Short-circuit current prediction device and method

Abstract

According to an embodiment of the present invention, an apparatus and method for predicting a short circuit current derives an internal equivalent circuit reflecting a short circuit state in a DC circuit, derives a first equivalent circuit taking into account the electrical characteristics of the battery, derives a second equivalent circuit taking into account the electrical characteristics of the fuse, acquires a short circuit current prediction model reflecting the first equivalent circuit and the second equivalent circuit based on the internal equivalent circuit, and predicts a short circuit current due to a battery voltage using the short circuit current prediction model, thereby reflecting both mechanical and chemical characteristics of a parallel-connected battery system, and enabling highly accurate short circuit current prediction for each battery module, rack, and system (bank) based on short circuit occurrence experimental data acquired in advance. This reduces the number of short circuit occurrence experiments to be performed when designing a battery protection device, and is used to determine the maximum number of parallel connections of batteries when developing a battery system, thereby preventing delays in development schedules.

Description

[Technical Field]

[0001] This specification claims the benefit of the filing date of Korean Patent Application No. 10-2021-0130860, filed with the Korean Intellectual Property Office on October 1, 2021, and all of the contents disclosed in the documents of said Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a short-circuit current prediction device and method, and more particularly to a short-circuit current prediction device and method for predicting in advance the magnitude of a short-circuit current that will occur in a battery system. [Background technology]

[0003] An energy storage system (ESS) is a system that connects renewable energy, batteries that store power, and existing grid power. In recent years, smart grids and renewable energy have become more widespread, and as the efficiency and stability of power systems become more important, the demand for energy storage systems is increasing to regulate power supply and demand and improve power quality. Energy storage systems vary in output and capacity depending on the purpose of use. Multiple battery systems can be connected to form a large-capacity energy storage system.

[0004] On the other hand, for sustainable ESS service, it is essential to manage the battery status.

[0005] For this reason, the ESS system requires information about the battery system, such as the battery voltage and whether the battery fuse has blown. However, since the battery system is provided as a structure in which a plurality of battery cells and various elements are connected, if charging or discharging is not performed, it is difficult to determine whether the problem is due to the battery fuse or another element. Furthermore, when predicting short-circuit current, the electrical characteristics of the battery are not taken into consideration, making it difficult to predict the magnitude of the short-circuit current that will be cut off by the fuse.

[0006] Therefore, in order to design a battery protection system, an experiment to measure the maximum short circuit current is essential, but this involves problems of high cost and high risk. Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a highly efficient and low-cost short circuit current prediction device that can check the voltage of a battery and whether a fuse has blown.

[0008] Another object of the present invention to solve the above problems is to provide a highly efficient and low-cost method for predicting short circuit current, which can check the battery voltage and whether a fuse has blown. [Means for solving the problem]

[0009] In order to achieve the above object, one embodiment of the present invention provides a short circuit current prediction device for predicting a short circuit current in a battery system including a battery and a fuse for protecting the battery, the device comprising: a memory; and a processor for executing at least one instruction in the memory, the at least one instruction including: an instruction for deriving an internal equivalent circuit of the battery that reflects a short circuit state in a DC circuit; an instruction for deriving a first equivalent circuit taking into account the electrical characteristics of the battery; an instruction for deriving a second equivalent circuit taking into account the electrical characteristics of the fuse; an instruction for acquiring a short circuit current prediction model that reflects the first equivalent circuit and the second equivalent circuit based on the internal equivalent circuit; and an instruction for predicting a short circuit current depending on a battery voltage using the short circuit current prediction model.

[0010] Here, the first equivalent circuit can include a circuit in which a first resistor and a second resistor in the battery are connected in series, and the second resistor is connected in parallel with a capacitor.

[0011] The second equivalent circuit may include a circuit in which the resistor and capacitor of the fuse are connected in series, and a switch.

[0012] Meanwhile, depending on the ON / OFF state, the switch can indicate a first state in which the conductor begins to melt due to heat generated inside the fuse before an arc occurs, or a second state in which the conductor melts due to the occurrence of an arc and current flows into the air.

