Power supply control device, power supply control system, and power supply control method

Abstract

To provide a power supply control device, a power supply control system, and a power supply control method that improve the accuracy of power switch connection determination and enable early power startup.SOLUTION: A power supply control device includes a controller that controls a plurality of batteries connected in parallel and connected to a load via power switches. At startup, the controller calculates an estimated current value that is to flow through each of the plurality of batteries when the plurality of power switches are turned on, on the basis of the internal resistance values of each of the plurality of batteries stored in a memory. When the calculated current value is greater than a preset current threshold, the controller keeps at least some of the plurality of power switches off when turning on the power switches.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply control device, a power supply control system, and a power supply control method. [Background technology]

[0002] Conventionally, systems have been known in which power is supplied to a load from multiple batteries connected in parallel. The batteries may be replaceable. In such systems, if a power switch connecting the batteries to the load is turned on while there is a relatively large potential difference or internal resistance difference between the multiple batteries, a relatively large current may flow between the batteries, potentially causing battery degradation. Therefore, various technologies have been proposed to prevent such battery degradation (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-066025 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the prior art has had problems such as delays in power supply startup due to the process of preventing battery degradation, or problems with the accuracy of power switch connection determination. Specifically, the prior art performs a process of turning on a power switch equipped with a limiting resistor that makes it difficult for current to flow until the potential difference between multiple batteries becomes sufficiently small, thereby preventing a relatively large current from flowing between the batteries and causing battery degradation. However, this process requires time for the potential difference to become sufficiently small, resulting in a problem of delays in power supply startup.

[0005] Furthermore, in the prior art, the connection of the power switch is determined by determining whether the potential difference between multiple batteries is a value that prevents a relatively large current from flowing between the batteries when the power switch is turned on. However, a determination based on the potential difference does not accurately reflect the amount of current estimated to flow between the batteries. Therefore, even if the amount of current estimated to flow between the batteries is a value that does not cause any problems when the power switch is turned on, the determination based on the potential difference may determine that a large current is flowing between the batteries, and the power switch may not be turned on. In other words, there is a problem with the accuracy of determining the connection of the power switch using only the potential difference.

[0006] The present invention has been made in consideration of the above, and aims to provide a power supply control device, a power supply control system, and a power supply control method that improve the accuracy of determining whether a power switch is connected and enable early power startup. [Means for solving the problem]

[0007] To solve the above problems and achieve the object, a power supply control device according to the present invention includes a controller that controls multiple batteries connected in parallel and connected to a load via each power switch. At startup, the controller calculates an estimated current value that will flow through each of the multiple batteries when the multiple power switches are turned on, based on the internal resistance values ​​of each of the multiple batteries stored in memory. If the calculated current value is greater than a preset current threshold, the controller keeps at least some of the multiple power switches off when turning on the power switches. [Effects of the Invention]

[0008] According to the present invention, the current value estimated to flow through each of a plurality of batteries is calculated based on the internal resistance value of each of the plurality of batteries stored in memory, and by using the calculated current value, the accuracy of determining the connection of the power switch can be improved and early power start-up is possible. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram showing an example of the configuration of a power supply control system including a power supply control device 1 according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of a power supply control system including a power supply control device. [Figure 3] FIG. 3 is an explanatory diagram illustrating an example of battery information. [Figure 4] FIG. 4 is a flowchart (part 1) showing a processing procedure executed by the power supply control device. [Figure 5] FIG. 5 is a flowchart (part 2) illustrating the processing procedure executed by the power supply control device. [Figure 6] FIG. 6 is a flowchart (part 3) illustrating the processing procedure executed by the power supply control device. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a power supply control device, a power supply control system, and a power supply control method disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiments.

[0011] A power supply control system including a power supply control device according to an embodiment will be described with reference to Fig. 1. Fig. 1 is an explanatory diagram showing an example of the configuration of a power supply control system 100 including a power supply control device 1 according to an embodiment. Note that the following description will be given taking as an example a case where the power supply control system 100 is mounted on a vehicle, but the present invention is not limited to this.

[0012] As shown in FIG. 1, the power supply control system 100 includes a power supply control device 1, a first battery pack 10, a second battery pack 20, a third battery pack 30, a fourth battery pack 40, an inverter 50, and a motor 60.

[0013] The power supply control device 1 is a device that controls the entire power supply control system 100, including the first to fourth battery packs 10 to 40 and the inverter 50. The detailed configuration of the power supply control device 1 will be described later with reference to FIG.

[0014] The first to fourth battery packs 10 to 40 are battery devices connected in parallel. Note that, although the power supply control system 100 will be described here as having four battery devices, the first to fourth battery packs 10 to 40, the number of battery devices may be two, three, five or more, provided that there is more than one.

[0015] The first battery pack 10 includes a battery 11, a power switch (hereinafter referred to as "power SW") 12, a pre-charge switch (hereinafter referred to as "pre-charge SW") 13, and a limiting resistor 14.

[0016] The battery 11 is, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery. The battery 11 includes a plurality of battery cells 11a (only one is shown in FIG. 1) connected in series. In other words, the battery 11 is an assembled battery. The battery 11 also has an internal resistance 11b.

[0017] The power supply SW12 connects the battery 11 and the motor 60. When the power supply SW12 is turned on, it electrically connects the battery 11 and the motor 60, and when it is turned off, it cuts off the electrical connection between the battery 11 and the motor 60. The power supply SW12 is also called a power supply relay or a battery relay.

[0018] The precharge SW13 and limiting resistor 14 are connected in series. The series-connected precharge SW13 and limiting resistor 14 are then connected in parallel with the power supply SW12. The precharge SW13 and limiting resistor 14 prevent a high-voltage inrush current from flowing from the first battery pack 10 to the inverter 50 and motor 60. Specifically, the precharge SW13 is turned on during precharge, and the limiting resistor 14 allows a relatively small current to flow from the battery 11 to the inverter 50, charging the capacitor 52 of the inverter 50. When this charging causes the voltage of the capacitor 52 and the voltage of the battery 11 to become the same or nearly the same (equipotential state), the inrush current is prevented from flowing and precharge is completed. Upon completion of precharge, the precharge SW13 is turned off.

[0019] The first battery pack 10 also includes a BMS (Battery Management System) 15, a voltage sensor 16, and a current sensor 17. The BMS 15 is a battery monitoring device that monitors the state of the first battery pack 10. The BMS 15 includes a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and various other circuits.

[0020] The voltage sensor 16 is connected in parallel to the battery 11 and detects the voltage of the battery 11. The voltage sensor 16 outputs a signal indicating the detected voltage value of the battery 11 to the BMS 15. The current sensor 17 is provided between the battery 11 and the power supply SW 12 (in other words, between the battery 11 and the motor 60 (or the inverter 50)) and detects the current flowing through the battery 11. The current sensor 17 outputs a signal indicating the detected current value of the battery 11 to the BMS 15.

