Power supply device, power supply system and control method

Abstract

To provide "power supply device, power supply system and control method" which suppress an occurrence of a defect in a process until power is supplied in accordance with a distribution after a new device is connected as for the power supply device that supplies power to a plurality of devices in accordance with the distribution.SOLUTION: A power supply device 1 includes: a power supply unit 21 capable of supplying power to a plurality of connected devices DV; and a control unit 20 that has a function of communicating with each of the devices for negotiation, and of deciding the distribution of power to each of the devices in such a way that the total power to be supplied does not exceed the upper limit. With the one or more devices DV being already connected, when a new device DV is connected, the control unit 20 decreases, step by step, the voltage of the power supplied to the already-connected device DV so as to be a first voltage, and then negotiates with each of the devices DV.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 configured to simultaneously supply power to a plurality of devices, a power supply system including the power supply device, and a control method using the power supply device.

Background Art

[0002] Conventionally, a power supply device configured to be connectable to a plurality of devices and capable of supplying power to each of the plurality of devices has been known. In particular, in USB PD (Power Delivery), which is a charging standard for USB-TypeC, it is possible to supply a large amount of power. Utilizing this, a power supply device corresponding to USB PD, which is provided with a plurality of connectors and configured to be able to supply power to a plurality of devices connected to the plurality of connectors, has become widespread.

[0003] Regarding a power supply device capable of supplying power to each of a plurality of devices as described above, Patent Document 1 discloses the following technology. That is, the hub 10 of Patent Document 1 is a power supply device to which an electronic device 7 (device) and a mobile device 8 (device) are connected, supplies power to these devices, and charges these devices. The hub 10 is provided with a power supply module 12 that supplies power to these devices and a power distribution control circuit 13 that measures the power value of the power supplied by the power supply module 12. When supplying power to the electronic device 7 and the mobile device 8, the hub 10 adjusts the power supplied to the electronic device 7 and the power supplied to the mobile device 8 so that the power value measured by the power distribution control circuit 13 does not exceed the upper limit value that can be stably supplied by the power supply module 12. The above technology is disclosed. According to Patent Document 1, appropriate active distribution of the total power output of the power supply device becomes possible.

[0004] In addition, Patent Document 2 discloses the following technology. That is, the master controller 124 on the device side acquires charger capability information regarding the capabilities of the USB charger 110 (power supply device) from the USB charger 110, and sets an optimal power supply level based on this information and its own device charging capability information. The above technology is disclosed. According to Patent Document 2, it is possible to suppress a mismatch in the charging / power supply level.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Here, in a power supply device capable of supplying power to a plurality of connected devices, when a new device is connected while one or more devices are already connected, there are some that perform the following operations. Hereinafter, the newly connected device is referred to as the "new device", and the device connected before the new device is connected is referred to as the "already connected device". That is, in response to the connection of the new device, the power supply device immediately drops the voltage of the power supplied to the already connected devices to a certain value. Next, the power supply device negotiates with each device (new device + already connected devices) and determines the distribution of the power to be supplied within a range where the total power to be supplied does not exceed the upper limit value. Next, the power supply device supplies power to each device according to the determined distribution. The reason why the voltage of the power supplied to the already connected devices is dropped to a certain value is to prevent the total power supplied to each device from exceeding the upper limit value even for an instant due to the connection of the new device. There is a power supply device that performs the above operations. Note that a device corresponding to this type of power supply device is a device compatible with USB PD.

[0007] Regarding the power supply device that performs the above operations, there are the following needs. That is, after connecting a new device, there is a need to suppress as much as possible the occurrence of problems during the process of starting to supply power to each device according to the power distribution determined through negotiation. This is because if the occurrence of problems can be suppressed, it will lead to a reduction in the risk of failure and an extension of the device life.

[0008] The present invention has been made to solve such problems. When a new device is newly connected during the connection of devices, it negotiates with each device to determine the power distribution, and for a power supply device that supplies power to each device according to the distribution, it aims to suppress the occurrence of problems during the process until the power supply according to the distribution is performed after the new device is connected.

Means for Solving the Problems

[0009] In order to solve the above problems, the power supply device according to the present invention includes a power supply unit capable of supplying power to a plurality of connected devices, a function of controlling the power supplied by the power supply unit, a function of communicating with the connected devices, and a function of negotiating with each of the plurality of devices to determine the distribution of the power supplied to each device within a range where the total power supplied does not exceed the upper limit value when supplying power to the plurality of devices. And when one or more devices are connected, when a new device is connected, the control unit gradually drops the voltage of the power supplied to the devices that have already been connected to obtain a first voltage, and then negotiates with each of the devices.

