Battery monitoring and balancing system and control method thereof

Abstract

The invention discloses a battery monitoring and balancing system and a control method thereof. In a balancing circuit, a battery discharging circuit and a flyback converter are combined for selectively charging or discharging and improving balancing efficiency. A single-chip microcomputer MCU is utilized for directly switching on or switching off a switch array, thereby realizing direct samplingof a single battery through an analog-to-digital converter ADC. Furthermore a switch tube in the flyback converter is directly controlled through the single-chip microcomputer MCU, thereby realizing no requirement for a sampling switch, a balancing switch, a control chip in the flyback converter, and a peripheral device, reducing the number of switches, simplifying the circuit, reducing circuit loss and cost. Furthermore simple control logic of the system is realized, and no requirement for a specialized battery balancing chip is obtained. Furthermore balancing and single battery voltage detection are simultaneously performed in the balancing step, thereby realizing loop controlling to the flyback converter and the discharging circuit and improving balancing efficiency.

Description

technical field [0001] The invention relates to battery management, in particular to a battery monitoring and equalizing system and a control method for a battery pack composed of multiple batteries. Background technique [0002] In recent years, more and more products use lithium-ion batteries as the main power source, mainly because lithium-ion batteries have the advantages of small size, high energy density, no memory effect, high cycle life, and low self-discharge rate; but at the same time, lithium-ion batteries Ion batteries have high requirements for charging and discharging. When overcharge, overdischarge, overcurrent and short circuit occur, the pressure and heat of lithium ion batteries will increase greatly, which will easily generate sparks, burn and even explode. Therefore, lithium ion batteries are without exception Both grounds are equipped with an overcharge and discharge protection circuit. In addition, when charging and discharging a group of lithium-ion b...

AI Technical Summary

Problems solved by technology

[0007] (1) The circuit needs to add a pair of sampling switches S1, S2 and a pair of equalization switches S3, S4, and control the opening and closing of the sampling switch, switch array and equalization switch to realize battery sampling operation and battery equalization operation , there are 4 sampling switches and equalizing switches, and they need to be disconnected and closed frequently, the circuit cost is still high, and the circuit loss is also large

[0008] (2) The sampling operation of the circuit is performed separately from the battery equalization operation, and the working efficiency of the circuit is low

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