Power supply control method and power supply control device

Abstract

The present invention provides a power supply control method and a power supply control device. The power supply control device (100) comprises: a high-voltage battery (12), a low-voltage battery (15), a relay (13) electrically connecting the high-voltage battery (12) and the low-voltage battery (15), a power switch (11), and a controller (10) for controlling the on / off switching of the relay (13). When the power supply state is in a state where power is supplied from the high-voltage battery (12) to the low-voltage battery (15) via the relay (13), the controller (10) switches the relay (13) from on to off upon receiving a first signal, and then prohibits the relay (13) from switching from off to on.

Description

Technical Field

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

[0002] Conventionally, an invention for controlling the power mode of an electric vehicle is known (Patent Document 1). The invention described in Patent Document 1 maintains the power mode on even after charging of the driving battery is stopped while electrical equipment mounted on the electric vehicle is operating.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: (Japanese) Patent Publication No. 2018-98844 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] There is a method for transitioning from a state where the high-voltage battery and the low-voltage battery are not connected to a state where they are connected (the so-called high-voltage state) by using a situation other than switch operation (such as signal reception) as a trigger. According to the above method, it is possible to transition to the high-voltage state relatively easily. However, when the above method is adopted, it is estimated that even if the high-voltage state is released, it is easy to transition to the high-voltage state again. Therefore, it is required to prevent the transition to the high-voltage state again after the high-voltage state is released. However, the invention described in Patent Document 1 does not mention this.

[0008] The present invention has been proposed in view of the above-mentioned problems, and an object of the present invention is to provide a power supply control method and a power supply control device that can prevent the high-voltage state from being transitioned to again after the high-voltage state has been released.

[0009] Technical solutions to technical problems

[0010] A power supply control method according to one embodiment of the present invention switches the relay from on to off upon receiving a first signal when the power supply state is in a state where power is supplied from the high-voltage battery to the low-voltage battery via the relay, and then prohibits the relay from switching from off to on.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to prevent the high pressure state from being shifted back to the high pressure state after the high pressure state is released. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 1 is a block diagram of a power supply control device 100 according to an embodiment of the present invention.

[0014] Figure 2 This is a diagram illustrating the power supply posture according to the embodiment of the present invention.

[0015] Figure 3 This is a diagram for explaining the on / off operation of relay 13 according to the embodiment of the present invention.

[0016] Figure 4 The diagram explains the power supply status in the electric vehicle in each state of the power supply.

[0017] Figure 5 This is a timing chart illustrating an operation example of the power supply control device 100 according to the embodiment of the present invention.

[0018] Figure 6 This is a timing chart for explaining another operation example of the power supply control device 100 according to the embodiment of the present invention.

[0019] Figure 7 This is a timing chart for explaining another operation example of the power supply control device 100 according to the embodiment of the present invention.

[0020] Figure 8 This is a flowchart for explaining an operation example of the power supply control device 100 according to the embodiment of the present invention. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same parts, and the description thereof will be omitted.

[0022] Reference Figure 1 , the following describes a configuration example of a power supply control device 100 mounted on a vehicle. Figure 1 As shown, power supply control device 100 includes controller 10, power switch 11, high voltage battery 12, relay 13, DC-DC rectifier 14, low voltage battery 15, and electrical equipment 16. The vehicle of this embodiment is an electric vehicle that uses electrical energy as energy.

[0023] The controller 10 is an electronic control unit (ECU) that includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and a CAN (Controller Area Network) communication circuit. The controller 10 controls various functions of the electric vehicle. For example, the controller 10 controls the on / off operation of the relay 13 based on received signals (first to third signals).

[0024] The power switch 11 is a push-type switch provided in the vehicle. The location of the power switch 11 is not particularly limited, but is generally provided in a location that is easily accessible to a user seated in the driver's seat. As an example, the power switch 11 is provided near the steering wheel. Each time the user presses the power switch 11, the power state is switched. In this embodiment, the power state is referred to as "power attitude." The details of the power attitude will be described later. The power switch 11 is provided with an indicator indicating on / off.