[0013] Furthermore, the instruction to acquire the short circuit current prediction model can include an instruction to mathematically formulate the first equivalent circuit, an instruction to mathematically formulate the second equivalent circuit, and an instruction to reflect the mathematically formulated first equivalent circuit and second equivalent circuit in the internal equivalent circuit and acquire the short circuit current prediction model according to the first state or the second state using short circuit occurrence experimental data.

[0014] In this case, the internal equivalent circuit may include an internal resistance and an internal inductor of the battery based on an RL circuit.

[0015] Furthermore, the short circuit current prediction model in the first state may include mechanical characteristics of the battery in a transient state, and the short circuit current prediction model in the second state may include mechanical characteristics of the battery in a transient state and chemical characteristics of the battery in a stationary state.

[0016] In order to achieve the above object, according to another embodiment of the present invention, a short circuit current prediction method for predicting a short circuit current in a battery system including a battery and a fuse for protecting the battery includes the steps of: deriving an internal equivalent circuit of the battery that reflects a short circuit state in a DC circuit; deriving a first equivalent circuit taking into account electrical characteristics of the battery; deriving a second equivalent circuit taking into account electrical characteristics of the fuse; acquiring a short circuit current prediction model that reflects the first equivalent circuit and the second equivalent circuit based on the internal equivalent circuit; and predicting the short circuit current depending on the battery voltage using the short circuit current prediction model.

[0017] Here, the first equivalent circuit can include a circuit in which a first resistor and a second resistor in the battery are connected in series, and the second resistor is connected in parallel with a capacitor.

[0018] The second equivalent circuit may include a circuit in which the resistor and capacitor of the fuse are connected in series, and a switch.

[0019] Furthermore, depending on the ON / OFF state, the switch can indicate a first state in which the conductor begins to melt due to heat generated inside the fuse before an arc occurs, or a second state in which the conductor melts due to the generation of an arc and current flows into the air.

[0020] On the other hand, the step of acquiring the short circuit current prediction model may include a step of mathematically formulating the first equivalent circuit, a step of mathematically formulating the second equivalent circuit, and a step of reflecting the mathematically formulated first equivalent circuit and second equivalent circuit in the internal equivalent circuit and acquiring the short circuit current prediction model according to the first state or the second state using short circuit occurrence experimental data.

[0021] In this case, the internal equivalent circuit may include an internal resistance and an internal inductor of the battery based on an RL circuit.

[0022] Furthermore, the short circuit current prediction model in the first state may include mechanical characteristics of the battery in a transient state, and the short circuit current prediction model in the second state may include mechanical characteristics of the battery in a transient state and chemical characteristics of the battery in a stationary state. [Effects of the Invention]

[0023] The short circuit current prediction device and method according to the embodiment of the present invention derive an internal equivalent circuit that reflects a short circuit state in a DC circuit, derive a first equivalent circuit that takes into account the electrical characteristics of the battery, derive a second equivalent circuit that takes into account the electrical characteristics of the fuse, obtain a short circuit current prediction model that reflects the first equivalent circuit and the second equivalent circuit based on the internal equivalent circuit, and predicts the short circuit current according to the battery voltage using the short circuit current prediction model, thereby reflecting both the mechanical and chemical characteristics of a parallel-connected battery system and enabling highly accurate short circuit current prediction for each battery module, rack, and system (bank) based on short circuit occurrence experimental data obtained in advance. This reduces the number of short circuit occurrence experiments to be performed when designing a battery protection device, and is used to determine the maximum number of parallel-connected batteries when developing a battery system, thereby preventing delays in development schedules. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a circuit diagram of a battery short circuit fault. [Figure 2] FIG. 1 is a flow chart showing a design process for a conventional battery protection device. [Figure 3] 1 is a block diagram of a short-circuit current prediction device according to an embodiment of the present invention. [Figure 4] 1 is an equivalent model circuit diagram of a battery system in a short-circuit state according to an embodiment of the present invention; [Figure 5] FIG. 2 is a flow chart of a short-circuit current prediction method according to an embodiment of the present invention. [Figure 6]1 is an internal equivalent circuit diagram of a short-circuit current prediction device according to an embodiment of the present invention. [Figure 7] 10 is a graph showing voltage-current characteristics in an internal equivalent circuit under switch control according to an embodiment of the present invention. [Figure 8] FIG. 1 is a first equivalent circuit diagram reflecting the electrical characteristics of a battery according to an embodiment of the present invention. [Figure 9] FIG. 2 is a second equivalent circuit diagram reflecting the electrical characteristics of a fuse in a battery protection device according to an embodiment of the present invention. [Figure 10] 4 is a voltage-current graph of a first equivalent circuit according to the state of a battery according to an embodiment of the present invention. [Figure 11] 10 is a graph showing voltage-current characteristics in a second equivalent circuit under switch control according to an embodiment of the present invention. [Figure 12] 4 is a graph showing voltage-current changes according to a short-circuit state of a fuse according to an embodiment of the present invention; [Figure 13] FIG. 4 is a flow chart for calculating parameter values of a short-circuit current prediction model according to an embodiment of the present invention. [Figure 14] 10 is a graph showing a short circuit test in which changes in voltage and current of a battery are measured depending on the state of a fuse according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, it should be understood that this is not intended to limit the present invention to the specific embodiments, but rather to include all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention. Similar reference numerals are used to refer to similar components throughout the various drawings.

