Power supply device, power supply system, and control method

Abstract

To provide a power supply device, a power supply system, and a control method that can prevent a device from becoming excessively hot due to power supply while suppressing the effects of differences in device models and individual differences.SOLUTION: A control unit 20 of a power supply device 1 has a function of intermittently acquiring, from a device 2, temperature information indicating the temperature of the device 2 and status information indicating which status the device's temperature belongs to among two or more statuses divided into temperature ranges, a function of determining, on the basis of the intermittently acquired status information, whether the status of the device 2 has changed from a first status to a second status in a temperature range higher than the first status, and, if so, storing the temperature information acquired at the time of the change as reference temperature information, and a function of controlling the output voltage of the power supply unit 11 on the basis of the reference temperature information.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply device, a power supply system, and a control method, and is particularly suitable for use in a power supply device capable of supplying power to a connected device, a power supply system including the power supply device and the device, and a control method using the power supply device. [Background technology]

[0002] Conventionally, power supply devices that can connect to devices and supply power to the connected devices have been known. Among these power supply devices, there are some that have the ability to communicate with connected devices and acquire temperature and status information from the devices. Temperature information indicates the temperature measured by the device's temperature sensor. Status information indicates which of two or more temperature ranges the device's temperature is in. Examples of status types include normal (0°C to less than 50°C), warning (50°C to less than 60°C), and overheat (60°C to less than 255°C). Hereinafter, a power supply device that can acquire temperature and status information from a device is referred to as a "conventional power supply device." In recent years, USB PD (Power Delivery), a USB-Type-C charging standard, has become widespread, and a power supply device that supports USB PD is considered a conventional power supply device.

[0003] Patent Document 1 describes the following technology related to this type of power supply device. Specifically, Patent Document 1 discloses a charging system 1 including a charging device 50 and a battery 20 connected to the charging device 50 via a charging cable 70, and charging the battery 20 using the charging device 50. The battery 20 is, for example, a battery mounted on an electric vehicle such as a battery-powered forklift. The charging system 1 also includes a monitoring device 30 that monitors the state of the battery 20 and transmits individual information about the battery 20 to the charging device 50. Based on the individual information transmitted from the monitoring device 30, the charging device 50 determines whether to charge the battery 20 before charging the battery 20, and whether to continue charging the battery 20 as is or whether to continue charging with restrictions while the battery 20 is being charged. The above technology is described. Patent Document 1 enables safe charging of batteries. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-039880 Summary of the Invention [Problem to be solved by the invention]

[0005] When a power supply device supplies power to a device, it is necessary to prevent the device from becoming excessively hot due to the power supply. This is because excessively high temperatures can have adverse effects on various parts of the device and can also cause the device to shut down due to its functions. Conventional power supply devices can acquire temperature information, and this information is used to control the power supply to prevent the device from becoming excessively hot in the following ways.

[0006] In other words, a control unit of a conventional power supply device intermittently acquires temperature information from a device. When the temperature indicated by the temperature information exceeds a threshold value T1, the control unit reduces the output voltage of the power supplied to the device to suppress heat generation due to power supply. When the temperature indicated by the temperature information falls below a threshold value T2, the control unit increases the output voltage of the power supplied to the device to allow heat generation due to power supply. However, this method has the following problem. To properly control the power supply to prevent the device from overheating, the temperature indicated by the temperature information must be equal to the temperature of the battery, which generates heat due to power supply. However, depending on the model, the temperature indicated by the temperature information may not be equal to the temperature of the battery. Furthermore, even for the same model, the temperature indicated by the temperature information may vary due to individual differences. This creates a problem in that the power supply control to prevent the device from overheating may not be properly performed due to differences in device model and individual differences.