[0025] The high-voltage battery 12 is a driving battery used primarily as a power source for the motor (not shown). It is a high-capacity secondary battery composed of multiple battery modules. An external power source 30 is used to charge the high-voltage battery 12. The user charges the high-voltage battery 12 by connecting the external power source 30 to the electric vehicle via a dedicated charging cable.

[0026] The low-voltage battery 15 is used as a power source for electrical devices 16 mounted in the vehicle. For example, the low-voltage battery 15 is a lead-acid battery that stores electricity at a voltage of 12 V to 15 V. The electrical devices 16 to which the low-voltage battery 15 supplies power include navigation devices, audio equipment, and the like.

[0027] A relay 13 and a DC-DC rectifier 14 are connected between the high-voltage battery 12 and the low-voltage battery 15. The relay 13 electrically connects the low-voltage battery 15 to the high-voltage battery 12. The on / off of the relay 13 is controlled by the controller 10. When the power switch 11 is not turned off, the relay 13 is usually turned on. The DC-DC rectifier 14 reduces the power of the high-voltage battery 12 and supplies power to the low-voltage battery 15. It should be noted that Figure 1 In FIG. 1 , the electrical device 16 and the DC-DC rectifier 14 are shown separately, but the DC-DC rectifier 14 is also a type of the electrical device 16 .

[0028] The smart key 20 is used to remotely unlock and lock the vehicle doors. When the user presses the unlock switch of the smart key 20, all the doors of the electric vehicle are unlocked. However, the function of the smart key 20 is not limited to this. The vehicle doors can also be unlocked when the user presses the switch attached to the door handle or the trunk. To briefly explain the system, both the electric vehicle and the smart key 20 are provided with an antenna for transmitting radio waves and a receiver for receiving radio waves. When the user installs the switch attached to the door handle or the trunk, radio waves are transmitted from the antenna of the electric vehicle, and the smart key 20 that receives the radio waves automatically returns radio waves. The radio waves are received by the receiver of the electric vehicle, and the vehicle doors are unlocked. It should be noted that the smart key 20 is sometimes also called a smart key.

[0029] Figure 1 The first signal shown is a signal sent from the power switch 11 to the controller 10. The second signal is a signal sent to the controller 10 when the external power supply 30 and the electric vehicle are connected via a dedicated charging cable. The third signal is a signal sent from the smart key 20 to the controller 10. When the controller 10 receives the first to third signals, it controls the on / off switching of the relay 13 based on the received signals.

[0030] Next, refer to Figure 2 , explaining the power posture.

[0031] In this embodiment, if Figure 2 As shown, the power posture includes four states: power off (first state), second state, third state, and fourth state. In addition, the power posture includes a fifth state, namely the fifth state. Here, the first to fourth states are described, and the fifth state will be described later.

[0032] Power off is the state in which the power switch 11 is disconnected. When the power posture is in the power off state, all devices except some do not work. The so-called some devices refer to the door locks (including unlocking), communication devices, and safety devices. In addition, even when the power posture is in the power off state, a small current (so-called dark current) flows in the electrical equipment 16 for functional backup, etc. This dark current is supplied from the low-voltage battery 15. When the power posture is in the power off state, the indicator of the power switch 11 goes out.

[0033] The second state is when the power switch 11 is on, and the indicator on the power switch 11 is illuminated. When the power is in the second state, relay 13 is on, and power is supplied from the high-voltage battery 12 to the low-voltage battery 15 via relay 13. More specifically, when the power is in the second state, relay 13 is on, and power is supplied from the high-voltage battery 12 to the low-voltage battery 15 via the DC-DC rectifier 14. In the second state, the user can use most electrical devices 16, with the exception of some. Specifically, in the second state, the user can operate the navigation device to set a route or the audio device to listen to the radio.