[0026] Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by these terms. These terms are used only to distinguish one component from another. For example, a first component can be designated as a second component, and similarly, a second component can be designated as a first component, without departing from the scope of the present invention. The term "and / or" includes a combination of multiple associated listed items or any item among multiple associated listed items.

[0027] When a component is said to be "coupled" or "connected" to another component, it is understood that the component may be directly coupled or connected to the other component, but that there may be other components in between. In contrast, when a component is said to be "directly coupled" or "directly connected" to another component, it is understood that there are no other components in between.

[0028] The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly indicates otherwise. It should be understood that the terms "comprise" or "have" and the like are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and do not preclude the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this invention belongs. Terms as defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted as idealized or overly formal unless explicitly defined herein.

[0030] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0031] FIG. 1 is a circuit diagram of a battery short circuit fault.

[0032] 1, a conventional battery protection device may be a device that protects a battery from short-circuit current by controlling the on / off operation of a fuse when a short circuit occurs. Here, the short circuit may be an accident in which the positive and negative electrodes of a battery are connected to each other, causing an overcurrent to flow.

[0033] Generally, when calculating the short-circuit current, conventional battery protection devices only consider the basic RL equivalent circuit, in which a basic resistor (R) and an inductor (L) are connected in series, to predict the maximum short-circuit current in a transient state.

[0034] In other words, conventional battery protection devices do not take into account the electrical characteristics of the battery when calculating the short-circuit current in a battery system, nor do they take into account the short-circuit current that is interrupted by a fuse. As a result, conventional battery protection devices have the problem of large errors occurring when calculating the maximum short-circuit current, which can damage the battery and reduce reliability.

[0035] Therefore, in the past, before designing a battery protection device, a large number of short-circuit generation experiments were separately conducted to calculate the maximum short-circuit current that can be interrupted by controlling the operation of the fuse.

[0036] FIG. 2 is a flow chart showing the design process of a conventional battery protection device.

[0037] Referring to FIG. 2, the conventional battery protection device predicts the maximum short circuit current based on the magnitude of the short circuit current calculated through the basic RL equivalent circuit, checks the short circuit occurrence experiment data previously conducted for the predicted maximum short circuit current value (S100), checks whether a short circuit occurs due to the short circuit current value, and determines the maximum short circuit current value (S200).

[0038] On the other hand, if there is no experimental data previously conducted for the predicted maximum short circuit current value, the user conducts a short circuit generation experiment for the assumed maximum short circuit current (S300) to confirm whether the short circuit current is one that can be controlled by the fuse, and determines the maximum short circuit current value based on the experimental result value and reflects it in the conventional battery protection device.

[0039] However, conventional battery protection design methods require a large number of experiments to calculate the optimum short-circuit current value, which is time-consuming and expensive.