[0007] The present invention has been made to solve such problems, and aims to provide a power supply device that supplies power to connected devices, capable of preventing the devices from becoming excessively hot due to power supply while suppressing the effects of differences in device model and individual differences. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the power supply device of the present invention has a function of controlling the output voltage of a power supply unit capable of supplying power to a device, a function of communicating with the device, a function of intermittently acquiring temperature information indicating the temperature of the device via communication from the device and status information indicating which status the device's temperature belongs to among two or more statuses classified according to temperature range, a function of determining whether the device's status has changed from a first status to a second status in a temperature range higher than the first status based on the intermittently acquired status information, and if so, storing the temperature information acquired at the time of the change as reference temperature information, and a function of controlling the output voltage of the power supply unit based on the reference temperature information. [Effects of the Invention]

[0009] According to the configuration of the present invention, temperature information acquired when the device status changes from status 1 to status 2 is stored as reference temperature information, and output voltage is controlled based on this reference temperature information. This makes it possible to manage the device's temperature from the perspective of "the device's temperature relative to the temperature indicated by the reference temperature information," which is not affected by differences in device model and individual differences. Under this management, power supply control can be performed to prevent the device from becoming excessively hot due to power supply. In other words, according to the present invention, a power supply device that supplies power to a connected device can prevent the device from becoming excessively hot due to power supply while suppressing the effects of differences in device model and individual differences. [Brief explanation of the drawings]

[0010] [Figure 1] 2 is a block diagram illustrating an example of a functional configuration of a power supply apparatus and a device according to an embodiment. FIG. [Figure 2] 10 is a flowchart illustrating an example of an operation of a power supply device according to an embodiment. [Figure 3] 10 is a flowchart illustrating an example of an operation of a power supply device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment will be described below with reference to the drawings. Fig. 1 is a block diagram showing an example of the functional configuration of a power supply device 1 and a device 2 according to this embodiment. A power supply system 3 is configured by the power supply device 1 and a device 2 connectable thereto. The power supply system 3 complies with USB Type-C, and the power supply device 1 and the device 2 are connected via a USB Type-C cable 4 (hereinafter referred to as "cable 4").

[0012] The power supply device 1 according to this embodiment is a device mounted on a vehicle. The power supply device 1 is mounted on, for example, a car navigation system, a car audio system, or other in-vehicle device. However, the power supply device 1 may be mounted on an adapter or may be an independent device. The power supply device 1 is a device compliant with USB PD (Power Delivery) and has a function of supplying power (a function of supplying power) in accordance with USB PD. The power supply device 1 has a power supply device connector 5 and can supply power to a device 2 connected to the power supply device connector 5. The device 2 that receives the power charges its battery or supplies power to a load. Hereinafter, connecting the device 2 to the power supply device connector 5 of the power supply device 1 via the cable 4 may be simply expressed as "the device 2 is connected to the power supply device 1."

[0013] In this embodiment, the power supply device connector 5 is a receptacle compatible with USB Type-C, and includes a VBUS terminal for supplying a bus voltage, a GND terminal related to a ground voltage, and a CC (Configuration Channel) port. When the device 2 is connected to the power supply device 1, power is supplied from the power supply device 1 to the device 2 via a power supply line 6 through the cable 4. In this state, communication between the power supply device 1 and the device 2 is performed via a CC line 7 through the cable 4.

[0014] As shown in FIG. 1, the power supply device 1 includes a control unit 10, a power supply unit 11, and a communication unit 12.

[0015] The control unit 10 is a controller compatible with USB PD and USB Type-C, and includes an IC in which various circuits, including a processor, are integrated. The control unit 10 executes processing through cooperation between hardware and software, such as the processor reading and executing a program stored in a predetermined memory.

[0016] The power supply unit 11 includes a power supply circuit including a DC / DC converter, a switch element that opens and closes the power supply line 6, and other elements (for example, necessary switches and necessary capacitors). The power supply unit 11 receives power from an on-board battery 13, which is an external power source. Under the control of the control unit 10, the power supply unit 11 converts the voltage of the on-board battery 13, which is an external power source, to an appropriate voltage and supplies the power to the device 2 connected to the power supply apparatus 1 via the power supply line 6. The on-board battery 13 is a battery installed in the vehicle.

