Charging control device, vehicle, and charging control method

Abstract

This allows us to provide a charging control device that can accurately detect abnormalities in the power receiver. [Solution] The charging control device according to the present invention is a charging control device that controls charging of a battery in a vehicle equipped with a battery, and comprises an acquisition unit that acquires the temperature of a first power terminal and a second power terminal of a power receiver provided in the vehicle, and a determination unit that determines the state of the power receiver based on the difference between the temperature of the first power terminal and the temperature of the second power terminal.

Description

Technical Field

[0001] The present invention relates to a charging control device, a vehicle, and a charging control method.

Background Art

[0002] Charging of an electric vehicle is performed with a relatively large current. A technique for detecting overheating of a terminal contact portion between a charging connector and a power receiver, which may occur at that time, is known. Patent Document 1 discloses a technique for determining an abnormality based on the temperature or temperature change of a power receiving port detected by a temperature sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When determining an abnormality based on the temperature or temperature change of a power receiving port as in the technique described in Patent Document 1, there are a delay in determining an abnormality due to a time lag in measurement by a temperature sensor and a risk of misjudgment due to a change in outside air temperature.

[0005] An object of the present invention is to provide a charging control device that can accurately determine an abnormality of a power receiver.

Means for Solving the Problems

[0006] The charging control device according to the present invention is a charging control device that controls charging of the battery in a vehicle equipped with a battery, and includes an acquisition unit that acquires the temperature of a first power supply terminal of a power receiver provided in the vehicle and the temperature of a second power supply terminal of the power receiver, and a determination unit that determines the state of the power receiver based on the difference between the temperature of the first power supply terminal and the temperature of the second power supply terminal.

Effects of the Invention

[0007] The present invention provides a charging control device that can accurately determine abnormalities in a power receiver. [Brief explanation of the drawing]

[0008] [Figure 1] This is a configuration diagram of a charging system equipped with a charging control device according to one embodiment of the present invention. [Figure 2] This is a front view showing an example of the structure of a power receiver according to one embodiment of the present invention. [Figure 3] This is a block diagram showing the functional configuration of a charging control device according to one embodiment of the present invention. [Figure 4] This graph shows the temperature changes of each power terminal when only the first power terminal overheats in a charging control device according to one embodiment of the present invention. [Figure 5] This graph shows the temperature changes of each power terminal when only the first power terminal overheats in a charging control device according to one embodiment of the present invention, in the event of a change in ambient temperature. [Figure 6] This diagram shows a flow chart of a charging control method performed by a charging control device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings. Note that the drawings are simplified, and the technical scope of the embodiments should not be narrowly interpreted based on their depiction. Furthermore, the same elements are denoted by the same reference numerals, and redundant explanations are omitted. Also, in the following embodiments, when referring to the number of elements (including quantity, numerical value, amount, range, etc.), unless specifically stated or clearly limited to a particular number in principle, the number is not limited to that particular number and may be greater than or less than that number.

[0010] Furthermore, in the following embodiments, the components are not necessarily essential unless otherwise explicitly stated or considered to be clearly essential in principle. Similarly, in the following embodiments, when referring to the shape, positional relationship, etc., of the components, etc., it shall include those that substantially approximate or resemble their shape, etc., unless otherwise explicitly stated or considered to be clearly not essential in principle. The same applies to the numbers, etc. (including the number of items, numerical values, quantities, ranges, etc.).

[0011] <Background of considerations leading to the design of the charging control device 10 according to this embodiment> Electric vehicles and other vehicles are charged via a charging device and a power receiver such as a charging inlet installed on the vehicle. To detect overheating of the power terminal contact area between the charging connector and the power receiver that occurs during this process, a method based on the temperature of the power terminals installed on the power receiver and connected to the charging cable is used.

[0012] Temperature sensors used to detect the temperature of the power terminals of a power receiver are structurally positioned at a certain distance from the power terminals. Therefore, their response to temperature changes at the power terminals is not always good.