[0040] Therefore, this invention provides an equivalent circuit model that takes into account the electrical characteristics of a battery, internal circuit characteristics, and the electrical characteristics of a fuse in a battery protection unit (BPU), and predicts short-circuit current values with high accuracy, thereby reducing the number of short-circuit occurrence experiments to be performed when designing a battery protection unit, and preventing delays in development schedules by being used to determine the maximum number of batteries connected in parallel when developing a battery system.

[0041] FIG. 3 is a block diagram of a short-circuit current prediction device according to an embodiment of the present invention.

[0042] Referring to FIG. 3, the short circuit current prediction device according to the embodiment of the present invention can predict in advance the magnitude of the short circuit current that will occur in the battery system depending on the magnitude of the battery voltage, as described above.

[0043] For example, the short circuit current prediction device can be used when designing a battery protection device in an energy serving system (ESS) to prevent short circuit accidents occurring in the battery system in the energy storage system in advance.

[0044] More specifically, the short circuit current prediction device predicts the short circuit current value for each configuration in a battery system in which at least one battery rack or module is connected in series and parallel through simulation, and can be used when applying a maximum short circuit current value for controlling the operation of the fuse of the battery protection device.

[0045] To explain the short circuit current prediction device according to an embodiment of the present invention in more detail, the short circuit current prediction device may further include a memory 1000 for storing at least one instruction, a processor 2000 for executing at least one instruction from the memory, a transceiver 3000, an input interface device 4000, an output interface device 5000, and a storage device 6000.

[0046] According to the embodiment, the components 1000, 2000, 3000, 4000, and 5000 included in the short circuit current prediction device are connected by a bus 7000 and can communicate with each other.

[0047] The memory 1000 and the storage device 6000 in the above-described configurations 1000, 2000, 3000, 4000, 5000, and 6000 of the short circuit current prediction device may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 1000 and the storage device 6000 may be configured with at least one of a read only memory (ROM) and a random access memory (RAM).

[0048] The memory 1000 may contain at least one instruction that is executed by the processor 2000, which will be described below.

[0049] According to an embodiment, the at least one instruction may include an instruction to derive an internal equivalent circuit of the battery that reflects a short-circuit state in a DC circuit, an instruction to derive a first equivalent circuit taking into account the electrical characteristics of the battery, an instruction to derive a second equivalent circuit taking into account the electrical characteristics of the fuse, an instruction to obtain a short-circuit current prediction model that reflects the first equivalent circuit and the second equivalent circuit based on the internal equivalent circuit, and an instruction to predict the short-circuit current due to the battery voltage using the short-circuit current prediction model.

[0050] The processor 2000 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the methods according to the embodiments of the present invention are performed.

[0051] The processor 2000 is capable of executing at least one program command stored in the memory 100, as described above.

[0052] The short circuit current prediction device according to the embodiment of the present invention has been described above.

[0053] Hereinafter, the short circuit current prediction method executed by the processor in the short circuit current prediction device according to the embodiment of the present invention will be described in more detail with reference to FIG.

[0054] FIG. 4 is an equivalent model circuit diagram of a battery system in a short-circuit state according to an embodiment of the present invention.

[0055] Referring to FIG. 4, a processor 2000 in the short circuit current prediction device can obtain an equivalent circuit representing the electrical characteristics of the battery system and predict the short circuit current in the battery system.

[0056] According to the embodiment, the short circuit current prediction device according to the present invention can acquire a short circuit current prediction model that reflects internal circuit characteristics, battery electrical characteristics, and fuse electrical characteristics based on an RL series circuit that reflects the characteristics of a short circuit state in a DC circuit. As a result, the short circuit current prediction device can predict the value of the short circuit current in the battery system using the acquired short circuit current prediction model.

[0057] FIG. 5 below provides a more detailed step-by-step explanation of the operation of processor 2000.

[0058] FIG. 5 is a flow diagram of a short-circuit current prediction method according to an embodiment of the present invention.

