Current estimation device

Abstract

Provided is a current estimation device that can suppress the failure of heat generation protection of a protection target part. The current estimation device includes a current sensor that detects a current of an electrical storage module and a processor. If a current flowing from a junction box to a heater, an indoor socket, or the like is set as an additional current, the processor performs a calculation process of calculating an energization current estimation value estimated as a current flowing into the junction box, from an additional current estimation value estimated as the additional current corresponding to a control state of a vehicle and a current detected by the current sensor.

Description

Technical Field

[0001] This invention relates to a current estimation device. Background Technology

[0002] Japanese Patent Application Publication No. 2023-152422 (Patent Document 1) discloses a battery system that calculates a current accumulation value by accumulating the current detected by a current sensor over a predetermined period, and sets a current limit value for heat protection of energized parts based on the current accumulation value.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-152422 Summary of the Invention

[0004] In the aforementioned Patent Document 1, overheat protection is based on the detection value of a current sensor. However, sometimes due to current shunting, the actual current flowing into the protected component is greater than the detected value. In this case, there is a possibility that the overheat protection of the protected component may not be effective.

[0005] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a current estimation device that can suppress the failure of the protection against overheating of the protected part.

[0006] One aspect of the present invention relates to a current estimation device that estimates the current flowing into energized parts of a vehicle equipped with an energy storage device. The current estimation device includes: a current sensor that detects input and output currents for an energy storage module included in the energy storage device; and a control unit. The vehicle includes electrical equipment electrically connected to the energy storage module. The energized parts are electrically connected to both the energy storage module and the electrical equipment. If the current flowing from the energized parts to the electrical equipment is defined as an additional current, the control unit performs the following calculation process: acquiring additional current information representing an estimated additional current value corresponding to the control state of the vehicle; and calculating an estimated current value as the current flowing into the energized parts based on the input / output currents detected by the current sensor and the additional current information.

[0007] Based on this structure, in addition to the current flowing into the current sensor, the additional current flowing from the energized component to the electrical equipment is also considered when calculating the estimated current. Therefore, compared to the case where only the current flowing into the current sensor is considered, the underestimation of the current flowing into the energized component can be suppressed. As a result, the heating of the energized component, which is the part to be protected, can be suppressed.

[0008] In its calculations, the control unit can set the maximum value among the absolute values ​​of the input and output currents, the absolute value of the difference between the input and output currents and the estimated additional current, as the energizing current estimate. Based on this structure, when the input and output currents are negative (when charging the energy storage module), the absolute value of the difference can be set as the energizing current estimate; and when the input and output currents are positive (when the energy storage module is discharging), the larger of the absolute values ​​of the input and output currents or the estimated additional current can be set as the energizing current estimate. Therefore, with this configuration, the energizing current estimate can be easily changed to an appropriate value to accommodate changes in the polarity of the input and output currents.

[0009] The current estimation device may include a storage unit that stores a mapping representing the relationship between the input / output current and the estimated additional current for each control state. The control unit uses the mapping stored in the storage unit corresponding to the control state to obtain information about the estimated additional current corresponding to the input / output current. With this structure, the estimated additional current information can be easily obtained by using the mapping. Furthermore, since the estimated additional current information can be obtained without adding current sensors, the number of parts in the current estimation device can be reduced, and the structure of the current estimation device can be simplified.

[0010] The control states can include AC charging state, DC charging state, DC power supply state, and driving state. The energized component can be a junction box disposed in the energy storage device. The mapping can include a first mapping corresponding to the AC charging state, a second mapping corresponding to the DC charging state, a third mapping corresponding to the DC power supply state, and a fourth mapping corresponding to the driving state. According to this structure, information on the estimated additional current flowing from the junction box can be easily obtained using the first to fourth mappings in the AC charging state, DC charging state, DC power supply state, and driving state, respectively.

[0011] When the input / output current is less than a negative threshold, the control unit can set the absolute value of the input / output current as the estimated current value without performing calculations. This structure reduces the processing load on the control unit by eliminating calculations when the input / output current is less than the negative threshold.

[0012] Invention Effects

[0013] According to the present invention, the protection against overheating of the protected part is not feasible. Attached Figure Description

[0014] Figure 1 This is a diagram showing the structure of a vehicle equipped with the current estimation device based on this embodiment.

[0015] Figure 2(A) is a diagram representing the AC charging state (driving state) and the IB current > 0. Figure 2 (B) is a diagram representing the AC charging state (driving state) and the IB current > 0.

