Control method for a battery system, battery control device, and battery system for performing the same

Abstract

To provide a control method of a battery system capable of preventing an occurrence of a safety problem by a wrong adjustment of a critical value at the time of testing the battery system, a battery control device performing the method, and the battery system.SOLUTION: A battery control device of a battery system according to this disclosure includes a storage device for storing a safe limit range for a parameter related to at least one battery module state, and a critical value setting value for the parameter, a communication device for communicating with a test device, and a controller for operating a protection function of the battery system based on the critical value setting value, changing the critical value setting value based on a change value received from the test device when receiving a request of a change of the critical value setting value, and limiting the change of the critical value setting value when the change value deviates from the safe limit range.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for controlling a battery system, a battery control device, and a battery system that perform the method.

Background Art

[0002] An Energy Storage System (ESS) is a system that stores a large amount of electrical energy and supplies the stored electrical energy when electrical energy is needed, thereby improving energy use efficiency.

[0003] Generally, an ESS can include a battery system, a Battery Management System (BMS) that manages the battery system, such as monitoring the voltage, current, temperature, etc. of the battery system, a Power Conversion System (PCS) that performs AC-DC conversion and power distribution functions, and an Energy Management System (EMS) that integrally controls the entire ESS system, such as controlling the energy flow of the ESS and collecting and managing information related to the state of the ESS. Further, the battery system can include a plurality of battery racks that are electrically connected to each other. Each battery rack can include a plurality of battery modules that are electrically connected to each other, and each battery module can include a plurality of cells that are electrically connected to each other.

[0004] Generally, a test run is performed to check whether the ESS operates normally before the ESS is applied on site. During the test run, work is carried out to test whether the protection function of the battery system operates normally. When testing the battery system, the operator changes the critical values of parameters (such as voltage, current, temperature, etc.) that determine whether to activate the protection function arbitrarily in order to prevent damage to the battery system, and then conducts the test. In this process, if the critical values are adjusted incorrectly due to operator error or the like, safety problems such as damage to the battery system may occur because the protection function does not operate even though actual problems occur in the battery system during the test.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The technical problem to be solved by the present disclosure is to provide a control method for a battery system that can prevent safety problems caused by incorrect adjustment of critical values during testing of the battery system, and a battery control device and a battery system for performing the same.

Means for Solving the Problems

[0006] A battery control device for a battery system according to an embodiment for solving the above problems may include a storage device that stores a safety limit range for parameters related to the state of at least one battery module and a critical value setting value for the parameters, a communication device that communicates with a test device, and a controller that activates the protection function of the battery system based on the critical value setting value, changes the critical value setting value based on a change value received from the test device when a request to change the critical value setting value is received, and restricts the change of the critical value setting value when the change value exceeds the safety limit range.

[0007] When the change value exceeds the safety limit range, the controller may maintain the critical value setting value at the previous value.

[0008] When the change value exceeds the safety limit range, the controller can change the threshold value setting to a value corresponding to the safety limit range.

[0009] When the change value exceeds the safety limit range, the controller can notify the test device that the change value is not a valid value.

[0010] When receiving a request to enter the test mode from the test device, the controller changes the operating mode of the battery system to the test mode and can allow the change of the threshold value setting only while the battery system is operating in the test mode.

[0011] When the threshold value setting is changed while the battery system is operating in the test mode, the controller can control the operation of the protection function based on the changed threshold value setting.

[0012] When the connection between the battery system and the test device is interrupted or when receiving a request to end the test mode from the test device, the controller can change the operating mode of the battery system to the normal mode.

[0013] When the operating mode of the battery system is changed to the normal mode, the controller can change the threshold value setting to a default value. The default value can be a value outside the safety limit range.

[0014] The parameter can be the cell voltage, module voltage, current, or temperature of the at least one battery module. The threshold value setting can be the overvoltage threshold value, low voltage threshold value, overcurrent threshold value, or over-temperature threshold value of the at least one battery module.