[0059] Referring to Figures 4 and 5, the processor 2000 can obtain a short circuit current prediction model in a battery system based on an RL series circuit that indicates the characteristics of a short circuit state in a DC circuit, taking into account the internal circuit characteristics of the battery, the electrical characteristics of the battery, and the electrical characteristics of the fuse in the battery protection unit (BPU).

[0060] The processor 2000 may then predict the magnitude of the short circuit current that will be generated by a particular voltage magnitude based on the obtained short circuit current prediction model.

[0061] More specifically, the operation of the processor 2000 can be explained by the processor 2000 obtaining an internal equivalent circuit of the battery from an RL series circuit that reflects the characteristics of a short circuit state in a DC circuit (S1000). The step of obtaining the internal equivalent circuit will be described in more detail below.

[0062] FIG. 6 is an internal equivalent circuit diagram of the short circuit current prediction device according to the embodiment of the present invention.

[0063] Referring to FIG. 6, the internal equivalent circuit applied to the short circuit current prediction device may include an RL series circuit.

[0064] More specifically, the internal equivalent circuit of the battery system may be a circuit that represents the electrical characteristics within the battery system based on an RL series circuit that efficiently represents the characteristics of a short circuit state in a DC circuit. For example, the internal equivalent circuit may be configured in a form in which a voltage (OCV), a resistance (R), an inductor (L), and a switch (S) are connected in series. Here, the voltage may be the open circuit voltage (OCV), and the resistance (R) may be the internal resistance (R ic ), the inductor (L) is the internal inductance (L ic ) values can be shown.

[0065] Here, the RL circuit applied to the short circuit current prediction device may be the same as the circuit used in the conventional battery protection device to obtain the maximum short circuit current.

[0066] For example, in the internal equivalent circuit, the battery resistance (R i ) and the maximum current value (I max ) can be determined. Also, the inductor (L) can characterize the maximum current that can flow in the circuit.

[0067] FIG. 7 is a graph showing voltage-current characteristics in an internal equivalent circuit under switch control according to an embodiment of the present invention.

[0068] Referring to FIG. 7, when the internal equivalent circuit is open, in other words, when the switch is in the OFF state, the voltage in the internal equivalent circuit is kept constant and no current flows.

[0069] On the other hand, when the internal equivalent circuit is closed, in other words, when the switch is on, the voltage in the internal equivalent circuit is reduced to 0 by the resistance, allowing current to flow. Here, the maximum current value (I max ) can be expressed as follows:

[0070]

number

[0071] FIG. 8 is a first equivalent circuit diagram reflecting the electrical characteristics of the battery according to the embodiment of the present invention.

[0072] Referring to FIG. 8, the processor 2000 can obtain a first equivalent circuit that reflects the electrical characteristics of the battery in the battery system (S2000).

[0073] More specifically, the first equivalent circuit includes a first resistance (R i ) and a second resistor (R d ) and capacitor (C d ) can be connected to a circuit in which a second resistor (R d ) and capacitor (C d ) can be connected in parallel with a first resistor (R i ) in series. This allows the first equivalent circuit to reflect the mechanical and chemical characteristics of the battery in the battery system.

[0074] 5, the processor 2000 may obtain a second equivalent circuit that takes into account the electrical characteristics of the fuse in the battery protection device (S3000). The method for obtaining the second equivalent circuit will be described in more detail below with reference to FIG. 9.

[0075] FIG. 9 is a second equivalent circuit diagram reflecting the electrical characteristics of the fuse in the battery protection device according to the embodiment of the present invention.

[0076] Referring to FIG. 9, the processor 2000 can obtain a second equivalent circuit that reflects the electrical characteristics of the fuse in the battery protection device of the battery system.

[0077] Generally, in a battery system, voltage and current characteristics change based on the occurrence of a short circuit due to an arc, and thus, a fuse may change state from a first state (melting) to a second state (clearing) based on the occurrence of a short circuit.

[0078] Here, the first state may be a state before an arc occurs in which the conductor begins to melt due to heat generated inside the fuse, and the second state may be a state in which an arc occurs, melts the conductor, and causes current to flow into the air.