[0034] In the second state, the instrument and the blower motor do not work. This is because in the second state, when there is no user operation and a specified time (for example, about 1 to 10 minutes) has passed, the power state automatically transitions from the second state to a power-off structure. The blower motor is a motor used to send air from the air conditioner into the vehicle compartment and is equipped with a fan. In this structure, when there is no user operation and a specified time has passed, the blower motor stops sending air, that is, the air conditioner is disconnected. When the air conditioner is automatically disconnected, the user may be dissatisfied. Therefore, in the second state, the blower motor does not work. The instrument is an electrical device that provides various information to the user, so when the instrument is automatically disconnected, the user may feel inconvenienced. Therefore, the instrument does not work in the second state. The so-called no user operation means that the user has no input to the electrical device 16. It should be noted that the second state is sometimes called AUTOACC.

[0035] The third state, similar to the second state, is when the power switch 11 is on, and the indicator on the power switch 11 is illuminated. In the third state, as in the second state, relay 13 is on, supplying power from the high-voltage battery 12 to the low-voltage battery 15 via relay 13. The third state differs from the second state in the following respects. Specifically, in the second state, the instruments and blower motor are inoperative. In contrast, in the third state, all electrical equipment, including the instruments and blower motor, are operational. The third state is sometimes referred to as "IGN-ON."

[0036] Next, the transition of the power supply attitude is explained. Figure 2As shown, each time the user presses the power switch 11, the power posture transitions in the order of power off (first state), second state, and third state. In addition, when the power posture is in the third state, when the user presses the power switch 11, the power posture transitions to the second state. When the power posture is in the second state, as described above, when there is no user operation and a specified time has passed, the power posture automatically transitions to power off. Here, the transition from power off to the second state is not limited to the operation of the power switch 11. When the user presses the unlock switch of the smart key 20, the power posture also transitions from power off to the second state. In more detail, when the user presses the unlock switch of the smart key 20 held by the user before getting on the electric car, the third signal is sent from the smart key 20 to the controller 10 (refer to Figure 1 ). The controller 10 that receives the third signal transitions the power state from power off to the second state. As a result, the user can use the navigation device, audio device, etc. immediately after getting on the vehicle. On the contrary, in the second state of the present embodiment, the time for supplying power from the low-voltage battery 15 to the electrical equipment 16 is extended, and the remaining capacity of the battery (SOC: STATE OF CHARGE) may decrease. Therefore, as described above, in the second state, the controller 10 turns on the relay 13, and supplies power from the high-voltage battery 12 to the low-voltage battery 15 via the relay 13. Thus, even in the case where the time for supplying power from the low-voltage battery 15 to the electrical equipment 16 is extended, the SOC of the low-voltage battery 15 can be prevented from decreasing.

[0037] Thus, in the second state (the same applies to the third state) of this embodiment, the power supply from the high voltage battery 12 to the low voltage battery 15 via the relay 13 can be rewritten as a request from the power system. Requests from the power system are hereinafter referred to as "system requests."

[0038] like Figure 2 As shown, the electric vehicle cannot be driven when the power state is in the power-off, second state, or third state. To enable the electric vehicle to drive, the user must perform a prescribed operation. For example, the prescribed operation is to step on the brake pedal and press the power switch 11. This operation can be performed in any of the power states: power-off, second state, or third state.

[0039] like Figure 2As shown, when the user steps on the brake pedal and presses the power switch 11, the power state transitions from the power off, the second state, or the third state to the fourth state. In the fourth state, the electric vehicle can travel. In addition, in the fourth state, the power switch 11 is in the on state, and the indicator of the power switch 11 is on. In addition, in the fourth state, the relay 13 is turned on, and power is supplied from the high-voltage battery 12 to the low-voltage battery 15 via the relay 13. In addition, in the fourth state, as in the third state, all electrical equipment including the instrument and the blower motor are working. In addition, in the fourth state, the instrument displays an icon indicating that it can travel. As shown Figure 2 As shown, after the journey is finished, when the user presses the power switch 11, the power attitude transitions from the fourth state to the second state. This is because even after the journey is finished, there is still a need to use the audio device, etc. It should be noted that the fourth state is sometimes called READY-ON.