[0013] Overheating of the power terminals is detected when the temperature of the power terminals exceeds a predetermined threshold, or when the temperature rise of the power terminals exceeds a predetermined threshold. When overheating is detected by the temperature of the power terminals exceeding a predetermined value, there is a risk that the detection of overheating may be delayed if a rapid temperature change occurs. Also, if the temperature threshold used for overheating detection is set too low, there is a risk of false detection under normal conditions.

[0014] When overheating of the power terminal is detected when the temperature rise of the power terminal exceeds a predetermined threshold, the possibility of false detection is reduced even in the event of abrupt temperature changes. However, there is a risk of misjudgment due to changes in ambient temperature and changes in ambient temperature due to solar radiation. Therefore, it is desirable to be able to more accurately determine the abnormality of the power receiver when detecting overheating based on the measured temperature of the power terminal.

[0015] Therefore, the charging control device 10 according to the present embodiment was found. Hereinafter, the charging control device 10 according to an embodiment of the present invention will be described.

[0016] [Embodiment] [Configuration of Charging System 1] FIG. 1 shows a configuration diagram of a charging system 1 including a charging control device 10 according to an embodiment of the present invention. The charging system 1 of this embodiment includes a vehicle V, a charging device 20, and a charging cable 21 connecting these. Note that the configurations and functions of the charging system 1, the vehicle V, and the charging device 20 are not limited to the example of FIG. 1.

[0017] The vehicle V includes a high-voltage battery 12 that can supply operating power to a motor that generates driving power. The vehicle V is, for example, a plug-in vehicle or an electric vehicle that can travel electrically using the motor as a driving power source.

[0018] The high-voltage battery 12 is a high-voltage DC power source, for example, at 200 volts to 600 volts, and is a vehicle drive battery including a rechargeable secondary battery such as nickel-hydrogen or lithium-ion. The high-voltage battery 12 can be charged by power supply from the charging device 20.

[0019] The charging device 20 is a charging stand installed at a gas station, convenience store, vehicle repair shop, or ordinary household, etc. It can supply power to the high-voltage battery 12 of the vehicle V connected via the charging cable 21 using an external power source connected via, for example, a power outlet. When the charging device 20 supplies power to the high-voltage battery 12 of the vehicle V via the charging cable 21, it is possible to transmit and receive data exchanged between a control circuit (not shown) provided in the charging device 20 and the charging control device 10 provided in the vehicle V.

[0020] When power is supplied from the charging device 20 to the high-voltage battery 12, the data transmitted and received between the charging device 20 and the charge control device 10 is data necessary for performing a charging process, such as whether or not power supply from the charging device 20 to the high-voltage battery 12 is possible. Further, the data transmitted and received between the charging device 20 and the charge control device 10 may be input ID data of the person charging the high-voltage battery 12, data regarding the charging content from the charging device 20 to the charge control device 10 such as the charging amount and charging fee, and the like.

[0021] One end of a charging cable 21 is connected to the charging device 20. The charging cable 21 is attached to the charging device 20. The charging cable 21 includes a power line 22 through which electricity from the charging device 20 flows, and a signal line 23 through which data transmitted and received between the charging device 20 and the charge control device 10 flows. The charging device 20 can supply power for charging the high-voltage battery 12 toward the charge control device 10 using the power line 22 of the charging cable 21. Further, the charging device 20 can transmit data to be provided to the charge control device 10 to the charge control device 10 using the signal line 23 of the charging cable 21.

[0022] Note that the data transmitted and received between the charging device 20 and the charge control device 10 during charging of the high-voltage battery 12 may be sent using the power line 22 instead of the signal line 23 or together with the signal line 23.

[0023] A charging connector 13 for connecting to the power receiver 11 is provided at the other end of the charging cable 21. The charging connector 13 is a male connector including power supply terminals that are respectively connected to the above-described power line 22 and the above-described signal line 23 included in the charging cable 21. The vehicle V includes a power receiver 11 to which the charging connector 13 provided at the other end of the charging cable 21 is connected. The power receiver 11 is also referred to as, for example, a "charging inlet", and is a female insertion port including a plurality of power supply terminals corresponding to the power line 22 and the signal line 23 included in the charging cable 21. Hereinafter, the plurality of power supply terminals included in the power receiver 11 are referred to as a "first power supply terminal" and a "second power supply terminal", but the number of power supply terminals is not limited to two.

