Power supply system

Abstract

To provide a technique that is able to cope with a situation where a load with large current consumption is connected to a connection part of a vehicle by a user.SOLUTION: In a power supply system 1 mounted on a vehicle, a user can connect a load (an external load 70) to a connection part 14. A power supply unit 10 supplies power to the load via the connection part 14. A current detection unit (a first current detection unit 32a) detects a current flowing from the power supply unit 10 to the load. When the detected current is equal to or higher than the rated current, a notification unit 42 notifies the user of caution information.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an in-vehicle power supply system.

Background Art

[0002] Patent Document 1 discloses a protection device for a load circuit that detects a current flowing through a load provided in a vehicle and interrupts the load circuit based on the detected current.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, a general vehicle is provided with a connection part to which a user can connect an electrical load, and power can be supplied from the vehicle to the electrical load connected to the connection part. The connection part includes, for example, a cigarette lighter socket or the like. A rated current is defined for the connection part. However, there is a possibility that a user may connect a load that draws a current greater than the rated current to the connection part.

[0005] An object of the present invention is to provide a technology that can cope with a situation where a load with a large current consumption is connected to a connection part of a vehicle by a user.

Means for Solving the Problems

[0006] In order to solve the above problems, a power supply system according to an aspect of the present invention is a power supply system mounted on a vehicle, and includes a connection part to which a user can connect a load, a power supply part that supplies power to the load via the connection part, a current detection part that detects a current flowing from the power supply part to the load, and a notification part that notifies a user of caution information when the detected current is greater than or equal to a rated current.

Effects of the Invention

[0007] According to the present invention, a technology is available that can address situations where a user connects a load with high current consumption to a vehicle's connection point. [Brief explanation of the drawing]

[0008] [Figure 1] This diagram schematically shows the configuration of the power supply system in the embodiment. [Figure 2] This flowchart shows the process related to power supply to the connection point shown in Figure 1. [Modes for carrying out the invention]

[0009] Figure 1 schematically shows the configuration of the power supply system 1 of the embodiment. The power supply system 1 is mounted on a vehicle (not shown) and supplies power to various electrical loads. The vehicle may be a vehicle that uses only an internal combustion engine as the driving force source, or it may be an electric vehicle that uses an electric motor as the driving force source. Examples of electric vehicles include electric vehicles (BEV: Battery Electric Vehicle), hybrid vehicles (HEV: Hybrid Electric Vehicle), plug-in hybrid vehicles (PHEV: Plug-in Hybrid Electric Vehicle), or fuel cell vehicles (FCEV: Fuel Cell Electric Vehicle). The vehicle may be a vehicle driven by a driver, or it may be an autonomous vehicle.

[0010] As shown in Figure 1, the power supply system 1 comprises a power supply unit 10, a switch unit 12, a connection unit 14, a first on-board load 16a, a second on-board load 16b, an input unit 18, an output unit 20, and a processing unit 22.

[0011] Figure 1 shows the first on-board load 16a and the second on-board load 16b, but the power supply system 1 has more on-board loads than those shown. Hereafter, the multiple on-board loads, including the first on-board load 16a and the second on-board load 16b, will be collectively referred to as on-board load 16.

[0012] The power supply unit 10 supplies power to the connection unit 14 and the multiple vehicle loads 16 via the switch unit 12. The power supply unit 10 includes, for example, an auxiliary battery (not shown), which is a rechargeable secondary battery. The power supply unit 10 is capable of outputting power stored in the auxiliary battery. Various known configurations can be adopted for the power supply unit 10. The power supply unit 10 may include an alternator or a power conversion device such as a DC / DC converter. The voltage supplied to the connection unit 14 by the power supply unit 10 may be different from the voltage supplied to the multiple vehicle loads 16.

[0013] The switch unit 12 can individually control the current flowing from the power supply unit 10 to the connection unit 14, and the current flowing from the power supply unit 10 to each of the multiple vehicle loads 16.

