CN217415495U

CN217415495U - Battery replacement system for eliminating parallel circulation

Info

Publication number: CN217415495U
Application number: CN202220214633.2U
Authority: CN
Inventors: 卫云峰; 丁大勇; 高顺
Original assignee: Wuhu Etc Battery Ltd
Current assignee: Wuhu Etc Battery Ltd
Priority date: 2022-01-26
Filing date: 2022-01-26
Publication date: 2022-09-13
Anticipated expiration: 2032-01-26

Abstract

The utility model discloses a battery replacement system for eliminating doubling circulation, which comprises a battery string formed by connecting a plurality of battery monomers in series/parallel, wherein one end of the battery string is led out of the anode/cathode of a battery module, and the other end of the battery string is led out of the cathode/anode of the battery module after passing through a normally open contact of a relay K1; a microprocessor and a parallel loop protection branch circuit are arranged in the battery module, and the parallel loop protection branch circuit is connected in parallel with two ends of a normally open contact of the relay K1; and the output end of the microprocessor is respectively connected with the parallel loop current protection branch and the control end of the relay K1. The utility model has the advantages that: the structure is simple, the control is convenient, and the damage of the circulation current to the battery and the circuit thereof can be effectively reduced; the electric quantity difference among the battery modules in the battery bins can be consumed through a simple circuit, and the current of the circulation current can be limited to play a certain protection role; the battery box is suitable for the electric vehicle with batteries in a plurality of battery bins which are connected in parallel for battery replacement.

Description

Battery replacing system for eliminating parallel circulation

Technical Field

The utility model relates to a power battery trades the electric field, in particular to eliminate trading electric battery system of doubling circulation.

Background

Lithium ion batteries are popular because of their advantages such as high cell voltage and long cycle life. With the development of new energy industry, the pursuit of consumers for the mileage and the functional configuration of new energy vehicles is higher and higher. Manufacturers accelerate the development of higher-energy cells, and increase the number of series-parallel cells on a vehicle to increase the charge capacity as much as possible. The problem that the charging is needed to be solved urgently at present is that the charging rapidity is improved while the long endurance is improved, most vehicles are high in electric quantity and adopt a large number of combined battery systems due to the requirements of the operation environments of the vehicles in the subdivision fields of electric heavy trucks and the like, and a battery replacement mode is used in a charging mode. The design scheme greatly improves the running mileage of the vehicle and also greatly shortens the charging time. But also brings the risk that circulation current may occur in the power switching process of the multi-parallel system.

Fig. 1 is a schematic diagram showing the connection between a battery and a battery compartment of an electric heavy truck after the battery is replaced in the prior art, in which a power unit includes N battery compartments, and a battery module is correspondingly installed in each battery compartment. The battery module is connected with battery packs in other battery bins through connectors in the battery bins and the like after being installed in the battery bins, communicates with the vehicle-mounted BMS through communication terminals on the connectors, and receives control signals of the BMS. As shown in fig. 1, a battery replacing module is installed in a single battery compartment, each battery replacing module is composed of a plurality of single battery cells, the plurality of single battery cells are connected in series and in parallel to form a battery pack, and then one end of each battery replacing module is connected to a positive terminal/a negative terminal of the battery module through a relay, one end of each battery replacing module is directly connected to the battery module to form a negative terminal/a positive terminal, the positive terminal and the negative terminal are respectively connected to positive and negative connectors in the battery compartment, and N battery compartments are connected in parallel to each other on a whole vehicle and controlled through a plurality of relays to provide kinetic energy for a load of the whole vehicle. Because the whole battery system is complex in series-parallel connection and high in electric quantity, the electric quantity of the whole vehicle is generally supplemented by adopting a battery replacement mode, namely when the electric quantity of the whole vehicle is low, the vehicle runs to a battery replacement station, the battery replacement station can rapidly detach the battery modules in the 1-N # battery bins and replace the fully charged battery modules to the 1-N # battery bins, the charging time of the vehicle is greatly saved, but the consistency of battery cells for replacing the battery cells in practical application cannot be completely ensured, and the situation that new and old battery cells exist among different battery bins can exist in the battery replacement process, the situation that the total voltage among the battery modules in the 1-N # battery bins is different in the battery replacement process can be caused by various situations, and the following 2 risks can be caused by the difference:

