Consistency evaluation method of power battery pack

Abstract

The invention discloses a consistency evaluation method of a power battery pack. The consistency evaluation method comprises the following steps: at preset environment temperature, the power battery pack begins to discharge according to 100 percent of a preset discharge multiplying power self-charge state, when the charge state reduces a preset charge state after preset time, preset pulse discharge current is used for carrying out pulse discharge, and discharge is carried out continuously under the current charge state after pulse discharge; pulse discharge voltage drop of each battery cell in the process of pulse discharge is calculated when the preset charge state is reduced, direct current internal resistance of each battery cell is calculated according to the pulse discharge voltage drop and preset pulse discharge current, and standard deviation of the direct current internal resistance is calculated according to the direct current internal resistance of each battery cell; and the standard deviation of the direct current internal resistance of each battery cell is compared with a standard deviation threshold value, and therefore consistency of the power battery pack can be evaluated. The consistency evaluation method is simple and convenient to operate, high in judgment accuracy, quick in judgment process, stable and reliable.

Description

technical field [0001] The invention relates to the technical field of power batteries, in particular to a consistency evaluation method for power batteries. Background technique [0002] With the increasing environmental pollution and energy crisis, there is an urgent need to develop new energy vehicles that are energy-saving and environmentally friendly. Among them, battery technology is the bottleneck that hinders the further development of new energy vehicles. In order to achieve a certain level of voltage, power and energy, it is necessary to connect multiple single cells in series or in parallel to form a group. The performance of other aspects is far inferior to that of a single battery, which makes the power battery pack unable to meet the performance requirements of the whole vehicle. [0003] To solve this problem, the traditional solution is to conduct strict consistency screening before the batteries are used in groups, and select single cells with good consist...

AI Technical Summary

Problems solved by technology

In order to achieve a certain level of voltage, power and energy, it is necessary to connect multiple single cells in series or in parallel to form a group. The performance of other aspects is far inferior to that of a single battery, which makes the power battery pack unable to meet the performance requirements of the whole vehicle.

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