[0017] The communication unit 12 has a transceiver for communication via the CC line 7, and communicates with the device 2 under the control of the control unit 10. Hereinafter, it is assumed that communication between the power supply device 1 and the device 2 is appropriately performed by the communication unit 12, and a detailed description of the communication itself will be omitted. The control unit 10 has a function of communicating with each of the devices 2 connected to the power supply device 1 via the communication unit 12.

[0018] The control unit 10 has a function to control the power supplied by the power supply unit 11. That is, the control unit 10 has a function to control the output voltage of the power supply unit 11. In particular, the control unit 10 controls the power supply unit 11 to supply power of a specific voltage value and a specific maximum current value (current upper limit value) to the device 2 connected to the power supply device 1. Note that the current value of the supplied power basically varies depending on the circumstances of the device 2, but cannot exceed the maximum current value set by the power supply device 1. Hereinafter, when referring to the power supplied by the power supply device 1, the term "current" simply means "current below the maximum current value" unless otherwise specified. Furthermore, when referring to the power supplied by the power supply device 1, the term "current value" means "maximum current value" (current upper limit value) unless otherwise specified. Furthermore, when referring to the power supplied by the power supply device 1, the term "current value" means "maximum current value" (current upper limit value) unless otherwise specified. Furthermore, when referring to the power supplied by the power supply device 1, the combination of the voltage value and the current value is sometimes referred to as a "power-related value." Hereinafter, the control unit 10 controlling the power supply unit 11 to increase or decrease the output voltage may be simply expressed as "the control unit 10 increases / decreases the output voltage."

[0019] The device 2 is an electronic device. There are no limitations on the type of electronic device that the device 2 is. Examples of the device 2 include a laptop computer, a tablet device (including a so-called smartphone), a portable game console, and a wearable device.

[0020] As shown in Fig. 1, the device 2 includes a device connector 15 that is compatible with USB Type-C. The device connector 15 is configured as a receptacle to which a plug can be connected. The device connector 15 and the power supply device connector 5 of the power supply device 1 are connected via a cable 4. The device 2 also includes a device battery 16, which is a secondary battery.

[0021] As shown in FIG. 1, the device 2 includes a device control unit 17, a device communication unit 18, and a device charging unit 19 as functional blocks.

[0022] The device control unit 17 is a controller compatible with USB PD and USB Type-C, and includes an IC in which various circuits including a processor are integrated. The device control unit 17 executes processes through cooperation between hardware and software, such as the processor reading and executing a program stored in a predetermined memory.

[0023] The device communication unit 18 has a transceiver for communication via the CC line 7, and realizes communication with the power supply device 1 under the control of the device control unit 17. Hereinafter, it is assumed that communication between the device 2 and the power supply device 1 is appropriately performed by the device communication unit 18, and a detailed description of the communication itself will be omitted. The device control unit 17 has a function of communicating with the control unit 10 via the device communication unit 18.

[0024] The device charging unit 19 includes a charging circuit including a DC / DC converter, a switch element that opens and closes the power supply line 6, and other elements (for example, necessary switches and necessary capacitors). The device charging unit 19 receives power from the power supply unit 11 of the power supply device 1 via the power supply line 6. Under the control of the device control unit 17, the device charging unit 19 adjusts the voltage / current, adjusts the timing of power supply, and performs other necessary processing related to charging to charge the device battery 16.

[0025] Although not shown in the figure, the device 2 includes a load that receives power from the device battery 16.

[0026] Incidentally, when the power supply device 1 supplies power to the device 2, it is necessary to prevent the device 2 from becoming excessively hot due to the power supply. This is because an excessively high temperature can adversely affect each part of the device 2, and the device 2 may shut down due to its functions if the temperature becomes too high. In light of this, the power supply device 1 controls the power supply so as to prevent the device 2 from becoming excessively hot. The operation of the power supply device 1 in relation to the supply of power to the device 2 will be described in detail below.

