System for realizing balanced discharging of battery sets

Abstract

The invention discloses a system for realizing balanced discharging of battery sets. The system comprises a plurality of balanced discharging modules, wherein the plurality of balanced discharging modules are connected in series in sequence to form positive and negative terminals of the system; the input end of each balanced discharging module corresponds to a battery; and the control end of each balanced discharging module is connected with a single chip system for keeping residual electric capacities of the batteries in the battery sets to be consistent by logic control. According to the system, the battery sets are connected in series by the balanced discharging modules; as the balanced discharging modules are connected in series, the discharging currents are the same, so that the discharging power of a monomer battery can be controlled by controlling the discharging voltages of the balanced discharging modules, therefore, the balanced discharging of the battery sets is realized and the over-discharging phenomenon caused by different SOC (state of charge) values is avoided. According to the system, a switch control principle is adopted, so that the energy consumption of the traditional passive balancing is avoided and the energy loss caused by energy transfer in active balancing is also avoided. The system can be widely applied to the field of battery management.

Description

technical field [0001] The invention relates to battery management technology, in particular to a system and method for realizing balanced discharge of battery packs. Background technique [0002] Due to the large energy consumption of products such as electric vehicles and uninterruptible power systems, in order to avoid excessive current, the application of batteries in series and parallel has become a common phenomenon. A series lithium-ion battery pack is composed of two or more batteries connected in series. In this configuration, the battery voltage is equal to the sum of the individual battery voltages. After adding the load, that is, during the discharge process of the battery pack, the load current is provided by all the batteries connected in series. If the battery is charged, the charger needs to provide charging current to the battery pack connected in series. In both cases, the discharge and charge currents are the same for all cells. Over a lifetime, a batt...

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Problems solved by technology

[0005] Transfer is to transfer part of the energy of the battery with high energy to the battery with low energy, and it can also make the battery power consistent; the ideal transfer is to maximize the effective capacity of the battery; but in fact, the transfer of electric energy must require It is completed by the energy storage element; the charging and discharging of the energy storage element is accompanied by energy loss. If the energy transfer is too frequent, it will cause a lot of energy waste; at the same time, to achieve effective energy transfer, there must be a large-capacity element (or high-frequency switch control), such components will add considerable volume or cost to the entire battery management system

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