CN212085824U

CN212085824U - Parallel control circuit for echelon utilization of power storage battery module

Info

Publication number: CN212085824U
Application number: CN201921902888.2U
Authority: CN
Inventors: 高峰; 林武; 蒋丽丽; 朱家伟; 琚贇
Original assignee: Anhui Ruisaike Renewable Resource Technology Co ltd
Current assignee: Anhui Jiaqi Energy Technology Co ltd
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-12-04
Anticipated expiration: 2029-11-06

Abstract

The invention discloses a parallel control circuit for echelon utilization of a power storage battery module, which comprises a plurality of battery modules connected in parallel, wherein each battery module comprises a power battery, and the parallel control circuit is characterized in that: each battery module still include diode, switch, power battery's positive pole is connected with the anodal of diode, the negative pole leading-out terminal of diode is as battery module's positive pole, be in diode both ends parallel connection has the switch. The utility model has the advantages that: the circuit is simple, the cost is low, the parallel echelon utilization of the retired storage battery can be realized, the defects of parallel connection of batteries in echelon utilization in the prior art are overcome, and the parallel connection of the retired lithium batteries is facilitated.

Description

Parallel control circuit for echelon utilization of power storage battery module

Technical Field

The utility model relates to a retired power battery recycle field, in particular to parallel control circuit that power battery module echelon utilized.

Background

With the great popularization of electric vehicles, the disposal problem of power storage batteries used by the electric vehicles is increasingly outstanding, and various policies and regulations are provided for recycling retired power storage batteries in China. Among them, the echelon utilization of the retired power storage battery is also an important direction. The retired power storage battery is a battery which is not suitable for being used as a power battery any more when the capacity of the battery is reduced to 80% of the nominal capacity; although the battery is not suitable for being used as a power battery for continuous use, the battery still has 80% of residual capacity and can be continuously used in scenes with low requirements on energy storage or power performance, so that the value of the battery is fully utilized.

After the retired power storage battery is used for a period of time, the performance of the battery is reduced to some extent, and the consistency is poor; therefore, certain measures are required during echelon utilization, and troubles caused by consistency problems are avoided.

When the batteries are applied in parallel, the following defects and hidden dangers can be caused if the consistency is poor:

1. when discharging, the large capacity battery is always in shallow discharge and tends to slow capacity attenuation and prolong service life, while the small capacity battery is always in over discharge and tends to accelerate capacity attenuation and shorten service life, the difference of performance parameters between the two is larger and larger, and the small capacity battery fails in advance.

2. The discharge of the battery pack is always terminated when the capacity is small, and the actual capacity of the battery module cannot be fully utilized.

3. Potential safety hazards such as battery damage and heating caused by uncontrollable large-current discharge between batteries with voltage difference

Most circuits in the existing solutions are complex and high in cost, complex in implementation and poor in safety and reliability.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a parallel control circuit for echelon utilization of power storage battery modules, which is used for parallel utilization of retired power storage battery modules and reducing the influence of corresponding utilization of consistency defects existing in parallel connection after retired power batteries are retired.

In order to achieve the purpose, the invention adopts the technical scheme that: the utility model provides a parallel circuit that power storage battery module echelon utilized, includes a plurality of parallelly connected battery module each other, every the battery module include power battery, every the battery module still include diode, switch, power battery's positive pole is connected with the positive pole of diode, the negative pole leading-out terminal of diode is as the positive pole of battery module the diode both ends parallel connection has the switch.

Furthermore, the input end of the switch is connected with the control unit and is used for receiving the control of the control unit to be switched on and off.

Furthermore, the control unit is connected with the key module and used for controlling the opening and closing of the electric control switch according to the key module signal.

Furthermore, the electric control switch comprises relays, coils of each relay are connected in series and then connected with a power supply, and the output end of the power supply is connected with a manual switch in series.

And the control unit is connected with the power storage battery working state detection unit.

The utility model has the advantages that: the circuit is simple, the cost is low, the parallel echelon utilization of the retired storage battery can be realized, the defects of parallel connection of batteries in echelon utilization in the prior art are overcome, and the parallel connection of the retired lithium batteries is facilitated.

Drawings

The contents of the expressions in the various figures of the present specification and the labels in the figures are briefly described as follows:

fig. 1 is a schematic diagram of the parallel connection principle of the battery modules of the present invention;

fig. 2 is a schematic diagram of the control of the opening and closing of the relay according to the present invention.

Detailed Description

The following description of preferred embodiments of the invention will be made in further detail with reference to the accompanying drawings.

As shown in fig. 1, a parallel circuit for echelon utilization of power storage battery modules comprises a plurality of battery modules connected in parallel, wherein a battery pack formed by connecting the battery modules connected in parallel realizes echelon recycling of the battery modules, a battery pack anode connected with a positive terminal of the battery module and a battery pack cathode connected with a negative terminal of the battery module are arranged on the parallel circuit, and when power is supplied to the outside, the anode and the cathode of the battery pack are respectively charged and discharged.

