A sorting method for cascade utilization power battery

Abstract

The invention discloses a sorting method for cascade utilization power batteries. Although traditional methods can accurately measure battery capacity, internal resistance, self-discharge and other parameters, the test takes a long time and requires a lot of charge and discharge test equipment, which results in a significant increase in the cost of cascade utilization power battery sorting. The present invention tests the open circuit voltage of the cascade utilization power battery, the change value of the battery voltage during charging or discharging, and the impedance value at different frequency points, and on this basis, sets a corresponding deviation range for the test results of different parameters to realize the cascade utilization of power Rapid sorting of batteries. The invention uses the open circuit voltage of the power battery, the voltage change value during the 10-minute charging and discharging process, and the impedance value at high frequency, medium frequency and low frequency to sort the power battery according to the steps, and the sorting of the battery can be completed within 15 minutes The work realizes the rapid sorting of the cascade utilization power battery, and greatly shortens the sorting time of the cascade utilization power battery.

Description

Technical field [0001] The present invention belongs to the field of electric vehicles and energy storage, and more particularly to a ladder that determines which ladder utilization power cells can be used together to be used together. Background technique [0002] Since 2012, my country's electric vehicle industry has entered a rapid development period. In 2018, the electric vehicle sales exceeded 1 million, as of the end of 2019, my country's electric vehicle has more than 3.4 million. At present, electric vehicles mainly use lithium-ion batteries as a power source. During the use of electric vehicles, the performance of the power battery continues to decline. When its performance does not meet the application needs of new energy vehicles, it is necessary to retire from the car. In these retired power batteries, a large part has high residual energy, and these batteries have been re-evaluated and sorted, which can be used to achieve powerful scenarios for battery performance, m...

AI Technical Summary

Problems solved by technology

Although the traditional method can accurately measure the battery capacity, internal resistance, self-discharge and other parameters, the test time is relatively long. It needs to occupy a lot of charge and discharge test equipment, which leads to a significant increase in the cost of sorting power batteries for cascade utilization; for power batteries with cascade utilization, their residual value is already significantly lower than that of new batteries, and higher sorting costs will be greatly increased. Reduce the economy of the cascade utilization stage; and if only the voltage and internal resistance are tested (usually only 1000Hz frequency), the capacity and self-discharge performance that take a long time are not tested, and the status of the cascade utilization power battery cannot be accurately reflected , resulting in unsatisfactory sorting effect

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