Series connection battery pack two-way charging and discharging equalization circuit based on inductor energy storage

Abstract

The invention discloses a series connection battery pack two-way charging and discharging equalization circuit based on inductor energy storage. At least three battery single bodies are connected in series, at most seven battery single bodies are connected in series, a series connection battery pack is divided into an upper portion and a lower portion, the connection point of the upper portion and the lower portion is N, the upper portion includes battery single bodies from the positive end of the series connection battery pack to the connection point N, the lower portion includes the battery single bodies from the connection point N to the negative end of the series connection battery pack, m is an odd number, n is an even number larger than or equal to 2, m=n-1 or m=n+1, and m <=7. An equalization sub circuit connected with odd batteries is an odd equalization circuit, and an equalization sub circuit connected with even batteries is an even equalization circuit. By means of the circuit, overcharging and overdischarging are avoided in the charging and discharging process, the series connection battery pack unequalization is avoided, the battery pack available capacity is improved, the maintenance and replacement period of the series connection battery pack is reduced, the service life of the battery pack is prolonged, and the cost of hybrid electric vehicles, electric automobiles and energy storage power stations is reduced.

Description

technical field [0001] The invention relates to a balancing technology for series battery packs, in particular to a bidirectional charge-discharge equalization circuit for series battery packs based on inductive energy storage for hybrid electric vehicles, pure electric vehicles or battery management systems of energy storage power stations. Background technique [0002] After multiple charge-discharge cycles of series batteries, the distribution of the remaining capacity of each battery cell will generally appear in three situations: the remaining capacity of individual battery cells is high; the remaining capacity of individual battery cells is low; the remaining capacity of individual battery cells is low; The remaining capacity of the body is high and the remaining capacity of individual battery cells is low. [0003] In view of the above three situations, domestic and foreign scholars have put forward their own solutions. For example, in view of the high remaining capa...

AI Technical Summary

Problems solved by technology

For example, in view of the high remaining capacity of individual battery cells, some researchers have proposed a parallel resistor shunt method, which consumes the energy of the battery cells with high remaining capacity through resistance by controlling the corresponding switching devices. Energy is wasted in vain, and a lot of heat is generated during the equalization process, which increases the load of battery thermal management

Some researchers have also proposed equalization circuits such as bidirectional DC-DC equalization method and coaxial transformer equalization method. These circuits all use transformers, which increases the cost of equalization circuits.

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