[0040] Hereinafter, the state in which electric power is supplied from the high-voltage battery 12 to the low-voltage battery 15 via the relay 13 may be referred to as a “high-voltage state”. Figure 2 The second state, the third state, and the fourth state shown are high pressure states.

[0041] Next, refer to Figure 3 , the on / off operation of the relay 13 will be described.

[0042] Figure 3 The table shown shows how the on / off control of the relay 13 is performed according to the power supply attitude.

[0043] like Figure 3 As shown, when the power state is in the power off state, the relay 13 is normally off. When the power state is in the second state, the relay 13 is normally on. When the power state is in the third state, the relay 13 is normally on. When the power state is in the fourth state, the relay 13 is normally on.

[0044] like Figure 3 As shown, when the power attitude is in the second state, when the power switch 11 is pressed for a predetermined time (for example, two seconds) or more, the controller 10 switches the relay 13 from on to off. More specifically, when the power switch 11 is pressed for a predetermined time or more, the first signal (refer to Figure 1 ) is sent from the power switch 11 to the controller 10. Upon receiving this first signal, the controller 10 switches the relay 13 from on to off. This disconnects the low-voltage battery 15 from the high-voltage battery 12, stopping the power supply from the high-voltage battery 12. This releases the high-voltage state.

[0045] One of the reasons for releasing the high-voltage state when the power switch 11 is pressed for a long time or longer than a prescribed time is to deal with unexpected events. In the event of an unexpected event and the need for rescue, it is required to quickly release the high-voltage state. Therefore, upon receiving the first signal, the controller 10 of the present embodiment switches the relay 13 from on to off. The first signal is sent by pressing the power switch 11 for a long time (for example, more than two seconds), so according to the present embodiment, the high-voltage state can be easily and quickly released. The above-mentioned prescribed time is not limited to two seconds and can be appropriately changed.

[0046] When the power supply attitude is in the third state, similarly to the second state, when the power switch 11 is pressed for a predetermined time or longer, the controller 10 switches the relay 13 from on to off.

[0047] It should be noted that the first signal is sent from the power switch 11 only when the power attitude is in the second state or the third state. In other words, when the power attitude is in the power off state or the fourth state, for example, even if the power switch 11 is pressed for a predetermined time or longer, the first signal will not be sent from the power switch 11. Therefore, when the power attitude is in the power off state or the fourth state, even if the power switch 11 is pressed for a predetermined time or longer, Figure 3 As shown, the state of relay 13 does not change.

[0048] In addition, in addition to the above-mentioned rescue, the high-voltage state is also required to be released in factory operations, software update operations of controllers mainly related to high voltage, etc. In the above-mentioned operations, the high-voltage state is also required to be released quickly, just like in the rescue. According to the present embodiment, since the high-voltage state can be released by long pressing the power switch 11, the high-voltage state can be easily and quickly released. As a result, factory operations, software update operations of controllers mainly related to high voltage, etc. are smooth. It should be noted that in the present embodiment, even in the state where the high-voltage state has been released (the second state and the third state), power can be supplied from the low-voltage battery 15 to the electrical equipment 16.

[0049] Next, refer to Figure 4 , the power supply status in the electric vehicle under each power supply state is explained.

[0050] Figure 4 The table shows the power supply status of the door locks, communication devices, security devices, dark current, electrical equipment 16, and the EV system as the power supply status within the electric vehicle. Electrical equipment 16 is categorized as the navigation system, audio equipment, instrument panel, blower motor, power windows, and DC-DC rectifier 14. Furthermore, the EV system is categorized as the heater, compressor, and inverter. The heater is used to heat the high-voltage battery 12.

