Capacitive voltage balance system and method for series-connected energy storage system

Abstract

The invention discloses a capacitive voltage balance system and a capacitive voltage balance method for a series-connected energy storage system. The capacitive voltage balance system is designed by adopting a voltage balance method on the basis of a conventional switching capacitor balance circuit. The voltage balance method has the main technical characteristics that a first-layer switching capacitor C4 and second-layer switching capacitors C5, C6 and C7 are added to a four-single-body series-connected energy storage element on the basis of a conventional switching capacitor network balance circuit, so that a path capable of directly transferring charges is formed between every two single bodies in a four-single-body series-connected energy storage unit. A voltage detection circuit unit feeds back the voltage consistency situation of a battery pack, and then a balance control unit sends a control signal to control the turn-on and turn-off of a corresponding switch, so that the transfer of electric quantity between a high-voltage battery and a low-voltage battery is realized; the voltage balance of each single body in the series-connected energy storage unit is completed finally, so that the potential risk caused by voltage inconsistency of the single energy storage bodies in the energy storage unit can be effectively reduced.

Description

technical field [0001] The invention relates to the technical field of energy storage power management systems, in particular to a voltage equalization method and system for energy storage units connected in series in the energy storage power management system. Background technique [0002] With the rapid development of the new energy industry, whether it is new energy vehicles or large-scale energy storage applications, a large number of single batteries need to be used in series, but the inconsistency of the series of single batteries seriously affects the effective capacity of the power battery pack. Cycle life, safety and economy make it difficult for power pools to meet such requirements. At the same time, the consistency of a single battery is relative. Too much emphasis on the consistency of the manufacturing process or the consistency of the environment during use can only be at the cost of increasing the cost of the power system. How to ensure the safe and efficien...

AI Technical Summary

Problems solved by technology

[0002] With the rapid development of the new energy industry, whether it is a new energy vehicle or a large-scale energy storage application, a large number of single batteries need to be used in series, but the inconsistency of the series of single batteries seriously affects the effective capacity of the power battery pack. Cycle life, safety and economy make it difficult for power pools to meet such requirements

At the same time, the consistency of the single battery is relative, too much emphasis on the consistency of the manufacturing process or the consistency of the environment during use can only be at the expense of increasing the cost of the power system

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