[0027] 2 and 3 are flowcharts illustrating an example of the operation of the power supply device 1 according to this embodiment. As shown in the flowchart FA, when the device 2 is connected to the power supply device 1 (step SX1), the control unit 10 of the power supply device 1 starts normal power supply (step SA1). In this embodiment, normal power supply refers to the supply of power at an output voltage greater than 5V (e.g., 9V, 15V, or 20V). For example, the power-related values ​​in normal power supply are 9V, 3A, or 27W. When starting normal power supply in step SA1, the control unit 10 executes the following process. Specifically, the control unit 10 detects the connection of the device 2. Next, the control unit 10 communicates with the device control unit 17 of the device 2, negotiates according to the USB PD standard, and determines the power-related values ​​(voltage and current values) of the power to be supplied to the device 2. Next, the control unit 10 starts supplying power according to the determined power-related values ​​(i.e., starts normal power supply).

[0028] As a result of the negotiation, the output voltage of normal power supply may not be greater than 5V. However, in this embodiment, for the sake of convenience, the output voltage of normal power supply is assumed to be greater than 5V. In the following explanation, even if not otherwise specified, when the control unit 10 needs to negotiate with the device control unit 17 to execute some process, the negotiation is assumed to be executed appropriately. Processes requiring negotiation include at least "changing the output voltage of the supplied power."

[0029] As shown in flowchart FA, in response to the start of normal power supply, control unit 10 starts a polling process (step SA2). More specifically, control unit 10 communicates with device control unit 17 and intermittently acquires temperature information and status information from device control unit 17 at predetermined intervals (e.g., every 100 ms). For example, control unit 10 requests device control unit 17 to respond with this information at predetermined intervals in accordance with USB PD, and acquires this information. Device control unit 17 has a function of communicating with power supply device 1 and a function of intermittently transmitting temperature information indicating the temperature of its own device and status information to power supply device 1 via communication.

[0030] Temperature information is information indicating the temperature measured by the temperature sensor of device 2. Depending on the model of the device, the temperature indicated by the temperature information may not be the same as the temperature of the battery, which is a component that generates heat due to power supply. Even if the model is the same, there may be variations in the temperature indicated by the temperature information output by each device due to individual differences. Hereinafter, the temperature indicated by the temperature information will be referred to as the "device-reported temperature."

[0031] Status information is information that indicates which status the device 2 temperature belongs to, out of two or more status categories based on temperature ranges. For device 2, the following status types are defined: Normal (first status), Warning (second status), and Over Temperature. The temperature ranges increase in order from Normal to Warning to Over Temperature. For device 2, normal is defined as 0°C or higher but less than 50°C, warning is defined as 50°C or higher but less than 60°C, and over Temperature is defined as 60°C or higher but less than 255°C. The temperature ranges assigned to statuses may differ depending on the device model. For example, for a device DA different from device 2, normal may be defined as 0°C or higher but less than 40°C, warning is defined as 40°C or higher but less than 50°C, and over Temperature is defined as 50°C or higher but less than 255°C. Furthermore, the actual battery temperature when a status change occurs may vary due to individual differences between devices. For example, for device A and device B of the same model, when the status changes from normal to warning, the actual battery temperature of device A and the actual battery temperature of device B will not necessarily be the same due to individual differences. Hereinafter, the status indicated by the status information will be referred to as the "device notification status."

[0032] After step SA2, the control unit 10 continues to execute polling processing, acquiring temperature information and status information from the device 2 at predetermined intervals. In the following explanation, it is assumed that the status of the device 2 is normal when the device 2 is connected to the power supply unit 1. Although a detailed explanation is omitted, if the status is already warning or overheated when power supply starts, the control unit 10 executes appropriate error processing.