Each battery module comprises a power battery, a diode and a switch, wherein the anode of the power battery is connected with the anode of the diode, the cathode leading-out terminal of the diode is used as the anode of the battery module, the anode of the battery module is connected with the anode of a battery pack formed by parallel connection, and the switches are connected in parallel at the two ends of the diode. And the negative lead-out terminal of the battery module is connected with the negative electrode of the battery pack.

This application is directly parallelly connected back then draws positive negative pole and carries out energy storage and power supply difference in original battery module together, has increased switch and diode, utilizes switch and diode to realize the control of charge-discharge to solve the parallelly connected defect that the battery parameter among the prior art discordance caused, its principle as follows:

when the battery pack formed by parallel connection is discharged, the control switches K1, K2 and … … Kn are disconnected, at the moment, the diodes D1, D2 and … … Dn are connected in each branch in series, and when the voltage difference between the branches in the battery pack is smaller than the conduction voltage drop of the diodes, the branches are simultaneously discharged to the load; the voltage of the branch circuit with small capacity is reduced rapidly in the discharging process, when the voltage difference between the branch circuit and other branch circuits is larger than the conduction voltage drop of the diode, the diode of the branch circuit is cut off under the action of reverse voltage, discharging is stopped, and other branch circuits continue discharging; when the voltage of other branches is reduced to the voltage difference with the branch stopping discharging along with the continuous discharging, the voltage difference is smaller than the conduction voltage drop of the diode, and the branch recovers discharging again; thus, the energy waste generated by charging the battery by the battery and the damage of the generated heat to the battery can be prevented.

When the battery pack is charged, the K1, the K2 and the Kn are controlled to be closed, the diodes D1, D2 and Dn are short-circuited and failed, the voltages of the branches are equal, the voltage of the battery pack gradually rises to a termination voltage along with the continuous charging, the charging is finished, and the K1, the K2 and the Kn are disconnected. Whether to terminate is determined by detecting the cutoff voltage of the battery. The control unit is connected with the battery management system to acquire the charge-discharge state of the battery and monitor the voltage.

By adopting the scheme, the parallel battery module utilizes the one-way conductivity of the diode when discharging, the module with the voltage lower than that of other modules can be discharged in a pause mode, and other modules can not be charged, so that the discharging safety performance of the module can be improved, the capacity loss and the heating loss between batteries can be reduced, and the use of the retired battery module is facilitated.

The control of the opening and closing of the switch can be realized by adopting one of the following two schemes or other schemes:

in one scheme, the control switch is an electric control switch such as a relay, an input control end of the relay is connected with the single chip microcomputer, and the single chip microcomputer 51 outputs a control signal to drive the relay to be opened and closed. The I/O of the 51 single chip microcomputer is connected with the keys, the control signal is output through the key signal, after the key signal is received, the 51 single chip microcomputer outputs a driving signal to drive the coil to be electrified, and then the coil attracts the contact, so that the relay is closed. Therefore, the on-off of the relay is controlled according to the charging and discharging requirements.

In another implementation scheme, the switch adopts relays, each relay corresponds to a coil, two ends of the coils are connected between the anode and the cathode of the lithium battery respectively after being connected in series with each other, then a manual switch is arranged at the anode or cathode output end of the power supply in series, so that the anode of the lithium battery reaches the cathode after passing through the serially connected relay coils and the manual switch, and then whether the relay coils are electrified or not is controlled according to the on-off of the manual switch, so as to control the on-off of the normally open contacts of the relays, the manual switch can adopt a single-pole switch or other types of manual switches, the coils are electrified and the normally open contacts are closed when the switches are closed, otherwise, the normally open contacts are opened, and therefore whether the relays are opened or not is controlled according to different charging and discharging states.

The battery pack comprises a plurality of battery modules which are connected in parallel in a gradient manner to form a high-capacity battery pack, wherein the battery pack comprises a plurality of battery modules which are connected in parallel, and diodes and relays which are connected in series by each module branch; the method has the advantages of simple structure, high reliability and low cost, does not have a control unit and a detection unit, automatically realizes balanced discharge among all branches by the characteristics of the diodes, effectively prevents the problem of mutual charging among the branches, and solves the problem of parallel operation of battery modules with poor consistency.

It is clear that the specific implementation of the invention is not restricted to the above-described embodiments, but that various insubstantial modifications of the inventive process concept and technical solutions are within the scope of protection of the invention.

Claims

1. The utility model provides a parallel control circuit that power battery module echelon utilized, includes a plurality of parallelly connected battery module each other, every the battery module include power battery, its characterized in that: each battery module further comprises a diode and a switch, the anode of the power battery is connected with the anode of the diode, the cathode leading-out terminal of the diode is used as the anode of the battery module, and the switches are connected in parallel at two ends of the diode;

the input end of the switch is connected with the control unit and is used for receiving the control of the control unit to be switched on and off;

the control unit is connected with the key module and is used for controlling the opening and closing of the electric control switch according to the key module signal;

the electric control switch comprises relays, coils of each relay are connected in series and then connected with a power supply, and a manual switch is arranged at the output end of the power supply in series;