Power control method of energy storage system

Abstract

The invention discloses a power control method of an energy storage system, which is used for secondary recycling of power batteries. The power control method comprises the following steps of: sequentially classifying power battery packs into a priority discharging battery pack, an effective working battery pack and a priority charging battery pack according to charged state values of the secondarily-recycled power battery packs from large to small; charging the priority charging battery pack and then the effective working battery pack during charging; and discharging the priority discharging battery pack and then the effective working battery pack during discharging. By the power control method, the battery packs are sequenced and classified in terms of priorities according to the charged states of all power battery packs, power is allocated to the battery pack with a high charging/discharging level by referring to a power given value, thus, charging and discharging frequencies of each power pack are reduced, power balance of the plurality of battery packs running in a parallel-connection manner is achieved, a part of battery packs are prevented from frequently running in charging and discharging ways, the service life of the energy storage system is comprehensively prolonged, and the running stability and safety of the system can be further improved.

Description

technical field [0001] The invention relates to the technical field of battery energy storage, in particular to a power control method for an energy storage system for secondary utilization of a power battery providing a power source for an electric vehicle. Background technique [0002] With the rapid development of new energy vehicles, it is estimated that by 2020, the production capacity of pure electric vehicles and plug-in hybrid vehicles will reach 2 million, and the cumulative production and sales will exceed 5 million. Since the core component of new energy vehicles is the power battery, which accounts for a relatively high proportion of the cost of new energy vehicles, and the current normal service life of power batteries may only be three to five years. Under the huge incremental space, with the end of the service life of the power battery, there will be a large number of power batteries scrapped from electric vehicles. If these batteries are directly eliminated, ...

AI Technical Summary

Problems solved by technology

[0004] In the actual operation of power battery packs for secondary use, due to the aging of their own materials, temperature and other factors, the working performance and charge and discharge status of different battery packs are significantly different. If no optimization measures are taken, some parallel battery packs will be more serious. Frequent charging and discharging operation will cause the battery life to decay rapidly, affect the stability and safety of the system operation, and also reduce the working efficiency of the energy storage system. Therefore, it is necessary to optimize the distribution control of power according to the charging and discharging characteristics of different battery packs

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