[0021] The BMS 15 outputs a signal indicating the voltage value of the battery 11 input from the voltage sensor 16 and a signal indicating the current value of the battery 11 input from the current sensor 17 to the power supply control device 1. Note that, below, the voltage value of the battery 11 of the first battery pack 10 may be referred to as "V1" and the current value of the battery 11 may be referred to as "I1".

[0022] The second to fourth battery packs 20-40 have the same configuration as the first battery pack 10, so the following description of the second to fourth battery packs 20-40 will be simplified. The second battery pack 20 includes a battery 21, a power supply SW 22, a pre-charge SW 23, and a limiting resistor 24. The battery 21 is an assembled battery including multiple battery cells 21a connected in series. The battery 21 has an internal resistor 21b.

[0023] The power supply SW22 connects the battery 21 and the motor 60. When the power supply SW22 is turned on, it electrically connects the battery 21 and the motor 60, and when it is turned off, it cuts off the electrical connection between the battery 21 and the motor 60. The pre-charge SW23 and the limiting resistor 24 are connected in series and are also connected in parallel with the power supply SW22. The pre-charge SW23 and the limiting resistor 24 prevent a high-voltage inrush current from flowing from the second battery pack 20 to the inverter 50 and the motor 60.

[0024] The second battery pack 20 also includes a BMS 25, a voltage sensor 26, and a current sensor 27. The BMS 25 is a battery monitoring device that monitors the state of the second battery pack 20. The voltage sensor 26 is connected in parallel to the battery 21 and detects the voltage of the battery 21. The voltage sensor 26 outputs a signal indicating the detected voltage value of the battery 21 to the BMS 25. The current sensor 27 is provided between the battery 21 and the power supply SW22 (in other words, between the battery 21 and the motor 60 (or the inverter 50)) and detects the current flowing through the battery 21. The current sensor 27 outputs a signal indicating the detected current value of the battery 21 to the BMS 25.

[0025] The BMS 25 outputs a signal indicating the voltage value of the battery 21 input from the voltage sensor 26 and a signal indicating the current value of the battery 21 input from the current sensor 27 to the power supply control device 1. Note that, below, the voltage value of the battery 21 of the second battery pack 20 may be referred to as "V2" and the current value of the battery 21 may be referred to as "I2".

[0026] The third battery pack 30 includes a battery 31, a power supply switch 32, a precharge switch 33, and a limiting resistor 34. The battery 31 is an assembled battery including a plurality of battery cells 31a connected in series. The battery 31 has an internal resistor 31b.

[0027] The power supply SW32 connects the battery 31 and the motor 60. When the power supply SW32 is turned on, it electrically connects the battery 31 and the motor 60, and when it is turned off, it cuts off the electrical connection between the battery 31 and the motor 60. The pre-charge SW33 and the limiting resistor 34 are connected in series and in parallel with the power supply SW32. The pre-charge SW33 and the limiting resistor 34 prevent a high-voltage inrush current from flowing from the third battery pack 30 to the inverter 50 and the motor 60.

[0028] The third battery pack 30 also includes a BMS 35, a voltage sensor 36, and a current sensor 37. The BMS 35 is a battery monitoring device that monitors the state of the third battery pack 30. The voltage sensor 36 is connected in parallel to the battery 31 and detects the voltage of the battery 31. The voltage sensor 36 outputs a signal indicating the detected voltage value of the battery 31 to the BMS 35. The current sensor 37 is provided between the battery 31 and the power supply SW 32 (in other words, between the battery 31 and the motor 60 (or the inverter 50)) and detects the current flowing through the battery 31. The current sensor 37 outputs a signal indicating the detected current value of the battery 31 to the BMS 35.

[0029] The BMS 35 outputs a signal indicating the voltage value of the battery 31 input from the voltage sensor 36 and a signal indicating the current value of the battery 31 input from the current sensor 37 to the power supply control device 1. Note that, below, the voltage value of the battery 31 of the third battery pack 30 may be referred to as "V3" and the current value of the battery 31 may be referred to as "I3".

[0030] The fourth battery pack 40 includes a battery 41, a power switch 42, a precharge switch 43, and a limiting resistor 44. The battery 41 is an assembled battery including a plurality of battery cells 41a connected in series. The battery 41 has an internal resistor 41b.

[0031] The power supply SW42 connects the battery 41 and the motor 60. When the power supply SW42 is turned on, it electrically connects the battery 41 and the motor 60, and when it is turned off, it cuts off the electrical connection between the battery 41 and the motor 60. The pre-charge SW43 and the limiting resistor 44 are connected in series and are also connected in parallel with the power supply SW42. The pre-charge SW43 and the limiting resistor 44 prevent a high-voltage inrush current from flowing from the fourth battery pack 40 to the inverter 50 and the motor 60.

[0032] The fourth battery pack 40 also includes a BMS 45, a voltage sensor 46, and a current sensor 47. The BMS 45 is a battery monitoring device that monitors the state of the fourth battery pack 40. The voltage sensor 46 is connected in parallel to the battery 41 and detects the voltage of the battery 41. The voltage sensor 46 outputs a signal indicating the detected voltage value of the battery 41 to the BMS 45. The current sensor 47 is provided between the battery 41 and the power supply SW 42 (in other words, between the battery 41 and the motor 60 (or the inverter 50)) and detects the current flowing through the battery 41. The current sensor 47 outputs a signal indicating the detected current value of the battery 41 to the BMS 45.

[0033] The BMS 45 outputs a signal indicating the voltage value of the battery 41 input from the voltage sensor 46 and a signal indicating the current value of the battery 41 input from the current sensor 47 to the power supply control device 1. Note that, below, the voltage value of the battery 41 of the fourth battery pack 40 may be referred to as "V4" and the current value of the battery 41 may be referred to as "I4".

[0034] In the above description, the voltage values ​​V1, V2, V3, and V4 of the batteries 11, 21, 31, and 41 are input to the power supply control device 1 from the voltage sensors 16, 26, 36, and 46 via the BMSs 15, 25, 35, and 45, but this is not limiting. For example, the voltage values ​​V1, V2, V3, and V4 of the batteries 11, 21, 31, and 41 may be input to the power supply control device 1 directly from the voltage sensors 16, 26, 36, and 46. Similarly, the current values ​​I1, I2, I3, and I4 of the batteries 11, 21, 31, and 41 may be input to the power supply control device 1 directly from the current sensors 17, 27, 37, and 47.

[0035] In this way, the batteries 11, 21, 31, and 41 of the first to fourth battery packs 10 to 40 are connected in parallel. The batteries 11, 21, 31, and 41 are also connected to the inverter 50 via the power supply switches 12, 22, 32, and 42, respectively. The batteries 11, 21, 31, and 41 are each configured to be replaceable.

