Battery control device and vehicle control device

Abstract

The invention provides a battery control device and a vehicle control device. A battery control device (100) is provided with a calculation device (battery controller (101)) that calculates an internal resistance value (DCR) of a battery (300). A battery controller (101) calculates a current difference value ([Delta] I) on the basis of a first current value (I1) measured at a first time (t1) as a target measurement time, and a second current value (I2) measured at a second time (t2), which has elapsed a predetermined time from the first time (t1), as a target measurement time. A battery controller (101) calculates a voltage difference value ([delta] V) on the basis of a first voltage value (V1) measured with a predetermined time after a first time (t1) as a target measurement time, and a second current value (V2) measured with a third time (t3) as a target measurement time after the predetermined time, the third time (t3) having elapsed a predetermined time from a second time (t2). The battery controller (101) calculates an internal resistance value (DCR) of the battery (300) based on the current difference value ([delta] I) and the voltage difference value ([delta] V).

Description

Technical Field

[0001] The present invention relates to a battery control device and a vehicle control device. Background Art

[0002] Conventionally, a technique for calculating an internal resistance value of a battery in order to know the deterioration state of the battery or the like has been known (see Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2021-092403 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In the control of a battery and a vehicle, it is required to improve the reliability of the calculated internal resistance value of the battery. In order to calculate the internal resistance value of the battery, the current value and voltage value of the battery are measured. Due to measurement errors of the battery, even if there is a slight time difference, there is a case where the current value and voltage value of the battery are not measured at the same time, and the voltage value of the battery is measured relatively earlier than the current value. In this case, there is a possibility that the current value and voltage value of the battery change relatively greatly during the short time from measuring the voltage value of the battery to measuring the current value.

[0008] Means for Solving the Problems

[0009] A battery control device according to one aspect of the present invention includes a calculation device that calculates an internal resistance value of a battery. The calculation device calculates a current difference based on a first current value measured with a first moment as a target measurement moment and a second current value measured with a second moment that is a predetermined time after the first moment as a target measurement moment. The calculation device calculates a voltage difference based on a first voltage value measured with a predetermined moment after the first moment as a target measurement moment and a second current value measured with a third moment that is a predetermined time after the second moment after the predetermined moment as a target measurement moment. The calculation device calculates the internal resistance value of the battery based on the current difference and the voltage difference.

[0010] A vehicle control device according to one aspect of the present invention includes the battery control device. The vehicle control device controls a vehicle having the battery and an electrical device that operates using electric power from the battery.

[0011] Effects of the Invention

[0012] According to the present invention, the reliability of the calculated internal resistance value of the battery can be improved. Brief Description of the Drawings

[0013] Figure 1 It is a diagram showing the schematic structure of the vehicle 1 equipped with the battery control device 100 of the mounting embodiment.

[0014] Figure 2 It is a diagram showing an example of the hardware structure of the vehicle control system mounted in the vehicle 1.

[0015] Figure 3 It is a functional block diagram of the battery control device 100.

[0016] Figure 4 It is a graph showing the time change of the current value I measured by the current sensor 102, and the time change of the voltage value V measured by the voltage sensor 103, regarding the ideal (error-free state) measurement timing, and shows the deviation range of the measurement timing of the voltage value V.

[0017] Figure 5 It is a graph showing the time change of the current value I measured by the current sensor 102, and the time change of the voltage value V measured by the voltage sensor 103, regarding the measurement timing of the comparative example, and shows an example of underestimating the internal resistance.

[0018] Figure 6 It is a graph showing the time change of the current value I measured by the current sensor 102, and the time change of the voltage value V measured by the voltage sensor 103, regarding the measurement timing of the present embodiment, and shows the measurement timing of the current value I and the voltage value V.

[0019] Figure 7 It is a flowchart showing an example of the process executed by the battery controller 101.

[0020] Figure 8 It is a table showing the target measurement time, the time from a specified time to each target measurement time, and the actual measurement values (current value and voltage value).

[0021] Figure 9 It is a table showing the target measurement time, the time from a specified time to each target measurement time, and the actual measurement values (current value and voltage value), and shows an example in which the measurement period of the current value is set to 1 / 2 of the measurement period of the voltage value. Detailed Embodiment

[0022] (Structure of the Embodiment)

[0023] Regarding the structure of the battery control device 100 of the embodiment and the vehicle control device 10 having the battery control device 100, refer to Figure 1 for description.

[0024] Figure 1 FIG. 1 is a diagram showing a schematic configuration of a vehicle 1 equipped with a battery control device 100 according to an embodiment.