[0014] The switch unit 12 includes a first semiconductor switch 30a, a second semiconductor switch 30b, a third semiconductor switch 30c, a first current detection unit 32a, a second current detection unit 32b, and a third current detection unit 32c. The switch unit 12 may have more semiconductor switches and current detection units than those shown. Hereinafter, the multiple semiconductor switches, including the first semiconductor switch 30a, the second semiconductor switch 30b, and the third semiconductor switch 30c, will be collectively referred to as the semiconductor switch 30. Similarly, the multiple current detection units, including the first current detection unit 32a, the second current detection unit 32b, and the third current detection unit 32c, will be collectively referred to as the current detection unit 32.

[0015] Each of the multiple semiconductor switches 30 is, for example, a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor), and has one end to which the output power of the power supply unit 10 is supplied, the other end which is electrically connected to one end of the corresponding current detection unit 32, and a control terminal to which a control signal is supplied from the processing unit 22.

[0016] The other end of the first current detection unit 32a is electrically connected to the connection unit 14. The first current detection unit 32a detects the current flowing from the power supply unit 10 to the external load 70 via the connection unit 14 and supplies the detected current value information to the processing unit 22.

[0017] The other end of the second current detection unit 32b is electrically connected to the first on-board load 16a. The second current detection unit 32b detects the current flowing from the power supply unit 10 to the first on-board load 16a and supplies the detected current value information to the processing unit 22.

[0018] The other end of the third current detection unit 32c is electrically connected to the second on-board load 16b. The third current detection unit 32c detects the current flowing from the power supply unit 10 to the second on-board load 16b and supplies the detected current value information to the processing unit 22.

[0019] The connection section 14 is a port to which a user can electrically connect an external load 70 and to which power is supplied. The connection section 14 is a connector to which the power connector 72 of the external load 70 can be connected. The external load 70 is an external device that is not a component of the vehicle, and can be various electrical devices, such as mobile terminals. The connection section 14 can also be called an external power supply port or external power outlet. The connection section 14 is, for example, a cigarette lighter socket, a USB (Universal Serial Bus) port, or an accessory outlet located inside the vehicle's cabin. An accessory outlet can supply AC power. If the connection section 14 is an accessory outlet, the power supply section 10 is configured to supply AC power to the accessory outlet. Multiple connection sections 14 may be provided. The connection section 14 may be located on the vehicle body and may be capable of electrically connecting external loads used outside the vehicle.

[0020] The multiple vehicle loads 16 are electrical loads installed in the vehicle and are components of the vehicle. These multiple vehicle loads 16 may include, for example, headlights, turn signals, navigation systems, audio systems, air conditioners, defoggers, seat heaters, wipers, and various ECUs (Electronic Control Units). The vehicle loads 16 operate using power supplied from the power supply unit 10. The vehicle loads 16 can also be called vehicle electrical components or auxiliary loads.

[0021] The input unit 18 includes, for example, a switch provided on the steering wheel of a vehicle, and is a device into which various operations of a user are input. The input unit 18 outputs an operation signal resulting from a user operation to the processing unit 22. The input unit 18 may be another input device such as a touch sensor into which a user operation is input.

[0022] The output unit 20 includes at least one of a display unit and a speaker provided inside the vehicle cabin, and outputs various types of information to the user by at least one of display and sound in accordance with an instruction from the processing unit 22. The display unit includes, for example, a MID (Multi Information Display) provided on the meter panel inside the vehicle cabin. The display includes, for example, an image and characters representing a message. The display unit may include an indicator composed of, for example, an LED (Light Emitting Diode) provided near the connection unit 14.

[0023] The processing unit 22 controls the switch unit 12. The processing unit 22 has a control unit 40, a notification unit 42, and a reception unit 44. In terms of hardware, the configuration of the processing unit 22 can be realized by a CPU, a memory, and other LSIs of an arbitrary computer, and in terms of software, it is realized by a program loaded into the memory or the like. Here, functional blocks realized by their cooperation are depicted. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by only hardware, only software, or a combination thereof.

[0024] The control unit 40 controls the switch unit 12 to limit the current flowing to a predetermined onboard load 16 among a plurality of onboard loads 16, for example, when the output voltage of the power supply unit 10 detected by a voltage sensor (not shown) is below a predetermined voltage threshold. The voltage threshold can be appropriately determined by experiment or simulation. When the output voltage of the power supply unit 10 falls below the voltage threshold, it corresponds to the State of Charge (SOC) of the auxiliary battery of the power supply unit 10 falling below a threshold. In this case, the control unit 40 controls the control voltage supplied to the control terminal of the semiconductor switch 30 connected to the predetermined onboard load 16 to limit the current flowing to the semiconductor switch 30. The predetermined onboard load 16 is a load that does not directly affect the vehicle's operation even if the current is reduced, for example, an air conditioner.