[0015] When the critical value setting value is the overvoltage critical value, the default value of the overvoltage critical value may be even higher than the upper voltage limit value of the safety limit range. When the critical value setting value is the low voltage critical value, the default value of the low voltage critical value may be even lower than the lower voltage limit value of the safety limit range. When the critical value setting value is the overcurrent critical value, the default value of the overcurrent critical value may be even higher than the upper current limit value of the safety limit range. When the critical value setting value is the overtemperature critical value, the default value of the overtemperature critical value may be even higher than the upper temperature limit value of the safety limit range. The protection function may include a function of shutting off a switch connected between the at least one battery module and the load of the battery system.

[0016] A battery system according to an embodiment may include at least one battery module and a battery control device including at least one of the features described above.

[0017] A control method of a battery system according to an embodiment may include a step of receiving a request to change a critical value setting value of a parameter related to the state of at least one battery module, a step of determining whether the changed value of the critical value setting value is outside a preset safety limit range, a step of changing the critical value setting value to the changed value when the changed value is within the safety limit range, a step of restricting the change of the critical value setting value when the changed value is outside the safety limit range, and a step of controlling the operation of the protection function of the battery system based on the critical value setting value.

[0018] The restricting step may include a step of maintaining the critical value setting value at the previous value when the changed value is outside the safety limit range, or a step of changing the critical value setting value to a value corresponding to the safety limit range when the changed value is outside the safety limit range.

[0019] The control method may further include receiving a request to change to a test mode and changing an operating mode of the battery system to the test mode. The change of the threshold setting value may be allowed only while the battery system operates in the test mode.

[0020] When the connection between the battery system and the test device is interrupted or a request to end the test mode is received, the control method may further include changing the operating mode of the battery system to a normal mode, and when the operating mode of the battery system is changed to the normal mode, changing the threshold setting value to a default value. The default value may be a value outside the safety limit range.

[0021] In the control method, the parameter may be a cell voltage, a module voltage, a current, or a temperature of the at least one battery module. The threshold setting value may be an overvoltage threshold value, an undervoltage threshold value, an overcurrent threshold value, or an overtemperature threshold value of the at least one battery module.

[0022] In the control method, when the threshold setting value is the overvoltage threshold value, the default value of the overvoltage threshold value may be even higher than the voltage upper limit value of the safety limit range. When the threshold setting value is the undervoltage threshold value, the default value of the undervoltage threshold value may be even lower than the voltage lower limit value of the safety limit range. When the threshold setting value is the overcurrent threshold value, the default value of the overcurrent threshold value may be even higher than the current upper limit value of the safety limit range. When the threshold setting value is the overtemperature threshold value, the default value of the overtemperature threshold value may be even higher than the temperature upper limit value of the safety limit range.

Advantages of the Invention

[0023] According to the present disclosure, it is possible to prevent a safety problem from occurring due to an incorrect adjustment of a threshold value during a test of a battery system.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The effects, features, and realization methods of the embodiments will be described in detail with reference to the accompanying drawings below. In the drawings, the same reference numerals denote the same components, and the overlapping descriptions thereof will be omitted. However, the present invention can be realized in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided as examples so that this disclosure will be thorough and complete, and will fully convey the aspects and features of the present invention to those of ordinary skill in the art.

[0026] Therefore, processes, elements, and techniques that are considered unnecessary for those skilled in the art to fully understand the aspects and features of the present invention will not be described. In the drawings, the relative sizes of elements, layers, and regions can be exaggerated for clarity.

[0027] In the present invention, the term "and / or" includes all combinations or any combination of a plurality of items listed in relation thereto. When describing embodiments of the present invention, the use of "can do" and "can be" means "one or more embodiments of the present invention". In the present invention, singular terms can include plural forms unless otherwise indicated in the context.

[0028] In the present invention, terms including ordinal numbers such as "first", "second", "third", etc. are used to describe various components, but these components are not limited by these terms. These terms are only used for the purpose of distinguishing one component from another. For example, unless it exceeds the scope of the rights of the present invention, the second component may be named the first component, and similarly, the first component may also be named the second component.

[0029] When one component or layer in the present invention is described as "on", "connected to", or "coupled to" another component or layer, "on", "connected to", and "coupled to" all include being formed directly or through one or more other components or layers. Also, when one component or layer is described as being "between" two components or layers, it must be understood as being the only component or layer between the two components or layers, or as having one or more intervening other elements or layers.

