Active voltage balancing system and active voltage balancing method for serial energy storage element group

Abstract

Disclosed are an active voltage balancing system and an active voltage balancing method for a serial energy storage element group. The active voltage balancing system is designed on the basis of the active voltage balancing method. The main technical points of the active voltage balancing method are as follows: a switched capacitor is connected in parallel with each battery or super capacitor in a battery bank or super capacitor bank, all the switched capacitors are connected in parallel with a large-capacity energy storage capacitor, consequently, the redundant electric energy in all the batteries or super capacitors can be first transferred to the switched capacitors and then to the energy storage capacitor together, and finally, the energy storage capacitor is utilized to feed the electric energy back into the whole serial battery bank or super capacitor bank, thus realizing reallocation of the electric energy, enabling the voltage of each battery or super capacitor body in the battery bank or super capacitor bank to be balanced and preventing certain monomers from damage or explosion due to over-high voltage.

Description

technical field [0001] The present invention relates to a system and method for equalizing the voltage of a bank of series-connected energy storage elements (batteries or supercapacitors). Background technique [0002] Electric vehicles and other electric vehicles are new vehicles that have emerged in recent years. They have attracted widespread attention for their energy saving and environmental protection. In recent years, with the rapid development of power electronics technology and battery and supercapacitor technology, the development of electric vehicles is also very fast. Electric vehicles use high-power power battery packs or super capacitor packs to provide energy sources. The working voltage level of electric vehicle energy storage components is generally 300-400V, and the voltage level of pure electric buses is higher, usually around 400-600V. To meet the design index, it is necessary to use multiple energy storage elements such as batteries or supercapacitors i...

AI Technical Summary

Problems solved by technology

The active equalization in the above three patents is to detect the voltage of each battery cell, and directly transfer the energy of the battery with high voltage to the battery with low voltage through the capacitor one by one. Only secondary energy transmission can basically achieve battery balance, so the balance speed is relatively slow, and it is not suitable for high-voltage (large number of series-connected batteries) and large-capacity series-connected battery packs; in addition, each energy storage unit in the above three patents requires two Switching devices and two sets of driving circuits, so there are many circuit devices, complex circuits, and high cost

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