Effects of the Invention

[0010] In a situation where a device is connected to a power supply device and power is being supplied from the power supply device to the device, if the voltage of the power supplied to the device drops steeply, problems may occur due to this voltage drop. As an example, there are cases where some error occurs in the device in response to a sudden voltage drop, or the device executes error processing for error prevention in response to a sudden voltage drop. In this case, problems may occur due to the error or error processing. Based on this, according to the present invention, when a new device is connected while a device is already connected, the voltage of the power supplied to the already connected device does not drop steeply toward the first voltage, but rather the voltage drops step by step until it reaches the first voltage. Therefore, it is possible to suppress the occurrence of problems caused by the voltage drop of the power supplied to the device.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a functional configuration example of a power supply device 1 according to this embodiment together with a first device DV1 and a second device DV2 in a state of being connected to the power supply device 1. A power supply system 4 is constituted by the power supply device 1 and one or more devices connected thereto. The power supply system 4 complies with USB Type-C, and the power supply device 1 and the first device DV1 are connected via a USB Type-C cable 5 (hereinafter referred to as "first cable 5"). Also, the power supply device 1 and the second device DV2 are connected via a USB Type-C cable 6 (hereinafter referred to as "second cable 6").

[0013] 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, or other in-vehicle devices. 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 according to USB PD. In particular, the power supply device 1 includes two (a plurality of) first source-side connectors 8 and a second source-side connector 9, and can simultaneously supply power to each of the two devices DV connected to each of the first source-side connector 8 and the second source-side connector 9. Note that the device DV means a device that can be the target of power supply by the power supply device 1. The device DV that receives power supply charges a battery or supplies power to a load. Hereinafter, the case where the device DV is connected to the first source-side connector 8 or the second source-side connector 9 of the power supply device 1 via a cable may be simply expressed as "the device DV is connected to the power supply device 1".

[0014] In this embodiment, the first source-side connector 8 and the second source-side connector 9 are receptacles corresponding to USB Type-C, and include a VBUS terminal for supplying a bus voltage, a GND terminal related to a ground voltage, and a CC (Configuration Channel) port. Hereinafter, the power supply line corresponding to the first source-side connector 8 (the line used for supplying power to the device DV connected to the first source-side connector 8) is referred to as the first power supply line 10. Also, the power supply line corresponding to the second source-side connector 9 (the line used for supplying power to the device DV connected to the second source-side connector 9) is referred to as the second power supply line 11. Also, the CC line corresponding to the first source-side connector 8 (the communication line used for communication with the device connected to the first source-side connector 8) is referred to as the first CC line 12. Also, the CC line corresponding to the second source-side connector 9 (the communication line used for communication with the device connected to the second source-side connector 9) is referred to as the second CC line 13.

[0015] The first device DV1 and the second device DV2 are electronic devices. The type of the first device DV1 as an electronic device is not limited. The first device DV1 and the second device DV2 are, as an example, a notebook computer, a tablet terminal (including a smartphone), a portable game machine, or a wearable terminal.

[0016] As shown in FIG. 1, the power supply device 1 includes a control unit 20, a power supply unit 21, and a communication unit 22.

[0017] The control unit 20 is a controller corresponding to USB PD and USB Type-C, and includes an IC in which various circuits including a processor are integrated. The control unit 20 executes processing through cooperation between hardware and software, such as reading and executing a program stored in a predetermined memory by the processor.

[0018] The communication unit 22 includes a transceiver for communication via the first CC line 12 and the second CC line 13, and communicates with the device DV under the control of the control unit 20. Hereinafter, it is assumed that the communication between the device DV and the power supply device 1 is appropriately executed by the communication unit 22, and a detailed description of the communication itself is omitted. The control unit 20 has a function of communicating with each of the devices DV connected to the power supply device 1 via the communication unit 22.

[0019] The power supply unit 21 includes a power supply circuit including a DC / DC converter, a switch element that opens and closes the first power supply line 10 and the second power supply line 11, and other elements (for example, necessary switches and necessary capacitors). The power supply unit 21 receives power supply from an in-vehicle battery 23 which is an external power source. The power supply unit 21 converts the voltage of the in-vehicle battery 23 which is an external power source into an appropriate voltage under the control of the control unit 20, and then supplies power to one or more devices DV connected to the power supply device 1 via the first power supply line 10 and the second power supply line 11. The in-vehicle battery 23 is a battery mounted on a vehicle.

[0020] The control unit 20 has a function of controlling the power supplied by the power supply unit 21. That is, the control unit 20 controls the power supply unit 21 to supply power with a specific voltage value and a specific maximum current value (the upper limit value of the current) to each of the devices DV connected to the power supply device 1. Regarding the supplied power, although the current value basically varies depending on the circumstances on the device DV side, it cannot exceed the maximum current value set on the power supply device 1 side. Hereinafter, when simply expressing the supplied power of the power supply device 1 as "current", unless otherwise specified, it means "current below the maximum current value". Also, regarding the supplied power of the power supply device 1, when expressing it as "current value", unless otherwise specified, it means the "maximum current value" (the upper limit value of the current value). Also, regarding the supplied power of the power supply device 1, the combination of the voltage value and the current value may be referred to as a "power-related value".