[0030] In the present invention, electrically connecting two components can include not only the case where the two components are directly connected, but also the case where they are connected through other components between the two components. The other components can include switches, resistors, capacitors, etc. In the description of the embodiments, the expression "connect" means electrically connect when there is no expression of direct connection.

[0031] Hereinafter, a method for controlling a battery system according to an embodiment, and a battery control device and a battery system for performing the same will be described in detail with reference to the necessary drawings.

[0032] FIG. 1 is a diagram schematically showing a battery system according to an embodiment.

[0033] Referring to FIG. 1, a battery system 10 according to an embodiment may include a battery module 11, a switch 12, a measuring device 13, and a battery control device 14.

[0034] The battery module 11 may include a plurality of cells (not shown) that are electrically connected in series or in parallel with each other.

[0035] The switch 12 is located between the battery module 11 and the load 20 / charging device 30, and electrically connects the battery module 11 and the load 20 / charging device 30, or cuts off the electrical connection between the battery module 11 and the load 20 / charging device 30.

[0036] The measuring device 13 measures parameters related to the state of the battery module 11, such as the voltage (cell voltage, module voltage, etc.), current, and temperature of the battery module 11. The measuring device 13 may include a voltage detection device, a current detection device, a temperature sensor, and the like.

[0037] The battery control device 14 can perform a protection function of the battery system 10 based on measured values related to the state of the battery module 11 and these critical value setting values. The battery control device 14 communicates with the test device 40 to determine entry into the test mode, and when entering the test mode, can change the critical value setting values within a preset safety limit based on control information received from the test device 40.

[0038] The battery control device 14 may include a communication device 141, a storage device 142, and a controller 143.

[0039] The communication device 141 functions as a communication between the battery control device 14 and an external device. For example, the communication device 141 communicates with the test device 40 by CAN (Controller Area Network) communication. Also, for example, the communication device 141 can communicate with an upper controller (not shown) by CAN communication.

[0040] The storage device 142 stores information, data, etc. processed by the battery control device 14. For example, the storage device 142 stores the safety limit range of at least one parameter (such as voltage, current, temperature, etc.) related to the state of the battery module 11. Here, the safety limit range refers to the range in which the change of the critical value setting value is allowed in the test mode of the battery system 10. Also, for example, the storage device 142 can store the critical value setting value of at least one parameter related to the state of the battery module 11. Here, the critical value setting value refers to the value that serves as the criterion for determining whether to execute the protection function. The safety limit range is a fixed value and its change after initial setting is not allowed. On the contrary, the critical value setting value is a changeable value and can be changed when the battery system 10 operates in the test mode.

[0041] The controller 143 controls the overall operation of the battery control device 14.

[0042] The controller 143 can obtain the measured values of parameters related to the state of the battery module 11, such as voltage, current, temperature, etc. from the measuring device 13. The controller 143 compares the obtained measured values with the corresponding critical value setting values and determines whether to execute the protection function according to the comparison result. The protection function can include, for example, the function of opening the switch 12 to interrupt charging or discharging, the function of transmitting a warning message to a higher-level controller (not shown), etc.

[0043] For example, when the module voltage of the battery module 11 or at least one cell voltage is equal to or higher than the overvoltage critical value or equal to or lower than the undervoltage critical value, the controller 143 can open the switch 12 to cut off the charging or discharging of the battery module 11. Also, for example, when the charge and discharge current of the battery module 11 is equal to or higher than the overcurrent critical value, the controller 143 can open the switch 12 to cut off the charging or discharging of the battery module 11. Also, for example, when the temperature of the battery module 11 or at least one cell is equal to or higher than the overtemperature critical value, the controller 143 can open the switch 12 to cut off the charging or discharging of the battery module 11.

[0044] The controller 143 communicates with the test device 40 to determine the operation to the test mode. When the controller 143 receives a request to enter the test mode from the test device 40, it enters the test mode. When the connection with the test device 40 is released during the operation in the test mode or when the controller 143 receives a request to end the test mode from the test device 40, it ends the test mode and operates in the normal mode.