[0036] The first to fourth battery packs 10 to 40 (specifically, batteries 11, 21, 31, 41) supply power to a motor 60 via an inverter 50.

[0037] The inverter 50 generates an AC drive signal for driving the motor 60 and outputs it to the motor 60. The inverter 50 includes a plurality of (e.g., six) switch elements 51 and a smoothing capacitor 52. The switch elements 51 are configured by power devices such as IGBTs (Insulated Gate Bipolar Transistors) or MOS-FETs (Metal-Oxide-Semiconductor Field-Effect Transistors).

[0038] The inverter 50 converts DC power from the batteries 11, 21, 31, and 41 into three-phase AC power by controlling the switches of the switch elements 51 and supplies the AC power to the motor 60, thereby driving the motor 60.

[0039] Furthermore, a voltage sensor 53 is connected in parallel to capacitor 52. Voltage sensor 53 detects the voltage of inverter 50 (capacitor 52). The voltage detected by voltage sensor 53 is the same as the composite voltage of batteries 11, 21, 31, and 41 that are electrically connected when power supply switches 12, 22, 32, and 42 are turned on. Voltage sensor 53 outputs a signal indicating the detected voltage value of inverter 50 (capacitor 52), in other words, a signal indicating the composite voltage value, to power supply control device 1. Note that hereinafter, the composite voltage value may be referred to as "V," and voltage sensor 53 may be referred to as "composite voltage sensor 53."

[0040] The motor 60 is, for example, a three-phase motor that serves as a power source for the vehicle. The motor 60 is also a motor generator. For example, when the vehicle accelerates, the motor 60 functions as a motor that rotates using the power of the batteries 11, 21, 31, and 41 to assist the driving force of the engine. For example, when the vehicle decelerates, the motor 60 functions as a generator that converts regenerative energy of the engine into electrical energy to generate electricity. The power generated by the motor 60 can be used to charge the batteries 11, 21, 31, and 41.

[0041] In this embodiment, the power supply control device 1 of the power supply control system 100 is configured to improve the accuracy of connection determination of the power supply SW12, 22, 32, and 42 and enable early power supply startup.

[0042] Such a configuration will be described in detail with reference to Fig. 2 etc. Fig. 2 is a block diagram showing an example of the configuration of a power supply control system 100 including the power supply control device 1.

[0043] 2, voltage sensors 16, 26, 36, and 46 are connected to the power supply control device 1 via BMSs 15, 25, 35, and 45 (not shown), and signals indicating voltage values ​​V1, V2, V3, and V4 of batteries 11, 21, 31, and 41 are input. Current sensors 17, 27, 37, and 47 are connected to the power supply control device 1 via BMSs 15, 25, 35, and 45 (not shown), and signals indicating current values ​​I1, I2, I3, and I4 of batteries 11, 21, 31, and 41 are input. Combined voltage sensor 53 is also connected to the power supply control device 1, and a signal indicating combined voltage value V is input.

[0044] Also connected to the power supply control device 1 are power supply SW12, 22, 32, 42, pre-charge SW13, 23, 33, 43, and an inverter 50. The power supply SW12, 22, 32, 42 and pre-charge SW13, 23, 33, 43 are turned on or off in response to drive signals from the power supply control device 1. The inverter 50 controls the driving of the motor 60 (see FIG. 1 ) based on, for example, command signals for a target rotation speed and a target torque from the power supply control device 1. Specifically, the inverter 50 controls the motor 60 based on the command signals for the target rotation speed and the target torque from the power supply control device 1 so that the actual rotation speed and actual torque of the motor 60 become the target rotation speed and the target torque.

[0045] An operation unit 90 is also connected to the power supply control device 1. The operation unit 90 is an input device that accepts various operations from a user. The operation unit 90 outputs a signal corresponding to the accepted operation to the power supply control device 1. The operations accepted by the operation unit 90 will be described later.

[0046] The power supply control device 1 includes a controller (controller) 70 and a memory (storage unit) 80. The memory 80 is realized by, for example, a semiconductor memory element such as a RAM or a flash memory, or a storage device such as a hard disk or an optical disk. In the example of Fig. 2, the memory 80 stores battery information 81 and composite voltage information 82. The memory 80 also stores various data and programs.

[0047] It should be noted that the battery information 81 and the composite voltage information 82 are not always stored in the memory 80. That is, there may be times when the memory 80 does not store some or all of the battery information 81 and the composite voltage information 82.

[0048] The battery information 81 is information relating to the first to fourth battery packs 10 to 40, and more specifically, information relating to the batteries 11, 21, 31, and 41. The battery information 81 will now be described with reference to Fig. 3. Fig. 3 is an explanatory diagram showing an example of the battery information 81.

[0049] As shown in FIG. 3, in the battery information 81, information items such as "voltage value," "current value," "internal resistance value," and "history information" are associated with "battery ID."

[0050] "Battery ID" is identification information for identifying a battery. In the example of Fig. 3, the battery identified by battery ID "P01" is battery 11 of first battery pack 10, and the battery identified by battery ID "P02" is battery 21 of second battery pack 20. Furthermore, the battery identified by battery ID "P03" is battery 31 of third battery pack 30, and the battery identified by battery ID "P04" is battery 41 of fourth battery pack 40.

[0051] The "voltage value" is information indicating the voltage value of the batteries 11, 21, 31, and 41. Specifically, the "voltage value" is information indicating the voltage value of the batteries 11, 21, 31, and 41 detected by the voltage sensors 16, 26, 36, and 46.

[0052] The "current value" is information indicating the current value of the batteries 11, 21, 31, and 41. Specifically, the "current value" is the current value of the batteries 11, 21, 31, and 41 detected by the current sensors 17, 27, 37, and 47, or the current value of the batteries 11, 21, 31, and 41 calculated (estimated) by a calculation process described later.

[0053] "Internal resistance value" is information indicating the value (internal resistance value) of the internal resistances 11b, 21b, 31b, and 41b of the batteries 11, 21, 31, and 41. "Internal resistance value" is the internal resistance value of the batteries 11, 21, 31, and 41 calculated (estimated) by a calculation process described below. Note that "internal resistance value" also includes the wiring resistance values ​​of the first to fourth battery packs 10 to 40 corresponding to the batteries 11, 21, 31, and 41, but for convenience, it will be referred to as "internal resistance value" here.

[0054] "History information" is information relating to the history of batteries 11, 21, 31, and 41. "History information" includes, but is not limited to, information such as the date and time when the corresponding "voltage value," "current value," and "internal resistance value" were updated, and the date and time when batteries 11, 21, 31, and 41 were replaced. Note that in the example shown in FIG. 3, for convenience, "history information" is expressed abstractly as "Q1," but specific information is stored in "Q1."

[0055] In the example of Figure 3, the battery information identified by the battery ID "P01" (i.e., the information of the battery 11 in the first battery pack 10) indicates that the voltage value is "V1", the current value is "I1", the internal resistance value is "R1", and the history information is "Q1".