[0016] Figure 3 (A) is a diagram representing the DC charging state and the state where IB current > 0. Figure 3 (B) is a diagram representing the DC charging state and the state where IB current < 0.

[0017] Figure 4 (A) is a diagram representing the state where DC power supply is applied and IB current is greater than 0. Figure 4 (B) is a diagram representing the state where DC power supply is applied and IB current < 0.

[0018] Figure 5 This diagram illustrates an example of a mapping stored in memory according to this embodiment.

[0019] Figure 6 This is a flowchart illustrating the control of the current estimation device based on this embodiment. Detailed Implementation

[0020] The embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same or equivalent parts are labeled with the same symbols, and their descriptions will not be repeated.

[0021] Figure 1 This is a schematic diagram showing the structure of a vehicle 200 equipped with the current estimation device 100 according to this embodiment.

[0022] The current estimation device 100 includes an ECU 10, a current sensor 20, and a temperature sensor 21. The ECU 10 has the function of estimating the current flowing in the vehicle 200. The ECU 10 acquires (receives) information from the current sensor 20, which detects the current. The ECU 10 acquires (receives) information from the temperature sensor 21, which detects the temperature.

[0023] The ECU 10 includes a processor 11 and a memory 12. The memory 12 is configured to store information. In addition to the program, the memory 12 also stores information used in the program (e.g., mappings, formulas, and various parameters). In this embodiment, various processes based on the ECU 10 are performed by executing the program stored in the memory 12 by the processor 11. However, these processes can also be performed using only hardware (electronic circuitry) without using software. Furthermore, the processor 11 and the memory 12 are examples of the "control unit" and "storage unit" of the present invention, respectively.

[0024] The current sensor 20 is included in the battery pack 30, which will be described later. The current sensor 20 detects the input and output current (hereinafter referred to as the current IB) for the energy storage module 32 (described later) included in the battery pack 30.

[0025] Temperature sensor 21 detects the temperature of the energy storage module 32 (described later). For example, temperature sensor 21 can send the average temperature of the multiple energy storage cells contained in the energy storage module 32 as the temperature of the energy storage module 32 to ECU 10.

[0026] The vehicle 200 is configured to perform AC charging, DC charging, and DC power supply. Specifically, the vehicle 200 includes a DC charging port 201 for DC charging and DC power supply, and an AC charging port 202 for AC charging. Furthermore, the DC charging port 201 and the AC charging port 202 are examples of the "electrical equipment" of this invention.

[0027] The vehicle 200 also includes a battery pack 30, a heater 40, an interior socket 50, an electrically heated converter (EHC) 60, an air conditioner (A / C) 70, a DC-DC converter 80, and a boost converter 90. The heater 40, interior socket 50, EHC 60, air conditioner 70, DC-DC converter 80, and boost converter 90 are examples of the "electrical equipment" of the present invention. Furthermore, the battery pack 30 is an example of the "energy storage device" of the present invention.

[0028] The battery pack 30 includes a junction box 31, a power storage module 32, a DC connector 33, an HVH (High Voltage Heater) connector 34, and a PN connector 35. Additionally, the junction box 31 is an example of a "power-conducting component" of this invention.

[0029] The heater 40 is provided, for example, to heat the refrigerant (e.g., water) that exchanges heat with the battery pack 30 (energy storage module 32). The energy storage module 32 heats up by exchanging heat between the heated refrigerant and the battery pack 30 (energy storage module 32).

[0030] The DC charging port 201, heater 40, AC charging port 202, indoor socket 50, EHC 60, air conditioner 70, DC-DC converter 80 and boost converter 90 are each electrically connected to the energy storage module 32 and junction box 31.

[0031] Specifically, the DC charging port 201 is electrically connected to the current wiring 31a inside the junction box 31 via the DC connector 33. The current wiring 31a is electrically connected to the energy storage module 32.

[0032] The heater 40 is electrically connected to the current wiring 31a via the HVH connector 34.

[0033] AC charging port 202, indoor socket 50, EHC 60, air conditioner 70, DC-DC converter 80, and boost converter 90 are each electrically connected to current wiring 31a via PN connector 35. Furthermore, the current flowing into current wiring 31a will be described below as the current flowing into junction box 31.