[0051] The low-voltage battery 15 supplies power to the navigation device, audio device, meter, blower motor, power windows, and DC-DC rectifier 14. The high-voltage battery 12 supplies power to the heater, compressor, and inverter.

[0052] like Figure 4 As shown, the power state is divided into power off (first state), second state, third state, fourth state, and fifth state. Power off, second state, third state, and fourth state have been explained. The fifth state is a transition state when the power state is in the second or third state and the power switch 11 is pressed for a specified time or longer.

[0053] like Figure 4 As shown, when the power supply posture is in the power-off state, power is supplied from the low-voltage battery 15 to the door locks (including unlocking), communication devices, and safety equipment. On the other hand, power is not supplied from the low-voltage battery 15 to the electrical equipment 16. Similarly, power is not supplied from the high-voltage battery 12 to the EV system. However, in order to back up the functions, etc., a small current (so-called dark current) flows in the electrical equipment 16. It should be noted that in the first state to the fifth state, the power-on conditions of the door locks, communication devices, safety equipment, and dark current are the same, so the description is omitted.

[0054] like Figure 4 As shown, when the power posture is in the second state, power is supplied from the low-voltage battery 15 to the navigation device, audio device, power windows, and DC-DC rectifier 14. In addition, when the power posture is in the second state, it is a high-voltage state as described above, so power is supplied from the high-voltage battery 12 to the heater, compressor, and inverter. Here, when the power posture is in the second state, power is not supplied from the low-voltage battery 15 to the instrument and the blower motor. This is because, as described above, a structure is set in the second state that automatically transitions to power disconnection under specified conditions (the so-called time limit). As described above, when the air conditioner is automatically disconnected, the user may be dissatisfied. The instrument is an electrical device that provides various information to the user, so when the instrument is automatically disconnected, the user may feel inconvenienced. Therefore, in the second state, power is not supplied from the low-voltage battery 15 to the instrument and the blower motor.

[0055] When the power attitude is in the third state, Figure 4 All devices shown are powered. In the third state, unlike the second state, there is no time limit. That is, in the third state, even if there is no user operation and the specified time has passed, the power state will not automatically transition to power off.

[0056] When the power state is in the fourth state, Figure 4 All equipment shown is supplied with electrical power.

[0057] like Figure 4 As shown, when the power supply attitude is in the fifth state, as described above, the high voltage state is released, and therefore electric power is not supplied from the high voltage battery 12 to the heater, the compressor, and the inverter.

[0058] Here, a supplement is provided regarding the transition from the third state to the fifth state. As described above, when the power posture is in the third state, if the power switch 11 is pressed for a predetermined time or longer, the power posture transitions to the fifth state. At this time, by pressing the power switch 11, the power posture first transitions to the second state, and by pressing the power switch 11 for a predetermined time or longer, the power posture transitions to the fifth state. In this way, in either the second or third state, the high-voltage state can be released by the same operation (pressing the power switch 11 for a predetermined time), so compared to the case where the operation is different depending on the state of the power posture, the operation can be prevented from becoming complicated.

[0059] Next, refer to Figure 5 An operation example of the power supply control device 100 is described with reference to the timing diagram of FIG.

[0060] Figure 5 The initial state (time: 0) represents the second state. That is, Figure 5 The timing diagram shown receives a third signal from the controller 10 (see Figure 1 ), the power posture starts from the scenario where the power is disconnected and transitions to the second state.

[0061] exist Figure 5 In the initial state, the power supply is in the second state, so the system is requested to be turned on. This system request indicates a request for a high voltage state. Because the system is requested to be turned on, the controller 10 turns on the relay 13, and power is supplied from the high-voltage battery 12 to the low-voltage battery 15 via the relay 13.