[0033] After step SA2, the control unit 10 monitors whether the device notification status has changed from normal to warning based on the status information acquired at a predetermined interval (step SA3). If the status has changed (step SA3: YES), the control unit 10 stores the temperature information acquired at the time of the change as reference temperature information in a storage area of ​​a predetermined memory (step SA4). The time of the change is not strictly limited to the time when the device notification status changed from normal to warning, but may be any time close to the time when the status changed from normal to warning. Hereinafter, the temperature indicated by the reference temperature information will be referred to as the "reference temperature."

[0034] Next, the control unit 10 determines whether the output voltage of the power supplied to the device 2 is greater than 5V (step SA5). If normal power supply is continuing, the output voltage at the time of step SA5 is greater than 5V. However, there is a possibility that the output voltage may drop below 5V due to some event occurring during normal power supply. If the output voltage is not greater (less than 5V) (step SA5: NO), the control unit 10 proceeds to step SA8. On the other hand, if the output voltage is greater (step SA5: YES), the control unit 10 transitions the output voltage to 5V (step SA6). In processing step SA6, the control unit 10 appropriately negotiates with the device control unit 17. Next, the control unit 10 determines whether the device-notified temperature is on an upward trend based on temperature information acquired at a predetermined interval (step SA7). Specifically, the control unit 10 monitors the change in the device-notified temperature for a certain period (e.g., 10 seconds) based on the temperature information acquired at a predetermined interval. If the device notification temperature has increased during the given period, the control unit 10 determines that the device notification temperature is on an increasing trend, and if the device notification temperature has not increased, the control unit 10 determines that the device notification temperature is not on an increasing trend.

[0035] If it is determined in step SA7 that the device-notified temperature is not on an upward trend (step SA7: NO), the control unit 10 proceeds to step SA10. On the other hand, if it is determined that the device-notified temperature is on an upward trend (step SA7: YES), the control unit 10 proceeds to step SA8.

[0036] In step SA8, the control unit 10 stops the power supply to the device 2. This is to further suppress the temperature rise in the device 2. Next, the control unit 10 monitors whether the device notification status has changed from warning to normal based on the status information acquired at a predetermined interval (step SA9). If the device notification status has changed to normal (step SA9: YES), the control unit 10 proceeds to step SA10.

[0037] In step SA10, the control unit 10 monitors (determines) whether the device notification temperature indicated by the temperature information acquired at a predetermined interval has fallen below a first threshold temperature. The first threshold temperature is a temperature that is lower than the reference temperature indicated by the reference temperature information stored in step SA4 by a predetermined first temperature range. For example, if the first temperature range is set to 10°C and the reference temperature is 50°C, the first threshold temperature is 40°C. Here, the first threshold temperature is a "hypothetical temperature based on the reference temperature" that is considered to be a sufficiently low temperature at which the device battery 16 of the device 2 is safe to resume normal power supply (does not directly lead to an excessively high temperature), regardless of the device model or individual differences. The first temperature range that defines the first threshold temperature is appropriately set based on prior experiments and simulations so that the first threshold temperature is within this range.

[0038] If it is determined in step SA10 that the device notification temperature has become equal to or lower than the first threshold temperature, the control unit 10 negotiates with the device control unit 17 and starts normal power supply (power supply with an output voltage greater than 5V) (step SA11 in FIG. 3).

[0039] As described above, in this embodiment, the control unit 10 does not lower the output voltage of the power supply and then uniformly increase the output voltage when the device-notified temperature falls below a predetermined absolute temperature (threshold value). On the other hand, the control unit 10 lowers the output voltage of the power supply and then increases the power supply when the device-notified temperature falls below a "first threshold temperature determined relatively to the reference temperature." This allows the control unit 10 to manage the temperature status of the device 2 from the perspective of "the temperature of the device relative to the reference temperature," and under this management, can resume normal power supply when the temperature of the device 2 falls to a sufficiently low temperature that it is deemed safe to resume normal power supply.

