Equalization circuit for rapidly balancing battery pack of switch array and control method

Abstract

The invention discloses an equalization circuit for rapidly balancing a battery pack of a switch array and a control method. The circuit comprises a single battery switch selection sub circuit, a resistance discharging combination sub circuit, a single voltage acquisition sub circuit and a switch control driving sub circuit, wherein the single battery switch selection sub circuit is used for conducting a single battery needed to be discharged, the resistance discharging combination sub circuit is used for configuring the size of a discharging current, the single voltage acquisition sub circuit is used for acquiring an actual voltage value of each section of single battery and calculating the single battery needed to be balanced, and the switch control driving sub circuit is used for controlling a corresponding switch and balancing the single battery. By the single battery switch selection sub circuit, balanced discharging of multiple sections of single batteries can be simultaneously achieved; and during discharging, the switch of the single battery switch selection sub circuit is selected and the switch of the closed resistance discharging combination sub circuit is matched to form a discharging loop, and the balance of the selected single battery is achieved.

Description

technical field [0001] The invention relates to the technical field of new energy vehicles, and more specifically relates to an equalization circuit and a control method for quickly equalizing a battery pack with a switch array. Background technique [0002] The power battery pack of an electric vehicle is composed of hundreds of strings of lithium-ion cells. The consistency between lithium-ion cells is crucial to the performance and life of an electric vehicle. The balance current of the current passive balance circuit is small, and the balance discharge circuit is fixed, which limits the size of the balance current, so it is difficult to quickly reduce the voltage value of the highest single battery. The consistency evaluation of battery packs is one of the cores of battery series application technology, which directly affects the safety and efficiency of battery packs. In the prior art, there have been many documents discussing the consistency evaluation method of the ba...

AI Technical Summary

Problems solved by technology

In the prior art, there have been many literatures discussing the consistency evaluation method of the battery pack, and a variety of equalization circuits have been proposed, but most of them are based on the external voltage difference between the batteries for consistency evaluation and implementation of equalization. Control, this evaluation method can not effectively indicate the inherent differences between batteries and lead to the degradation of the balance effect

This makes the capacity, size, cost and heat dissipation of the on-board equalizer difficult to solve; while the off-line equalizer will significantly increase the workload of battery maintenance, and ultimately hinder the large-scale application of electric vehicles

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