Limit lithium iron phosphate battery SOC correction method

Abstract

The invention provides a limit lithium iron phosphate battery SOC correction method, and relates to the technical field of lithium iron phosphate battery SOC. The limit lithium iron phosphate battery SOC correction method comprises the following steps: S1, determining the state of the battery: acquiring the SOC of a lithium iron phosphate battery through a battery management controller, controlling and adjusting the actually detected SOC of the lithium iron phosphate battery, recording the actual SOC value of the lithium iron phosphate battery at the moment, and detecting the cut-off voltage of the lithium iron phosphate battery at the moment. According to the limit lithium iron phosphate battery SOC correction method, the SOC of the lithium iron phosphate battery can be effectively corrected when the lithium iron phosphate battery is not fully charged and not fully discharged for many times, the universality of SOC correction of the lithium iron phosphate battery is effectively improved, the actual electric quantity of the lithium iron phosphate battery is further effectively calibrated, meanwhile, the battery endurance time can be effectively mastered, electrical vehicle normal driving is ensured; and meanwhile, the actual service life of the lithium iron phosphate battery can be effectively prolonged, and the actual use effect of the lithium iron phosphate battery is improved.

Description

technical field [0001] The invention relates to the technical field of SOC of a lithium iron phosphate battery, in particular to an SOC correction method of a limit lithium iron phosphate battery. Background technique [0002] Electric vehicles refer to vehicles powered by on-board power supplies, driven by motors to drive wheels, and meet the requirements of road traffic and safety regulations. Due to their smaller impact on the environment than traditional vehicles, their prospects are widely optimistic. The existing SOC calculation method The calculations for lithium phosphate batteries are not perfect, because the OCV curve in the middle section of the SOC of lithium iron phosphate is relatively smooth, and there is not enough slope to provide SOC correction, so it can only be corrected with OCV close to the full charge, but customers in the actual use process It is not fully charged and discharged every time, which leads to SOC can not be corrected by OCV, but can only ...

AI Technical Summary

Problems solved by technology

[0002] Electric vehicles refer to vehicles powered by vehicle-mounted power supplies and driven by motors to drive wheels, which meet the requirements of road traffic and safety regulations. Because they have less impact on the environment than traditional vehicles, their prospects are widely optimistic. The existing SOC calculation method The calculations for lithium phosphate batteries are not perfect. Because the OCV curve in the middle section of the SOC of lithium iron phosphate is relatively smooth, there is not enough slope to provide SOC correction, so it can only be corrected with OCV close to the full charge, but the customer is actually using it. It is not fully charged and discharged every time, which leads to the fact that the SOC cannot be corrected by OCV, and can only be calculated by using the ampere-hour integral. The method is too simple, and long-term use will cause the SOC calculated by the BMS to be different from the actual value of the battery pack. The SOC error is getting bigger and bigger. Inaccurate SOC calculation will lead to insufficient discharge and insufficient charging. The power of the battery pack is much smaller, which has a great impact on the battery life and life of the vehicle.

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