Anti-floating charge protection circuit for spaceflight lithium battery

Abstract

The invention relates to an anti-floating charge protection circuit for a spaceflight lithium battery. The anti-floating charge protection circuit comprises a main power charging circuit, a charging termination circuit, a charging unlocking circuit and an execution circuit. In a spaceflight power supply system, a lithium battery is charged by adopting a mode of first constant current and then constant voltage, when a storage battery is converted from constant current charging to constant voltage charging, the battery voltage is gradually increased, the charging current is gradually reduced but does not reach zero, when the charging current is less than a charging termination current threshold value, a charging allowing signal in an execution circuit is turned into a low level, a charging switch tube is turned off, charging is stopped at the moment, and the charging current is zero; when the lithium battery is discharged and the voltage of the battery is lower than the unlocking voltage, the charging allowing signal is turned into a high level, the charging is unlocked, and the PWM signal drives the charging switch tube to charge the battery. According to the invention, the charging and discharging management of the lithium battery can be carried out without additionally controlling a lower computer, the functions of automatically stopping charging and recovering charge of the lithium battery can be realized, the floating charging of the lithium battery can be avoided, and the service life of the lithium battery can be prolonged.

Description

technical field [0001] The invention relates to the field of charging lithium-ion batteries, in particular to an anti-floating charge protection circuit for lithium batteries used in aerospace. Background technique [0002] The aerospace power supply receives the energy of the solar cell array during the light period, and receives the energy of the battery pack during the shadow period, provides stable working power for the whole star, and charges and maintains the battery. Lithium-ion batteries have the advantages of high single output voltage, long cycle life, large specific energy, and small size, and have been widely used in contemporary aerospace power systems. [0003] In order to prolong the service life and charging efficiency of lithium-ion batteries, lithium-ion batteries generally adopt the charging method of charging current termination and voltage unlocking, that is, when the battery is about to be fully charged, the charging current gradually decreases and the ...

AI Technical Summary

Problems solved by technology

However, this method requires the power supply to control the lower computer to perform calculations, the process is complicated, and once there are problems with sampling and instructions, the control of the lithium battery charging process will not be possible, and the cost is high, which cannot be used in low-cost aerospace power systems.

Images