[0025] If numerous in-vehicle loads 16 and external loads 70 continue to operate with relatively high current consumption, that is, if the power used by the vehicle remains relatively high, the output voltage of the power supply unit 10 may drop below the voltage threshold. In this case, this control reduces the current supplied to, for example, the air conditioner, thereby reducing its airflow, which reduces the power used by the vehicle and makes it easier for the output voltage of the power supply unit 10 to recover above the voltage threshold through charging. This prevents the operation of the in-vehicle loads 16, which directly affect the vehicle's operation, from being affected. Various known technologies can be used for this control.

[0026] The control unit 40 controls the switch unit 12 to interrupt the current flowing from the power supply unit 10 to the external load 70 when the current flowing to the external load 70 detected by the first current detection unit 32a is greater than or equal to the current interruption threshold. The current interruption threshold can be appropriately determined by experiment or simulation so as to suppress smoke emission from the wires between the switch unit 12 and the connection unit 14. In this case, the control unit 40 controls the control voltage supplied to the control terminal of the first semiconductor switch 30a to switch the first semiconductor switch 30a from a conductive state to a non-conductive state, so that no current flows through the first semiconductor switch 30a.

[0027] The notification unit 42 notifies the user via the output unit 20 of a warning that the current consumption of the external load 70 is high when the current flowing through the external load 70 detected by the first current detection unit 32a is equal to or greater than the rated current. The warning information may also include information indicating that the current to the external load 70 will be limited or cut off later. The warning information can also be called a warning. The rated current is a value less than the current cutoff threshold and is predetermined. The notification unit 42 does not notify the user of a warning if the current flowing through the external load 70 is less than the rated current.

[0028] For example, the notification unit 42 may issue a warning if a predetermined first time has elapsed while the detected current is equal to or greater than the rated current. The first time may be, for example, a few seconds, and can be determined appropriately by experiment or simulation. By waiting for the first time to elapse, it is possible to avoid issuing a warning if the current briefly exceeds the rated current, such as immediately after an external load 70 is connected.

[0029] For example, the notification unit 42 may control the MID of the output unit 20 to notify the user of warning information using at least one of an image and text such as "The power consumption of the external load is too high."

[0030] The notification unit 42 may also notify warning information by controlling the indicator of the output unit 20 and changing the display mode of the indicator. As a way of changing the display mode, for example, the display color of the indicator may be changed, or it may be changed from continuous display to flashing display.

[0031] The notification unit 42 may control the speaker of the output unit 20 to notify caution information by sound, or it may notify caution information by voice, such as "The power consumption of the external load is too high."

[0032] Upon receiving the warning notification, the user can recognize that the output current from the connection 14 is too high and that the connected external load 70 is consuming too much power. This allows the user to determine whether they need to take action, such as disconnecting the external load 70 from the connection 14.

[0033] If the detected current is greater than or equal to the rated current and a predetermined second time longer than the first time has elapsed, the control unit 40 controls the switch unit 12 to limit the current flowing from the power supply unit 10 to the external load 70 to less than the rated current. In this case, the control unit 40 may limit the current flowing from the power supply unit 10 to the external load 70 to a predetermined limiting current less than the rated current. The control unit 40 controls the control voltage supplied to the control terminal of the first semiconductor switch 30a to limit the current flowing through the first semiconductor switch 30a to the limiting current. If the detected current is greater than or equal to the rated current and the second time has not elapsed, the control unit 40 does not limit the current flowing from the power supply unit 10 to the external load 70. The second time may be, for example, a few seconds, and can be appropriately determined by experiment or simulation. The limiting current can be appropriately determined by experiment or simulation.

[0034] If a user who recognizes the warning information does not remove the external load 70 or stop its operation, the current to the external load 70 can be limited, thereby reducing the power used by the vehicle. Therefore, it is possible to prevent the current to a predetermined on-board load 16, such as an air conditioner, from being unintentionally limited due to excessive power usage by the vehicle. Furthermore, the output of the warning information prevents the current to the external load 70 from being limited in situations where the user is unaware of it.