[0062] Here, it is assumed that the power switch 11 is Figure 5 The person who long-presses the power switch 11 is assumed to be an electric vehicle user, a rescuer, a factory worker, a dealer, etc. When the power switch 11 is long-pressed, a timer (one of the functions of the controller 10) is started to measure the time the power switch 11 is long-pressed.

[0063] When the power switch 11 is pressed for a period exceeding a threshold (time T2), the controller 10 switches the relay 13 from on to off. This disconnects the low-voltage battery 15 from the high-voltage battery 12, stopping the power supply from the high-voltage battery 12. This releases the high-voltage state. At time T2, the power state transitions from the second state to the fifth state. It should be noted that the threshold mentioned here has the same meaning as the specified time mentioned above.

[0064] At time T2, the controller 10 switches the relay 13 from on to off and switches the prohibition flag from 0 to 1. The prohibition flag is a flag for prohibiting the controller 10 from switching the relay 13 from off to on. When the prohibition flag is set to 0, the controller 10 can switch the relay 13 from off to on. On the other hand, when the prohibition flag is set to 1, the controller 10 cannot switch the relay 13 from off to on.

[0065] Here, the purpose of setting the prohibition flag is explained. As described above, in this embodiment, to quickly release the high-voltage state, when the power switch 11 is pressed for a predetermined time or longer, the controller 10 switches the relay 13 from on to off. After the relay 13 is switched off, for example, if the user presses the unlock switch of the smart key 20 again, the controller 10 switches the relay 13 from off to on again. This causes the system to transition back to the high-voltage state. Therefore, it is necessary to prevent the system from transitioning back to the high-voltage state after the high-voltage state has been released.

[0066] Therefore, in this embodiment, when the power switch 11 is pressed for a predetermined time or longer, the prohibition flag is switched from 0 to 1. Thus, after the high-pressure state has been released, even if the user presses the unlock switch of the smart key 20 again, it is possible to prevent the high-pressure state from being restored.

[0067] It should be noted that if Figure 6 As shown, when the power switch 11 is pressed for a period shorter than the threshold (1.5 seconds), the controller 10 does not switch the relay 13 from on to off.

[0068] Next, refer to Figure 7 , other operation examples of the power supply control device 100 will be described with reference to the timing diagram.

[0069] Figure 7 The initial state (time: 0) indicates the state after the prohibition flag switches from 0 to 1. That is, Figure 7 The timing diagram shown is from Figure 5 The state starts after the moment T2.

[0070] exist Figure 7 In the initial state of the high voltage state is released, the power state is in the fifth state. Even if the power state is in the fifth state, the electrical device 16 is also working, so the system request is still connected. Figure 7At the moment T3, when other requests are connected, the controller 10 switches the prohibition flag from 1 to 0 and switches the relay 13 from off to on. In the above description, it is explained that when the power switch 11 is pressed for a specified time or longer, the controller 10 releases the high-voltage state to prevent it from transitioning to the high-voltage state again. Here, when the reason for releasing the high-voltage state is found (rescue, work in the factory, software update work, etc.), it is necessary to return to the high-voltage state again according to the situation. For example, when charging the high-voltage battery 12, when driving an electric car, etc. When charging the high-voltage battery 12, in order to charge the low-voltage battery 15 at the same time, it is necessary to return to the high-voltage state. When driving an electric car, in order to prevent the SOC of the low-voltage battery 15 from decreasing, it is necessary to return to the high-voltage state.

[0071] Figure 7 The other requests at time T3 are requests for charging the high-voltage battery 12, requests for driving the electric vehicle, etc. The other requests are turned on, which means that the controller 10 is sent a second signal indicating that the high-voltage battery 12 starts charging (see Figure 1 ), or a signal indicating that the brake pedal is stepped on and the power switch 11 is pressed is sent to the controller 10. It should be noted that other requests are different from system requests.