[0025] As Figure 1 shown, the vehicle 1 is, for example, a hybrid electric vehicle. The hybrid electric vehicle is, for example, an HEV (Hybrid Electric Vehicle) or a PHEV (Plug-in Hybrid Electric Vehicle). Among hybrid electric vehicles, there are a strong hybrid electric vehicle with an output voltage of, for example, several hundred V and a mild hybrid electric vehicle with an output voltage of, for example, 48V. The vehicle 1 may also be an EV (Electric Vehicle).

[0026] When the vehicle 1 is a hybrid electric vehicle, the vehicle 1 has a motor 600 as an electrical device for driving the vehicle 1 and an engine 700 as an internal combustion engine. The power generated in the motor 600 and the engine 700 is transmitted to the tires via a transmission mechanism. When the vehicle 1 is an EV (Electric Vehicle), the engine 700 is not provided in the vehicle 1. Accordingly, the power generated in the motor 600 is transmitted to the tires via a transmission mechanism. The motor 600 operates using the electric power (electricity) from the battery pack 20 and generates power.

[0027] The vehicle 1 includes a vehicle control device 10, a battery 300, a relay 400, a power conversion device (power converter / electric power conversion device / electric power transformation device) 500, a motor 600, and an engine 700. The vehicle control device 10 includes a battery control device 100 and a vehicle machine control device 200. The battery pack 20 includes the battery control device 100 and the battery 300. Details of the vehicle control device 10 will be described later.

[0028] The battery 300 is, for example, composed of a battery pack. The battery pack has a plurality of single cells. The plurality of secondary batteries are connected in series, in parallel, or in series and parallel by bus bars. The single cell is, for example, a secondary battery. The secondary battery is, for example, a lithium ion battery. In addition, the secondary battery may be composed of a device having a power storage function such as a nickel-metal hydride battery, a all-solid-state battery, a lead battery, and an electric double layer capacitor. In addition, the battery 300 is not limited to the case of being composed of a plurality of secondary batteries, and may be composed of one secondary battery. The battery 300 is not limited to the case of being composed of a plurality of secondary batteries, and may also be composed of a primary battery. The electric power of the battery 300 is supplied to the motor 600 via the relay 400 and the power conversion device 500.

[0029] The relay 400 is electrically connected to the battery 300 and the power conversion device 500. The relay 400 energizes the electric motor 600 from the battery 300, or cuts off the power supply from the battery 300 to the electric motor 600.

[0030] The power conversion device 500 converts the electric power between direct current (DC) and alternating current (AC) and steps up or down the voltage. The power conversion device 500 is electrically connected to the relay 400 and the electric motor 600. The power conversion device 500 includes an inverter circuit and a converter circuit.

[0031] The electric motor 600 performs a power running operation to generate a driving force and a regeneration operation to recover energy in accordance with the driving state of the vehicle 1. During the power running operation of the electric motor 600, the power conversion device 500 converts the electric power of the battery 300 from direct current to alternating current, steps up or down the voltage, and supplies it to the electric motor 600. Thus, the electric motor 600 generates power and the vehicle 1 travels. In addition, when the vehicle 1 travels using the power of the engine 700, the vehicle 1 accelerates using the power of the electric motor 600. During the regeneration operation of the electric motor 600, the power conversion device 500 converts the electric power generated by the electric motor 600 from alternating current to direct current, steps up or down the voltage, and supplies it to the battery 300. Thus, the battery 300 is charged.

[0032] The engine 700 is an example of an internal combustion engine. The engine 700 is used to drive the vehicle 1. The engine 700 serves as the power for the tires of the vehicle 1. When the vehicle 1 is an EV (Electric Vehicle), the engine 700 is not required.

[0033] The battery control device 100 and the vehicle machine control device 200 that constitute the vehicle control device 10 are each constituted by an ECU (Electronic Control Unit). In addition, the vehicle control device 10 may also be constituted by one ECU having the functions of the battery control device 100 and the vehicle machine control device 200. The battery control device 100 is also called a battery management system (BMS: Battery Management System), for example.

[0034] The vehicle machine control device 200 controls the drive machines of the vehicle 1 based on battery information and the like output by the battery control device 100. Among the drive machines of the vehicle 1, there are included the relay 400, the power conversion device 500, the electric motor 600, and the engine 700.

[0035] (Hardware Structure of the Vehicle Control System)

[0036] Figure 2This is a diagram showing an example of the hardware configuration of the vehicle control system installed in vehicle 1. As Figure 2 shown, the battery control device 100 includes a battery controller 101, a current sensor 102 connected in series with the battery 300, and a voltage sensor 103 connected in parallel with the battery 300. The current sensor 102 measures the value of the charge and discharge current of the battery 300 (hereinafter referred to as the current value) I. The voltage sensor 103 measures the value of the voltage of the battery 300 (hereinafter referred to as the voltage value) V. The measurement results of the current sensor 102 and the voltage sensor 103 are input to the battery controller 101.