[0024] The power receiver 11 is installed, for example, near the high-voltage battery 12, for example, at the rear, side, and front of the vehicle body V. The power terminals of the power receiver 11 and the high-voltage battery 12 are connected via a power line 14. Electricity supplied from the charging device 20 flows through the power line 14 via the power line 22 of the charging cable 21. The power from the charging device 20 flows through the power line 14 and is also converted to a DC voltage of, for example, 200 volts to 600 volts before being supplied to the high-voltage battery 12.

[0025] The charging control device 10 is an electronic control unit (ECU) for charging control, primarily composed of a microcomputer. The charging control device 10 includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), and an input / output interface (I / F) as its hardware configuration. These are electrically connected to each other via a bus. The CPU controls the operation of the charging control device 10. The ROM stores programs executed by the CPU. The RAM is used as the CPU's workspace. The HDD stores various data such as programs. The input / output interface is an interface for inputting and outputting various signals and data to and from external devices.

[0026] The charging control device 10 controls the charging of the high-voltage battery 12 mounted on the vehicle V. The signal terminal of the power receiver 11 and the charging control device 10 are connected via a signal line 15. The charging control device 10 generates data (hereinafter referred to as charging control data) that should be exchanged between the charging device 20 and the charging control device 10 via the signal line 23 when charging the high-voltage battery 12, and supplies it to the signal line 15. The charging control device 10 also receives the charging control data supplied from the charging device 20 via the signal line 15. Based on the charging control data exchanged between the charging device 20 and the charging control device 10 via the signal line 23, the charging control device 10 controls the charging of the high-voltage battery 12 by power supply from the charging device 20.

[0027] Vehicle V is equipped with a low-voltage battery 16 capable of supplying operating power to various auxiliary equipment mounted on Vehicle V. The low-voltage battery 16 is a low-voltage DC power source, such as 12 volts, which is lower than the voltage of the high-voltage battery 12, and is an auxiliary battery equipped with a rechargeable secondary battery such as nickel-metal hydride or lithium-ion. The low-voltage battery 16 can be charged by the power generated by the alternator, which generates electricity from the rotation of the onboard engine and regenerative braking during vehicle deceleration.

[0028] The high-voltage battery 12 and the low-voltage battery 16 are connected to each other via a DC-DC converter 17. The DC-DC converter 17 is a device that performs voltage conversion between the high-voltage battery 12 and the low-voltage battery 16. The DC-DC converter 17 operates when power is supplied from the high-voltage battery 12 to the low-voltage battery 16, or when power is supplied from the low-voltage battery 16 to the high-voltage battery 12. The low-voltage battery 16 can be charged by power supplied from the high-voltage battery 12.

[0029] A hybrid electronic control unit (HV-ECU) 18 is connected to the DC-DC converter 17. The HV-ECU 18 comprehensively controls the vehicle V's operation and the status of the high-voltage battery 12 and the low-voltage battery 16. The HV-ECU 18 controls the charging and discharging of the high-voltage battery 12 and the low-voltage battery 16, as well as the charging and discharging between the high-voltage battery 12 and the low-voltage battery 16. The HV-ECU 18 controls the DC-DC converter 17 to ensure that the charging and discharging of the high-voltage battery 12 and the low-voltage battery 16 are performed appropriately. The DC-DC converter 17 operates based on commands from the HV-ECU 18.

[0030] The charging control device 10 and the HV-ECU 18 are components that can communicate with the charging device 20 via the signal line 23 of the charging cable 21 regarding charging control data to be exchanged between the charging device 20 and the charging control device 10 via the signal line 23 when the high-voltage battery 12 is charged by power supply from the charging device 20 to the high-voltage battery 12, and other data different from the charging control data (hereinafter referred to as external communication data).

[0031] The charging control device 10 and the HV-ECU 18 are connected to each other via an in-vehicle LAN, such as CAN, and can exchange information with each other through the in-vehicle LAN. For example, the charging control device 10 determines whether or not the high-voltage battery 12 is being charged by power supply from the charging device 20 to the high-voltage battery 12 via the power line 22 of the charging cable 21, and information indicating the result of this determination is supplied from the charging control device 10 to the HV-ECU 18 via the in-vehicle LAN. Based on the information supplied from the charging control device 10 via the in-vehicle LAN, the HV-ECU 18 determines whether or not the high-voltage battery 12 is actually being charged by power supply from the charging device 20.