1. if the relay attracting the battery module in the battery compartment is controlled in a trade-off manner, circulation currents are inevitably generated between 1-N # battery compartments, and the battery compartment with high voltage forcibly charges the battery compartment with low voltage for balancing, so that the balancing cannot be controlled. If the voltage difference is large, the circuit is burnt by large current, and the risk of short circuit exists.

2. If the relay is not attracted, the 1-N # battery cabin cannot complete the doubling work, and the whole vehicle cannot be subjected to high pressure. The whole vehicle needs to replace the battery bin with the total voltage being too high or too low, and the operation also brings the conditions of long battery replacement period and poor customer experience.

Since there is a problem in the battery modules regardless of the parallel control due to internal problems, it is necessary to improve the battery modules for replacing the battery and the battery system thereof.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art's not enough, provide an eliminate doubling circulation trade galvanic cell system for realize trading the electric in-process and eliminate the doubling circulation, thereby reduce the circulation and produce the safety that the protection traded the electricity.

In order to realize the purpose, the utility model discloses a technical scheme be:

a battery replacement system for eliminating parallel loop current comprises a battery string formed by connecting a plurality of battery monomers in series/parallel, wherein one end of the battery string is led out of the positive electrode/negative electrode of a battery module, and the other end of the battery string is led out of the negative electrode/positive electrode of the battery module after passing through a normally open contact of a relay K1; a microprocessor and a parallel loop protection branch circuit are arranged in the battery module, and the parallel loop protection branch circuit is connected in parallel with two ends of a normally open contact of the relay K1; and the output end of the microprocessor is respectively connected with the parallel loop current protection branch and the control end of the relay K1.

The parallel loop protection branch comprises a protection branch relay and a loop resistor, and the protection branch relay is connected with the loop resistor in series and then connected to two ends of the relay K1 in parallel; and the output end of the microprocessor is connected with the control end of the protection branch relay.

And the microprocessor is connected with the vehicle-mounted BMS and is used for controlling the opening and closing of the parallel circulating current protection branch and the relay K1 according to the control command of the vehicle-mounted BMS.

The communication interface of the vehicle-mounted BMS is connected with a communication connector in the battery compartment, a battery module connector matched with the communication connector is arranged on the battery module, the communication end of the battery module connector is connected to the microprocessor, and when the battery module is installed in the battery compartment, the battery module connector is connected with the communication connector to complete the communication connection between the vehicle-mounted BMS and the microprocessor.

The utility model has the advantages that: the structure is simple, the control is convenient, and the damage of the circulation current to the battery and the circuit thereof can be effectively reduced; the electric quantity difference among the battery modules in the battery bins can be consumed through a simple circuit, and the current of the circulation current can be limited to play a certain protection role; the battery box is suitable for the electric vehicle with batteries in a plurality of battery bins which are connected in parallel for battery replacement.

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 a prior art battery replacement system;

fig. 2 is a schematic diagram of the battery replacement system of the present application.

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, for a battery replacing system in the prior art, each battery is installed in a battery compartment, when the battery needs to be replaced, a battery module is installed in the battery compartment through a device, and high-voltage output control is realized by controlling a parallel relay of each battery module, specifically: the number of the vehicle battery bins is N, the N battery modules correspond to the N battery bins respectively, the battery bins comprise 1#, 2# … N #, and the total number of the battery bins is N, corresponding n battery modules, each of which comprises a battery string and a relay for controlling the parallel connection, taking the battery module in the No. 1 battery compartment as an example, the system comprises a battery string P1 and a parallel control relay K1, wherein after the batteries are replaced, the BMS controls the relay K1 … Kn in each battery module to be closed, thereby enabling the N battery modules in the N battery bins to output high voltage after being connected in parallel to realize high voltage supply, but once the voltage or electric quantity difference occurs between the battery modules installed by replacing the battery, namely the parameters are inconsistent between the modules, when the control relay K1 … Kn is closed, the battery strings P1 … Pn are connected in parallel, and the high-power battery module charges the low-power battery module, which may cause the low-power battery module to be overcharged or damaged due to excessive current. The battery modules are improved, and the battery replacement system is improved to meet the requirement of a multi-parallel battery replacement system, so that damage and damage caused by mutual charging and discharging due to different battery consistencies are reduced or avoided.