[0056] 2, the controller 70 is realized by, for example, a CPU or an MPU (Micro Processing Unit) executing various programs (not shown) stored in the memory 80 using a RAM as a work area. The controller 70 can also be realized by, for example, an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0057] The controller 70 performs the precharge process described above. For example, the controller 70 turns on precharge SW13, 23, 33, and 43 to charge the capacitor 52 of the inverter 50. At this time, the power supply SW12, 22, 32, and 42 are turned off. When the voltage of the capacitor 52 becomes the same or approximately the same as the voltage of the battery 11 and the like due to the charging of the capacitor 52, high-voltage inrush current will no longer flow from the battery 11 and the like to the inverter 50 and the motor 60. Therefore, the controller 70 turns off the precharge SW13 to end the precharge process.

[0058] The controller 70 according to this embodiment prevents a relatively large current from flowing between the batteries 11, 21, 31, 41 and causing deterioration of the batteries 11, 21, 31, 41 when the power supply SW12, 22, 32, 42 are turned on after the precharge process.

[0059] Specifically, the controller 70 stores the internal resistance values ​​R1, R2, R3, and R4 of the batteries 11, 21, 31, and 41 in the memory 80. At startup, the controller 70 calculates the estimated current values ​​I1, I2, I3, and I4 that will flow through the batteries 11, 21, 31, and 41 when the power supply SWs 12, 22, 32, and 42 are turned on, based on the internal resistance values ​​R1, R2, R3, and R4 stored in the memory 80. If the calculated current values ​​I1, I2, I3, and I4 are greater than a preset allowable current value, the controller 70 keeps at least some of the power supply SWs 12, 22, 32, and 42 off when turning on the power supply SWs 12, 22, 32, and 42. The allowable current value is the upper limit of the current that can flow through the batteries 11, 21, 31, and 41 without causing degradation, and is an example of a current threshold.

[0060] <Method for calculating (estimating) battery current value> Here, a method for calculating the current values ​​I1, I2, I3, and I4 estimated to flow through the batteries 11, 21, 31, and 41, respectively, will be described in detail.

[0061] When the power supplies SW12, 22, 32, and 42 are turned on, the relationships among the voltage values ​​V1, V2, V3, and V4, the current values ​​I1, I2, I3, and I4, the internal resistance values ​​R1, R2, R3, and R4, and the composite voltage value V in the batteries 11, 21, 31, and 41 are as follows: (V1-V)=I1×R1...Equation (1) (V2-V)=I2×R2 Equation (2) (V3-V)=I3×R3...Equation (3) (V4-V)=I4×R4 Equation (4)

[0062] In order for the controller 70 to estimate and calculate the current values ​​I1, I2, I3, and I4 in equations (1) to (4), it is necessary to first determine the voltage values ​​V1, V2, V3, and V4, the internal resistance values ​​R1, R2, R3, and R4, and the composite voltage value V.

[0063] Specifically, the controller 70 acquires the voltage values ​​V1, V2, V3, and V4 from the voltage sensors 16, 26, 36, and 46 via the BMSs 15, 25, 35, and 45 with the power supply SWs 12, 22, 32, and 42 turned off.

[0064] The controller 70 performs processing to determine the internal resistance values ​​R1, R2, R3, and R4. Specifically, the controller 70 turns on the power supplies SW12, 22, 32, and 42, and acquires the current values ​​I1, I2, I3, and I4 from the current sensors 17, 27, 37, and 47 via the BMSs 15, 25, 35, and 45. Furthermore, with the power supplies SW12, 22, 32, and 42 turned on, the controller 70 acquires the composite voltage value V from the composite voltage sensor 53.

[0065] The controller 70 can calculate the internal resistance values ​​R1, R2, R3, and R4 using the acquired voltage values ​​V1, V2, V3, and V4, current values ​​I1, I2, I3, and I4, and composite voltage value V, and equations (1) to (4). As an example, equation (1) becomes "R1=(V1-V) / I1," and the internal resistance value R1 can be calculated. The controller 70 stores the calculated internal resistance values ​​R1, R2, R3, and R4 in the memory 80.

[0066] Once the internal resistance values ​​R1, R2, R3, and R4 are stored in memory 80, from the next processing onwards, the controller 70 can estimate and calculate the current values ​​I1, I2, I3, and I4 using the internal resistance values ​​R1, R2, R3, and R4 in memory 80 before turning on the power supplies SW12, 22, 32, and 42.

[0067] Specifically, in the circuit of the power supply control system 100 shown in FIG. 1, the following equation (5) holds true. I1+I2+I3+I4=0 Equation (5)

[0068] When the combined voltage value V is solved using equations (1) to (5), the following equation (6) is obtained. V=(R1×R3×R4×V2+R1×R2×R4×V3+R1×R2×R3×V4+R2×R3×R4×V1) / (R2×R3×R4+R1×R3×R4+R1×R2×R4+R1×R2×R3) Formula (6)

[0069] As a result, the controller 70 can calculate the composite voltage value V by substituting the internal resistance values ​​R1, R2, R3, and R4 of the memory 80 and the voltage values ​​V1, V2, V3, and V4 when the power supplies SW12, 22, 32, and 42 are turned off into equation (6).

[0070] The controller 70 can estimate and calculate the current values ​​I1, I2, I3, and I4 using the calculated composite voltage value V, the internal resistance values ​​R1, R2, R3, and R4 of the memory 80, the voltage values ​​V1, V2, V3, and V4 when the power supplies SW12, 22, 32, and 42 are turned off, and equations (1) to (4). As an example, equation (1) becomes "I1=(V1-V) / R1," and the current value I1 can be calculated.

[0071] In this way, the controller 70 uses the internal resistance values ​​R1, R2, R3, and R4 stored in the memory 80 to calculate the current values ​​I1, I2, I3, and I4 estimated to flow when the power supplies SW12, 22, 32, and 42 are turned on. The internal resistance values ​​stored in the memory 80 are stored by a process that calculates and stores internal resistance values ​​using measured values ​​measured during startup (hereinafter, this may be referred to as an "internal resistance storage process"). The measured values ​​include voltage values ​​V1, V2, V3, and V4, current values ​​I1, I2, I3, and I4, and a composite voltage value V.

[0072] The internal resistance values ​​R1, R2, R3, and R4 stored in the memory 80 are values ​​stored in the internal resistance storage process performed during the previous startup. This internal resistance storage process calculates the internal resistance values ​​R1, R2, R3, and R4 using the measured voltage values ​​V1, V2, V3, and V4 of the multiple batteries, and the current values ​​I1, I2, I3, and I4 and the combined voltage value V measured with the power supply SW12, 22, 32, and 42 turned on.