[0034] Hereinafter, the current flowing through DC connector 33 will be recorded as DC current, the current flowing through HVH connector 34 will be recorded as HVH current, and the current flowing through PN connector 35 will be recorded as PN current.

[0035] In the past, overheat protection was based on the detection value of a current sensor. However, sometimes, due to current shunting or other reasons, the actual current flowing into the protected component is greater than the detected value. In such cases, there is a possibility that the overheat protection for the protected component may fail.

[0036] Therefore, in this embodiment, the following calculation process is performed: based on the detection value detected by the current sensor 20 (hereinafter referred to as current IB) and the current flowing from the junction box 31 to various devices (various devices other than the battery pack 30) (hereinafter referred to as additional current), an estimated current value for the current flowing into the junction box 31 is calculated. Furthermore, current IB is an example of the "input / output current" of this invention.

[0037] Here, Figures 2-4 The direction of the DC current, HVH current, and PN current in each figure (the direction of the arrows) indicates the direction in which the absolute value of the estimated current under each control state of the vehicle 200 is the largest. Furthermore, in this embodiment, the current IB when the energy storage module 32 is discharging is assumed to be positive, and the current IB when the energy storage module 32 is charging is assumed to be negative.

[0038] Figure 2 This indicates the AC charging status or driving status. Figure 2 (A) indicates that the IB current is positive (i.e., the energy storage module 32 is discharging). Figure 2 (B) indicates that the IB current is negative (i.e., the energy storage module 32 is charging).

[0039] exist Figure 2 Under the control state shown in (A), when the HVH current flows out of junction box 31 and the PN current flows into junction box 31, the absolute value of the estimated energizing current becomes the maximum. In this case, the maximum value of the absolute value of the estimated energizing current becomes the maximum value of the absolute value of the HVH current.

[0040] exist Figure 2Under the control state shown in (B), when the HVH current flows out of junction box 31 and the PN current flows into junction box 31, the absolute value of the estimated energizing current becomes the maximum. In this case, the maximum value of the absolute value of the estimated energizing current becomes the maximum value of the sum of the absolute values ​​of the HVH current and the IB current.

[0041] exist Figure 2 (A) and Figure 2 In (B), the PN current flows into the junction box 31 because the charging power from the AC charging port 202 and the regenerative power during driving flow into the junction box 31 (battery pack 30) via the PN connector 35.

[0042] Figure 3 This indicates the state of DC charging. Specifically, Figure 3 (A) indicates the case where the IB current is positive. Figure 3 (B) indicates the case where the IB current is negative.

[0043] exist Figure 3 Under control state (A), when the HVH current and PN current flow out of junction box 31 and the DC current flows into junction box 31, the absolute value of the estimated energizing current becomes the maximum. In this case, the maximum value of the absolute value of the estimated energizing current becomes the maximum value of the sum of the absolute values ​​of the HVH current and the PN current.

[0044] exist Figure 3 Under control state (B), when the HVH current, PN current, and IB current flow out of junction box 31 and the DC current flows into junction box 31, the absolute value of the estimated energizing current becomes the maximum. In this case, the maximum value of the absolute value of the estimated energizing current becomes the maximum value of the sum of the absolute values ​​of the IB current, the absolute values ​​of the HVH current, and the absolute values ​​of the PN current.

[0045] Figure 4 This indicates the state of DC power supply. Specifically, Figure 4 (A) indicates the case where the IB current is positive. Figure 4 (B) indicates the case where the IB current is negative.

[0046] exist Figure 4 Under control state (A), with both HVH current and DC current flowing out of junction box 31, the absolute value of the estimated energizing current becomes maximum. In this case, the maximum value of the absolute value of the estimated energizing current can be the maximum value of the sum of the absolute values ​​of the HVH current and the DC current.

[0047] In addition, Figure 4In case (A), the HVH current and DC current are the currents shunted from the current IB. Therefore, when the current IB, which is attenuated due to heat and other factors in the junction box 31, is shunted as the HVH current and DC current, the maximum value of the absolute value of the estimated current becomes the absolute value of the current IB.

[0048] exist Figure 4 Under control state (B), when the HVH current, DC current, and IB current flow out of junction box 31, the absolute value of the estimated energizing current becomes the maximum. In this case, the maximum value of the absolute value of the estimated energizing current becomes the maximum value of the sum of the absolute values ​​of the HVH current, DC current, and IB current.

