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 shuts off 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 the vehicle can supply power to the electrical load connected to the connection part. The connection part includes, for example, a cigarette 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 capable of dealing 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] 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, including 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 equal to or greater than a rated current.

Effects of the Invention

[0007] According to the present invention, it is possible to provide a technology capable of coping with a situation in which a load with a large current consumption is connected to a connection part of a vehicle by a user.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0009] FIG. 1 schematically shows the configuration of a power supply system 1 according to an 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 a traveling drive power source, or may be an electric vehicle that uses an electric motor as a traveling drive power source. The electric vehicle may be, for example, a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a fuel cell electric vehicle (FCEV). The vehicle may be a vehicle driven by a driver or an autonomous vehicle.

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

[0011] Although the first in-vehicle load 16a and the second in-vehicle load 16b are shown in FIG. 1, the power supply system 1 includes more in-vehicle loads (not shown). Hereinafter, a plurality of in-vehicle loads including the first in-vehicle load 16a and the second in-vehicle load 16b are collectively referred to as the in-vehicle load 16 as appropriate.

[0012] The power supply unit 10 supplies power to the connection unit 14 and a plurality of in-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 can output the power stored in the auxiliary battery. As the power supply unit 10, various known configurations can be adopted. The power supply unit 10 may include an alternator or may include a power conversion device such as a DC / DC converter. The power supply unit 10 may make the voltage supplied to the connection unit 14 different from the voltage supplied to the plurality of in-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 plurality of in-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 (not shown). Hereinafter, a plurality of semiconductor switches including the first semiconductor switch 30a, the second semiconductor switch 30b, and the third semiconductor switch 30c are collectively referred to as semiconductor switches 30 as appropriate. Also, a plurality of current detection units including the first current detection unit 32a, the second current detection unit 32b, and the third current detection unit 32c are collectively referred to as current detection units 32 as appropriate.

[0015] Each of the plurality of 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 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 information on the detected current value to the processing unit 22.

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

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

[0019] The connection part 14 is a port to which a user can electrically connect an external load 70, and supplies power to the external load 70. The connection part 14 is a connector to which the power supply 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 includes various electrical devices such as, for example, a mobile terminal. The connection part 14 can also be called an external power supply port or an external power supply outlet. The connection part 14 is, for example, a cigarette socket, a USB (Universal Serial Bus) port, or an accessory power outlet provided in the vehicle interior. The accessory power outlet can supply AC power. When the connection part 14 is an accessory power outlet, the power supply unit 10 is configured to supply AC power to the accessory power outlet. A plurality of connection parts 14 may be provided. The connection part 14 may be provided on the vehicle body, and may be able to electrically connect an external load used outside the vehicle.

[0020] The plurality of in-vehicle loads 16 are electrical loads provided in the vehicle and are components of the vehicle. The plurality of in-vehicle loads 16 may include, for example, a headlamp, a direction indicator, a navigation device, an audio device, an air conditioner, a defroster, a seat heater, a wiper, various ECUs (Electronic Control Unit), and the like. The in-vehicle load 16 operates using the power supplied from the power supply unit 10. The in-vehicle load 16 can also be called a vehicle electrical component or an auxiliary load.

[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 the 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 the user's operation is input.

[0022] The output unit 20 includes at least one of a display unit and a speaker provided in the vehicle interior, 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 in the vehicle interior. 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 can be realized by a program loaded into the memory or the like. Here, however, functional blocks realized by the cooperation thereof are depicted. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

[0024] When the output voltage of the power supply unit 10 detected by a voltage sensor (not shown) is less than a predetermined voltage threshold, for example, the control unit 40 controls the switch unit 12 to limit the current flowing through a predetermined in-vehicle load 16 among the plurality of in-vehicle loads 16. The voltage threshold can be appropriately determined by experiments or simulations. The output voltage of the power supply unit 10 being less than the voltage threshold corresponds to the state of charge (SOC) of the auxiliary battery of the power supply unit 10 being less than the 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 in-vehicle load 16 to limit the current flowing through the semiconductor switch 30. The predetermined in-vehicle load 16 is a load that does not directly affect the running of the vehicle even if the current is reduced, for example, an air conditioner.

[0025] If a large number of in-vehicle loads 16 and external loads 70 continue to operate with a relatively large consumption current, that is, if the power used in the vehicle remains relatively too large, the output voltage of the power supply unit 10 may decrease and become less than the voltage threshold. In this case, by this control, for example, the current supplied to the air conditioner is reduced, and the air volume is reduced, so that the power used in the vehicle is reduced, and the output voltage of the power supply unit 10 is more likely to recover above the voltage threshold by charging. Thereby, it is possible not to affect the operation of the in-vehicle load 16 that directly affects the running of the vehicle. Various known techniques can be used for this control.