[0032] A charging communication unit 19 is connected to the in-vehicle LAN. The charging communication unit 19 is a component that acts as a gateway for data to be exchanged between the charging control device 10 and HV-ECU 18 connected to the in-vehicle LAN and the charging device 20 connected to the power receiver 11 via the charging connector 13 and the signal lines 23 of the charging cable 21. The charging communication unit 19 relays data supplied from the charging control device 10 or HV-ECU 18 via the in-vehicle LAN and supplies it to the charging device 20 via the signal lines 23 of the charging cable 21, and also relays data supplied from the charging device 20 via the signal lines 23 of the charging cable 21 and supplies it to the charging control device 10 or HV-ECU 18 via the in-vehicle LAN.

[0033] The charging communication unit 19 has a function to determine whether or not external communication data is being communicated between the charging control device 10 or HV-ECU 18 and the charging device 20. The data indicating the result of the communication determination made by the charging communication unit 19 regarding whether or not external communication data is being communicated between the charging control device 10 or HV-ECU 18 and the charging device 20 is sent from the charging communication unit 19 to the in-vehicle LAN.

[0034] The HV-ECU18 receives data indicating the result of the communication determination sent from the charging communication unit 19 to the in-vehicle LAN. Based on the ignition information of the vehicle V and the data indicating the result of the communication determination sent from the charging communication unit 19 to the in-vehicle LAN, the HV-ECU18 has a function to determine whether or not external communication data is being communicated between the charging control device 10 or the HV-ECU18 and the charging device 20 while the vehicle V's ignition is off.

[0035] The charging control device 10, HV-ECU 18, and charging communication unit 19, which are connected to the in-vehicle LAN 14 and communicate data for external communication with the charging device 20, are connected to a low-voltage battery 16 as a power source. The charging control device 10, HV-ECU 18, and charging communication unit 19 each operate by receiving power from the low-voltage battery 16.

[0036] <Charging inlet configuration> Figure 2 is a front view showing an example of the structure of a power receiver 11 according to one embodiment of the present invention. The power receiver 11 includes a guide wall 111, a first power terminal 112 and a second power terminal 113, communication terminals 114 and 115, a fastener 116, a charging lid 117, a charging lid actuator 118, and temperature detection units 119n and 119p. The first power terminal 112 and the second power terminal 113 may, for example, be an N (negative) terminal and a P (positive) terminal, respectively. Alternatively, the first power terminal 112 and the second power terminal 113 may, for example, be a P terminal and an N terminal, respectively.

[0037] The guide wall 111 is formed in a cylindrical shape. Power lines 14 are electrically connected to the first power terminal 112 and the second power terminal 113, respectively. Signal lines 15 are electrically connected to the communication terminals 114 and 115, respectively. A fastener 116 is provided at the upper end of the guide wall 111.

[0038] The charging lid 117 is configured to open and close within the guide wall 111 by rotating on the side of the guide wall 111. The charging lid actuator 118 controls the opening and closing of the charging lid 117 in response to a control signal from the charging control device 10.

[0039] The temperature detection units 119n and 119p are provided, for example, above the guide wall 111. The temperature detection unit 119n detects the temperature of the first power terminal 112, and the temperature detection unit 119p detects the temperature of the second power terminal 113. For example, thermocouples and thermistors can be used for the temperature detection units 119n and 119p. Note that the installation positions of the temperature detection units 119n and 119p are not limited to the configuration shown in the figure. In the following, the temperature detection units 119n and 119p will also be simply referred to as "temperature detection unit 119".

[0040] Figure 3 is a block diagram showing the functional configuration of a charging control device 10 according to one embodiment of the present invention. The charging control device 10 comprises an acquisition unit 2, a determination unit 3, and a control unit 4. The charging control device 10 controls the charging of a battery in a vehicle V equipped with a battery. The battery is, for example, the high-voltage battery 12 shown in Figure 1.