[0049] exist Figure 4 (A) and Figure 4 (B) In all diagrams, the PN current flowing from junction box 31 was not anticipated because the use of indoor socket 50 or air conditioner 70 in DC power supply was not anticipated. Furthermore, in Figure 4 (B) Under control conditions, the HVH current, DC current and IB current can be, for example, currents generated by a current branch from a generator driven by an engine.

[0050] Figure 5 This indicates that the memory 12 stored in ECU10 ( Figure 1 Multiple mappings in ) . For example Figure 5 As shown, the mapping is set separately for AC charging state, driving state, DC charging state, and DC power supply state. Furthermore, in each control state, a separate mapping is set for each temperature band of the energy storage module 32. In each mapping, the current IB is correlated with the estimated additional current. Additionally, in... Figure 5 In this document, the estimated additional current is recorded as "**" instead of a specific value. Furthermore, the mappings corresponding to AC charging state, DC charging state, DC power supply state, and driving state are examples of the "first mapping", "second mapping", "third mapping", and "fourth mapping" of this invention.

[0051] The estimated additional current refers to the value of the estimated additional current for each control state of the vehicle 200, assuming that the absolute value of the estimated current is at its maximum.

[0052] Therefore, in Figure 2 In case (A), the estimated additional current becomes the maximum absolute value of the HVH current. Figure 2 In case (B), the estimated additional current is the sum of the absolute values ​​of the HVH current and the IB current, which is the absolute value of the HVH current in the maximum case. Figure 3In (A), the estimated additional current is the maximum of the sum of the absolute values ​​of the HVH current and the absolute values ​​of the PN current. Figure 3 (B) represents the sum of the absolute values ​​of the IB current, HVH current, and PN current, which is the sum of the absolute values ​​of the HVH current and PN current when the sum is at its maximum. Figure 4 In (A), the estimated additional current is the maximum sum of the absolute values ​​of the HVH current and the DC current. Figure 4 (B) represents the sum of the absolute values ​​of the HVH current, DC current, and IB current, which is the sum of the absolute values ​​of the HVH current and DC current under the maximum condition.

[0053] exist Figure 5 The example shown illustrates the mapping of additional current estimates for current IB values ​​of -50, -30, -10, 10, 30, and 50. Furthermore, the mapping is not limited to... Figure 5 The example shown. For instance, as mentioned above, the interval (difference) between adjacent currents IB in the mapping does not have to be 20; the interval between currents IB can be 1. Furthermore, the mapping can also be separated for the cases where current IB is positive and negative.

[0054] In addition, the estimated additional current shown in the mapping is a value derived in advance during the manufacturing of ECU10.

[0055] (Control flow of the current estimation device)

[0056] Figure 6 This is a flowchart representing the control of the current estimation device 100 (processor 11). Figure 6 The flowchart shown can be executed at specified intervals (e.g., 10 minutes).

[0057] In step S1, processor 11 acquires current IB information from current sensor 20. In step S2, processor 11 determines whether the current IB acquired in step S1 is less than threshold A. Threshold A is a negative value. If the current IB is less than threshold A (yes in S2), the process proceeds to step S3. If the current IB is greater than threshold A (no in S2), the process proceeds to step S4.

[0058] In step S3, the processor 11 sets the absolute value of the estimated current flowing into the junction box 31 as the current IB obtained in step S1. Then, the process proceeds to step S8.

[0059] In step S4, the processor 11 determines the control state of the vehicle 200. For example, the processor 11 determines the control state as AC charging, DC charging, DC power supply, or driving based on signals from other ECUs or external devices (such as charging brackets) mounted on the vehicle 200. Other ECUs may include plug ECUs that detect the status of DC charging port 201 and AC charging port 202, and ECUs that control the engine.

[0060] In step S5, processor 11 obtains information about the estimated additional current. Specifically, processor 11 uses a mapping corresponding to the control state determined in step S4. Figure 5 The system obtains information on the additional current estimate corresponding to the current IB obtained in step S1. Alternatively, if the value of the current IB obtained in step S1 is not included in the mapping, the additional current estimate corresponding to the current IB can be calculated, for example, by linear interpolation.

[0061] In step S6, processor 11 calculates the difference between the current IB obtained in step S1 and the additional current estimate obtained in step S5.

[0062] In step S7, the processor 11 sets the absolute value of the current estimate to the absolute value of the current IB, the absolute value of the difference (current IB - additional current estimate) calculated in step S6, and the maximum value among the additional current estimates.

