Charge-discharge equalization control circuit of battery pack

Abstract

The invention discloses a charge-discharge equalization control circuit of a battery pack. The charge-discharge equalization control circuit comprises a charge-discharge circuit, a voltage detection circuit, a voltage comparator, a controller, a current-sharing circuit and a discharge switch. An input end of the charge-discharge circuit is connected with a power line, and an output end of the charge-discharge circuit is connected with at least two battery single bodies respectively. An input end of the voltage detection circuit is connected with at least two battery single bodies respectively. An input end of the voltage comparator is connected with an output end of the voltage detection circuit. An input end of the controller is connected with the voltage comparator, and an output end of the controller is connected with the charge-discharge circuit. The current-sharing circuit is connected with the charge-discharge circuit and the controller. The discharge switch is located in the charge-discharge circuit. The charge-discharge equalization control circuit can ensure charging equalization between the battery single bodies through a replacing mode and a current-sharing mode in the charging process, can control the high-voltage battery single bodies to charge the low-voltage battery single bodies, and further ensures the mutual equalization between the battery single bodies in the discharging process.

Description

technical field [0001] The present application relates to the technical field of battery pack control, in particular to a battery pack charge and discharge equalization control circuit. Background technique [0002] Lithium iron phosphate battery is a new type of secondary power supply newly developed in recent years. Its main advantages are large input and output power, wide operating temperature range, no memory effect, long life of more than 2000 times, green environmental protection and floating charge characteristics. Outstanding features, widely used in the field of electric vehicles and energy storage power stations. [0003] However, when the lithium iron phosphate battery is charged and discharged at a high rate, the actual specific capacity is low. Therefore, although the lithium iron phosphate battery has the above-mentioned advantages, it is used in the field of backup power, especially in the field of backup power for substations. Obviously, shallow charging an...

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Problems solved by technology

[0003] However, when the lithium iron phosphate battery is charged and discharged at a high rate, the actual specific capacity is low. Therefore, although the lithium iron phosphate battery has the above-mentioned advantages, it is used in the field of backup power, especially in the field of backup power for substations. Obviously, shallow charging and shallow discharging of lithium iron phosphate batteries cannot be effectively performed, and high-rate charging and discharging are prone to occur, so that the physical and chemical characteristics of lithium iron phosphate batteries cannot be effectively maintained.

[0004] When the physical and chemical properties of a certain battery change, there will be differences between the individual batteries in the battery pack, which will lead to over-discharge of some batteries in the long run

The same is true during the charging process. If you do not consider the difference between the battery cells and charge them, it may lead to overcharging of a single battery.

If a single battery is over-discharged or overcharged for a long time, its battery capacity will be reduced, its service life will be shortened, and the consistency of the entire battery pack will be destroyed, thereby shortening the battery pack's life.

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