[0041] The temperature detection unit 119 of the power receiver 11 detects the temperatures of the first power terminal 112 and the second power terminal 113 provided on the vehicle V. The acquisition unit 2 acquires the temperatures of the first power terminal 112 and the second power terminal 113 detected by the temperature detection unit 119.

[0042] The determination unit 3 determines the state of the power receiver 11 based on the difference between the temperature of the first power terminal 112 and the temperature of the second power terminal 113. The state of the power receiver 11 is, for example, whether or not the first power terminal 112 or the second power terminal 113 is overheating.

[0043] More specifically, the determination unit 3 determines that there is an abnormality in the power terminal with the higher temperature among the first power terminal 112 and the second power terminal 113 if the difference between the temperatures of the first power terminal 112 and the second power terminal 113 is greater than or equal to a predetermined threshold. The predetermined threshold is preferably a value that does not hinder the charging operation of the vehicle V's battery under normal conditions.

[0044] If the determination unit 3 determines that there is an abnormality in either the first power terminal 112 or the second power terminal 113, the control unit 4 restricts charging to the vehicle V's battery. The restrictions on charging performed by the control unit 4 are either a restriction on the charging current or a complete halt to charging.

[0045] Figure 4 is a graph showing the temperature changes of each power terminal in a charging control device 10 according to one embodiment of the present invention when only the first power terminal 112 overheats. The graph shows an example of the time-series changes in the temperature of the first power terminal 112 and the second power terminal 113 when there is no change in ambient temperature. The temperatures of the first power terminal 112 and the second power terminal 113 are the temperatures detected by the temperature detection unit 119.

[0046] In the figure, D represents the difference between the temperature of the first power terminal 112 and the temperature of the second power terminal 113 at time t. In the illustrated example, the determination unit 3 determines that the first power terminal 112, which has a higher temperature, is abnormally overheated if the difference D between the temperature of the first power terminal 112 and the temperature of the second power terminal 113 is greater than or equal to a predetermined threshold. At this time, the control unit 4 issues a command to the charging device 20 to limit the charging current or to stop charging.

[0047] Figure 5 is a graph showing the temperature changes of each power terminal in a charging control device 10 according to one embodiment of the present invention, when only the first power terminal 112 overheats due to a change in ambient temperature. The graph shows temperature on the vertical axis and time on the horizontal axis, illustrating an example of the time-series changes in the temperature of the first power terminal 112 and the second power terminal 113 when there is a change in ambient temperature. The figure also shows an example of the time-series changes in the temperature of the first power terminal 112 and the second power terminal 113 when there is no change in ambient temperature. As in Figure 4, the temperature of each power terminal is the temperature detected by the temperature detection unit 119.

[0048] In the figure, D represents the difference between the temperature of the first power terminal 112 and the temperature of the second power terminal 113 at time t. Furthermore, c1 represents the temperature change of the first power terminal 112 due to the influence of ambient temperature, and c2 represents the temperature change of the second power terminal 113 due to the influence of ambient temperature.

[0049] Since the first power terminal 112 and the second power terminal 113 are included in the same power receiver 11, the temperature changes c1 and c2 of each terminal are considered to be approximately equal. Therefore, the difference D between the temperature of the first power terminal 112 and the temperature of the second power terminal 113 is considered to be less affected by the ambient temperature.

[0050] Therefore, as in the charging control device 10 according to this embodiment, when an abnormality such as overheating of the power terminals is determined based on the difference D between the temperature of the first power terminal 112 and the temperature of the second power terminal 113 of the power receiver 11, there is little possibility of misjudgment due to changes in ambient temperature and changes in ambient temperature due to solar radiation, and a fail-safe mechanism for the power receiver 11 can be appropriately implemented.

[0051] <Charging control method> Figure 6 is a diagram showing the flow of a charging control method executed by a charging control device 10 according to one embodiment of the present invention. When charging of the vehicle V's high-voltage battery 12 from the charging device 20 begins (S101), the temperature detection unit 119 of the power receiver 11 detects the temperature T1 of the first power terminal 112 and the temperature T2 of the second power terminal 113. Then, the acquisition unit 2 of the charging control device 10 detects the temperature T1 of the first power terminal 112 and the temperature T2 of the second power terminal 113 (S102).

