Method and system for detecting polymer lithium battery pack consistency

Abstract

The invention discloses a method and a system for detecting polymer lithium battery pack consistency. The system comprises a capacitance sensor, a data collector and an image imager. The capacitance value between capacitance sensor electrodes of the to-be-detected polymer lithium battery pack is measured, a capacitance tomography image reconstruction algorithm is adopted to reconstruct the capacitance value to a polymer lithium battery pack inner dielectric constant distribution, a standard relation curve for the polymer lithium battery pack inner dielectric constant distribution and the consistency is built, the standard relation curve is compared with the to-be-detected polymer lithium battery pack inner dielectric constant distribution, and the consistency of the to-be-detected polymer lithium battery pack is obtained. The method and the system have the advantages of non intrusion, quick response speed and convenient operation and the like.

Description

technical field [0001] The invention relates to the field of battery detection, in particular to a consistency detection method and system for a polymer lithium battery pack. Background technique [0002] From various electronic products, communication equipment, automated instruments and meters, and various electric tools to electric bicycles, electric vehicles, and even military fields such as aerospace and aviation, all of them are closely connected with lithium batteries because of their high energy density, light weight, and safety. With incomparable advantages such as good performance and other energy storage batteries, the future development prospects of lithium batteries are very broad. Lithium batteries include traditional metal shell lithium batteries and polymer lithium batteries. Polymer lithium batteries have more development prospects due to their high specific energy density. [0003] As we all know, under the existing technical level of power batteries, it i...

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Problems solved by technology

[0004] At present, there are two main methods for consistency detection of battery packs at home and abroad: the consistency classification and screening of battery cells according to the internal resistance, voltage and capacity tested under constant current discharge before assembly, this method can only reflect the The consistency of voltage, capacity and internal resistance of the body in this environment and conditions cannot reflect the consistency of high-voltage, large-capacity battery packs during operation. As the environment and conditions of use change, the consistency will also change significantly. Change; the state of the battery pack is monitored through the battery management system, and the necessary equalization processing is performed on the batteries. Most of these methods are based on the consistency evaluation of the external voltage difference between the batteries, and cannot effectively indicate the internal differences between the batteries.

[0005] It can be seen that the environment in which the battery pack is used is complex, the batteries are mostly used in parallel and in series, and the current changes frequently. The existing single battery consistency detection method cannot meet the demand for battery consistency.

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