[0035] If the control unit 40 limits the current flowing from the power supply unit 10 to the external load 70, the notification unit 42 may notify the user via the output unit 20 that the current supplied to the external load 70 is being limited.

[0036] Alternatively, the control unit 40 may control the switch unit 12 to interrupt the current flowing from the power supply unit 10 to the external load 70 after a second time has elapsed while the detected current is equal to or greater than the rated current.

[0037] This control allows the current to be cut off from the external load 70 if the user, upon recognizing the warning information, does not remove the external load 70 or stop its operation, thereby further reducing the power used by the vehicle. Therefore, it is possible to prevent the current to a predetermined on-board load 16, such as an air conditioner, from being unintentionally limited due to excessive power usage by the vehicle. Furthermore, the output of the warning information prevents the current to the external load 70 from being cut off when the user is unaware of the situation.

[0038] If the control unit 40 cuts off the current flowing from the power supply unit 10 to the external load 70, the notification unit 42 may notify the user via the output unit 20 that the current to the external load 70 has been cut off.

[0039] Whether the control unit 40 limits or cuts off the current flowing from the power supply unit 10 to the external load 70 may be switchable according to user settings, or it may be pre-set during vehicle manufacturing.

[0040] Herein, as will be explained below, the power supply system 1 may limit the current flowing to the selected restricted vehicle load 16 if the user selects a restricted vehicle load 16.

[0041] The notification unit 42 derives the power supplied to each of the multiple in-vehicle loads 16 and external loads 70 based on the current supplied to each of the multiple in-vehicle loads 16 and external loads 70 and the output voltage of the power supply unit 10. The notification unit 42 notifies the user of the derived information regarding the power supplied to each of the multiple in-vehicle loads 16 and external loads 70 via the output unit 20.

[0042] For example, the notification unit 42 notifies the power consumption of each of the multiple in-vehicle loads 16 and external loads 70 via the MID of the output unit 20 using images or text. The notification unit 42 may also notify the power consumption via the power consumption indicator of the output unit 20. With regard to the in-vehicle loads 16, the notification unit 42 may notify the power consumption only for the multiple in-vehicle loads 16 that are candidates for restriction. The multiple in-vehicle loads 16 that are candidates for restriction are loads that do not directly affect the driving of the vehicle even if the current is reduced, and include, in addition to the air conditioner, for example, a defogger, seat heater, navigation system, and audio system. The in-vehicle loads 16 that are candidates for restriction do not include loads that may directly affect the driving of the vehicle if the current is reduced, such as the engine ECU, hybrid ECU, brake ECU, and steering ECU.

[0043] The notification unit 42 notifies the user via the output unit 20, via a warning message, that the vehicle is using a lot of power, when the sum of the power supplied to the multiple on-board loads 16 and the external load 70 (hereinafter referred to as the sum of the power of the on-board loads 16, etc.) exceeds a predetermined power threshold. The power threshold can be determined as appropriate through experimentation or simulation.

[0044] If the sum of the power from the vehicle loads 16 and other components remains above the power threshold, as described above, the output voltage of the power supply unit 10 may drop below the voltage threshold, and the current flowing to the air conditioner, which is a predetermined vehicle load 16, may be limited.

[0045] The reception unit 44 receives user input to the input unit 18 to select a vehicle load 16 to be restricted from a plurality of candidate vehicle loads 16, and supplies the information of the received user input to the control unit 40. When the reception unit 44 receives user input to select a vehicle load 16 to be restricted, the control unit 40 controls the switch unit 12 to limit the current flowing from the power supply unit 10 to the vehicle load 16 to be restricted selected by the user input.

