Moreover, the equalization current can be regulated as needed by controlling the duty cycle of the BDDC, which not only prevents efficiently over-equalization but also abridges the balancing time. Simulation and experimental results show the proposed scheme exhibits outstanding balancing performance, and the energy conversion efficiency is higher than 98%. The validity of the proposed equalizer is further verified by a systematic and quantitative comparison with the typical representative of each active balancing method.
AB - In conventional equalizers, the facts of bulky size and high cost are widespread. Particularly, the zero switching loss and zero-voltage gap (ZVG) between cells are difficult to implement due to the high-frequency hard switching and the voltage drop across power devices. To overcome these difficulties, an innovative direct cell-to-cell battery equalizer based on quasi-resonant LC converter (QRLCC) and boost DC-DC converter (BDDC) is proposed. The QRLCC is employed to gain zero-current switching (ZCS), leading to a reduction of power losses. The BDDC is employed to enhance the equalization voltage gap for large balancing current and ZVG between cells. Instead of a dedicated equalizer for each cell, only one balancing converter is employed and shared by all cells, reducing the size and implementation cost. Moreover, the equalization current can be regulated as needed by controlling the duty cycle of the BDDC, which not only prevents efficiently over-equalization but also abridges the balancing time. Simulation and experimental results show the proposed scheme exhibits outstanding balancing performance, and the energy conversion efficiency is higher than 98%. The validity of the proposed equalizer is further verified by a systematic and quantitative comparison with the typical representative of each active balancing method.
KW - Battery equalizer
KW - Electric vehicle
KW - Lithium-ion battery
KW - Battery management system
U2 - 10.1109/TPEL.2014.2345672
DO - 10.1109/TPEL.2014.2345672
M3 - Journal article
SN - 0885-8993
VL - 30
SP - 3731
EP - 3747
JO - I E E E Transactions on Power Electronics
JF - I E E E Transactions on Power Electronics
IS - 7
ER -