[0073] By storing the internal resistance values ​​R1, R2, R3, and R4 calculated as described above in the memory 80, the controller 70 becomes able to calculate the current values ​​I1, I2, I3, and I4 during the current startup using the stored internal resistance values ​​R1, R2, R3, and R4.

[0074] Note that before the internal resistance values ​​R1, R2, R3, and R4 are stored in the memory 80, i.e., when the internal resistance values ​​R1, R2, R3, and R4 are not stored in the memory 80, the controller 70 turns on the power supplies SW12, 22, 32, and 42 and acquires the current values ​​I1, etc. When the controller 70 turns on the power supply SW12, etc., it is necessary to ensure that the current values ​​I1, etc. do not exceed the allowable current value.

[0075] Therefore, when the internal resistance values ​​R1, R2, R3, and R4 are not stored in the memory 80, the controller 70 according to this embodiment first calculates the potential difference between the batteries 11, 21, 31, and 41. The controller 70 turns on all of the power supply switches 12, 22, 32, and 42 and measures the current values ​​I1, I2, I3, and I4 of the batteries 11, 21, 31, and 41, respectively, on the condition that the calculated potential difference is equal to or less than a preset allowable voltage value. The allowable voltage value is set to a potential difference such that the current flowing through the batteries 11 and other batteries is equal to or less than the allowable current value, even if the internal resistance values ​​R1, R2, R3, and R4 are the minimum values ​​possible depending on the specifications of the batteries 11 and other batteries. The allowable voltage value is an example of a voltage threshold.

[0076] Then, as described above, the controller 70 calculates the internal resistance values ​​R1, R2, R3, and R4 based on the measured current values ​​I1, I2, I3, and I4, the composite voltage value V, and the voltage values ​​V1, V2, V3, and V4 when the power supplies SW12, 22, 32, and 42 are turned off. The controller 70 stores the calculated internal resistance values ​​R1, R2, R3, and R4 in the memory 80. As a result, even if the internal resistance values ​​R1, R2, R3, and R4 are not stored in the memory 80 and the current values ​​I1, I2, I3, and I4 cannot be estimated, the controller 70 can turn on the power supplies SW12, 22, 32, and 42 to calculate the internal resistance values ​​R1, R2, R3, and R4, and can then calculate the current values ​​I1, I2, I3, and I4 using the calculated internal resistance values ​​R1, R2, R3, and R4.

[0077] Furthermore, if the calculated potential difference exceeds the allowable voltage value during the internal resistance storage process, the controller 70 selects a combination of the batteries 11, 21, 31, and 41 such that the calculated potential difference is equal to or less than the allowable voltage value. The controller 70 then turns on the power supply SW corresponding to the selected battery among the batteries 11, 21, 31, and 41 to supply power to the inverter 50 and the motor 60. At this time, the controller 70 does not calculate the internal resistance values ​​R1, etc., because it cannot measure the current values ​​I1, etc., that would occur when all of the power supply SWs 12, 22, 32, and 42 are turned on. If the controller 70 does not calculate the internal resistance values ​​R1, etc., and the internal resistance values ​​R1, etc. are not stored in the memory 80, the controller 70 may execute the internal resistance storage process again at the next startup.

[0078] <Battery connection method> The controller 70 compares each of the calculated current values ​​I1, I2, I3, and I4 with the allowable current value, and selects the batteries 11, 21, 31, and 41 to be connected to the motor 60 based on the comparison results. In other words, the controller 70 controls the on / off of the power supply SW12, 22, 32, and 42 based on the comparison results.

[0079] Specifically, when the calculated current values ​​I1, I2, I3, and I4 are each equal to or less than the allowable voltage value, the controller 70 turns on the power supply SW12, 22, 32, and 42 because there is no risk of a large current flowing between the batteries 11, 21, 31, and 41, which would cause deterioration of the battery 11, etc. In other words, the controller 70 electrically connects the batteries 11, 21, 31, and 41 to the motor 60, and supplies power from the batteries 11, 21, 31, and 41 to the motor 60.

[0080] Furthermore, if the calculated current values ​​I1, I2, I3, and I4 are greater than the allowable voltage values, the controller 70 keeps at least some of the power supply SW12, 22, 32, and 42 off. In other words, the controller 70 prevents all of the power supply SW12, 22, 32, and 42 from being turned on. By keeping at least some of the power supply SW12, 22, 32, and 42 off in this manner, it is possible to prevent, for example, a large current from flowing between the batteries 11, 21, 31, and 41, which would otherwise deteriorate the battery 11, etc.

[0081] Here, a process for selecting which of the power supply SWs 12, 22, 32, and 42 to turn on and which to turn off will be described.

[0082] If the calculated current values ​​I1, I2, I3, and I4 are greater than the allowable voltage value, the controller 70 selects from among the batteries 11, 21, 31, and 41 a combination of batteries that makes the calculated current values ​​I1, I2, I3, and I4 equal to or less than the allowable voltage value. The controller 70 then turns on the power switch corresponding to the selected battery from among the batteries 11, 21, 31, and 41, and supplies power from the selected battery to the motor 60. This makes it possible to supply power to the motor 60 from the selected battery even if the calculated current values ​​I1, I2, I3, and I4 are greater than the allowable voltage value.

[0083] Specifically, if the calculated current values ​​I1, I2, I3, I4 are greater than the allowable voltage values, the controller 70 recalculates the combined voltage value V when one of the power supply SWs 12, 22, 32, 42 is turned off and the current value of the battery corresponding to the turned-on power supply SW. Here, as an example, a case will be described in which the power supply SW 12 of the first battery pack 10 is turned off and the power supply SWs 22, 32, 42 of the second to fourth battery packs 20-40 are turned on.

[0084] When the power switch 12 of the first battery pack 10 is turned off and the battery 11 is electrically disconnected, the combined voltage value V is calculated using the following equation (7). V=(R3×R4×V2+R2×R4×V3+R2×R3×V4) / (R2×R3+R3×R4+R2×R4) Formula (7)

[0085] The controller 70 estimates and calculates the current values ​​I2, I3, I4 using the combined voltage value V calculated by equation (7), the internal resistance values ​​R2, R3, R4 of the memory 80, the voltage values ​​V2, V3, V4 when the power supplies SW22, 32, 42 are turned off, and equations (2) to (4). If the calculated current values ​​I2, I3, I4 are each equal to or less than the allowable voltage value, the controller 70 determines that the combination of the batteries 21, 31, 41 corresponding to this power supply SW22, 32, 42 is a selectable battery combination.

[0086] The controller 70 performs the above-described processing for the cases where the power SW 22 is turned off, the power SW 32 is turned off, and the power SW 42 is turned off, and extracts selectable battery combinations.

[0087] If the extracted selectable battery combination is one (one set), the controller 70 turns on the power switch corresponding to the battery, and supplies power to the motor 60 from the selected battery.

