Battery module balancing device

Abstract

The present invention relates to a system (1) which enables the gas formed in the module located in the electric vehicle battery packs to be discharged without spreading into the pack.

Description

[0001] DESCRIPTION

[0002] BATTERY MODULE BALANCING DEVICE

[0003] Technical Field

[0004] The present invention relates to a device which is used for state of charge (SoC) and voltage balancing between old and new modules after replacement of modules in electric vehicle batteries.

[0005] Background of the Invention

[0006] Electric vehicles (EVs) have gained widespread acceptance as an environmentally friendly alternative to conventional internal combustion engine vehicles. The core component of EVs is the battery pack, which usually consists of multiple modules connected in series and parallel configurations. However, during the use of EVs, defects in the electrochemical structure of the cells in some modules or manufacturing defects during module production can cause situations that can directly affect vehicle performance and safety, such as capacity loss and internal resistance change in the battery pack. For this reason, in order to increase battery efficiency and performance, the modules in which such and similar conditions are detected are replaced in the services. After this replacement process, an imbalance is observed between the battery modules due to different SoC and SoH (state of health) values. This situation leads to a decrease in vehicle and overall battery performance, limited range and short battery life.

[0007] For this reason, there is a need for a new device which will improve the overall performance, efficiency and lifetime of the EV battery pack by eliminating the problem of imbalance between repaired or replaced modules and other modules inside the battery pack. Module, cell or battery balancing is a process that regulates the differences in capacity, voltage or internal resistance between cells in battery packs formed by bringing together several cells or modules. These imbalances can be caused by cells aging differently or by small differences in manufacturing processes. Balancing is important to improve the performance, extend the life and ensure the safety of the battery.

[0008] Various methods and techniques have been developed for module, cell or battery balancing. These methods can vary depending on the battery type, use case and application area. Some common balancing methods are: 1. Passive Balancing: Passive balancing enables energy to be balanced by using series or parallel resistors or circuit elements in which battery cells or modules are connected to each other. Passive balancing can have the advantages of cost effectiveness and simple design but can be slow and inefficient. 2. Active balancing: Active balancing manages energy transfer by using a balancing control system. Active balancing can be faster and more effective than passive balancing as it can better control the energy transfer between the cell or module. 3. History -Based Balancing: This method makes balancing decisions by using the previous imbalance data of the battery. History-based balancing can help optimize the balancing process, but its ability to react to changing operating conditions may be limited. 4. Model-Based Balancing: This uses mathematical models in order to predict imbalances between battery cells or modules and to develop balancing strategies based on the model. This method can improve efficiency and optimize energy management. 5. Distributed Balancing: This method uses a built-in balancing mechanism in each cell or module and does not need a central balancing control unit. In this way, the complexity and cost of the system can be reduced.

[0009] In the current technique, with the continuous advancement in battery technologies, significant developments are also taking place in the field of module, cell or battery balancing. Current research focuses on more efficient and safer balancing techniques. New algorithms, control strategies and hardware solutions are developing systems that can correct battery imbalances more quickly and precisely and can optimize battery performance and lifetime. Especially in applications with high energy density, such as electric vehicles, battery imbalance can affect vehicle range, acceleration performance and safety. Therefore, research on balancing techniques contributes to making electric vehicles more competitive and user-friendly. Consequently, research and development in the field of module, cell or battery balancing is an important area supporting the advancement of battery technologies and the more widespread use of electric vehicles. Balancing methods are constantly being optimized in order to improve the performance, lifetime and safety of batteries.

