Battery cluster inconsistency on-line monitoring method based on polarization impedance voltage rises

Abstract

The invention discloses an energy storage power station battery cluster inconsistency online evaluation method based on polarization impedance voltage rises. The method comprises the steps: screening battery pack boxes based on two parameter indexes which are available capacity and DC internal resistance, and selecting characterization monomers; acquiring voltage rises [delta]Up and [delta]up, caused by polarization impedance, of the battery clusters and the characterization monomers in real time; acquiring a linear fitting relation f(n*[delta]up, [delta]Up), and performing derivation on the linear fitting relation to obtain a change rate k(n*[delta]up, [delta]Up), with n being the number of battery pack boxes. If the k(n*[delta]up, [delta]Up) is in an increasing trend along with the proceeding of the circulation, it shows that the inconsistency of the battery clusters is intensified. The method is low in implementation cost and easy in practical application, and online evaluation of the inconsistency of the battery clusters is effectively carried out.

Description

technical field [0001] The invention relates to the field of electrochemical energy storage, in particular to the field of detection of the health status of lithium-ion battery clusters for electric energy storage. Background technique [0002] Today, energy storage is the main track for the development of new power systems. With the large-scale promotion of the "renewable energy + energy storage" development model, the safety of energy storage batteries has attracted increasing attention from all walks of life. However, the battery management system (Battery Management System, BMS) is limited by the hardware level and has limited computing power. While the evaluation methods for the operation status of energy storage batteries are constantly being updated, practical application issues should be considered. [0003] Today's lithium-ion battery energy storage power stations use the battery module unit box phase (referred to as: battery pack box) as the basic unit to build bat...

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Problems solved by technology

[0003] Today's lithium-ion battery energy storage power stations use the battery module unit box phase (referred to as: battery pack box) as the basic unit to build battery clusters, but because the operating environment in the battery cluster is different for each battery pack box, resulting in pack The inconsistency of the packs gradually increases during operation, thereby reducing the efficiency of the battery pack. If it is not monitored and managed, it will easily cause irreversible damage to the operating life of the energy storage power station, that is, the safety of the battery pack is closely related to the operation of the internal battery pack. directly related to status

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