[0040] Referring to FIG. 3, after starting normal power supply in step SA11, the control unit 10 monitors (determines) whether the device notification temperature indicated by the temperature information acquired at a predetermined interval is equal to or higher than the second threshold temperature (step SA12). The second threshold temperature is a temperature that is lower than the reference temperature indicated by the reference temperature information stored in step SA4 by a predetermined second temperature range. For example, if the second temperature range is set to 5°C and the reference temperature is 50°C, the second threshold temperature is 45°C. The second threshold temperature is a "temperature relative to the reference temperature" that indicates a temperature at which the device battery 16 of the device 2 should be careful not to become excessively hot, regardless of the device model or individual differences, and that requires reducing the output voltage to suppress heat generation associated with power supply. The second temperature range that defines the second threshold temperature is appropriately set based on prior experiments and simulations so that the second threshold temperature is within this range. Note that the second temperature range is naturally smaller than the first temperature range.

[0041] If it is determined in step SA12 that the device notification temperature is equal to or higher than the second threshold temperature, the control unit 10 determines whether the output voltage of the power supplied to the device 2 is greater than 5V (step SA13). If it is not greater (less than or equal to 5V) (step SA13: NO), the control unit 10 proceeds to step SA16. On the other hand, if it is greater (step SA13: YES), the control unit 10 transitions the output voltage to 5V (step SA14). Next, the control unit 10 determines whether the device notification temperature is on the rise (step SA15).

[0042] If the temperature is not on an upward trend (step SA15: NO), the control unit 10 proceeds to step SA17. If the temperature is on an upward trend (step SA15: YES), the control unit 10 proceeds to step SA16.

[0043] In step SA16, the control unit 10 stops the power supply to the device 2. Next, the control unit 10 moves the processing procedure to step SA17.

[0044] As described above, in this embodiment, the control unit 10 does not uniformly reduce the output voltage when the device-notified temperature becomes equal to or higher than a predetermined absolute temperature (threshold) after normal power supply is resumed. On the other hand, the control unit 10 reduces the output voltage when the device-notified temperature becomes equal to or higher than a "second threshold temperature determined relatively to the reference temperature" after normal power supply is resumed. This allows the control unit 10 to manage the temperature state of the device 2 from the perspective of "the temperature of the device relative to the reference temperature." Under this management, when the device-notified temperature becomes a temperature at which attention should be paid to excessive temperature rise of the device 2, the control unit 10 reduces the output voltage to suppress heat generation of the device battery 16.

[0045] In step SA17, the control unit 10 monitors (determines) whether the device notification temperature indicated by the temperature information acquired at a predetermined interval has become equal to or lower than the first threshold temperature. If the temperature has become equal to or lower than the first threshold temperature (step SA17: YES), the control unit 10 returns the processing procedure to step SA11 and starts normal power supply (power supply with an output voltage higher than 5V).

[0046] By performing the above process, after power supply starts, the device notification temperature is basically maintained between the first threshold temperature and the second threshold temperature (however, there may be times when the device notification temperature temporarily drops below the first threshold temperature or temporarily exceeds the second threshold temperature). Therefore, once the status has become a warning in step SA3, it is possible to prevent the status from becoming a warning again, and to prevent a situation in which a safety measure (for example, a shutdown due to high temperature of device 2) is taken by a function on the device 2 side. This allows for continuous power supply and actively reduces damage to the device battery 16 and other components.

[0047] As described above, the control unit 10 of the power supply device 1 of this embodiment has the following functions: a function to control the output voltage of the power supply unit 11 capable of supplying power to the device 2; a function to communicate with the device 2; a function to intermittently acquire, via communication from the device 2, temperature information indicating the temperature of the device 2 and status information indicating which status the temperature of the device 2 belongs to among two or more statuses classified according to temperature range; a function to determine, based on the intermittently acquired status information, whether the status of the device 2 has changed from normal (first status) to warning (second status) in a temperature range higher than normal, and, if so, to store the temperature information acquired at the time of the change as reference temperature information; and a function to control the output voltage of the power supply unit 11 based on the reference temperature information.

