An optimized charging method for on-board energy storage lithium-ion batteries for rail transit

Abstract

The invention belongs to the technical field of charging of a lithium ion battery, and particularly relates to an optimized charging method of a vehicle-mounted energy storage lithium ion battery for rail transit. The optimized charging method comprises the steps of calculating maximum charging current and a charging cutoff voltage of a lithium ion battery within a full-life period according to cycle lifetime attenuation characteristic of the lithium ion battery; constructing an optimized charging target function under the constraint of the maximum charging current and the charging cutoff voltage by taking charging time reduction and battery charging temperature rising control as targets; and seeking an optimal charging current by a genetic algorithm so as to balance the two conflict targets of charging time reduction and the charging temperature rising reduction. A result shows that the optimal charging current is used for ensuring charging rapidness and simultaneously controlling a polarization voltage and the temperature rising during the charging process to be within allowable ranges, and the charging capacity, the charging efficiency, the charging safety and the battery lifetime are ensured.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery charging, and in particular relates to an optimized charging method for a vehicle-mounted energy storage lithium-ion battery for rail transit. Background technique [0002] According to the needs of the rail transit power system, the on-board energy storage system with the characteristics of long life, wide temperature range, high rate and light weight is selected, which not only responds to the national call for energy conservation and environmental protection, but also reduces labor maintenance costs, which is in line with my country's railway construction long-term planning goals. Lithium-ion batteries have become the most commonly used energy storage components for rail transit vehicles due to their high energy density, modularity, and reliability. [0003] Currently, a constant current constant voltage (CC-CV) charging method is widely used for lithium-ion batteries. First, use a...

AI Technical Summary

Problems solved by technology

Excessive polarization voltage will cause the battery to be fully charged and cause the loss of active materials inside the battery, thereby affecting battery life

High current charging will lead to excessive polarization voltage, therefore, the polarization voltage limits the maximum charging current of lithium-ion batteries

Temperature is an important factor to be considered in the charging process of lithium-ion batteries. If the temperature is too high, the stability of the lattice structure of the positive electrode of the battery will deteriorate, the safety of the battery will decrease, and it will easily cause thermal runaway of the battery.

Images