A kind of interleaved modular pack to cell equalization circuit and control method

Abstract

The invention discloses an interlaced modular Pack to Cell equalizer circuit and a control method. According to the interlaced modular Pack to Cell equalizer circuit, a power battery pack is divided into M stages of battery modules, and each battery module comprises N individual batteries, wherein the Kth stage of battery module is connected with the input end of the kth stage of LC resonant transformation circuit and the output end of the kth stage of LC resonant transformation circuit is connected with the individual batteries of the (K+1)th stage of battery module through a selective switch module; by the analogy, the Mth stage of battery module is connected to the input end of the Mth stage of LC resonant transformation circuit and the output end of the Mth stage of LC resonant transformation circuit is connected with the individual batteries of the first stage of battery module by use of a switching module. The interlaced modular Pack to Cell equalizer circuit has the advantages that the balance between the modules can be realized without increasing an extra equalizer, the problem of discharging the individual batteries at the same time of performing charging equalization on the individual batteries in the battery pack of the traditional Pack to Cell equalizer circuit is solved, and the net equalizing current and the equalizing efficiency are effectively improved.

Description

technical field [0001] The invention relates to an interleaved modular Pack to Cell equalization circuit and a control method. Background technique [0002] As we all know, the world is facing an unprecedented energy and environmental crisis. Electric vehicles have the characteristics of energy saving and environmental protection, which is the key way to solve this major crisis. Lithium-ion batteries are widely used as power sources in electric vehicles and hybrid electric vehicles due to their advantages such as high energy density, low self-discharge rate and no memory effect. Due to the relatively low voltage level and available capacity of single batteries, they must be used in series to meet the power requirements of electric vehicles. However, the series battery pack brings a serious problem: Due to the difference in the manufacturing process, the battery cells cannot be exactly the same, and the battery voltage will be unbalanced after a period of use. This imbalanc...

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Problems solved by technology

But the series battery pack brings a serious problem: Due to the difference in the manufacturing process, the battery cells cannot be exactly the same, and the battery voltage will be unbalanced after a period of use, which will cause some battery cells to be damaged. Overcharge and overdischarge, which greatly reduces the service life and available capacity of the power battery pack

However, the main problem of this equalization circuit is: when the battery pack charges and equalizes the battery cell with the lowest voltage, it also discharges the battery cell at the same time, and its net equalizing current is small, which also causes unnecessary energy waste

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