As shown in fig. 2, which is a modified schematic diagram of the present application, each battery pack is modified, and each battery pack is the same, and is installed in a different battery compartment during battery replacement, for the purpose of differentiation, the present application uses P1 … Pn, K1 … Kn, R1 … Rn, etc. to differentiate the battery modules in different battery compartments, but each battery module is the same, and introduces the structure in the battery module by using the battery module installed in the 1# battery compartment, which includes a battery string P1 formed by connecting a plurality of battery cells in series/parallel, wherein one end of the positive electrode of the battery string leads out the positive electrode of the battery module, and the other end leads out the negative electrode of the battery module after passing through the normally open contact of the relay K1; a microprocessor, a protection branch relay K11 and a loop resistor R are arranged in the battery module, and the protection branch relay K11 and the loop resistor R1 are used for protecting the battery module; the protective branch relay K11 is connected in series with the loop resistor R1 and then connected in parallel at two ends of the relay K1; the output end of the microprocessor is connected with the control end of the protective branch relay K11. The microprocessor is used for controlling the on and off of the relay K11 and the relay K1.

The microprocessor receives the control of the vehicle-mounted BMS, and is connected with the vehicle-mounted BMS and used for controlling the opening and closing of the relay K11 and the relay K1 according to the control command of the vehicle-mounted BMS.

Because the battery changing mode is adopted, the microprocessor in the battery module is communicated with the vehicle-mounted BMS and is arranged in the battery bin in a contact or connector mode to be connected with the contact or connector on the battery module to finish communication; specifically, a communication interface of the vehicle-mounted BMS is connected with a communication connector in a battery compartment, a battery module connector matched with the communication connector is arranged on the battery module, a communication end of the battery module connector is connected to a microprocessor, and when the battery module is installed in the battery compartment, the battery module connector is connected with the communication connector to complete the communication connection between the vehicle-mounted BMS and the microprocessor.

And the microprocessor in each battery module is connected with the battery electric quantity acquisition module and is used for respectively acquiring the battery electric quantity information in the corresponding battery module. The positive and negative electrodes led out after the plurality of battery bins are connected in parallel can control the connection of the output high voltage and the load of the whole vehicle through a main positive relay.