[0037] The battery controller 101 is composed of a computer including a processing device 101a, a storage device 101b, an input interface, an output interface, and other peripheral circuits. These hardware components cooperate to run software and implement multiple functions described later (refer to Figure 3 ). In addition, the battery controller 101 can be composed of one computer or multiple computers.

[0038] The processing device 101a includes, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), etc. In the storage device 101b, there are non-volatile memories such as a ROM (Read Only Memory), a flash memory, and a hard disk drive. In addition, the storage device 101b includes a volatile memory called a RAM (Random Access Memory).

[0039] In the non-volatile memory of the storage device 101b, programs capable of performing various calculations are stored. That is, the non-volatile memory is a storage medium (storage device) capable of reading programs for implementing the functions of this embodiment. The volatile memory is a storage medium (storage device) that temporarily stores the calculation results of the processing device 101a and the signals input from the input interface. The processing device 101a is a device that deploys the programs stored in the non-volatile memory to the volatile memory and performs calculations, and performs specified calculation processing on the data imported from the input interface and the storage device 101b according to the programs.

[0040] (Functions of the battery control device 100)

[0041] Figure 3 This is a functional block diagram of the battery control device 100. As Figure 3 shown, the battery controller 101 has a timing unit 110, a battery information acquisition unit 111, an internal resistance calculation unit 112, an SOC calculation unit 113, a permissible current calculation unit 114, and an SOHR calculation unit 115.

[0042] The timing unit 110 measures time. The battery information acquisition unit 111 acquires information about the state of the battery 300, i.e., battery information, at a prescribed time interval based on the time measured by the timing unit 110. The battery information includes the measurement results of the current sensor 102 and the voltage sensor 103.

[0043] The internal resistance calculation unit 112 calculates the internal resistance value R of the battery 300 based on the voltage value V and the current value I of the battery 300 acquired by the battery information acquisition unit 111. Details of the calculation method of the internal resistance value R will be described later.

[0044] The SOC calculation unit 113 calculates the state of charge (SOC) of the battery 300. The SOC calculation unit 113 calculates the state of charge SOC, for example, by accumulating the battery value I acquired by the battery information acquisition unit 111. In addition, the SOC calculation unit 113 may also calculate the state of charge SOC based on the open circuit voltage OCV when no charge or discharge is performed.

[0045] The allowable current calculation unit 114 calculates the allowable current value based on the internal resistance value R calculated by the internal resistance calculation unit 112 and the state of charge SOC calculated by the SOC calculation unit 113. The calculation result of the allowable current calculation unit 114 is input to the vehicle machine control device 200.

[0046] The SOHR calculation unit (resistance state of health calculation unit) 115 calculates the resistance increase rate SOHR based on the internal resistance value R calculated by the internal resistance calculation unit 112 and the internal resistance value at the time of new product, i.e., the reference resistance value Ri, stored in the storage device 101b. The resistance increase rate SOHR is calculated by dividing the internal resistance value R by the reference resistance value Ri (SOHR = R / Ri). The calculation result of the SOHR calculation unit 115 is input to the vehicle machine control device 200. The resistance increase rate SOHR is one of the indexes indicating the deterioration state of the battery 300.

[0047] The vehicle machine control device 200 controls each part of the vehicle 1 based on the battery information acquired from the battery control device 100. For example, the vehicle machine control device 200 controls electrical equipment (such as the motor 600) based on the allowable current and the resistance increase rate SOHR acquired from the battery control device 100.

[0048] Figures 4 - 6 It is a graph showing the time change of the current value I measured by the current sensor 102 and the time change of the voltage value V measured by the voltage sensor 103. Figure 4 It is about the ideal (error-free state) measurement timing. Figure 5 It is about the measurement time of the comparison ratio. Figure 6It is about the measurement timing of this embodiment.

[0049] When the current value I changes, etc., the internal resistance calculation unit 112 calculates the internal resistance value R (DC resistance value DCR) using the following formula (1).

[0050] R = (V2 - V1) / (I2 - I1) …… (1)

[0051] Here, the first current value I1 is the current value before the change in the current value I. The first voltage value V1 is the voltage value before the change in the current value I. The second current value I2 is the current value after the change in the current value I. The second voltage value V2 is the voltage value after the change in the current value I.

[0052] As Figure 4 shown in the ideal (error - free state) measurement timing, generally, if the current value I and the voltage value V are measured at the same timing before and after a large current change, the internal resistance value R can be appropriately calculated. However, the current value I and the voltage value V are measured by separate circuits (refer to Figure 2 ). Therefore, even if the target measurement times of the current value I and the voltage value V are set to the same time, a slight deviation occurs between the actual measurement time of the current value I and the actual measurement time of the voltage value V. This deviation is the cause of a large error in the estimation of the internal resistance value R.

