A power balance control method for series power battery packs

Abstract

The present invention relates to a power balance control method for series-connected power battery packs, comprising the following steps: step S1, calculating the remaining power of each unit according to the capacity of the units in the series-connected battery pack and the state of charge (SOC) of the unit batteries and calculating the remaining power of each unit Sort from small to large; step S2, calculate the standard deviation a of the remaining power of the cells in the series battery pack; step S3, if the standard deviation a of the remaining power of the cells is greater than the set value of the dispersion b, enter step S4, otherwise do not perform the power balancing operation ; Step S4, according to the principle of pairing balance between the maximum value and the minimum value of the remaining power, and the second largest value and the second smallest value, the remaining power of each monomer is balanced. Compared with the existing equalization method for the series power battery pack, the present invention can realize the full charge and discharge of the series power battery pack, improve the energy utilization efficiency of the series power battery pack and prolong the service life.

Description

technical field [0001] The invention belongs to the field of battery research, and in particular relates to a power balance control method for series-connected power battery packs. Background technique [0002] The power battery pack is the energy source of electric vehicles. In order to meet the performance requirements of electric vehicles, it is necessary to form a power battery pack by connecting thousands of single cells in series and in parallel. Due to different manufacturing processes, grouping methods and operating conditions The inconsistencies in parameters such as capacity, internal resistance, and self-discharge rate among the cells will reduce the energy utilization efficiency of the power battery pack, accelerate battery aging, and limit the power of the power battery pack. The balance control of each monomer is carried out. [0003] At present, the equalization algorithm is mainly divided into the equalization control based on the voltage and the equalizatio...

AI Technical Summary

Problems solved by technology

Based on the voltage scheme, the equalization algorithm aims at the real-time cell voltage consistency, but when the cell capacity is inconsistent, there may be a wrong balance problem that some cells need to be charged and balanced at a certain moment, but need to be discharged at another moment.

However, the SOC-based equalization algorithm aims at the real-time SOC consistency. When the cell capacity is inconsistent, some cells may also need to be charged and balanced at a certain moment, but they need to be discharged at another moment. Misbalanced problem

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