The introduction of the structure of the battery module is completed, and when the battery is replaced, each battery module is arranged in each battery bin to form a circuit structure shown in fig. 2; before the battery replacement is finished and the high voltage is needed to be applied, the main positive relay is disconnected, so that each parallel battery module in the battery bin cannot supply power to the external high voltage; and then, carrying out sequential doubling among the N battery modules, namely respectively controlling K11 and K21 … Kn1 to be closed sequentially or according to a certain sequence, and then closing the main positive relay to realize high-voltage output after the equalization among the battery modules is finished. When K11, K21 and Kn1 are closed, K1, K2 and Kn are opened, so that each battery module is balanced in charging and discharging in a loop resistor access mode, and batteries R1, R2 and Rn can achieve the current limiting effect, so that the risk caused by overlarge circulating current is avoided, and meanwhile, the resistor R can consume part of discharging electricity to avoid the risk of overcharging. After the balance is completed, K11, K21 and Kn1 are disconnected, and then the closing of K1, K2 and Kn is controlled according to the power-on requirement, and the main positive relay is closed to complete the high-voltage power-on control. Or the following method is adopted for power-on control: the BMS rapidly detects the total pressure of the 1-N # battery bins (the voltage or the electric quantity of each battery module is obtained through a microprocessor in each battery module), and the BMS controls a protection loop relay for closing the lowest-voltage battery bin; and then the protective circuit relay of the secondary low-voltage battery compartment is closed. So that the battery packs in the two battery bins are balanced. And the secondary low-voltage battery compartment and the lowest-voltage battery compartment are subjected to doubling, the doubling is connected to loop resistors R of the two battery compartments, and the current is completely controllable. There is no risk of high current surge. After the balancing of the secondary low-voltage battery compartment and the lowest-voltage battery compartment is finished, a protection loop relay in a third low-voltage battery compartment is attracted again to carry out the balancing of the three compartments; repeating the steps until the loop protection relays in all the battery bins are closed; the parallel control among all battery modules is realized after the closing is finished, the safety of the parallel is ensured due to the existence of the resistors R1 and Rn, and then the BMS can control the K1 and K2Kn relays to be closed and control the protective circuit relays K11, K21 and Kn1 to be opened. The whole battery system finishes the doubling work by N battery bins

Compared with the prior art, the technical scheme of the patent has the following main characteristics:

n battery bins are connected in parallel on the whole vehicle and are controlled by a plurality of relays to provide kinetic energy for the load of the whole vehicle. The plurality of battery bins can be quickly installed and quickly disassembled on the whole vehicle, namely, the battery bins with low electric quantity can be quickly replaced in the battery replacing station of the whole vehicle, and the full-electric new bin is installed. Circulating currents can be suppressed by controlled balancing.

2. When the conditions that the total pressure difference of the 1-N # battery bins is too large and the batteries cannot be combined occur in the prior art, the battery bins need to be replaced again until the total pressure difference of the 1-N # battery bins reaches the limit value, but the total pressure difference of the 1-N # battery bins cannot reach the same value. This operation increases the battery change time. However, if the pressure difference is too large, the low-voltage battery compartment can be charged directly by the high-voltage battery compartment through controllable balancing without continuous bin adjustment.

It is clear that the specific implementation of the invention is not restricted to the above-described modes, and that various insubstantial modifications of the inventive concept and solution are within the scope of protection of the invention.

Claims

1. A battery replacement system for eliminating parallel loop current comprises a battery string formed by connecting a plurality of battery monomers in series/parallel, wherein one end of the battery string is led out of the positive electrode/negative electrode of a battery module, and the other end of the battery string is led out of the negative electrode/positive electrode of the battery module after passing through a normally open contact of a relay K1; the method is characterized in that: a microprocessor and a parallel loop protection branch circuit are arranged in the battery module, and the parallel loop protection branch circuit is connected in parallel with two ends of a normally open contact of the relay K1; and the output end of the microprocessor is respectively connected with the parallel loop current protection branch and the control end of the relay K1.

2. The battery replacement system for eliminating the parallel loop current as claimed in claim 1, wherein: the parallel loop protection branch circuit comprises a protection branch circuit relay and a loop resistor, and the protection branch circuit relay is connected with the loop resistor in series and then connected to two ends of the relay K1 in parallel; and the output end of the microprocessor is connected with the control end of the protection branch relay.

3. The battery replacement system for eliminating the parallel loop current as claimed in claim 1 or 2, wherein: and the microprocessor is connected with the vehicle-mounted BMS and is used for controlling the opening and closing of the parallel circulating current protection branch and the relay K1 according to the control command of the vehicle-mounted BMS.

4. The battery replacement system for eliminating the parallel loop current as claimed in claim 3, wherein: the communication interface of on-vehicle BMS is connected with the communication connector in the battery compartment, be provided with on the battery module with communication connector assorted battery module connector, the communication end of battery module connector is connected to microprocessor, and when the battery module was installed in the battery compartment, the battery module connector was connected with communication connector in order to accomplish on-vehicle BMS and microprocessor's communication connection.