[0053] The deviation of the actual measurement time of the second voltage value V2 relative to the actual measurement time of the second current value I2 occurs within the deviation range ΔN (= 2×n) from time (t2 - n) to time (t2 + n). The deviation range ΔN of the measurement timing is the maximum value of the error in the measurement timing of the voltage value V generated in the design. The maximum value of the error in the measurement timing is determined by multiple factors such as the synchronization deviation between the processing device 101a and the voltage sensor 103, the error in the communication delay amount, and the error in the clock accuracy. For the deviation range ΔN of the measurement timing, the required specifications are determined based on the calculation error that can be tolerated for the internal resistance value (DC resistance value) of the battery 300. The multiple factors are designed to meet the required specifications of the deviation range ΔN. n is the maximum deviation amount (the maximum deviation amount on the negative side and the maximum deviation amount on the positive side) of the actual measurement time of the second voltage value V2 with respect to the actual measurement time of the second current value I2 as the reference. The negative side is the side where the time is relatively earlier. The positive side is the side where the time is relatively later.

[0054] As Figure 5When the measurement timing of the comparative example shown is average, for example, when the voltage value V measured at the timing of time t20 before the change in the current value I is used as the second voltage value V2 for the calculation of Equation (1), there are the following risks. That is, there is a risk that the calculated internal resistance value R is too small compared to the actual value, that is, a value with low reliability. As a result, there is a risk that the reliability of the calculation results of calculation processes such as the calculation of the resistance increase rate SOHR, which use the internal resistance value R, decreases.

[0055] The deviation between the actual measurement timing of the current value I and the actual measurement timing of the voltage value V is generated in the design and is difficult to completely prevent. Thus, in the present embodiment, considering the above deviation amplitude ΔN, the measurement timings of the current value I and the voltage value V are deliberately deviated. Specifically, the measurement timing of the voltage value V is controlled such that the actual measurement timing of the second voltage value V2 used in the calculation of the internal resistance value R is after the actual measurement timing of the second current value I2 measured after the current change.

[0056] Reference Figure 6 , the measurement timings of the current value I and the voltage value V in the present embodiment will be described. By making the target value of the measurement timing of the voltage value delay a specified time with respect to the target value of the measurement timing of the current value, regardless of the magnitude of the deviation between the measurement timing of the current value I and the measurement timing of the voltage value V, the internal resistance value R is calculated using the voltage value V measured after the change in the current value I. Thereby, it is possible to prevent the calculated internal resistance value R from becoming too small. That is, it is possible to reduce the influence on the calculation of the internal resistance value R caused by the deviation of the measurement timing. Thus, according to the present embodiment, with respect to the error cause of the deviation between the measurement timings of the current value I and the voltage value V, the robustness of the calculation of the internal resistance value R is improved, and the reliability and accuracy of the calculated internal resistance value R are improved.

[0057] Figure 6 In, the first time t1 is the target measurement timing of the first current value I1, and the second time t2 is the target measurement timing of the second current value I2. Figure 6 In, for ease of explanation, an example where the target measurement timing of the current value I coincides with the actual measurement timing is shown. In addition, Figure 6 In, the fourth time t4 is the target measurement timing of the first voltage value V1, and the third time t3 is the target measurement timing of the second voltage value V2. Figure 6 In, the time from the target measurement timing of the current value I to the target measurement timing of the voltage value V is exaggeratedly shown. Actually, the time from the target measurement timing of the current value I to the target measurement timing of the voltage value V is, for example, about 1 / 100 of the measurement period of the current value I and the voltage value V, that is, the specified time Δtn.

[0058] As Figure 6As shown, in this embodiment, the current value I is periodically measured repeatedly at the measurement period, i.e., the specified time Δtn. The voltage value V is periodically measured repeatedly at the specified time Δtn. The specified time Δtn is, for example, on the order of several tens to several hundreds of [ms (milliseconds)]. The specified time Δtn is determined in advance based on specifications such as the control specifications of the vehicle 1, the DC resistance value DCR, the state of charge SOC, the state of discharge SOF, etc., and the specifications for the monitoring and protection of the battery 300.

