Dual-voltage hybrid equalization control method of series battery pack

Abstract

The invention discloses a dual-voltage hybrid equalization control method of a series battery pack. Dual voltages mean maximum single battery end voltage and minimum single battery end voltage in allsingle batteries of a series battery pack, hybrid equalization is in a way that discharging equalization is performed on the single battery corresponding to the highest end voltage and charging equalization is also performed on the single battery corresponding to the lowest end voltage during the charging equalization process, the charging equalization is performed on the single battery corresponding to the lowest end voltage and the discharging equalization is also performed on the single battery corresponding to the highest end voltage during the discharging equalization process until the voltage of each single battery in the battery pack conforms to consistency index, namely equalization stopping. By the control method, the equalization speed of the end voltage of the battery pack can be remarkably improved on the basis of existing hardware. The control method is suitable for a battery pack equalization management system.

Description

technical field [0001] The invention relates to a balance control method for series battery packs, which is suitable for battery management systems in new energy vehicles or micro-grid energy storage systems. Background technique [0002] Due to the inconsistency of the single cells in the battery pack, after the charging of the battery pack is completed, some of the single cells are not fully charged; after the discharge of the battery pack is completed, some of the single cells are not discharged. The sum of the capacity of each single battery is reduced, and the cycle life of the battery pack is also affected. The function of the equalization circuit is to reduce the impact of the inconsistency of the single cells on the overall battery pack, thereby improving the energy utilization rate of the battery pack. Extend battery life. [0003] As the most important function of the battery management system, battery equalization has been studied by many scholars at home and abr...

AI Technical Summary

Problems solved by technology

Kyung-Min Lee et al. of Pohang University of Science and Technology in South Korea, Mohammad et al. of National Energy University of Malaysia and Zhang Chenghui of Shandong University of my country have designed an active equalization circuit based on a transformer, using the battery terminal voltage as an equalization indicator. effect, but the expansion of the transformer-type equalization circuit is poor. When the number of single cells contained in the battery pack changes, the circuit needs to be redesigned, and the transformer may have magnetic flux leakage.

Dah-Chuan of Hong Kong Polytechnic University and others designed a high-precision balanced topology by using inductors and capacitors at the same time. Although the precision is high, its structure is complex and may not be suitable for practical applications.

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