Voltage equalization circuit for series super capacitor bank and control method thereof

Abstract

The invention relates to a voltage equalization circuit for a series super capacitor bank, which is connected in parallel at two ends of each monolithic super capacitor in the series super capacitor bank. A first leading-out terminal of the voltage equalization circuit is connected with external signals (600), a second leading-out terminal is connected with the positive terminal of a monolithic super capacitor of the series super capacitor bank, and a leading-out terminal is connected with the negative terminal of the monolithic super capacitor. When the voltage deviation of a super capacitor monomer caused by long-time operation needs to be eliminated, the voltage equalization circuit is enabled through the external signals; if the voltage of the super capacitor monomer is larger than the set value of voltage of the voltage equalization circuit, the discharge is carried out; and then, an external charge and discharge circuit is controlled to carry out corresponding charge and discharge actions, so that after a period of time, the voltage of any super capacitor monomer is equal to the set value of the voltage equalization circuit, thereby achieving the purpose of eliminating the historical accumulated voltage deviation of the super capacitor monomer.

Description

technical field [0001] The invention relates to a voltage equalization circuit and a control method thereof, in particular to a circuit capable of equalizing the voltage between individual cells of a series supercapacitor bank. Background technique [0002] The rated operating voltage of a single supercapacitor is low. In order to make it more widely used in the field of energy storage, a typical practice is to connect multiple supercapacitors in series to obtain a higher voltage. Due to the dispersion of the characteristic parameters between each supercapacitor, the voltage between the monomers of the supercapacitor bank will be unbalanced under normal charge and discharge or standby state, and the phenomenon of overcharging and overdischarging will cause permanent damage to the supercapacitor. And then cause the failure of the whole energy storage system. The voltage equalization circuit can equalize the voltage of each monomer in the module, thereby reducing the probabil...

AI Technical Summary

Problems solved by technology

[0005] A common disadvantage of these balancing circuits is that as the working time increases, the cumulative effect of the voltage deviation between cells will weaken the balancing effect of these voltage balancing circuits, and even cause these voltage balancing circuits to fail.

With the increase of the working time of the switch resistor type voltage equalization circuit, due to the different leakage current of the supercapacitor monomers, the voltage deviation between the monomers becomes larger and larger, and the balance effect will be greatly reduced; the pairwise comparison voltage equalization circuit is due to the dead The existence of the area, and due to the deviation of the parameters of the voltage balance circuit, with the increase of the working time, the voltage deviation between the monomers will also accumulate, which will reduce the balance effect

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