[0059] In this embodiment, the target measurement time of the voltage value V is set after a specified time Δtm (fixed value) from the target measurement time of the current value I regardless of the change in the current value I. For example, the target measurement time of the second voltage value V2 after the current change, i.e., the third time t3, is set after a specified time Δtm from the second time t2. In addition, the target measurement time of the first voltage value V1 before the current change, i.e., the fourth time t4, is set after a specified time Δtm from the first time t1. The specified time Δtm is, for example, on the order of 0.5 to several [ms]. It is preferable to set the specified time Δtm to be greater than half of the deviation amplitude ΔN of the actual measurement time of the second voltage value V2 relative to the actual measurement time of the second current value I2, i.e., the maximum deviation amount n.

[0060] As described above, the specified time Δtn of the current value I and the specified time Δtn of the voltage value V are set to the same value. Therefore, the time Δtm from the first time t1 to the fourth time t4 is equal to the time Δtm from the second time t2 to the third time t3.

[0061] In the case where the actual measurement time of the second current value I2 is maximally shifted to the positive side compared to the target measurement time and the actual measurement time of the second voltage value V2 is maximally shifted to the negative side compared to the target measurement time, the specified time Δtm is determined as follows. That is, the specified time Δtm is determined such that the actual measurement time of the second voltage value V2 is after the actual measurement time of the second current value I2. In other words, the specified time Δtm is determined to be greater than the maximum value of the time from the actual measurement time of the second current value I2 to the actual measurement time of the second voltage value V2 when the target measurement times of the second current value I2 and the second voltage value V2 are the same. In addition, when the specified time Δtm becomes too large, the reliability of the calculated internal resistance value R decreases. Therefore, the specified time Δtm is at least shorter than the time from the fourth time t4 to the second time t2. In addition, the specified time Δtm is preferably set to a time that satisfies the above conditions and is as short as possible.

[0062] (An example of the flow of the process executed by the battery controller 101)

[0063] Figure 7 It is a flowchart showing an example of the flow of the process executed by the battery controller 101.Figure 7 The process shown in the flowchart starts, for example, when the ignition switch (not shown) of the vehicle 1 is turned on and is repeatedly executed.

[0064] As Figure 7 shown, in step S110, the battery controller 101 acquires the detection result of the battery sensor 102. In the next step S120, after a predetermined time Δtm has elapsed since step S110, the battery controller 101 acquires the detection result of the voltage sensor 103. In other words, the battery controller 101 acquires the detection result of the voltage sensor 103 at the time when a predetermined time Δtm has elapsed from the target measurement time of the current value I as the target measurement time.

[0065] In the next step S130, the battery controller 101 calculates the difference between the current value of the current value acquired in step S110 and the previous value, that is, the current difference ΔI.

[0066] In the next step S140, the battery controller 101 determines whether the current value I has changed based on the current difference ΔI calculated in step S130. The battery controller 101 determines that the current value I has changed when the absolute value |ΔI| of the current difference ΔI is equal to or greater than the threshold value ΔI0. In this case, the process proceeds to step S150. The battery controller 101 determines that the current value I has not changed when the absolute value |ΔI| of the current difference ΔI is less than the threshold value ΔI0. In this case, the process returns to step S110.

[0067] In step S150, the battery controller 101 calculates the difference between the current value of the voltage value acquired in step S120 and the previous value, that is, the voltage difference ΔV.

[0068] In the next step S160, the battery controller 101 calculates the internal resistance value R (R = ΔV / ΔI = (V2 - V1) / (I2 - I1)) based on the current difference ΔI calculated in step S130 and the voltage difference ΔV calculated in step S150.

[0069] In the next step S170, the battery controller 101 calculates the resistance increase rate SOHR and the allowable current using the internal resistance value R calculated in step S160 and the state of charge SOC calculated by a process not shown.

[0070] In the next step S180, the battery controller 101 outputs the calculation results in steps S160 and S170 to the vehicle machine control device 200.

[0071] (Operation example of the battery controller 101)

[0072] Refer to Figure 8, an example of the operation of the battery controller 101 of this embodiment will be described. Figure 8 It is a table showing the target measurement times, the times from a specified time to each target measurement time, and the actual measurement values (current value and voltage value). In addition, the numerical values are examples.

[0073] As Figure 8 shown, the measurement periods of the current value I and the voltage value V, that is, the specified times Δtn, are each 100 [ms]. The target measurement time of the voltage value V is set to be after the deviation time from the target measurement time of the current value I, that is, the specified time Δtm = 2 [ms]. That is, the deviation of the measurement timing of the voltage value relative to the measurement timing of the current value is fixed. In addition, the battery controller 101 does not set the target measurement time itself. The battery controller 101 sets the specified time Δtn and the deviation time of the measurement timing of the voltage value V relative to the measurement timing of the current value I, that is, the specified time Δtm. The target measurement time is determined by setting the specified time Δtn and the specified time Δtm of the measurement timing.