[0048] According to this configuration, the temperature information acquired when the status of the device 2 changes from normal to warning is stored as reference temperature information, and the output voltage is controlled based on this reference temperature information. This makes it possible to manage the temperature status of the device 2 from the perspective of "the temperature of the device 2 relative to the temperature indicated by the reference temperature information," which is not affected by differences in the model and individual differences of the device 2. Under this management, power supply control can be performed to prevent the device 2 from becoming excessively hot due to power supply. In other words, according to this embodiment, the power supply unit 1 that supplies power to the connected device 2 can prevent the device 2 from becoming excessively hot due to power supply, while suppressing the effects of differences in the model and individual differences of the device 2.

[0049] Although one embodiment of the present invention has been described above, the above embodiment is merely an example of a specific embodiment for carrying out the present invention, and the technical scope of the present invention should not be interpreted as being limited thereby. In other words, the present invention can be carried out in various forms without departing from the gist or main characteristics thereof.

[0050] For example, in the above embodiment, the control unit 10 increases the output voltage when the device notification temperature becomes equal to or lower than the first threshold temperature, and decreases the output voltage when the device notification temperature becomes equal to or higher than the second threshold temperature. In this regard, the following configuration may be used. That is, the control unit 10 may increase the output voltage when the device notification temperature becomes equal to or lower than the first threshold temperature, and decrease the output voltage when a predetermined condition (≠ the condition that the device notification temperature is equal to or higher than the second threshold temperature) is met. Alternatively, the control unit 10 may decrease the output voltage, and then increase the output voltage when a predetermined condition (≠ the condition that the device notification temperature is equal to or lower than the first threshold temperature) is met, and then decrease the output voltage when the device notification temperature becomes equal to or higher than the second temperature threshold.

[0051] In the above embodiment, the power supply device 1 is mounted on a vehicle. However, the power supply device 1 does not have to be mounted on a vehicle. When AC power such as a commercial power source is supplied to the power supply device 1, the power supply unit 11 is configured to include an AC / DC converter and performs appropriate AC / DC conversion.

[0052] The functional blocks shown in the above embodiments can be realized by any hardware or by a combination of any hardware and any software, and are not limited to specific hardware.

[0053] The power supply device 1 described above includes the power supply device connector 5. However, the power supply device may be a device that does not include a connector and is integrated with a cable that complies with a standard.

[0054] Furthermore, a configuration may be possible in which a plurality of devices 2 can be connected to the power supply unit 1, and the power supply unit 1 can supply power to the plurality of devices 2 simultaneously.

[0055] Furthermore, for example, the control unit 10 may be configured to execute various processes in cooperation with an external device in addition to the processes described as being executed solely by the control unit 10. As an example, the control unit 10 may execute processes in cooperation with a processor of a device in which the power supply device 1 is installed, or may execute processes in cooperation with an external device with which it can communicate via a network.

[0056] Furthermore, the order of the processes in the illustrated flowcharts may be changed, the processes may be divided into smaller processes, processes may be added, or processes may be deleted, as long as the purpose can be achieved.

[0057] In the above embodiment, the power supply device 1 is a device that supplies power in accordance with the USB PD standard. However, the standard that the power supply device 1 complies with is not limited to the USB PD standard.

