A lithium battery pack power management system

Abstract

The invention relates to a lithium battery pack power management system which comprises batteries in a battery pack connected in series. Each battery is connected with a change-over switch in parallel, and each change-over switch is connected with a battery pack control unit, wherein the battery pack control unit can monitor whether the battery pack is in an over-charge, or over-discharge or superheat state or not and give out a corresponding drive signal, and motor type relays are adopted for the change-over switches. An existing battery management system is based on a divided flow theory and is not suitable for the use condition that battery monomers are greatly different from one another; when balanced matching is poor, aging of batteries is prone to acceleration. According to the lithium battery pack power management system, the motor type relays are adopted as the change-over switches, the lithium battery pack power management system has the advantages of being large in impact-resistant current, suitable for the large power use environment, high in reliability, low in power consumption, small in size, low in cost and the like, a lithium battery charge-discharge protection strategy can be simplified, the adverse condition that the battery monomers are greatly different from one another is overcome, and the service life of the battery pack is prolonged.

Description

technical field [0001] The invention belongs to the technical field of lithium battery charging and discharging protection, and in particular relates to a lithium battery pack power management system. Background technique [0002] At present, electric vehicles have attracted more and more countries' attention due to their unique advantages of energy saving and environmental protection, and a lot of related research and development work has been carried out. Among them, power lithium battery power supply has become the mainstream electric power source technology due to its advantages of small size, light weight, high energy density, no memory effect, long service life, wide application range, high working voltage and low self-discharge rate. However, the power lithium battery power supply is composed of multiple lithium battery cells connected in series or in parallel; in the battery pack, there are always differences between the monomers, which causes some disadvantages. Ta...

AI Technical Summary

Problems solved by technology

Although this method is simple, power batteries are often used in high-power and high-current occasions, which makes it difficult to implement technically.

If the switch is implemented with MOSFET and IGBT power tubes, the cost will increase greatly, and it is prone to overheating and other unfavorable conditions when the current is high, and the isolation measures of the low-voltage and high-voltage parts are complicated.

If the electromagnetic relay scheme is adopted, the reliability problem of the electromagnetic drive is difficult to solve and the safety will be reduced

For conventional electromagnetic relays, the driving mechanism that drives the relay contacts to close and open is an electromagnetic coil. In high-power use, there will be burning contacts and inexplicable tripping phenomena. The root cause is that the contact pressure is not large enough. of

Due to these limiting factors, the method of cut-off equalization cannot be applied in engineering

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