Active equalization circuit and method for echelon utilization of retired power batteries

Abstract

The invention discloses an active equalization circuit for echelon utilization of retired power batteries, which comprises a data acquisition module and a main control unit MCU. The data acquisition module is used for respectively acquiring voltage and current data of each single battery in the power batteries, and the output end of the data acquisition module is connected with the main control unit MCU; the circuit further comprises a PWM drive circuit, a bidirectional DCDC equalization module, a capacitance equalization module and a switch array, the output end of the main control unit MCU is connected with the PWM drive circuit, and the output end of the PWM drive circuit is connected to the switch array and used for controlling on and off of the switch array. The positive electrode andthe negative electrode of each single battery are connected with the two ends of the bidirectional DCDC equalization module and the capacitance equalization module respectively, and the switch arrayis used for controlling on-off between the single batteries and the bidirectional DCDC equalization module and on-off between the single batteries and the capacitance equalization module respectively.The circuit has the advantages that the circuit is simple in structure, equalization is reliable, and rapid equalization can be achieved for power battery packs which are high in capacity level and connected in series.

Description

technical field [0001] The invention relates to the field of recycling and utilization of power batteries, in particular to an active equalization circuit and method for inscription utilization of decommissioned power batteries. Background technique [0002] After being used for a certain period of time or cycled for a certain number of times, the power battery for new energy electric vehicles will have obvious decline in capacity or power characteristics, which cannot meet the requirements of the vehicle and needs to be retired from the vehicle. However, the decommissioned power batteries still have a huge residual value, and their capacity and power can still meet the needs of other energy storage occasions that do not require high power performance, that is, they can be used in cascades. [0003] The main reason for the safety problems of decommissioned power batteries during cascade utilization focuses on the charging and discharging process. Although decommissioned pow...

AI Technical Summary

Problems solved by technology

Although decommissioned power batteries are used in cascade utilization, unlike cars that use thousands of batteries, there are generally dozens or hundreds of batteries. Due to the constraints of production technology and production materials, there are gaps between each battery. There is a certain difference, and the difference between retired batteries will be more obvious

The difference in capacity can easily cause imbalances, which can lead to problems such as overcharging and over-discharging. Therefore, in order to use decommissioned power batteries in cascades, you must first solve their safety problems, and the core of solving their safety problems is to solve their problems first. imbalance

[0004] Existing equalization circuits are divided into active equalization and passive equalization. Passive equalization is mainly used in low-series and low-capacity scenarios, mainly relying on energy consumption to achieve equalization, which takes a long time; the commonly used active equalization is more targeted. Usually the equalization effect on a certain kind of unbalanced state is very good, but the effect on dealing with other unbalanced situations is not satisfactory, and the equalization circuit of the prior art cannot adapt to multi-series, large-capacity recycling On the used power battery, the equalization time will be very long, so that the equalization circuit of the prior art cannot better adapt to the recycling of decommissioned batteries

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