[0045] After entering the test mode, the controller 143 can change the threshold setting value stored in the storage device 142 based on the control information received from the test device 40. The threshold setting value stored in the storage device 142 before entering the test mode may be set as a default value. The controller 143 receives the changed value of the threshold setting value together with the request to change the threshold setting value from the test device 40, and can change the corresponding threshold setting value stored in the storage device 142 according to the received changed value. When the changed value received by the controller 143 from the test device 40 is outside the safety limit range of the corresponding parameter, the controller 143 interrupts the change of the threshold setting value and notifies the test device 40 that the changed value is not a valid value. When the changed value received by the controller 143 from the test device 40 is outside the safety limit range of the corresponding parameter, the controller 143 can also set the corresponding threshold setting value to a value corresponding to the safety limit range.

[0046] When the test mode ends, the controller 143 restores the changed threshold setting value to the default value. Here, the default value of each threshold setting value is the value actually used to determine the operation of the protection function when the battery system 10 is actually used, and the safety limit range is set so as not to deviate from this default value. For example, the default value of the overvoltage threshold may be even higher than the upper voltage limit value defined by the safety limit range. Also, for example, the default value of the undervoltage threshold may be even lower than the lower voltage limit value defined by the safety limit range. Also, for example, the default value of the overcurrent threshold may be even higher than the upper current limit value defined by the safety limit range. Also, for example, the default value of the overtemperature threshold may be even higher than the upper temperature limit value defined by the safety limit range.

[0047] The controller 143 can be composed of a processor having a circuit physically structured to execute functions represented as codes or instructions included in a program, such as a microprocessor, a microcontroller, a central processing unit (CPU), a processor core, a multiprocessor, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), etc.

[0048] The battery control device 14 described above can be integrated into a battery management system.

[0049] On the one hand, FIG. 1 illustrates an example in which the battery system 10 includes one battery module 11 and one switch 12 connected between the battery module 11 and the load 20 / charging device 30. However, the embodiments are not limited thereto. According to other embodiments, the battery system 10 may include a plurality of battery modules or may include a plurality of switches between the battery module 11 and the load 20 / charging device 30.

[0050] FIG. 2 is a diagram schematically showing a control method of a battery system according to an embodiment. The control method of FIG. 2 can be performed by the battery control device 14 of FIG. 1.

[0051] Referring to FIG. 2, when the battery control device 14 of the battery system 10 according to an embodiment is requested to operate in the test mode from the test device 40 while the battery system 10 is operating in the normal mode (S11) (S12), the battery control device 14 changes the operating mode of the battery system 10 to the test mode (S13).

[0052] When operating in the test mode, the change of the threshold setting value stored in the storage device 142 is allowed. When the battery control device 14 receives a request for changing the threshold setting value from the test device 40 (S14), the battery control device 14 determines whether the changed value received from the test device 40 is within the corresponding safety limit range (S15).

[0053] When the changed value received by the battery control device 14 is within the safety limit range, the battery control device 14 changes the threshold setting value corresponding to the received changed value (S16). When the threshold setting value is changed, the battery control device 14 can control the operation of the protection function of the battery system 10 based on the changed threshold setting value while the battery system 10 is operating in the test mode.

[0054] When the received change value of the battery control device 14 is outside the safety limit range, the battery control device 14 transmits information notifying that the change value is outside the safety limit range to the test device 40 and restricts the change of the corresponding threshold setting value (S17). For example, the battery control device 14 can maintain the previous value without changing the requested threshold setting value. Also, for example, the battery control device 14 can change the requested threshold setting value to a value corresponding to the safety limit range.

[0055] After that, when the test device 40 is separated from the battery system 10 or the battery control device 14 receives a request to end the test mode from the test device 40 and the test mode ends (S18), the battery control device 14 changes the operating mode of the battery system 10 to the normal mode (S19). The battery control device 14 also automatically restores the threshold setting value changed during the test mode to the default value before the change when the battery system 10 operates in the normal mode (S20).