[0072] Alternatively, another request may be a request to control the air conditioning system installed in the electric vehicle. In this case, the "other request" is enabled, indicating that a signal for controlling the air conditioning system is being sent to the controller 10. The signal for controlling the air conditioning system may be a signal for controlling the air conditioning system (remote control or timer control) by a user operating a smartphone, or a signal for heating or cooling the high-voltage battery 12.

[0073] Thus, when a request different from the system request is turned on, the controller 10 switches the prohibition flag from 1 to 0 and switches the relay 13 from off to on. Thus, after the high-pressure state is released and prevented from transitioning to the high-pressure state again, it is possible to return to the high-pressure state again.

[0074] exist Figures 5 to 7 In the example shown, the case where the power supply posture is in the second state is described, but the same applies to the case where the power supply posture is in the third state.

[0075] Next, refer to Figure 8 An operation example of the power supply control device 100 will be described with reference to the flowchart of FIG.

[0076] In step S101, when the user presses the unlock switch of the smart key 20, the third signal is sent from the smart key 20 to the controller 10 (refer to Figure 1). The process proceeds to step S103, and the controller 10 that receives the third signal transitions the power state from the power off state (first state) to the second state (refer to Figure 2 ). Thus, the user can use the navigation device etc. immediately after getting on the vehicle. In the second state, the relay 13 is turned on, and power is supplied from the high-voltage battery 12 to the low-voltage battery 15 via the relay 13.

[0077] If the power switch 11 is pressed for a predetermined time or longer (YES in step S105), the process proceeds to step S107, and the controller 10 switches the relay 13 from on to off. As a result, the low-voltage battery 15 is separated from the high-voltage battery 12, and the power supply from the high-voltage battery 12 is stopped. This releases the high-voltage state. Furthermore, the controller 10 switches the prohibition flag from 0 to 1 (step S109). This prevents the relay 13 from switching from off to on, and prevents it from transitioning to the high-voltage state again. If NO in step S105, the process proceeds to standby.

[0078] After the processing of step S109, when the user connects the external power supply 30 to the electric car using a dedicated charging cable and starts charging the high-voltage battery 12, a second signal indicating that the high-voltage battery 12 has started charging is sent to the controller 10. When the controller 10 receives the second signal (YES in step S111), the process enters step S113, and the controller 10 switches the prohibition flag from 1 to 0. As a result, the controller 10 can switch the relay 13 from disconnection to connection. Then, in step S115, the controller 10 switches the relay 13 from disconnection to connection. In this way, according to this embodiment, the high-voltage state can be quickly released, or the high-voltage state can be restored again according to the situation.

[0079] exist Figure 8 In the illustrated example, the case where the power supply attitude transitions to the second state in step S103 is described, but the same applies to the case where the power supply attitude transitions to the third state.

[0080] (Effect)

[0081] As described above, according to the power supply control device 100 of this embodiment, the following operational effects can be obtained.

[0082] When the power state is in the second state or the third state, the controller 10 receives the first signal (refer to Figure 1 ), the controller 10 switches the relay 13 from on to off, and then prohibits the relay 13 from switching from off to on. Thus, after the high-pressure state is released, even if the user presses the unlock switch of the smart key 20 again, it is possible to prevent the high-pressure state from being transferred again.

[0083] The controller 10 receives the second signal after the inhibit relay 13 switches from OFF to ON (refer to Figure 1 ) in the case of, the relay 13 is switched from off to on. Thus, after the high-pressure state is released and prevented from transitioning to the high-pressure state again, it is possible to return to the high-pressure state again.

[0084] The second signal includes at least one of a signal for making the electric vehicle drivable, a signal indicating that charging of the high-voltage battery 12 has started, a signal for controlling an air-conditioning device mounted on the electric vehicle, or a signal for preventing the remaining capacity of the low-voltage battery 15 from decreasing.