[0079] Therefore, the processor 2000 in the short circuit current prediction device according to an embodiment of the present invention can obtain a second equivalent circuit for generating a state transition depending on the switch position in order to embody the fuse melting characteristics.

[0080] More specifically, the second equivalent circuit is a resistor (R arc ) and capacitor (C arc ) and a switch connected in series. In this case, the second equivalent circuit may include a circuit in which a capacitor (C arc ) and resistance (R arc ) components can be designed to be reflected or not reflected in the circuit.

[0081] Referring again to FIG. 5, the processor 2000 may acquire a short-circuit current prediction model based on the acquired internal equivalent circuit, the first equivalent circuit, and the second equivalent circuit (S4000).

[0082] More specifically, the processor 2000 may mathematically formulate the first equivalent circuit (S4100). A method for formulating the first equivalent circuit will be described in more detail with reference to FIG.

[0083] FIG. 10 is a voltage-current graph of the first equivalent circuit according to the state of the battery according to an embodiment of the present invention.

[0084] Referring to FIG. 10, in the first equivalent circuit, when a change occurs in the battery voltage, the capacitor (C d ) allows current to flow.

[0085] According to one embodiment, when the battery is in a transient state, the voltage of the battery is measured across a first resistor (R i ) in the first equivalent circuit. d ) may behave as if it is conducting in a transient state. In other words, when the battery is in a transient state, the first equivalent circuit has a first resistor (R i ) components may be considered.

[0086]

number

[0087]

number

[0088] As a result, the processor 2000 in the short circuit current prediction device according to the embodiment of the present invention may obtain a first equation reflecting both physical and chemical characteristics of the battery in a transient state and a steady state, as shown in Equation 4 below. In other words, the first equation may reflect electrical characteristics of not only the series-connected battery cells but also the parallel-connected battery modules, battery racks, and battery systems. Here, CCV may be a closed circuit voltage, and the battery modules and battery systems may be referred to interchangeably as a battery pack and a battery bank, respectively.

[0089]

number

[0090] FIG. 11 is a graph showing voltage-current characteristics in a second equivalent circuit under switch control according to an embodiment of the present invention.

[0091] Referring to FIG. 11, as described above, in the second equivalent circuit, the state of the fuse can be transitioned depending on the state of the switch.

[0092] FIG. 12 is a graph showing voltage-current changes according to a short-circuit state of a fuse according to an embodiment of the present invention.

[0093] 11 and 12, in the second equivalent circuit according to one embodiment, when the switch is in the circled state 1, the first state (Melting) may be reflected.

[0094] More specifically, in the first state, the capacitor (C arc ) and resistance (R arc ) The components are not reflected, so no voltage is applied and current can flow.

[0095] In a second equivalent circuit according to another embodiment, when the switch is in the circled state 2, the second state (Clearing) may be reflected.

[0096] More specifically, in the second state, the capacitor (C arc ) charges are accumulated and the current decreases. arc When the accumulation of the second equivalent circuit is completed, the second equivalent circuit can be opened.

[0097] At this time, in the second equivalent circuit, the back electromotive force (V peak Here, the back electromotive force can be generated by the inductance component in the second equivalent circuit as shown in the following Equation 5.

[0098]

number

[0099] 5, processor 2000 may acquire a short circuit current prediction model to be provided in the first mode or the second mode depending on the state of the fuse when a short circuit occurs by reflecting the mathematically formulated first equivalent circuit and second equivalent circuit in an internal equivalent circuit (S4500). Here, the short circuit current prediction model may be a model that mathematically expresses values of short circuit voltage and short circuit current generated in the battery system depending on the state of the fuse when a short circuit occurs.

[0100] To explain in more detail how to obtain the short circuit current prediction model, the processor 2000 may combine the internal equivalent circuit, the mathematically formulated first equivalent circuit, and the second equivalent circuit according to the short circuit state of the fuse.

[0101] According to one embodiment, the processor 2000 can acquire a short circuit current prediction model for the first mode based on the internal equivalent circuit by reflecting the internal equivalent circuit in a mathematical formula of a first equivalent circuit that reflects the electrical characteristics of the battery in a transient state and a mathematical formula of a second equivalent circuit that reflects the electrical characteristics of the fuse in a first state (melting).