[0056] FIG. 3 is a diagram schematically showing an energy storage system (ESS) to which a battery system according to an embodiment is applied.

[0057] Referring to FIG. 3, an ESS according to an embodiment may include a battery system 1, an energy management system (EMS) 2, and a power conversion system (PCS) 3.

[0058] The battery system 1 may include at least one battery bank 100. Each battery bank 100 may include a plurality of battery racks 110 that are electrically connected in series or in parallel with each other. Also, each battery rack 110 includes a plurality of battery modules 111 that are electrically connected in series or in parallel with each other, and each battery module 111 may include a plurality of battery cells (not shown) that are electrically connected in series or in parallel with each other.

[0059] The battery system 10 may include a rack BMS 120 corresponding to each battery rack 110.

[0060] The rack BMS 120 monitors the state of the corresponding battery rack 110 and controls it so that the battery system 1 operates in an optimal state. For this purpose, the rack BMS 120 can perform functions such as state (voltage, current, temperature, state of charge (SOC), state of health (SOH), etc.) monitoring, control functions (e.g., temperature control, cell balance control), and protection functions (e.g., over-discharge, over-charge, over-current prevention, etc.) for the battery cells constituting the corresponding battery rack 110.

[0061] The system BMS 130 collects the data collected by the rack BMS 120 from the rack BMS 120, and aggregates and manages the collected data. Also, when a data transfer is requested from the EMS 2, the system BMS 130 collects the data received from each rack BMS 120 and transmits it to the EMS 2.

[0062] The EMS 2 is an integrated control device that monitors and controls the power usage of the power grid and the power supply of the ESS in real time for efficient energy management of the ESS. The EMS 2 monitors the state of the entire system (battery system 10, PCS 3, etc.) constituting the ESS and controls the operation of the ESS.

[0063] The PCS 3 operates as a power conversion device that converts electrical characteristics (DC, AC, voltage, frequency, etc.) to transfer electrical energy between the battery system 10 and the power grid. Usually, in the battery system 10, electrical energy in DC form is used, and in the power grid, electrical energy in AC form is used. Therefore, the PCS 3 can transfer the electrical energy stored in the battery system 10 to the power grid through DC-AC conversion, or transfer the electrical energy supplied from the power grid to the battery system 10 through AC-DC conversion.

[0064] In addition to the power conversion and power distribution functions described above, PCS3 can further perform functions such as monitoring / control functions for controlling the electrical quality such as the active power and reactive power of the ESS and monitoring the voltage and operating state of the ESS, system connection protection functions for protecting the power system during power outages, and independent operation functions for operating the ESS by utilizing the battery system 10 even when there is no power supply.

[0065] In the ESS with the above-described structure, the battery system 1 and the battery module 111 respectively correspond to the battery system 10 and the battery module 11 described with reference to FIG. 1. Further, the battery control device 14 in FIG. 1 can be incorporated into the rack BMS 120 of the ESS. Further, the switch 12 and the measuring device 13 in FIG. 1 can be attached in the battery rack 110.

[0066] The above description of the detailed invention with reference to the drawings is merely for exemplifying the present invention, which is used solely for the purpose of explaining the present invention and is not used for limiting the meaning or the scope of the present invention described in the claims. Therefore, those skilled in the art can understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical idea of the appended claims.

Description of Reference Numerals

[0067] 1 Battery system 2 EMS 3 PCS 100 Battery bank 110 Battery rack 111 Battery module 120 Rack BMS 130 System BMS 10 Battery system 11 Battery module 12 Switch 13 Measuring device 14 Battery control device 141 Communication device 142 Storage device 143 Controller

Claims

1. A battery control device for a battery system including at least one battery module, a storage device that stores a safety limit range for a parameter related to the state of the at least one battery module and a critical value setting value for the parameter, a communication device that communicates with a test device, and a controller that activates a protection function of the battery system based on the critical value setting value, changes the critical value setting value based on a change value received from the test device when a request to change the critical value setting value is received, and restricts the change of the critical value setting value when the change value is outside the safety limit range. A battery control device.

2. The battery control device according to claim 1, wherein the controller maintains the critical value setting value at a previous value when the change value is outside the safety limit range.