[0058] Furthermore, for example, the provision of a program executed by the computer of the power supply device 1 can be included in the embodiments. Furthermore, the provision of a recording medium on which the program is recorded so as to be readable by a computer can be included in the embodiments. The recording medium can be a magnetic or optical recording medium or a semiconductor memory device. Specific examples include portable or fixed recording media such as a flexible disk, a hard disk drive (HDD), a compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a Blu-ray (registered trademark) disc, a magneto-optical disk, a flash memory, and a card-type recording medium. [Explanation of symbols]

[0059] 1 Power supply device 2 Devices 3 Power Supply System 10 Control Unit 17 Device control section

Claims

1. A power supply device capable of supplying power to a connected device, a power supply capable of supplying power to the device; a control unit having a function of controlling the output voltage of the power supply unit, a function of communicating with the device, a function of intermittently acquiring from the device temperature information indicating the temperature of the device and status information indicating which status the temperature of the device belongs to among two or more statuses divided into temperature ranges, a function of determining whether the status of the device has changed from a first status to a second status in a temperature range higher than the first status based on the intermittently acquired status information, and, if a change has occurred, storing the temperature information acquired at the time of the change as reference temperature information, and a function of controlling the output voltage of the power supply unit based on the reference temperature information. A power supply device characterized by:

2. The control unit When it is determined that the status of the device has changed from the first status to the second status, the power supply unit is controlled so as to reduce the output voltage, and thereafter, the power supply unit is controlled to determine whether or not the temperature indicated by the temperature information intermittently acquired has become equal to or lower than a first threshold temperature that is lower than the temperature indicated by the reference temperature information by a first temperature width, and when the temperature has become equal to or lower than the first threshold temperature, the power supply unit is controlled to increase the output voltage. The power supply device according to claim 1 .

3. The control unit When it is determined that the status of the device has changed from the first status to the second status, the power supply unit is controlled so that an output voltage decreases, and thereafter, the power supply unit is controlled so that an output voltage increases in response to the establishment of a predetermined condition. Thereafter, the power supply unit is controlled so that an output voltage decreases when a predetermined condition is satisfied. Thereafter, the power supply unit is controlled so that an output voltage decreases when a predetermined condition is satisfied. The power supply device according to claim 1 .

4. The control unit When it is determined that the status of the device has changed from the first status to the second status, the power supply unit is controlled to reduce the output voltage; thereafter, it is determined whether the temperature indicated by the temperature information obtained intermittently is equal to or lower than a first threshold temperature that is lower than the temperature indicated by the reference temperature information by a first temperature width, and if so, the power supply unit is controlled to increase the output voltage; thereafter, it is determined whether the temperature indicated by the temperature information obtained intermittently is equal to or higher than a second threshold temperature that is lower than the temperature indicated by the reference temperature information by a second temperature width, and if so, the power supply unit is controlled to reduce the output voltage. The power supply device according to claim 1 .

5. A power supply system including a device and a power supply device capable of supplying power to the connected device, The device comprises: a device control unit having a function of communicating with the power supply device and a function of intermittently transmitting temperature information indicating the temperature of the device itself and status information indicating to which of two or more statuses the temperature of the device itself belongs, by communication with the power supply device; The power supply device is a power supply capable of supplying power to the device; a control unit having a function of controlling the output voltage of the power supply unit, a function of communicating with the device, a function of intermittently acquiring the temperature information and the status information from the device by communication, a function of determining whether the status of the device has changed from a first status to a second status in a temperature range higher than the first status based on the intermittently acquired status information, and, if a change has occurred, a function of storing the temperature information acquired at the time of the change as reference temperature information, and a function of controlling the output voltage of the power supply unit based on the reference temperature information. A power supply system characterized by:

6. A control method for a power supply device capable of supplying power to a connected device, comprising: a step in which a control unit of the power supply device intermittently acquires, via communication from the device, temperature information indicating a temperature of the device and status information indicating to which status the temperature of the device belongs, out of two or more statuses classified according to temperature zones; the control unit of the power supply device determines whether the status of the device has changed from a first status to a second status in a temperature range higher than the first status, based on the status information intermittently acquired, and if the status has changed, stores the temperature information acquired at the time of the change as reference temperature information; and a step of the control unit of the power supply device controlling an output voltage of the power supply unit based on the reference temperature information. A control method comprising:

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