[0102] The short circuit current prediction model in the first mode can be expressed as Equation 6 below.

[0103]

number

[0104] The short circuit current prediction model in the second mode can be expressed as Equation 7 below.

[0105]

number

[0106] The method for calculating the parameter values of the short circuit current prediction model is described in more detail below with reference to FIG.

[0107] FIG. 13 is a flowchart for calculating parameter values of a short-circuit current prediction model according to an embodiment of the present invention.

[0108] Referring to FIG. 13, the processor 2000 may apply parameter values, except for the inductance (L), in the short circuit current prediction model using previously acquired short circuit occurrence experimental data (S5100).

[0109] FIG. 14 is a graph showing a short circuit occurrence experiment in which changes in voltage-current of a battery are measured depending on the state of the fuse, according to an embodiment of the present invention.

[0110] 13 and 14, the short circuit occurrence experiment data may be data obtained by previously simulating a short circuit current in a battery system according to the state of a fuse.

[0111] The processor 2000 calculates the total inductance (L total ), the values of parameters such as voltage, resistance and capacitance can be obtained and applied to the short circuit current prediction model.

[0112] Thereafter, the processor 2000 may extract the value of the inductance (L), which is the remaining unknown, from the short circuit current prediction model to which the parameter values have been applied (S5300). For example, the inductance (L) may be calculated using curve fitting from the characteristic curve of the short circuit current in section A shown in FIG. 12. Here, the inductance (L) may be calculated by using the inductance (L) inside the battery. ic ) and external inductance (L ec ) and the total inductance (L total ) value.

[0113] More specifically, in the case of a battery system, the value of the inductance (L) may have a dominant effect due to the high frequency component at the beginning. Therefore, the processor 2000 calculates the short circuit voltage (V) which changes depending on the ratio of the inductances (L) as shown in the following Equations 8 and 9. sc ) characteristics, the internal inductance (L ic) can be calculated (S5500), where the external inductance is given through experimentation.

[0114]

number

[0115]

number

[0116]

number

[0117] The processor 2000 then calculates the remaining unknown in the short circuit current prediction model, the capacitor (C arc For example, the processor 2000 may use curve fitting to extract the value of the capacitor (C arc ) value can be extracted.

[0118] In short, the processor 2000 can calculate all of the constituent parameters of the short circuit current prediction model in the first mode or the second mode based on the short circuit occurrence experimental data acquired in advance, thereby enabling accurate prediction of the short circuit current that reflects both the electrical characteristics of the battery and the electrical characteristics of the fuse within the battery system.

[0119] The above describes the short circuit current prediction apparatus and method according to the embodiment of the present invention.

[0120] The short circuit current prediction device and method according to the embodiment of the present invention derive an internal equivalent circuit that reflects a short circuit state in a DC circuit, derive a first equivalent circuit that takes into account the electrical characteristics of the battery, derive a second equivalent circuit that takes into account the electrical characteristics of the fuse, obtain a short circuit current prediction model that reflects the first equivalent circuit and the second equivalent circuit based on the internal equivalent circuit, and predicts the short circuit current according to the battery voltage using the short circuit current prediction model, thereby reflecting both the mechanical and chemical characteristics of a parallel-connected battery system and enabling highly accurate short circuit current prediction for each battery module, rack, and system (bank) based on previously obtained short circuit occurrence experimental data. This reduces the number of short circuit occurrence experiments to be performed when designing a battery protection device, and can be used to determine the maximum number of parallel-connected batteries when developing a battery system, thereby preventing delays in development schedules.

[0121] Some aspects of the invention have been described in the context of an apparatus, but they may also be described in terms of a corresponding method, where a block or apparatus corresponds to a method step or feature of a method step. Similarly, aspects described in the context of a method may be described in terms of a corresponding block or item or feature of a corresponding apparatus. Some or all of the method steps may be performed by (or using) a hardware apparatus, such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most important method steps may be performed by such an apparatus.