3. The battery control device according to claim 1, wherein the controller changes the critical value setting value to a value corresponding to the safety limit range when the change value is outside the safety limit range.

4. The battery control device according to claim 1, wherein the controller notifies the test device that the change value is not a valid value when the change value is outside the safety limit range.

5. The battery control device according to claim 1, wherein the controller changes the operating mode of the battery system to the test mode when a request to enter the test mode is received from the test device, and allows the change of the critical value setting value only while the battery system is operating in the test mode.

6. The battery control device according to claim 5, wherein the controller controls the operation of the protection function based on the changed critical value setting value when the critical value setting value is changed while the battery system is operating in the test mode.

7. When the connection between the battery system and the test device is interrupted or the test device requests the end of the test mode, the controller changes the operating mode of the battery system to the normal mode. The battery control device according to claim 5.

8. When the operating mode of the battery system is changed to the normal mode, the controller changes the threshold setting value to the default value. The default value is a value outside the safety limit range. The battery control device according to claim 7.

9. The parameter is the cell voltage, module voltage, current, or temperature of the at least one battery module. The threshold setting value is the overvoltage threshold value, low voltage threshold value, overcurrent threshold value, or overtemperature threshold value of the at least one battery module. The battery control device according to claim 8.

10. When the threshold setting value is the overvoltage threshold value, the default value of the overvoltage threshold value is higher than the voltage upper limit value of the safety limit range. The battery control device according to claim 9.

11. When the threshold setting value is the low voltage threshold value, the default value of the low voltage threshold value is lower than the voltage lower limit value of the safety limit range. The battery control device according to claim 9.

12. When the threshold setting value is the overcurrent threshold value, the default value of the overcurrent threshold value is higher than the current upper limit value of the safety limit range. The battery control device according to claim 9.

13. When the threshold setting value is the overtemperature threshold value, the default value of the overtemperature threshold value is higher than the temperature upper limit value of the safety limit range. The battery control device according to claim 9.

14. The battery control device according to claim 1, wherein the protection function includes a function of shutting off a switch connected between the at least one battery module and a load of the battery system.

15. At least one battery module, and A battery system including the battery control device according to any one of claims 1 to 14.

16. A control method for a battery system including at least one battery module, comprising: receiving a request to change a threshold setting value of a parameter related to the state of the at least one battery module; determining whether the changed value of the threshold setting value is outside a preset safety limit range; when the changed value is within the safety limit range, changing the threshold setting value to the changed value; limiting the change of the threshold setting value when the changed value is outside the safety limit range; and controlling the operation of the protection function of the battery system based on the threshold setting value.

17. The limiting step includes: when the changed value is outside the safety limit range, maintaining the threshold setting value at the previous value, or when the changed value is outside the safety limit range, changing the threshold setting value to a value corresponding to the safety limit range. The control method according to claim 16.

18. receiving a request to change to a test mode; and further including changing the operation mode of the battery system to the test mode, wherein the change of the threshold setting value is allowed only while the battery system is operating in the test mode. The control method according to claim 16.

19. When the connection between the battery system and the test device is interrupted or a request to end the test mode is received, changing the operating mode of the battery system to the normal mode, and when the operating mode of the battery system is changed to the normal mode, further including changing the threshold setting value to a default value, The control method according to claim 18, wherein the default value is a value outside the safety limit range.

20. The parameter is the cell voltage, module voltage, current, or temperature of the at least one battery module, The threshold setting value is the overvoltage threshold, low voltage threshold, overcurrent threshold, or overtemperature threshold of the at least one battery module, When the threshold setting value is the overvoltage threshold, the default value of the overvoltage threshold is higher than the voltage upper limit value of the safety limit range, When the threshold setting value is the low voltage threshold, the default value of the low voltage threshold is lower than the voltage lower limit value of the safety limit range, When the threshold setting value is the overcurrent threshold, the default value of the overcurrent threshold is higher than the current upper limit value of the safety limit range, The control method according to claim 19, wherein when the threshold setting value is the overtemperature threshold, the default value of the overtemperature threshold is higher than the temperature upper limit value of the safety limit range.

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