[0010] The Chinese patent document no. CN108199445A, an application included in the state of the art, relates to an energy transfer active balancing system for series battery pack. The invention consists of a series battery pack, electronic switch network, battery voltage collection module, control module and bidirectional DC- DC module. The electronic switch network consists of electronic switches connected to the positive and negative poles of each battery in the series battery pack. These switches can be switched on and off by the control module and each battery can be individually selected. The electronic switch network is connected to the battery voltage collection module and the bidirectional DC-DC module. The control module decides which battery is balanced by assessing the state of each battery. The control module detects the input and output currents of the bidirectional DC-DC module and adjusts them according to the balancing requirements. Simultaneously, the control module enables each battery in the battery pack to be evenly discharged or charged via the bidirectional DC-DC module in order to charge low-voltage or low-energy batteries and discharge high- voltage or high-energy batteries by monitoring the status of each battery. The control module measures the voltages of the batteries connected to the battery voltage collection module by switching on the electronic switches KI and K2. These voltages represent the voltage values of all batteries from Bl to Bn and calculate the dynamic internal resistance of each battery. The SOC value of the battery that deviates the most from the control module is calculated by analyzing the measured voltages. The SOC value of the battery is compared with the average SOC value of the series battery pack and if the maximum deviation is greater than a certain threshold value, the balancing process is started by discharging the battery or if the maximum deviation is less than the threshold value, the charging process is started. In order to reduce the voltage of the specified battery, the electronic switches are turned off and the balancing current and balancing time are dynamically adjusted according to the voltage and internal resistance of a specific battery by bidirectional DC-DC module. When the balancing period is over, the control module switches off the balancing process of the bidirectional DC-DC module and then the electronic switches are switched off and repeated continuously, keeping the voltages of the batteries at an optimal level.

[0011] Summary of the Invention

[0012] An object of the present invention is to realize a device which is used for state of charge (SoC) and voltage balancing between old and new modules after replacement of modules in electric vehicle batteries.

[0013] Detailed Description of the Invention

[0014] “Battery Module Balancing Device” realized to fulfil the objective of the present invention is shown in the figure attached, in which:

[0015] Figure l is a general view of the inventive device.

[0016] Figure 2 is another view of the inventive device.

[0017] Figure 3 is a view showing the inventive device connected to the battery module. The components illustrated in the figure are individually numbered, where the numbers refer to the following:

[0018] 1. Device

[0019] 2. Bottom cover

[0020] 3. Top cover

[0021] 4. Module connection cable

[0022] 5. Positive pole isolated connection

[0023] 6. Charge LED

[0024] 7. Discharge LED

[0025] 8. Balance LED

[0026] 9. On / off switch

[0027] 10. Fuse

[0028] 11. Negative pole isolated connection

[0029] 12. Negative terminal internal connection bolt

[0030] 13. Negative terminal connection bolt

[0031] 14. Positive terminal internal connection bolt

[0032] 15. Positive terminal connection bolt

[0033] M: Battery module

[0034] The inventive device (1) which is used for state of charge (SoC) and voltage balancing between old and new modules after replacement of modules in electric vehicle batteries comprises; at least one bottom cover (2) which has an open box-shaped structure on one surface and acts as a protective cover for the elements placed therein; at least one top cover (3) which has an open box-shaped structure on one surface, the open surface of which is joined together with the open surface of the bottom cover (2) and enables the elements therein to be protected; at least one module connection cable (4) which extends inside the chamber formed by joining the bottom cover (2) and the top cover (3), enables connection to be established with the battery module (M) and forms the connection required for charge / voltage balancing with other battery modules in the module (M); at least one positive pole isolated connection (5) which is located on the top cover (3) on the input side of the module connection cable (4) and has a plastic injection molded busbar housing protected against possible short circuits; at least one charge LED (6) which is located on the top cover (3) and is an indicator indicating that the charge of the module (M) is lower than that of other battery modules in connection and is being charged by other modules when charge / voltage balancing is performed on the module (M); at least one discharge LED (7) which is located on the top cover (3) and is an indicator indicating that the charge of the module (M) is higher than that of the other battery modules in connection and that the charge is transferred to the other modules when charge / voltage balancing is performed on the module (M); at least one balance LED (8) which is an indicator located on the top cover (3) and indicates that the charging and discharging processes are finished in the process of charge / voltage balancing of the module; at least one on / off switch (9) which is located on the top cover (3) and enables the connected battery module (M) to start and stop charge / voltage balancing from other battery modules; at least one fuse (10) which is located on the top cover (3) and is used for protecting the whole structure against possible short circuits or incorrect connections; at least one negative pole isolated connection (11) which is located on the top cover (3) on the opposite side of the input of the module connection cable (4) and has a plastic injection molded busbar housing protected against possible short circuits; at least one negative terminal internal connection bolt (12) which is placed on the negative pole isolated connection (11) and provides the internal connection of the bottom cover (3) and the top cover (4) at least one negative terminal connection bolt (13) which is located next to the negative pole isolated connection (11) and is used for establishing connection with the battery module (M); at least one positive terminal internal connection bolt (14) which is placed on the positive pole isolated connection (5) and provides the internal connection of the bottom cover (3) and the top cover (4); and at least one positive terminal connection bolt (15) which is located next to the positive pole isolated connection (5) and is used for establishing connection with the battery module (M).