[0063] Furthermore, in step S7, when the IB current is negative (the energy storage module 32 is charging), the absolute value of the aforementioned difference becomes the maximum. When the IB current is positive (the energy storage module 32 is discharging), the absolute value of the current IB or the absolute value of the estimated additional current becomes the maximum. Additionally, the case where the absolute value of the current IB is greater than the absolute value of the estimated additional current can be considered, for example, in the following situations: Figure 4 As described in (A), the discharge current from the energy storage module 32 becomes an additional current after it is attenuated in the junction box 31 due to heat or other factors.

[0064] In step S8, the processor 11 determines whether the heat generated based on the absolute value of the determined estimated current is greater than a threshold B. For example, the processor 11 determines whether the product of the internal resistance within the junction box 31 and the square of the absolute value of the determined estimated current is greater than the threshold B. If the heat generated is greater than the threshold B (yes in S8), the process proceeds to step S9. If the heat generated is less than the threshold B (no in S8), the process ends. Alternatively, the absolute value of the estimated current can be compared with a predetermined threshold instead of the heat generated with the threshold B.

[0065] In step S9, the processor 11 executes prescribed exception handling procedures. For example, the processor 11 executes a process to reduce the additional current. Specifically, the processor 11 may execute processes to reduce the set value of the heater 40, reduce the power consumption of the indoor socket 50, EHC 60, air conditioner 70, DC-DC converter 80, and boost converter 90, etc. Furthermore, the processor 11 may execute processes to reduce the AC charging power (current) or DC charging (power supply) power (current). Furthermore, the processor 11 may stop both AC charging and DC charging (power supply). Furthermore, the processor 11 may send a notification to a user terminal (e.g., a smartphone) or car navigation device to prompt the vehicle 200 to stop while it is in motion. Then, the process ends.

[0066] As described above, in this embodiment, the processor 11 performs the following calculation: acquiring additional current information corresponding to the control state of the vehicle 200, and calculating the estimated energizing current of the junction box 31 based on the current IB detected by the current sensor 20 and the additional current information. Therefore, compared to the case where overheat protection is based solely on the estimated energizing current IB flowing into the junction box 31, overheat protection based on a more accurate energizing current can be implemented. As a result, overheat protection in the junction box 31 can be appropriately implemented. Consequently, overheat protection of the junction box 31 can be prevented from failing.

[0067] Furthermore, in this embodiment, during the calculation process, the processor 11 sets the absolute value of the current IB, the absolute value of the difference obtained by subtracting the additional current estimate from the current IB, and the maximum value of the additional current estimate as the absolute value of the energized current estimate. Therefore, without changing the process of calculating the energized current estimate based on the control state of the vehicle 200 or the sign of the current IB, the energized current estimate can be easily calculated simply by taking the maximum value of the above three values.

[0068] Furthermore, in this embodiment, when the current IB is less than the negative threshold A, the processor 11 does not perform calculation processing but sets the absolute value of the current IB as the estimated current. Here, when the current IB is less than the threshold A, the difference obtained by subtracting the estimated current from the current IB sometimes becomes too small. In this case, the heat generated based on the difference becomes excessive, and therefore it is considered that excessive abnormal response processing will be performed. Therefore, by configuring it as in this embodiment, excessive execution of abnormal response processing can be suppressed.

[0069] (Modified Example)

[0070] In the above embodiment, an example was shown where the maximum value among the absolute value of the current IB, the absolute value of the difference obtained by subtracting the additional current estimate from the current IB, and the additional current estimate was set as the energizing current estimate; however, the present invention is not limited to this. For example, the larger value among the absolute value of the difference and the additional current estimate can be set as the energizing current estimate. Furthermore, when the current IB is negative (the energy storage module 32 is charging), the energizing current estimate can be set as the absolute value of the difference obtained by subtracting the additional current estimate from the current IB. Furthermore, when the current IB is positive (the energy storage module 32 is discharging), the energizing current estimate can be set as the larger value among the absolute value of the current IB and the additional current estimate.

[0071] In the above embodiments, an example of using mapping to obtain information on the estimated additional current is shown, but the invention is not limited thereto. For example, the processor 11 can calculate the estimated additional current based on the control state of the vehicle 200, the current IB detected by the current sensor 20, and the temperature detected by the temperature sensor 21.

