Research on novel equalization topology of series battery pack based on flyback converter

doi:10.19799/j.cnki.2095-4239.2019.0221

Abstract

Abstract:

Lithium batteries have become the main power source for new energy vehicles because they provide high energy density at a low self-discharge rate. In actual use, the battery characteristics, temperatures, and self-discharge rates vary among the individual cells of series battery packs. Such inconsistencies reduce the energy utilization rate and service life of a battery pack. To improve this situation, this paper proposes an equalization method based on a flyback converter. The residual power of a single cell is used as the inconsistency index. A set of flyback converters balances the energy in the entire battery and the transfer between arbitrary monomers. The proposed equalization topology requires fewer components and realizes a lower-volume equalization system than the traditional equalization topology. Moreover, the primary side of the energy transfer requires only a set of control signals, which reduces the control difficulty. The effectiveness of the proposed equalization method was evaluated using a simulation model built in MATLAB/Simulink.

Key words: battery pack, active equalization, flyback converter

CLC Number:

TM 912.1

GUO Xiangwei, GENG Jiahao, BU Xuhui, HOU Rui, YU Wei. Research on novel equalization topology of series battery pack based on flyback converter[J]. Energy Storage Science and Technology, 2020, 9(3): 979-985.

Figures/Tables 12

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References 21

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参数名称	数值
电池容量/A·h	3.2
开关频率/kHz	10
PWM1占空比	32%
开关导通延迟时间	0.01T
PWM2占空比	66%
均衡电流/A	1.2
均衡精度	ΔSOC<1%
初始剩余电量	75%、74%、69%、72%
变压器匝比	1∶1
变压器原边电感量/μH	50
变压器副边电感量/μH	50
二极管导通压降/ V	0.6
电容/μF	7
电阻/Ω	70

均衡拓扑	拓扑类型	元件类型						性能参数
均衡拓扑	拓扑类型	电力开关	电感	电容	二极管	变压器	电阻	成本	均衡效率	均衡速度	控制复杂度	尺寸
文献[17]	开关电容型	2n	0	n	0	0	0	低	较低	较快	较高	较小
文献[18]	开关电感型	n	n	0	n	0	0	较高	较高	较快	中等	较小
文献[19,20]	多绕组变压器型	n	0	0	0	n	0	高	高	快	高	大
文献[21]	LC谐振型	4n+2	1	2	0	0	0	较高	高	较快	高	较小
本文拓扑	单变压器型	2n+1	0	1	2n	1	1	低	高	快	较低	较小

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