[0074] When the current flowing through the battery 300 changes from 0 [A] to 100 [A], the battery controller 101 selects 0 [A] measured at the first time t1 before the current change as the target measurement time as the first current value I1. In addition, the battery controller 101 selects 3.5 [V] measured at the fourth time t4 after a specified time Δtm = 2 [ms] from the first time t1 as the target measurement time as the first voltage value V1. The battery controller 101 selects 100 [A] measured at the second time t2 after the current change as the target measurement time as the second current value I2. Further, the battery controller 101 selects 3.8 [V] measured at the third time t3 after a specified time Δtm from the second time t2 as the target measurement time as the second voltage value V2. The battery controller 101 calculates the internal resistance value R based on the selected first current value I1, second current value I2, first voltage value V1, and second voltage value V2.

[0075] In this embodiment, the target measurement time of the current value I and the target measurement time of the voltage value V are intentionally deviated by the specified time Δtm. As a result, the actual measurement timing of the voltage value V is necessarily after the actual measurement timing of the current value I. The actual measurement timing can be confirmed at the time of product shipment and maintenance work.

[0076] For example, during maintenance, the maintenance operator connects the maintenance device to the battery 300. The maintenance device is a device that can control the current flowing through the battery 300 and can measure the voltage value V and current value I of the battery 300. The maintenance operator uses the maintenance device to vary the current flowing through the battery 300 in a prescribed current waveform. For example, the maintenance device varies the charging current of the battery 300 in a charging waveform such as 0 [A] for 100 seconds, 100 [A] for 1 second, 0 [A] for 100 seconds, 100 [A] for 1 second, and so on.

[0077] The maintenance device statistically analyzes the voltage values (equivalent to the second voltage values) measured after the current change. Based on the statistically analyzed voltage values and the characteristic data of the change in the voltage values after the current change, the maintenance device reversely calculates the time (voltage measurement time) when the actual measured voltage value is obtained. The maintenance device calculates the voltage measurement time for all the voltage values after the current change that have been statistically analyzed. In the storage device of the maintenance device, the current change time and the voltage measurement time are stored. Thus, the error in the voltage measurement time when the current in the battery 300 changes multiple times is measured.

[0078] The maintenance device displays on the display device the data of the current change time and the voltage measurement time stored in the storage device. The maintenance operator confirms the current change time and the voltage measurement time displayed on the display device. If, for all the current change times, the voltage measurement time closest to each current change time is after that current change time, it can be confirmed that the calculation function of the present embodiment operates properly.

[0079] (Function and effect of the embodiment)

[0080] According to the present embodiment, the following function and effect can be achieved.

[0081] As Figure 3 shown, the battery control device 100 includes the battery controller 101 as a calculation device for calculating the internal resistance value R of the battery 300. As Figure 6 and Figure 7As shown, the battery controller 101 calculates a battery difference ΔI (ΔI = I2 - I1) based on a first current value I1 and a second current value I2. The first current value I1 is a value measured with the first time t1 as the target measurement time. The second current value I2 is a value measured with the second time t2, which is a specified time Δtn after the first time t1, as the target measurement time. The battery controller 101 calculates a voltage difference ΔV (ΔV = V2 - V1) based on a first voltage value V1 and a second voltage value V2. The first voltage value V1 is a value measured with a specified time (the fourth time t4 in this embodiment) after the first time t1 as the target measurement time. The second voltage value V2 is a value measured with the third time t3, which is a specified time Δtm after the second time t2 after the above-mentioned specified time (the fourth time t4 in this embodiment), as the target measurement time. The battery controller 101 calculates an internal resistance value R of the battery 300 based on the current difference ΔI and the voltage difference ΔV (R = ΔV / ΔI). According to this structure, in the case where the current changes between the first time t1 and the second time t2, it is possible to prevent the second voltage value V2 used in the calculation of the internal resistance value R measured before the current change. Thus, in this embodiment, the reliability of the calculated internal resistance value R can be improved. As a result, the battery 300 can, for example, maximize its battery performance until the end of the life (EOL: End Of Life) of the battery 300.

[0082] The battery controller 101 measures the first voltage value V1 with the fourth time t4, which is after the first time t1 and before the second time t2, as the target measurement time. According to this structure, the first voltage value V1 before the current change can be appropriately measured.

[0083] The time Δtm from the first time t1 to the fourth time t4 is equal to the time Δtm from the second time t2 to the third time t3. That is, the measurement period of the current value I by the battery controller 101 is equal to the measurement period of the voltage value V. In this way, in a structure where the target measurement time of the current value I and the target measurement time of the voltage value V are always offset, the control design is easy and simple. In addition, since the processing of the battery controller 101 is simplified, the memory usage can be reduced.