[0088] If there are multiple selectable battery combinations extracted, the controller 70 compares the batteries with the lowest voltage values ​​among the battery combinations. The controller 70 selects the combination containing the battery with the highest voltage value among the compared batteries. The controller 70 turns on the power switch corresponding to the selected battery combination, and supplies power to the motor 60 from the selected battery.

[0089] The reason why the battery combination including the battery with the highest minimum voltage value is selected from among multiple battery combinations in this way is because the amount of current that can flow from each battery to the motor 60 depends on this minimum voltage value. That is, the amount of current that can flow from the battery to the motor 60 increases as the voltage (in other words, the SOC) increases, but this current amount corresponds to the battery with the lowest voltage value when the batteries are combined. Therefore, in this embodiment, by selecting the combination including the battery with the highest voltage value among the compared batteries, the amount of current that can flow from the batteries to the motor 60 can be maximized. Note that, although the voltage values ​​of the batteries in each combination are compared in the above, this is not limiting and the SOC may also be compared.

[0090] <Method for determining limits when restricting battery connections> As described above, when the calculated current values ​​I1, I2, I3, and I4 are greater than the allowable current values, the controller 70 limits the number of batteries connected to the motor 60. This reduces the power supplied to the motor 60 compared to when all of the batteries 11, 21, 31, and 41 are connected.

[0091] The controller 70 according to this embodiment turns off at least some of the power supply SW12, 22, 32, 42, and when the power supplied to the motor 60 decreases, the controller 70 notifies the user that the power supply to the motor 60 will decrease. This makes it possible for the user to recognize that the power supply to the motor 60 will decrease.

[0092] Furthermore, in this embodiment, if the power supplied to the motor 60 drops and, for example, the motor 60 is unable to perform the desired operation, the user can select how to deal with this situation.

[0093] Specifically, the controller 70 first calculates the power to be supplied to the motor 60 when turning off at least some of the power supply switches 12, 22, 32, and 42. Specifically, the controller 70 multiplies the minimum allowable current value among the combined batteries by the voltage value of each battery to calculate the power supply of each battery, and then calculates the total power supply from the sum of these values. If the calculated total power supply is less than a preset allowable power, the controller 70 executes a process selected by the user. The allowable power is, for example, the lower limit of the power at which the motor 60 can perform the intended operation, and is an example of a power threshold.

[0094] The controller 70 provides the corresponding processing content to the user and executes the processing selected by the user's operation on the operation unit 90. There are three examples of processing content as follows.

[0095] Process 1: The system is not started, and the batteries 11, 21, 31, and 41 are charged using a charger. Process 2: A process is performed to start the system in a state where the power supplied to the motor 60 is reduced. Process 3: The precharge state is continued, and the process of charging the batteries 11, 21, 31, and 41 is performed.

[0096] The charger in process 1 may be a charger mounted on the vehicle or a separate charger. When executing process 1 or process 2, the controller 70 may calculate the time required for charging and notify the user.

[0097] <Limitation on charging using regenerative energy> Furthermore, as described above, if the calculated current values ​​I1, I2, I3, and I4 become larger than the allowable voltage values ​​and the number of batteries connected to the motor 60 is limited, it is preferable to increase the number of batteries connected as soon as possible.

[0098] Therefore, when the controller 70 according to this embodiment turns off at least some of the power supplies SW12, 22, 32, 42, it limits charging of the battery using regenerative energy (regenerative power) from the motor 60. That is, the voltage of the battery connected to the motor 60 drops due to the operation of the motor 60, but by further limiting the regenerative power to such battery, the voltage can quickly approach that of the battery not connected to the motor 60.

[0099] This allows the potential difference between batteries 11, 21, 31, and 41 to be reduced early, making it easier for the calculated current values ​​I1, I2, I3, and I4 to fall below the allowable voltage value, and as a result, it becomes possible to increase the number of batteries connected to motor 60.

[0100] <Memory internal resistance update timing> As described above, the internal resistance values ​​R1, R2, R3, and R4 are stored in the memory 80. In this embodiment, the internal resistance values ​​R1, R2, R3, and R4 are updated when the system is shut down.

[0101] Specifically, when the controller 70 receives a system termination command, it stops excitation of the inverter 50, causing no current to flow to the motor 60. Next, the controller 70 acquires the current values ​​I1, I2, I3, and I4 and the composite voltage value V with the power supplies SW12, 22, 32, and 42 turned on. Next, the controller 70 turns off the power supplies SW12, 22, 32, and 42, and acquires the voltage values ​​V1, V2, V3, and V4 with the power supplies SW12, 22, 32, and 42 turned off.

[0102] The controller 70 then calculates the internal resistance values ​​R1, R2, R3, and R4 based on the current values ​​I1, I2, I3, and I4 and the composite voltage value V when the power supply SW12 etc. is turned on, and the voltage values ​​V1, V2, V3, and V4 when the power supply SW12 etc. is turned off. The controller 70 stores (updates) the calculated new internal resistance values ​​R1, R2, R3, and R4 in the memory 80.

[0103] <When replacing the battery> As described above, the batteries 11, 21, 31, and 41 are configured to be replaceable. When a battery is replaced, its internal resistance value changes. Therefore, when at least some of the batteries 11, 21, 31, and 41 are replaced, the controller 70 according to this embodiment performs the internal resistance storage process described above to recalculate the internal resistance values ​​R1, R2, R3, and R4, and stores the newly calculated internal resistance values ​​R1, R2, R3, and R4 in the memory 80.

[0104] For example, if the battery ID in the battery information 81 has changed since the previous processing, the controller 70 determines that the battery has been replaced. When the controller 70 determines that the battery has been replaced, it executes an internal resistance storage process. Specifically, the controller 70 calculates the potential difference between the batteries 11, 21, 31, and 41. The controller 70 turns on all of the power supply switches 12, 22, 32, and 42, providing that the calculated potential difference is equal to or less than the allowable voltage value, and measures the current values ​​I1, I2, I3, and I4 of the batteries 11, 21, 31, and 41, respectively. The controller 70 then calculates the internal resistance values ​​R1, R2, R3, and R4 based on the measured current values ​​I1, I2, I3, and I4 and the voltage values ​​V1, V2, V3, and V4 when the power supply switches 12, 22, 32, and 42 are turned off. The controller 70 stores the calculated internal resistance values ​​R1, R2, R3, and R4 in the memory 80.

[0105] This allows the controller 70 to calculate and store the internal resistance values ​​R1, R2, R3, and R4 in the memory 80 even when the battery is replaced.

[0106] In the above example, the internal resistance storage process is executed to store the internal resistance values ​​R1, R2, R3, and R4 when the battery is replaced, but the present invention is not limited to this. For example, the internal resistance storage process may be executed when a relatively long time has passed since the internal resistance value or the like was updated in the history information of the battery information 81, or when a relatively long time has passed since the battery 11, 21, 31, or 41 was replaced.