[0026] When the current flowing through the external load 70 detected by the first current detection unit 32a is equal to or greater than the current cutoff threshold, the control unit 40 controls the switch unit 12 to cut off the current flowing from the power supply unit 10 to the external load 70. The current cutoff threshold can be appropriately determined by experiments or simulations so as to suppress the smoking of the electric wire 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 the conducting state to the non-conducting state so that no current flows through the first semiconductor switch 30a.

[0027] [[ID=]11] 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 notification unit 42 notifies the user via the output unit 20 of caution information indicating that the power consumption of the external load 70 is too large. The caution information may include information indicating that the current of the external load 70 will be restricted or interrupted later. The caution information can also be called a warning. The rated current is a value smaller than the current interruption threshold and is predetermined. The notification unit 42 does not notify the caution information when the current flowing through the external load 70 is less than the rated current.

[0028] For example, when a predetermined first time has elapsed while the detected current is equal to or greater than the rated current, the notification unit 42 may notify the caution information. The first time may be, for example, about several seconds and can be appropriately determined by experiments or simulations. By waiting for the elapse of the first time, it is possible not to notify the caution information when the current exceeds the rated current only for a short time immediately after the external load 70 is connected.

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

[0030] The notification unit 42 may control the indicator of the output unit 20 to notify the caution information by changing the display mode of the indicator. As the change in the display mode, for example, the display color of the indicator may be changed, or the display may be changed from continuous display to blinking display.

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

[0032] The user who has received the notification of the caution information can recognize that the output current from the connection unit 14 is too large and the power consumption of the connected external load 70 is too large. Thereby, the user can determine whether it is necessary to take measures such as removing the external load 70 from the connection unit 14.

[0033] When the detected current is equal to or greater than 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 limit 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 limit current. When the second time does not elapse while the detected current is equal to or greater than the rated current, 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, about several seconds and can be appropriately determined by experiments or simulations. The limit current can be appropriately determined by experiments or simulations.

[0034] When the user who has recognized the attention information does not remove the external load 70 or stop the operation of the external load 70, the current of the external load 70 can be limited, so that the power used in the vehicle can be reduced. Therefore, it is possible to suppress the situation where the current of a predetermined in-vehicle load 16 such as an air conditioner is limited unintentionally due to excessive power used in the vehicle. In addition, by outputting the attention information, it is possible to avoid the situation where the current of the external load 70 is limited in a situation not recognized by the user.

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

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

[0037] With this control, when the user who has recognized the warning information does not remove the external load 70 or stop the operation of the external load 70, the current of the external load 70 can be cut off, so that the power used in the vehicle can be further reduced. Therefore, it is possible to prevent the current of a predetermined in-vehicle load 16 such as an air conditioner from being restricted unintentionally due to excessive power used in the vehicle. Further, by outputting the warning information, it is possible to avoid the current of the external load 70 being cut off in a situation not recognized by the user.

[0038] When 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 of information indicating that the current of the external load 70 has been cut off.

[0039] Whether the control unit 40 restricts or cuts off the current flowing from the power supply unit 10 to the external load 70 may be switchable according to the user's setting operation, or may be preset at the time of vehicle manufacture.

[0040] Here, as described below, when the user selects the in-vehicle load 16 to be restricted, the power supply system 1 may restrict the current flowing through the selected in-vehicle load 16 to be restricted.

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

[0042] For example, the notification unit 42 notifies, in the form of an image or characters, the power consumption of each of the plurality of in-vehicle loads 16 and the external load 70 via the MID of the output unit 20. The notification unit 42 may notify the power consumption via the power consumption indicator of the output unit 20. Regarding the in-vehicle load 16, the notification unit 42 may notify the power consumption only for the plurality of in-vehicle loads 16 that are candidates for restriction. The plurality of in-vehicle loads 16 that are candidates for restriction are loads that do not directly affect the running of the vehicle even if the current is reduced. In addition to the air conditioner, for example, they include a defroster, a seat heater, a navigation device, and an audio device. The in-vehicle load 16 that is a candidate for restriction does not include loads that may directly affect the running of the vehicle if the current of, for example, an engine ECU, a hybrid ECU, a brake ECU, and a steering ECU is reduced.

[0043] When the sum of the power supplied to the plurality of in-vehicle loads 16 and the external load 70 (hereinafter referred to as the sum of the power of the in-vehicle load 16 etc.) is equal to or greater than a predetermined power threshold value, the notification unit 42 notifies the user via the output unit 20 of caution information indicating that a large amount of power is being used in the vehicle. The power threshold value can be appropriately determined by experiments or simulations.

[0044] If the state where the sum of the power of the in-vehicle load 16 etc. is equal to or greater than the power threshold value continues, as described above, the output voltage of the power supply unit 10 may drop below the voltage threshold value, and the current flowing through the air conditioner, which is a predetermined in-vehicle load 16, may be restricted.