[0122] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that various modifications and variations of the present invention can be made without departing from the spirit and scope of the present invention as set forth in the following claims. [Explanation of symbols]

[0123] 1000 memory 2000 processor 3000 Transmitter / Receiver 4000 Input Interface Device 5000 Output Interface Device 6000 storage device 7000 Bus

Claims

1. 1. An apparatus for predicting short circuit current in a battery system including a battery and a fuse for protecting the battery, comprising: memory, and a processor for executing at least one instruction in the memory; The at least one instruction: an instruction to derive an internal equivalent circuit that represents the characteristics of the battery system in a short-circuit state using an RL series circuit; instructions for deriving a first equivalent circuit that reflects an electrical characteristic of the battery, the first equivalent circuit including a circuit in which a first resistor and a second resistor are connected in series, and the second resistor is connected in parallel with a first capacitor; instructions for deriving a second equivalent circuit that reflects an electrical characteristic of the fuse, the second equivalent circuit comprising: a circuit corresponding to an equivalent circuit of the fuse in a state where an arc occurs, the fuse melts, and a current flows in the air, the circuit including a third resistor and a second capacitor connected in series; a switch for controlling whether or not the second capacitor and the third resistor are reflected in the short circuit current prediction model of the battery system; Including, instructions, instructions for obtaining the short circuit current prediction model by combining the internal equivalent circuit, the first equivalent circuit, and the second equivalent circuit; and A command to predict a short circuit current depending on a battery voltage using the short circuit current prediction model. A short circuit current prediction device comprising:

2. The switch, depending on the ON / OFF state, A first state in which the conductor begins to melt due to heat generated inside the fuse before an arc occurs; or The second state is when an arc occurs, melting the conductor and causing current to flow into the air.

2. The short circuit current prediction device according to claim 1, wherein:

3. The instruction to obtain the short circuit current prediction model includes: instructions for formulating the first equivalent circuit; instructions for formulating the second equivalent circuit; and 3. The short-circuit current prediction device according to claim 2, further comprising instructions for combining the mathematically formulated first equivalent circuit, the second equivalent circuit, and the internal equivalent circuit, and for acquiring the short-circuit current prediction model corresponding to the first state or the second state using short-circuit occurrence experimental data.

4. 1. A method for predicting short circuit current in a battery system including a battery and a fuse for protecting the battery, comprising: deriving an internal equivalent circuit that represents the characteristics of the battery system in a short-circuit state using an RL series circuit; a step of deriving a first equivalent circuit that reflects the electrical characteristics of the battery, the first equivalent circuit including a circuit in which a first resistor and a second resistor are connected in series and the second resistor is connected in parallel with a first capacitor; Deriving a second equivalent circuit that reflects an electrical characteristic of the fuse, the second equivalent circuit comprising: a circuit corresponding to an equivalent circuit of the fuse in a state where an arc occurs, the fuse melts, and a current flows in the air, the circuit including a third resistor and a second capacitor connected in series; a switch for controlling whether or not the second capacitor and the third resistor are reflected in a short circuit current prediction model of the battery system; obtaining the short circuit current prediction model by combining the internal equivalent circuit, the first equivalent circuit, and the second equivalent circuit; and A short-circuit current prediction method comprising the step of predicting a short-circuit current due to a battery voltage using the short-circuit current prediction model.

5. The switch, depending on the ON / OFF state, A first state in which the conductor begins to melt due to heat generated inside the fuse before an arc occurs; or 5. The short circuit current prediction method according to claim 4, wherein the second state is indicated by an arc occurring, causing the conductor to melt and current to flow into the air.

6. The step of obtaining the short circuit current prediction model includes: formulating the first equivalent circuit; formulating the second equivalent circuit; and 6. The short-circuit current prediction method according to claim 5, further comprising a step of combining the mathematically formulated first equivalent circuit, the second equivalent circuit, and the internal equivalent circuit, and acquiring the short-circuit current prediction model corresponding to the first state or the second state using short-circuit occurrence experimental data.

7. A computer program comprising instructions for causing a computer to carry out the short circuit current prediction method according to any one of claims 4 to 6.

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