[0107] <Power supply control process of the power supply control device according to the embodiment> Next, specific processing procedures in the power supply control device 1 will be described with reference to FIGS. 4 to 6. FIGS. 4 to 6 are flowcharts showing processing procedures executed by the power supply control device 1. The processing shown in FIGS. 4 and 5 is executed after a power-on operation, such as when the user turns on the ignition switch of the vehicle, and before precharging. The timing at which the processing shown in FIGS. 4 and 5 is executed is not limited to after the power-on operation described above, but may be before the user turns on the power, such as when it is detected that the battery 11 has been attached to the vehicle. The processing shown in FIG. 6 is executed after the power supply control system 100 is started. For example, the processing shown in FIG. 6 may be executed after the main power switch is turned on and the vehicle is ready to run, such as in a Ready-on state, or preferably when the power is turned off, such as after the user turns off the power, or after running has ended.

[0108] 4, the controller 70 of the power supply control device 1 determines whether the internal resistance values ​​R1, R2, R3, and R4 are stored in the memory 80 (step S10). If it is determined that the internal resistance values ​​R1, R2, R3, and R4 are stored (step S10, Yes), the controller 70 determines whether the battery has been replaced (step S11).

[0109] If it is determined that the battery has not been replaced (step S11, No), the controller 70 acquires the voltage values ​​V1, V2, V3, and V4 when the power supply SW12, 22, 32, and 42 are turned off (step S12). Next, the controller 70 calculates a composite voltage value V using the internal resistance values ​​R1, R2, R3, and R4 of the memory 80 and the acquired voltage values ​​V1, V2, V3, and V4 (step S13).

[0110] Next, the controller 70 estimates and calculates the current values ​​I1, I2, I3, and I4 using the calculated composite voltage value V, the internal resistance values ​​R1, R2, R3, and R4 of the memory 80, and the acquired voltage values ​​V1, V2, V3, and V4 (step S14).

[0111] Next, the controller 70 determines whether each of the calculated current values ​​I1, I2, I3, and I4 is equal to or less than the allowable current value (step S15). If the controller 70 determines that the calculated current values ​​I1, I2, I3, and I4 are equal to or less than the allowable current value (step S15, Yes), the controller 70 executes precharge processing (step S16). Specifically, the controller 70 turns on precharge SW13, 23, 33, and 43 to charge the capacitor 52 of the inverter 50. Next, the controller 70 turns on power supply SW12, 22, 32, and 42 (step S17) to supply power from the batteries 11, 21, 31, and 41 to the motor 60.

[0112] On the other hand, if the controller 70 determines that the current values ​​I1, I2, I3, and I4 are not equal to or less than the allowable current value (step S15, No), i.e., are greater than the allowable voltage value, it selects a combination of batteries in which the current values ​​I1, etc. are equal to or less than the allowable voltage value (step S18).

[0113] Next, the controller 70 calculates the total power supply from the combined batteries to the motor 60 (step S19). Next, the controller 70 determines whether the calculated total power supply is less than the allowable power (step S20).

[0114] If it is determined that the total supply power is not less than the allowable power (step S20, No), i.e., if it is equal to or greater than the allowable power, the controller 70 executes a precharge process (step S21). Next, the controller 70 turns on the power switch corresponding to the battery selected in step S18 (step S22) to supply power from that battery to the motor 60. In other words, in step S22, the controller 70 keeps at least some of the power switches off.

[0115] Furthermore, since the number of batteries connected to the motor 60 is limited, the controller 70 executes a process to limit charging of the batteries using regenerative energy from the motor 60 (step S23).

[0116] On the other hand, if it is determined that the total supply power is less than the allowable power (step S20, Yes), the controller 70 provides the user with the corresponding process content and accepts the user's process selection (step S24). Specifically, the controller 70 accepts the selection of one of the following processes: a process for charging the battery using a charger (process 1), a process for starting the system using the motor 60 with reduced power supply (process 2), and a process for charging the battery by pre-charging (process 3). The controller 70 then executes the process selected by the user (step S25).

[0117] If the controller 70 determines that the internal resistance values ​​R1, R2, R3, and R4 are not stored (step S10, No), it executes an internal resistance storage process (step S24). If the controller 70 determines that the battery has been replaced (step S11, Yes), it proceeds to step S24 and executes an internal resistance storage process.

[0118] 5 is a flowchart illustrating the internal resistance storage process when the internal resistance values ​​R1, R2, R3, and R4 are not stored in the memory 80. As shown in FIG. 5, the controller 70 acquires the voltage values ​​V1, V2, V3, and V4 of the batteries 11, 21, 31, and 41 (step S100). Next, the controller 70 calculates the potential difference between the batteries 11, 21, 31, and 41 (step S101). The controller 70 determines whether the calculated potential difference is equal to or less than the allowable voltage value (step S102).

[0119] If the controller 70 determines that the calculated potential difference is equal to or less than the allowable voltage value (Yes in step S102), it executes a precharge process (step S103) and then turns on the power supplies SW12, 22, 32, and 42 (step S104). Next, the controller 70 acquires the current values ​​I1, I2, I3, and I4 and the composite voltage value V (step S105).

[0120] The controller 70 calculates the internal resistance values ​​R1, R2, R3, R4 using the acquired voltage values ​​V1, V2, V3, V4, current values ​​I1, I2, I3, I4, and composite voltage value V (step S106). Then, the controller 70 stores the calculated internal resistance values ​​R1, R2, R3, R4 in the memory 80 (step S107).

[0121] On the other hand, if the controller 70 determines that the calculated potential difference is not equal to or less than the allowable voltage value (step S102, No), it selects a combination of the batteries 11, 21, 31, and 41 such that the calculated potential difference is equal to or less than the allowable voltage value (step S108).The controller 70 then executes a precharge process (step S109), and then turns on the power switch corresponding to the battery selected in step S108 (step S110), supplying power to the motor 60.

[0122] Next, the processing at the time of system shutdown will be described with reference to Fig. 6. As described above, in this embodiment, the internal resistance values ​​R1, R2, R3, and R4 are updated at the time of system shutdown. Therefore, at the time of system shutdown, an internal resistance storage process is performed to store (update) the internal resistance values ​​R1, R2, R3, and R4 in the memory 80.

[0123] 6, the controller 70 determines whether or not there is an instruction to terminate the system (step S201). If it is determined that there is no instruction to terminate the system (step S201, No), the controller 70 skips the subsequent processing.

[0124] On the other hand, if it is determined that an instruction to terminate the system has been issued (Yes at step S201), the controller 70 stops excitation of the inverter 50 (step S202) and puts the motor 60 into a state where no current flows.

[0125] Next, the controller 70 acquires the current values ​​I1, I2, I3, and I4 and the composite voltage value V when the power supplies SW12, 22, 32, and 42 are turned on (step S203). Next, the controller 70 turns off the power supplies SW12, 22, 32, and 42 (step S204). Next, the controller 70 acquires the voltage values ​​V1, V2, V3, and V4 when the power supplies SW12, 22, 32, and 42 are turned off (step S205).