[0045] The reception unit 44 receives a user operation on the input unit 18 that selects the in-vehicle load 16 to be restricted from the plurality of in-vehicle loads 16 that are candidates for restriction, and supplies information on the received user operation to the control unit 40. When a user operation for selecting the in-vehicle load 16 to be restricted is received by the reception unit 44, the control unit 40 controls the switch unit 12 to restrict the current flowing from the power supply unit 10 to the in-vehicle load 16 to be restricted selected by the user operation.

[0046] For example, assume that when the user connects an external load 70 to the connection part 14 during the operation of a plurality of in-vehicle loads 16 including an air conditioner and a defroster, caution information indicating that a large amount of power is being used in the vehicle is notified. For example, assume that the current flowing through the external load 70 is less than the rated current. Assume that the user who has received the caution information indicating that a large amount of power is being used in the vehicle wants to continue operating the in-vehicle load 16 that is operating and also continue to supply power to the external load 70, but wants to avoid limiting the current of the air conditioner. Therefore, the user checks the power consumption list displayed on the MID and operates the input part 18 to select the defroster, which has a relatively large power consumption, as the in-vehicle load 16 to be restricted. The control part 40 restricts the current supplied to the selected defroster. As a result, if the total power of the in-vehicle load 16 or the like becomes less than the power threshold value, it becomes difficult for the output voltage of the power supply part 10 to drop below the voltage threshold value, and the current limit of the air conditioner can be avoided.

[0047] In this way, since the current flowing through the in-vehicle load 16 to be restricted selected by the user operation is restricted, the power used in the vehicle can be reduced. Therefore, it is possible to suppress the situation where the current of a predetermined in-vehicle load 16 not intended by the user is restricted by the control part 40 due to too much power being used in the vehicle.

[0048] Next, the overall operation of the power supply system 1 with the above configuration will be described. FIG. 2 is a flowchart showing the process related to power supply to the connection part 14 in FIG. 1. The process in FIG. 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] When the current of the connection part 14 is equal to or greater than the rated current (Y in S10), if the first time has elapsed in the state where the current is equal to or greater than the rated current (Y in S12), the notification part 42 notifies the caution information (S14). When the second time has elapsed in the state where the current is equal to or greater than the rated current (Y in S16), the control part 40 controls the switch part 12 to cut off or limit the current of the connection part 14 (S18), and the process returns to S10.

[0050] When the current of the connection part 14 is less than the rated current in S10 (N in S10), the process returns to S10. When the current is not more than the rated current and the first hour has not elapsed in S12 (N in S12), the process returns to S10. When the current is not more than the rated current and the second hour has not elapsed in S16 (N in S16), the process returns to S10.

[0051] According to the embodiment, when the current flowing through the external load 70 is equal to or greater than the rated current, attention information is notified to the user, so that the user can be informed that the output current from the connection part 14 is too large. Therefore, the user can cope with the situation where an external load 70 with a large current consumption is connected to the connection part 14 of the vehicle.

[0052] As described above, the present invention has been described based on the embodiment. It should be understood by those skilled in the art that the embodiment is merely an example, and various modifications are possible for the combination of each component and each processing process, and such modifications are also within the scope of the present invention.

Description of Reference Numerals

[0053] 1... power supply system, 10... power supply unit, 12... switch unit, 14... connection part, 16... in-vehicle load, 16a... first in-vehicle load, 16b... second in-vehicle load, 18... input part, 20... output part, 22... processing part, 30... semiconductor switch, 30a... first semiconductor switch, 30b... second semiconductor switch, 30c... third semiconductor switch, 32... current detection part, 32a... first current detection part, 32b... second current detection part, 32c... third current detection part, 40... control part, 42... notification part, 44... reception part, 70... external load.

Claims

1. A power supply system mounted on a vehicle, a connection part where 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 the current flowing from the power supply part to the load, a notification part that notifies a user of caution information when the detected current is equal to or greater than the rated current, characterized by comprising the above.

2. The notification part notifies the caution 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 Claim 1, characterized by the above.

3. 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, the power supply system further comprises a control part that restricts the current flowing from the power supply part to the load to less than the rated current.

4. 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, the power supply system further comprises a control part that cuts off the current flowing from the power supply part to the load.

5. The power supply part supplies power to a plurality of in-vehicle loads, the notification part notifies the user of information regarding the power supplied to each of the plurality of in-vehicle loads, the power supply system further comprises a reception part that receives a user operation for selecting an in-vehicle load to be restricted from among the plurality of in-vehicle loads, and a control part that restricts the current flowing from the power supply part to the in-vehicle load selected by the user operation to be restricted. The power supply system according to Claim 1, characterized by comprising the above.

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