[0046] For example, suppose a user connects an external load 70 to the connection unit 14 while multiple in-vehicle loads 16, including an air conditioner and a defogger, are operating, and a warning message is issued indicating that the vehicle is using a lot of power. For example, suppose the current flowing to the external load 70 is less than the rated current. The user who receives the warning message indicating that the vehicle is using a lot of power wants to keep the operating in-vehicle loads 16 running and continue supplying power to the external load 70, but wants to avoid limiting the air conditioner's current. Therefore, the user checks the list of power consumption displayed on the MID and operates the input unit 18 to select the defogger, which has a relatively high power consumption, as the in-vehicle load 16 to be limited. The control unit 40 limits the current supplied to the selected defogger. As a result, if the sum of the power of the in-vehicle loads 16 etc. falls below the power threshold, the output voltage of the power supply unit 10 will not easily fall below the voltage threshold, and the limiting of the air conditioner's current can be avoided.

[0047] In this way, the current flowing to the vehicle load 16 selected by user operation is limited, thereby reducing the power used by the vehicle. Therefore, it is possible to prevent the control unit 40 from limiting the current of a predetermined vehicle load 16 unintended by the user due to excessive power usage by the vehicle.

[0048] Next, the overall operation of the power supply system 1 with the above configuration will be explained. Figure 2 is a flowchart showing the process related to power supply to the connection part 14 in Figure 1. The process in Figure 2 starts when an external load 70 is connected to the connection part 14 and ends when the external load 70 is removed from the connection part 14.

[0049] If the current in the connection section 14 is greater than or equal to the rated current (Y in S10), and if the current remains greater than or equal to the rated current for the first time (Y in S12), the notification unit 42 issues a warning (S14). If the current remains greater than or equal to the rated current for the second time (Y in S16), the control unit 40 controls the switch unit 12 to interrupt or limit the current in the connection section 14 (S18), and the process returns to S10.

[0050] If the current at connection 14 is less than the rated current in S10 (N in S10), the process returns to S10. If the current is greater than or equal to the rated current and the first time has not elapsed in S12 (N in S12), the process returns to S10. If the current is greater than or equal to the rated current and the second time has not elapsed in S16 (N in S16), the process returns to S10.

[0051] According to this embodiment, a warning is sent to the user when the current flowing through the external load 70 exceeds the rated current, so that the user can be notified that the output current from the connection part 14 is too high. Therefore, the user can deal with situations where an external load 70 with a high current consumption is connected to the vehicle's connection part 14.

[0052] The present invention has been described above based on embodiments. The embodiments are merely illustrative, and it will be understood by those skilled in the art that various modifications are possible in combinations of each component and each processing process, and that such modifications also fall within the scope of the present invention. [Explanation of symbols]

[0053] 1...Power supply system, 10...Power supply unit, 12...Switch unit, 14...Connection unit, 16...Vehicle load, 16a...First vehicle load, 16b...Second vehicle load, 18...Input unit, 20...Output unit, 22...Processing unit, 30...Semiconductor switch, 30a...First semiconductor switch, 30b...Second semiconductor switch, 30c...Third semiconductor switch, 32...Current detection unit, 32a...First current detection unit, 32b...Second current detection unit, 32c...Third current detection unit, 40...Control unit, 42...Notification unit, 44...Reception unit, 70...External load.

Claims

1. A power supply system installed in a vehicle, A connection section to which the user can connect a load, A power supply unit that supplies power to the load via the aforementioned connection part, A current detection unit for detecting the current flowing from the power supply unit to the load, A notification unit that alerts the user if the detected current is greater than or equal to the rated current, A power supply system characterized by comprising the following features.

2. The notification unit notifies the warning information when a predetermined first time has elapsed while the detected current is equal to or greater than the rated current. The power supply system according to feature 1.

3. The power supply system according to claim 2, further comprising a control unit that, when the detected current is equal to or greater than the rated current, a predetermined second time longer than the first time has elapsed, limits the current flowing from the power supply unit to the load to less than the rated current.

4. The power supply system according to claim 2, further comprising a control unit that cuts off the current flowing from the power supply unit to the load when a predetermined second time longer than the first time has elapsed while the detected current is equal to or greater than the rated current.

5. The power supply unit supplies power to multiple vehicle-mounted loads, The notification unit notifies the user of information regarding the power supplied to each of the plurality of onboard loads. The aforementioned power supply system is A reception unit that receives user input to select a vehicle load to be restricted from among the aforementioned multiple vehicle loads, The power supply unit includes a control unit that limits the current flowing to the vehicle load to be restricted, selected by user operation, The power supply system according to claim 1, further comprising:

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