[0126] Next, the controller 70 calculates the internal resistance values ​​R1, R2, R3, and R4 using the acquired current values ​​I1, I2, I3, and I4, the composite voltage value V, and the voltage values ​​V1, V2, V3, and V4 (step S206).The controller 70 then stores the calculated internal resistance values ​​R1, R2, R3, and R4 in the memory 80 (step S207).

[0127] The timing for measuring the measured values ​​(voltage values ​​V1, V2, V3, V4, current values ​​I1, I2, I3, I4 and composite voltage value V) used to calculate the internal resistance values ​​R1, R2, R3, R4 is not limited to the above.

[0128] That is, in the above example, values ​​measured before and after the power supply SW is turned from on to off (in other words, close to the timing of the turning from on to off) are used, as shown in steps S203 to S205 in Fig. 6. Specifically, the example shows that the values ​​measured for each current and composite voltage are used immediately before the power supply SW is turned from on to off, and the values ​​measured for each voltage are used immediately after the power supply SW is turned from on to off.

[0129] As another example, the voltages may be values ​​measured before the power switch is turned on for the current trip, and the currents and composite voltages may be values ​​measured while the power switch was on for the previous trip. Note that while the power switch is on here does not necessarily have to be immediately before the power is turned off, but it is desirable to measure as close to the time of power off as possible. Also, here, one trip is defined as the period from when the power is turned on based on the user's power operation, such as the ignition switch, to when the power is turned off.

[0130] As described above, the power supply control device 1 according to the embodiment includes a controller 70 that controls multiple batteries 11, 21, 31, and 41 that are connected in parallel and to a motor 60 (an example of a load) via power switches 12, 22, 32, and 42, respectively. At startup, the controller 70 calculates an estimated current value that will flow through each of the multiple batteries when the multiple power switches 12, 22, 32, and 42 are turned on, based on the internal resistance values ​​R1, R2, R3, and R4 of each of the multiple batteries stored in memory 80. If the calculated current value is greater than a preset current threshold, the controller 70 keeps at least some of the multiple power switches 12, 22, 32, and 42 off when turning on the power switches 12, 22, 32, and 42. In this way, the current value estimated to flow through each of the multiple batteries 11, 21, 31, and 41 is calculated based on the internal resistance values ​​R1, R2, R3, and R4 of each of the multiple batteries stored in memory 80, and by using the calculated current value, the accuracy of connection determination for the power switches 12, 22, 32, and 42 is improved and early power startup is possible.

[0131] In the above example, the memory (storage unit) 80 that stores the internal resistance value is provided in the power supply control device 1, but the present invention is not limited to this. That is, the memory may be provided outside the power supply control device 1. Furthermore, the memory is not limited to being provided inside the vehicle, but may be provided, for example, in a server device outside the vehicle. In a configuration in which the internal resistance value is stored in the memory of this server device, the server device may also perform arithmetic processing such as calculating the internal resistance value. That is, the measurement value may be transmitted from the in-vehicle device to the server device, and the internal resistance value may be calculated and stored in the server device using the measurement value.

[0132] In addition, although the above example shows a BMS provided for each battery pack, this is not limiting and, for example, a BMS may be provided outside the battery pack, with one BMS managing the status of multiple battery packs. In this case, the only component provided within the battery pack is a simple component such as a measurement circuit.

[0133] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0134] 1 Power supply control device 11,21,31,41 Batteries 60 motor 70 Controller 80 memory 100 Power Control System

Claims

1. a controller for controlling a plurality of batteries connected in parallel and connected to a load via a power switch, The controller At startup, a current value estimated to flow through each of the plurality of batteries when the plurality of power switches are turned on is calculated according to the internal resistance values ​​of each of the plurality of batteries stored in memory; If the calculated current value is greater than a preset current threshold, at least some of the power switches are maintained in an off state when the power switches are turned on. Power control device.

2. The internal resistance value stored in the memory is stored by an internal resistance storage process that calculates and stores an internal resistance value using a measurement value measured during startup. The power supply control device according to claim 1 .

3. The internal resistance value stored in the memory is a value stored in the internal resistance storage process performed during the previous startup. The power supply control device according to claim 2 .

4. The internal resistance storage process includes: a process of calculating the internal resistance value using the measured voltage values ​​of the plurality of batteries, and the current value and composite voltage value measured with the power switch on; The power supply control device according to claim 2 .

5. The controller If the internal resistance value is not stored in the memory, turning on all of the power switches and measuring the current values ​​of the batteries, provided that the potential difference between the batteries is equal to or less than a preset voltage threshold; calculating the internal resistance value in accordance with the measured current value, and storing the calculated internal resistance value in the memory; The power supply control device according to claim 1 .

6. The controller When at least some of the plurality of power switches are turned off, a user is notified that power supply to the load will be reduced. The power supply control device according to claim 1 .

7. The controller and when the power supplied to the load is less than a preset power threshold by turning off at least some of the power switches, executes a process of charging the battery. The power supply control device according to claim 1 .

8. The controller If the calculated current value is greater than the current threshold, a combination of batteries is selected from the plurality of batteries such that the calculated current value is equal to or less than the current threshold; turning on the power switch corresponding to the selected battery; The power supply control device according to claim 1 .

9. The controller when at least some of the plurality of batteries have been replaced, turning on all of the plurality of power switches and measuring the current values ​​of each of the plurality of batteries, provided that a potential difference between the plurality of batteries after replacement is equal to or less than a predetermined voltage threshold; calculating the internal resistance value in accordance with the measured current value, and storing the calculated internal resistance value in the memory; The power supply control device according to claim 1 .

10. the load is a motor-generator motor, The controller limiting charging of the battery using regenerative energy of the motor-generator motor when at least some of the power switches are turned off; The power supply control device according to claim 1 .

11. A plurality of batteries connected in parallel; a power switch provided between each of the plurality of batteries and a load; a power supply control device including a controller for controlling the plurality of batteries; A power supply control system including: The controller At startup, a current value estimated to flow through each of the plurality of batteries when the plurality of power switches are turned on is calculated according to the internal resistance values ​​of each of the plurality of batteries stored in memory; If the calculated current value is greater than a preset current threshold, at least some of the power switches are maintained in the ON state when the power switches are turned on. Power control system.

12. A power supply control method executed by a controller that controls a plurality of batteries connected in parallel and connected to a load via respective power switches, comprising: At startup, a current value estimated to flow through each of the plurality of batteries when the plurality of power switches are turned on is calculated according to the internal resistance values ​​of each of the plurality of batteries stored in memory; If the calculated current value is greater than a preset current threshold, at least some of the power switches are maintained in an off state when the power switches are turned on. Power control method.

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