[0052] If the charging device 20 does not continue charging the vehicle V's high-voltage battery 12 (No in S103), it terminates charging (S104). If charging the vehicle V's high-voltage battery 12 is to be continued (Yes in S103), the determination unit 3 of the charging control device 10 determines the state of the power receiver 11 based on the difference D between the temperature T1 of the first power terminal 112 and the temperature T2 of the second power terminal 113, and a predetermined threshold X (S105).

[0053] The determination unit 3 determines that overheating has not occurred at the power terminals if the difference D between the temperature T1 of the first power terminal 112 and the temperature T2 of the second power terminal 113 is less than a predetermined threshold X (No. in S105). At this time, the control unit 4 of the charging control device 10 instructs the charging device 20 to continue charging the vehicle V's high-voltage battery 12 and returns to the process in step S103.

[0054] The determination unit 3 determines that overheating has occurred at the power terminals if the difference D between the temperature T1 of the first power terminal 112 and the temperature T2 of the second power terminal 113 is greater than or equal to a predetermined threshold X (Yes in S105). At this time, the control unit 4 of the charging control device 10 issues a command to the charging device 20 to limit the charging current to the vehicle V battery or to stop charging (S106).

[0055] These steps carry out a charging control method according to one aspect of the present invention. However, the charging control method according to one aspect of the present invention may include other steps as appropriate, depending on the measurement conditions, measurement environment, etc.

[0056] <Effects of the charging control device 10 according to this embodiment> In this embodiment, the charging control device 10 determines overheating of the power terminals based on the difference D between the temperature of the first power terminal 112 and the temperature of the second power terminal 113 of the power receiver 11. Therefore, there is little possibility of misjudgment caused by changes in ambient temperature due to changes in outside temperature and changes in ambient temperature due to solar radiation.

[0057] Therefore, according to this embodiment, it is possible to provide a charging control device 10 that can accurately determine abnormalities in the power receiver 11.

[0058] Although the present invention has been described above in accordance with the embodiments described above, the present invention is not limited to the configuration of the embodiments described above, and of course includes various modifications, alterations, and combinations that can be made by a person skilled in the art within the scope of the claims of the present patent application. [Explanation of symbols]

[0059] 1 Charging System 2 Acquisition part 3 Judgment section 4. Control Unit 10 Charging control device 11 Power receiver 12 High-voltage batteries 20 Charging device 112 1st power supply terminal 113 2nd power supply terminal 119 Temperature detection unit V Vehicle

Claims

1. A charging control device for controlling the charging of a battery in a vehicle equipped with a battery, An acquisition unit that acquires the temperature of the first power terminal and the temperature of the second power terminal of a power receiver provided in the vehicle, A determination unit that determines the state of the power receiver based on the difference between the temperature of the first power terminal and the temperature of the second power terminal, A charging control device equipped with the following features.

2. The determination unit determines that if the difference between the temperature of the first power terminal and the temperature of the second power terminal is greater than or equal to a predetermined threshold, there is an abnormality in the terminal with the higher temperature. The charging control device according to claim 1.

3. The determination unit further includes a control unit that restricts charging to the battery if it determines that there is an abnormality in either the first power terminal or the second power terminal. The charging control device according to claim 1 or 2.

4. A charging control device that controls charging of a battery in a vehicle equipped with a battery, A power receiver including a first power terminal, a second power terminal, and a temperature detection unit for detecting the temperature of the first power terminal and the temperature of the second power terminal, Equipped with, The charging control device is An acquisition unit that acquires the temperature of the first power terminal and the temperature of the second power terminal detected by the temperature detection unit, The device includes a determination unit that determines the state of the power receiver based on the difference between the temperature of the first power terminal and the temperature of the second power terminal, vehicle.

5. A charging control method performed by a charging control device that controls charging of a battery in a vehicle equipped with a battery, The steps include obtaining the temperature of the first power terminal and the second power terminal of a power receiver installed in the vehicle, A step of determining the state of the power receiver based on the difference between the temperature of the first power terminal and the temperature of the second power terminal, A charging control method including the following.

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