Proportional balancing method for voltage of energy storage device and circuit

Abstract

The invention discloses a method and circuit for proportional balancing of voltage of an energy storage device (4), and is used for proportional balancing of voltages on both ends of the energy storage device (4). The method has the steps of :firstly, executing two-way isolation transform for voltage of the energy storage device (4) by the balancing module (3) according to a certain transformation ratio k, then using a balancing line to cause all voltages transformed by the balancing module (3) to connect in a parallel connection, thereby equalizing all voltages transformed by the balancing module (3). When the ratio of the energy storage device (4) to the balancing line voltage is greater than the transformation ratio k of the balancing module (3), the energy flows to the balancing line from the energy storage device (4); when the ratio of the energy storage device (4) to the balancing line voltage is less than the transformation ratio k of the balancing module (3), the energy flows to energy storage device (4) from the balancing line. Ultimately, every ratio of every energy storage device (4) to every balancing line voltage is close to or equal to the transformation ratio k of the balancing module (3), thereby keeping every terminal voltage of every energy storage device (4) in a certain ratio.

Description

technical field [0001] The invention provides a method and circuit for voltage equalization of energy storage devices, in particular a method and circuit for voltage equalization of capacitors, supercapacitors, storage batteries and other energy storage devices in proportion. Background technique [0002] Due to the relatively low voltage of the battery cells, they usually need to be connected in series to form a battery pack. For the battery cells that make up the battery pack, due to changes in capacity, internal resistance, and use conditions and environments, the terminal voltage of the battery cells will be inconsistent. , in the process of charging and discharging, it is easy to cause overvoltage or undervoltage of some battery cells, which will adversely affect the overall use and life of the battery pack, which requires voltage equalization of the terminal voltage of each single battery in the series battery pack. [0003] As an energy storage device, a supercapacito...

AI Technical Summary

Problems solved by technology

This invention provides a voltage equalization scheme of series energy storage devices using AC bus, which is beneficial to the expansion of the number of energy storage units, but this scheme is an incomplete decentralized scheme with a common DC / DC Converter and DC / AC converter, and this kind of balance is a one-way supplementary power balance, which charges the battery with the lowest battery voltage, and cannot directly transfer the energy of the battery with a higher battery voltage to the battery with a lower voltage , not a two-way equalization scheme

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