[0084] The above-mentioned specified time Δtm is greater than half (= n) of the deviation amplitude ΔN [ms] of the measurement time of the second voltage value V2 relative to the measurement time of the second current value I2. According to this structure, the voltage difference ΔV used in the calculation of the internal resistance value R is always calculated based on the second voltage value V2 measured after the current change and the first voltage value V1 measured before the current change. As a result, a highly reliable internal resistance value R can be obtained.

[0085] The battery control device 100 includes a voltage sensor 103 that measures the voltage of the battery 300 and a current sensor 102 that measures the current of the battery 300. According to this structure, a highly reliable internal resistance value R can be obtained based on the detection results of the voltage sensor 103 and the current sensor 102 included in the battery control device 100.

[0086] As Figure 1 shown, the vehicle control device 10 has a battery control device 100. The vehicle control device 10 controls a vehicle 1 having a battery 300 and electrical equipment (such as a motor 600) that operates using the electric power of the battery 300. According to this structure, the reliability of the internal resistance value R used in the calculation of the vehicle control device 10 is improved, so that the vehicle control device 10 can more appropriately control the above-mentioned electrical equipment (such as the motor 600).

[0087] As Figure 1 shown, the vehicle 1 has an internal combustion engine (engine 700) that drives the vehicle 1 to travel. Since the reliability of the internal resistance value R used in various calculations in the vehicle control device 10 is improved, the vehicle control device 10 can more appropriately control the motor 600 and the engine 700 when the vehicle is traveling.

[0088] The following-described modification examples are also within the scope of the present invention, and it is also possible to combine the structures shown in the modification examples with the structures described in the above-described embodiments, or to combine the structures described in the following different modification examples with each other.

[0089] (Modification Example 1)

[0090] In the above-described embodiment, an example in which the measurement period of the current value I, that is, a specified time, is the same as the measurement period of the voltage value V, that is, a specified time, has been described, but the present invention is not limited thereto. It is also possible to make the measurement period of the current value I different from the measurement period of the voltage value V. For example, as Figure 9 shown, the measurement period of the current value I can be set to 1 / 2 of the measurement period of the voltage value V.

[0091] (Modification Example 2)

[0092] In the above-described embodiment, an example in which the measurement period of the voltage value V is constant has been described. However, it is also possible to change only the measurement timing of the voltage value measured after the current of the battery 300 changes. In this configuration, when the current difference ΔI of the battery 300 exceeds a specified value, the battery controller 101 calculates a voltage difference ΔV based on a first voltage value V1 and a second voltage value V2 of the battery 300. The specified value is, for example, 100 times or more the variation range of the current value I of the battery 300 when the current value of the battery 300 is not intentionally changed. 100 times is just an example and is specified based on the variation range of the current value I of the battery 300. In Modification 2, when there is no current change in the battery 300, the target measurement time of the current value I is made to coincide with the target measurement time of the voltage value V. The battery controller 101 monitors the change in current, and when it determines that a current change has occurred (when it determines that the current difference ΔI has exceeded the specified value), it delays the target measurement time of the voltage value by a specified time. That is, the target measurement times of the first current value I1 and the first voltage value V1 are the first time t1, and the target measurement time of the second voltage value V2 is set after the target measurement time of the second current value I2 by the specified time. Such a configuration can also improve the reliability of the internal resistance value R.

[0093] (Modification 3)

[0094] In the above-described embodiment, an example in which the internal resistance value of a battery pack having a plurality of single cells is calculated using the voltage of the battery pack has been described. However, the present invention can also be applied to the calculation of the internal resistance value of a single cell using the voltage of the single cell constituting the battery pack.

[0095] The embodiments of the present invention have been described above, but the above-described embodiments only show a part of the application examples of the present invention and do not limit the technical scope of the present invention to the specific structures of the above-described embodiments. For example, the present invention is not limited to being applied to the battery control device 100 that controls the battery 300 mounted in the vehicle 1 as shown in Figure 1 . The present invention can be applied to the battery control device 100 that controls the battery 300 as a power source for operating various industrial machines such as aircraft and machine tools.

[0096] The structure of the embodiment of the present invention can also be determined as follows.

[0097] The battery control device 100 has a calculation device (battery controller 101) that calculates the internal resistance value R of the battery 300. The calculation device calculates a current difference ΔI based on a first current value I1 measured with a first time t1 as a target measurement time and a second current value I2 measured with a second time t2 that is a specified time Δtn after the first time t1. The calculation device calculates a voltage difference ΔV based on a first voltage value V1 measured with a specified time after the first time t1 and before the second time t2 as a target measurement time and a second voltage value V2 measured with a third time t3 that is a specified time Δtm after the second time t2. The calculation device calculates the internal resistance value R of the battery 300 based on the current difference ΔI and the voltage difference ΔV. With this configuration, it is possible to suppress a large difference in the measurement times of the current and the voltage, and thus it is possible to calculate the state of the target battery 300 with high accuracy.