[0035] The module connection cable (4) included in the inventive device (1) is configured to enable the battery module (M) to which charge / voltage balancing is desired to be performed to be connected to the DC link line to which other module groups in the battery are connected. The module connection cable (4) is configured to provide the connection to be established for the charging / discharging of the balanced battery module (M) by other battery modules.

[0036] Industrial Application of the Invention

[0037] The inventive device (1) is placed on the battery module (M) by using the negative terminal connection bolt (13) and the positive terminal connection bolt (15) by first removing the busbar connections of the battery module (M) to be balanced. Then, the module connection cable (4) is connected to the DC link line to which the other battery module groups are connected together. Then, the device (1) is enabled to operate in balancing mode by turning the on / off switch (8) on the device (1) to the active position. According to the situation, modules with low charge status are charged by modules with high charge status. When the charge LED (5) on the device (1) is on, it indicates that the module voltage has a lower charge level than the other modules in the system, and when the discharge LED (6) is on, it indicates that the module voltage is higher than the other modules and is trying to reach a balance by being discharged. When the balancing process is completed and the current value enters the +-5mA value range, the system stops balancing and the stopping of balancing is indicated by the balance LED (8) turning on.

[0038] Within these basic concepts; it is possible to develop various embodiments of the inventive “Battery Module Balancing Device (1)”; the invention cannot be limited to examples disclosed herein and it is essentially according to claims.

Claims

CLAIMS1. A device (1) which is used for state of charge (SoC) and voltage balancing between old and new modules after replacement of modules in electric vehicle batteries characterized by at least one bottom cover (2) which has an open box-shaped structure on one surface and acts as a protective cover for the elements placed therein; at least one top cover (3) which has an open box-shaped structure on one surface, the open surface of which is joined together with the open surface of the bottom cover (2) and enables the elements therein to be protected; at least one module connection cable (4) which extends inside the chamber formed by joining the bottom cover (2) and the top cover (3), enables connection to be established with the battery module (M) and forms the connection required for charge / voltage balancing with other battery modules in the module (M); at least one positive pole isolated connection (5) which is located on the top cover (3) on the input side of the module connection cable (4) and has a plastic injection molded busbar housing protected against possible short circuits; at least one charge LED (6) which is located on the top cover (3) and is an indicator indicating that the charge of the module (M) is lower than that of other battery modules in connection and is being charged by other modules when charge / voltage balancing is performed on the module (M); at least one discharge LED (7) which is located on the top cover (3) and is an indicator indicating that the charge of the module (M) is higher than that of the other battery modules in connection and that the charge is transferred to the other modules when charge / voltage balancing is performed on the module (M); at least one balance LED (8) which is an indicator located on the top cover (3) and indicates that the charging and discharging processes are finished in the process of charge / voltage balancing of the module;at least one on / off switch (9) which is located on the top cover (3) and enables the connected battery module (M) to start and stop charge / voltage balancing from other battery modules; at least one fuse (10) which is located on the top cover (3) and is used for protecting the whole structure against possible short circuits or incorrect connections; at least one negative pole isolated connection (11) which is located on the top cover (3) on the opposite side of the input of the module connection cable (4) and has a plastic injection molded busbar housing protected against possible short circuits; at least one negative terminal internal connection bolt (12) which is placed on the negative pole isolated connection (11) and provides the internal connection of the bottom cover (3) and the top cover (4) at least one negative terminal connection bolt (13) which is located next to the negative pole isolated connection (11) and is used for establishing connection with the battery module (M); at least one positive terminal internal connection bolt (14) which is placed on the positive pole isolated connection (5) and provides the internal connection of the bottom cover (3) and the top cover (4); and at least one positive terminal connection bolt (15) which is located next to the positive pole isolated connection (5) and is used for establishing connection with the battery module (M).

2. A device (1) according to Claim 1; characterized by the module connection cable (4) which is configured to enable the battery module (M) to which charge / voltage balancing is desired to be performed to be connected to the DC link line to which other module groups in the battery are connected.

3. A device (1) according to Claim 1 or 2; characterized by the module connection cable (4) which is configured to provide the connection to beestablished for the charging / discharging of the balanced battery module (M) by other battery modules.

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