Single capacitor centralized-type equalizer topology and equalization method thereof

Abstract

The invention belongs to the technical field of battery equalization and particularly discloses a single capacitor centralized-type equalizer topology and an equalization method thereof. N battery cells are sequentially serially connected to form a battery pack; each battery cell is connected with an energy converter; the energy converters are in mutual parallel connection at an output end and aretogether connected with an energy storage capacitor; two ends of the energy storage capacitor are connected with a discharge control switch and a rear diode, and the discharge control switch and therear diode are connected with the positive end and the negative end of the battery pack. The topology distributes one relatively-independent energy converter for each battery cell, one capacitor is adopted to temporarily store energy, the energy stored in the capacitor is periodically fed back to the battery pack, and overall equalization on the battery pack is realized. the discharge circuit of asingle battery passes through the whole battery pack, the battery equalization speeds at different positions are kept consistent, a voltage interleaving phenomenon caused by equalization speed differences is avoided, and the single capacitor centralized-type equalizer topology has the advantages of quick equalization speed, little energy loss and the like.

Description

technical field [0001] The invention belongs to the technical field of battery equalization, in particular to a single-capacitor centralized equalizer topology and an equalization method thereof. Background technique [0002] Lithium-ion batteries are widely used in daily life due to their advantages such as high energy density, low self-discharge, and long service life. The voltage of common lithium-ion battery cells is low, and it often requires multiple cells to be connected in series to achieve high-voltage output. Since it is difficult to ensure the consistency of the internal resistance and self-discharge rate of each monomer in the manufacturing process, the unbalanced phenomenon of series-connected units is easy to occur during use, and the phenomenon of overcharging and overdischarging of a single battery will greatly reduce the use of the battery. life, affecting the overall performance of the battery pack. Therefore, it is of great significance to study battery ...

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Problems solved by technology

[0004] Aiming at the disadvantages of the traditional Buck-Boost type equalization circuit, such as complex circuit, large equalization loss, and the correlation between the equalization speed and the position of the battery cells, the purpose of the present invention is to provide a new topology structure with low control difficulty, simple circuit, and consistent cell equalization speed. Make it overcome some shortcomings of the existing Buck-Boost balanced topology

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