[0098] The battery control device 100 has a calculation unit (battery controller 101) that inputs the voltage value V of the battery 300 and the current value I of the battery 300 and calculates the internal resistance value R of the battery 300. The calculation unit calculates a current difference ΔI (ΔI = I2 - I1) based on a second current value I2 measured and input at a second time t2 that is a specified time Δtn after a specified first time t1 and a first current value I1 measured and input at the first time t1. The calculation unit calculates a voltage difference ΔV (ΔV = V2 - V1) based on a specified second voltage value V2 measured and input between a second time t2 and a third time t3 that is a specified time after the second time t2 and a first voltage value V1 measured and input at the first time t1. The calculation unit calculates the internal resistance value R of the battery 300 based on the voltage difference ΔV and the current difference ΔI.

[0099] The battery control device 100 has a calculation unit that inputs the voltage value of the battery 300 measured at a specified time and the current value of the battery 300 measured at the above-specified time and calculates the internal resistance value of the battery 300. Among the above-specified times, a first time t1 < a second time t2 < a third time t3 are included. The calculation unit calculates a current difference ΔI (ΔI = I2 - I1) based on a second current value I2 measured by a current measurement unit (current sensor 102) at the second time t2 and a first current value I1 measured by the current measurement unit (current sensor 102) at the first time t1. The calculation unit calculates a voltage difference ΔV (ΔV = V2 - V1) based on a specified second voltage value V2 measured by a voltage measurement unit (voltage sensor 103) between the second time t2 and the third time t3 and a first voltage value V1 measured by the voltage measurement unit (voltage sensor 103) at the first time t1. The calculation unit calculates the internal resistance value R of the battery 300 based on the voltage difference ΔV and the current difference ΔI (I2 - I1).

[0100] Symbol Explanation

[0101] 1... Vehicle, 10... Vehicle control device, 20... Battery pack, 100... Battery control device, 101... Battery controller (computing device, computing unit), 101a... Processing device, 101b... Storage device, 102... Current sensor, 103... Voltage sensor, 110... Timing unit, 111... Battery information acquisition unit, 112... Internal resistance calculation unit, 113... SOC calculation unit, 114... Allowable current calculation unit, 115... SOHR calculation unit, 200... Vehicle machine control device, 300... Battery, 400... Relay, 500... Power conversion device, 600... Electric motor (electrical equipment), 700... Engine (internal combustion engine), DCR... DC resistance value, I... Current value, I1... First current value, I2... Second current value, R... Internal resistance value, Ri... Reference resistance value, SOC... Charge rate, SOF... Discharge performance, SOHR... Resistance increase rate, V... Voltage value, V1... First voltage value, V2... Second voltage value, n... Maximum deviation amount, t1... First time, t2... Second time, t3... Third time, t4... Fourth time, ΔI... Current difference, ΔI0... Threshold value, ΔN... Deviation amplitude, ΔV... Voltage difference, Δtm... Specified time, Δtn... Specified time.

Claims

1. A battery control device, having a calculation device for calculating the internal resistance value of the battery, The calculation device calculates a current difference based on a first current value and a second current value, wherein the first current value is a value measured at a first time as a target measurement time, and the second current value is a value measured at a second time after a predetermined time has passed from the first time as a target measurement time, The calculation device calculates a voltage difference value based on a first voltage value and a second voltage value, wherein the first voltage value is a value measured at a predetermined time after the first time as a target measurement time, and the second voltage value is a value measured at a third time after the predetermined time and a predetermined time from the second time as the target measurement time, The calculation means calculates the internal resistance value of the battery based on the current difference value and the voltage difference value.

2. The battery control device according to claim 1, wherein: The calculation device measures the first voltage value by taking a fourth time point after the first time point and before the second time point as a target measurement time point.

3. The battery control device according to claim 2, wherein: The time from the first moment to the fourth moment is equal to the time from the second moment to the third moment.

4. The battery control device according to claim 1, wherein: The calculation device calculates the voltage difference value based on the first voltage value and the second voltage value when the current difference value exceeds a prescribed value.

5. The battery control device according to claim 1, further comprising: a voltage sensor for measuring a voltage value of the battery; and A current sensor measures a current value of the battery. 6 . A vehicle control device having the battery control device according to claim 1 , which controls a vehicle having the battery and an electrical device that operates using electric power of the battery.

7. The vehicle control device according to claim 6, characterized in that: The vehicle has an internal combustion engine that drives the vehicle.

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