[0072] In the above embodiments, an example is shown where mappings are set separately for AC charging state, driving state, DC charging state, and DC power supply state, but the present invention is not limited thereto. For example, the mapping corresponding to the AC charging state and the mapping corresponding to the driving state can be the same.

[0073] In the above embodiment, an example was shown where, when the current IB is less than the threshold A, the absolute value of the estimated current is determined as the current IB without performing the above calculation process. However, the present invention is not limited thereto. The above calculation process can be performed even when the current IB is less than the threshold A.

[0074] In the above embodiment, an example is shown of calculating the estimated current flowing into the junction box 31, but the present invention is not limited thereto. The estimated current flowing into energized components other than the junction box can also be calculated.

[0075] In the above embodiment, an example of the current estimation device 100 being mounted on a vehicle 200 is shown, but the present invention is not limited thereto. The current estimation device may be mounted on electrical equipment other than a vehicle (e.g., a stationary energy storage device).

[0076] In the above embodiment, an example is shown where the detection value (current IB) of the current sensor 20 is positive when the energy storage module 32 is discharging and negative when the energy storage module 32 is charging; however, the present invention is not limited thereto. It is also possible for the detection value of the current sensor to be negative when the energy storage module 32 is discharging and positive when the energy storage module 32 is charging. In this case, the absolute value of the estimated current can be the absolute value of the current sensor detection value, the sum of the current sensor detection value and the estimated additional current, or the maximum value among the estimated additional current.

[0077] In the above embodiments, an example is shown where the estimated additional current is the value of the estimated additional current when the absolute value of the estimated energized current is at its maximum; however, the present invention is not limited thereto. The estimated additional current can also be the value of the estimated additional current when the absolute value of the estimated energized current is not at its maximum (when it becomes a value smaller than the maximum value).

[0078] The structures of the above-described embodiments and variations can be combined with each other.

[0079] It is understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the invention is defined by the claims rather than by the description of the above embodiments, and is intended to include all modifications within the equivalent meaning and scope of the claims.

[0080] Symbol Explanation

[0081] 11-Processor (Control Unit), 12-Memory (Storage Unit), 20-Current Sensor, 30-Battery Pack (Energy Storage Device), 31-Junction Box (Electrified Component), 40-Heater (Electrical Equipment), 50-Indoor Socket (Electrical Equipment), 60-EHC (Electrical Equipment), 70-Air Conditioner (Electrical Equipment), 80-DC-DC Converter (Electrical Equipment), 90-Boost Converter (Electrical Equipment), 100-Current Estimation Device, 200-Vehicle, 201-DC Charging Port (Electrical Equipment), 202-AC Charging Port (Electrical Equipment).

Claims

1. A current estimation device for estimating the current flowing into an energized component of a vehicle equipped with an energy storage device, the current estimation device being characterized by comprising: A current sensor that detects the input and output current for the energy storage modules included in the energy storage device; and Control Department The vehicle includes electrical equipment electrically connected to the energy storage module. The energized component is electrically connected to the energy storage module and the electrical equipment. If the current flowing from the energized component to the electrical equipment is set as the additional current, the control unit performs the following calculation: Acquire additional current information representing an estimated additional current value corresponding to the control state of the vehicle; and The estimated current is calculated as the current flowing into the energized component based on the input / output current detected by the current sensor and the additional current information.

2. The current estimation device according to claim 1, characterized in that, In the calculation process, the control unit sets the absolute value of the input and output current, the absolute value of the difference obtained by subtracting the additional current estimate from the input and output current, and the maximum value of the additional current estimate as the energizing current estimate.

3. The current estimation device according to claim 1 or 2, characterized in that, It also includes a storage unit that stores, for each of the control states, a mapping representing the relationship between the input / output current and the estimated additional current. The control unit uses the mapping stored in the storage unit corresponding to the control state to obtain information about the additional current estimate corresponding to the input and output currents.

4. The current estimation device according to claim 3, characterized in that, The control states include AC charging state, DC charging state, DC power supply state, and driving state. The energized component is a junction box disposed in the energy storage device. The mapping includes: The first mapping corresponding to the AC charging state; The second mapping corresponding to the DC charging state; The third mapping corresponding to the DC power supply state; and The fourth mapping corresponding to the driving state.

5. The current estimation device according to claim 1 or 2, characterized in that, When the input / output current is less than a negative threshold, the control unit does not perform the calculation process but sets the absolute value of the input / output current as the estimated value of the energized current.

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