A control method for constant current and constant voltage charging of lithium battery pack

Abstract

The invention provides a control method for constant-current constant-voltage charging of a lithium storage battery. The method includes the steps that work parameters such as voltage, currents and temperature are collected to judge whether a power source system is in the working state of charging the storage battery or not; if the power source system is in the charging state, whether the working temperature of the storage battery is normal or not is judged, and if the working temperature exceeds the limit, the upper limit of charging currents of a constant-current stage is revised as an allowable value at the current temperature; according to monomer voltage of the storage battery, whether the storage battery works in the constant-current stage or a constant-voltage stage is judged; if the storage battery works in the constant-current stage, control quantity is given according to the upper limit of the charging currents of the previous constant-current stage; if the storage battery works in the constant-voltage stage, control quantity needing to be given currently is calculated; when the lithium storage battery is fully charged, the charging currents are set to be zero to stop charging. The constant-current constant-voltage control method is more flexible than a traditional method, and the on-orbit service life of the storage battery is prolonged easily.

Description

technical field [0001] The invention relates to a control method for constant-current and constant-voltage charging of a lithium-ion battery pack, which is used for charging the lithium-ion battery pack. Background technique [0002] Due to its own characteristic requirements, lithium-ion battery packs cannot only use constant-current charging control like cadmium-nickel and nickel-hydrogen batteries. Because of their poor overcharge resistance, constant-current-constant-voltage charging control is required. The hardware constant current-constant voltage charging control method is generally adopted on satellites. Hardware constant current-constant voltage charging control usually controls the entire battery pack, that is, by measuring the entire pack voltage of the battery pack, it is judged whether the constant voltage reference value is reached. If the constant voltage reference value is not reached, the constant current method is used to charge the battery pack Carry out...

AI Technical Summary

Problems solved by technology

At the end of life, individual battery cells will fail. The failure modes of lithium-ion batteries include short circuit, open circuit, and capacity decline. The failure process is more complicated.

The optimal working temperature of lithium-ion batteries is 15-25°C. When the temperature is lower than 10°C, charging the battery pack with a large current will seriously affect the life of the battery pack.

Hardware control is not convenient for on-rail adjustment of charging parameters. If only hardware fixed charging control is used, it is difficult to achieve the best charging effect at different stages and under different conditions of use.

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