[0085] When the controller 10 receives the third signal from the smart key 20, the power state transitions from the power-off state to the second state. In other words, when the controller 10 receives the third signal from the smart key 20, the power state transitions from the power-off state (non-high-voltage state) to the state (high-voltage state) in which power is supplied from the high-voltage battery 12 to the low-voltage battery 15 via the relay 13. That is, in this embodiment, it is easy to transition from the non-high-voltage state to the high-voltage state. Therefore, when the controller 10 switches the relay 13 from on to off by long pressing the power switch 11, the controller 10 sets a prohibition flag so that even if the third signal is received later, the relay 13 will not switch from off to on again. Thus, after the high-voltage state is released, even if the user presses the unlock switch of the smart key 20 again, it is possible to prevent the transition to the high-voltage state again.

[0086] Each function described in the above embodiments can be implemented by one or more processing circuits. A processing circuit includes a programmed processing device such as a processing device with electronic circuits. A processing circuit also includes a device such as an application-specific integrated circuit (ASIC) or circuit components arranged to perform the described functions.

[0087] As described above, the embodiments of the present invention have been described, but the description and drawings forming part of this disclosure should not be construed as limiting the present invention. Based on this disclosure, various alternative embodiments, examples, and application techniques will be apparent to those skilled in the art.

[0088] Description of Reference Numerals

[0089] 100 Power supply control device; 10 Controller; 11 Power switch; 12 High-voltage battery; 13 Relay; 14 DC-DC rectifier; 15 Low-voltage battery; 16 Electrical equipment; 20 Smart key; 30 External power supply.

Claims

1. A power control method for a power control device comprising: a high-voltage battery, a low-voltage battery, a relay electrically connecting the high-voltage battery and the low-voltage battery, a power switch, and a controller that controls the on / off switching of the relay and receives at least a door unlocking signal for unlocking a vehicle door and a first signal for disconnecting the relay, wherein: When the controller receives the door unlock signal, the controller switches the power state from the state where the power switch is turned off to the state where power is supplied from the high-voltage battery to the low-voltage battery via the relay. The controller switches the relay from on to off when receiving the first signal, and thereafter prohibits the relay from switching from off to on based on receipt of the door unlock signal.

2. The power control method according to claim 1, wherein: When the controller receives the first signal and switches the relay from on to off, power is supplied from the low-voltage battery to the electrical equipment mounted on the vehicle.

3. The power control method according to claim 1, wherein: The first signal is a signal indicating that the power switch has been pressed for a predetermined time or longer.

4. The power control method according to claim 1, wherein: The controller switches the relay from off to on upon receiving a second signal after prohibiting the relay from switching from off to on.

5. The power control method according to claim 4, wherein: The second signal includes at least one of a signal for making the vehicle drivable, a signal indicating that charging of the high-voltage battery has started, a signal for controlling an air-conditioning device mounted on the vehicle, or a signal for preventing a decrease in the remaining capacity of the low-voltage battery.

6. The power supply control method according to any one of claims 1 to 5, wherein: The power status includes: a first state in which the power supply is disconnected; a second state in which electric power is supplied from the high-voltage battery to the low-voltage battery via the relay; The controller transitions the power state from the first state to the second state when receiving a third signal transmitted from a key held by the user before the user gets on the vehicle.

7. A power supply control device comprising: a high-voltage battery, a low-voltage battery, a relay electrically connecting the high-voltage battery and the low-voltage battery, a power switch, and a controller that controls the on / off switching of the relay and receives at least a door unlocking signal for unlocking a vehicle door and a first signal for disconnecting the relay, wherein: When the controller receives the door unlock signal, the controller switches the power state from a state in which the power switch is turned off to a state in which power is supplied from the high-voltage battery to the low-voltage battery via the relay. The controller switches the relay from on to off when receiving the first signal, and thereafter prohibits the relay from switching from off to on based on receipt of the door unlock signal.

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