[0021] Here, for the power supply device 1, an upper limit value of the power that can be supplied to all the connected devices DV simultaneously (hereinafter referred to as the "supply power upper limit value") is set in advance. The total value of the power supplied to each device DV simultaneously cannot exceed this supply power upper limit value. Hereinafter, the total value of the power supplied to all the connected devices DV is referred to as the "supply power total value". The supply power upper limit value is appropriately set in consideration of the fact that power (power source) is supplied from the in-vehicle battery 23. In this example, it is assumed that the supply power upper limit value is "60W".

[0022] As shown in FIG. 1, the first device DV1 includes a first device connector 25 corresponding to USB Type-C. The first device connector 25 is configured as a receptacle to which a plug can be connected. The first device connector 25 and the first source-side connector 8 of the power supply device 1 are connected via a first cable 5. Also, the first device DV1 incorporates a first device battery 26 which is a secondary battery.

[0023] As shown in FIG. 1, the first device DV1 includes, as functional blocks, a first device control unit 27, a first device communication unit 28, and a first device charging unit 29.

[0024] The first device control unit 27 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 first device control unit 27 executes processing through cooperation between hardware and software, such as reading and executing a program stored in a predetermined memory by the processor.

[0025] The first device communication unit 28 includes a transceiver for communication via the first CC line 12, and realizes communication with the power supply device 1 under the control of the first device control unit 27. Hereinafter, it is assumed that the communication between the first device DV1 and the power supply device 1 is appropriately executed by the first device communication unit 28, and a detailed description of the communication itself is omitted. The first device control unit 27 has a function of communicating with the control unit 20 via the first device communication unit 28.

[0026] The first device charging unit 29 includes a charging circuit including a DC / DC converter, a switch element for opening and closing the first power supply line 10, and other elements (for example, necessary switches and necessary capacitors). The first device charging unit 29 receives power supply from the power supply unit 21 of the power supply device 1 via the first power supply line 10. The first device charging unit 29 charges the first device battery 26 by performing necessary processes related to voltage / current adjustment, power supply timing adjustment, and other charging under the control of the first device control unit 27.

[0027] Although not shown in the figure, the first device DV1 includes a load that receives power supply from the first device battery 26.

[0028] As shown in FIG. 1, the second device DV2 includes a second device connector 30 compatible with USB Type-C. The second device connector 30 is configured as a receptacle to which a plug can be connected. The second device connector 30 and the second source-side connector 9 of the power supply device 1 are connected via a second cable 6. The second device DV2 also incorporates a second device battery 31 which is a secondary battery.

[0029] As shown in FIG. 1, the second device DV2 includes, as functional blocks, a second device control unit 32, a second device communication unit 33, and a second device charging unit 34.

[0030] The second device control unit 32 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 second device control unit 32 executes processing through cooperation between hardware and software, such as reading and executing a program stored in a predetermined memory by the processor.

[0031] The second device communication unit 33 includes a transceiver for communication via the second CC line 13, and realizes communication with the power supply device 1 under the control of the second device control unit 32. Hereinafter, it is assumed that the communication between the second device DV2 and the power supply device 1 is appropriately executed by the second device communication unit 33, and a detailed description of the communication itself is omitted. The second device control unit 32 has a function of communicating with the control unit 20 via the second device communication unit 33.

[0032] The second device charging unit 34 includes a charging circuit including a DC / DC converter, a switching element that opens and closes the second power supply line 11, and other elements (for example, necessary switches and necessary capacitors). The second device charging unit 34 receives power supply from the power supply unit 21 of the power supply device 1 via the second power supply line 11. The second device charging unit 34 charges the second device battery 31 by performing necessary processing related to voltage / current adjustment, power supply timing adjustment, and other charging under the control of the second device control unit 32.

[0033] Although not shown, the second device DV2 includes a load that receives power supply from the second device battery 31.

[0034] Next, an example will be given to describe the operation of the power supply system 4 when a plurality of devices DV are connected to the power supply device 1 and the power supply device 1 supplies power to the plurality of devices DV.

[0035] First, assume that the second device DV2 is connected to the power supply device 1. When the second device DV2 is connected to the power supply device 1, the control unit 20 of the power supply device 1 detects the connection. After detecting the connection, the control unit 20 communicates with the second device control unit 32 of the second device DV2 to conduct negotiation and determine the power-related values of the power supplied to the second device DV2. In this negotiation, the control unit 20 receives the desired power-related values (voltage value and current value) from the second device control unit 32. Hereinafter, the power-related values desired by the device DV are referred to as "desired power-related values". In this example, assume that the desired power-related values of the second device DV2 are 9V, 3A, which is 27W. Also in this example, assume that the control unit 20 determines the power-related values of the power supplied to the second device DV2 as 9V, 3A (27W). Hereinafter, for the device DV, the determined power-related values of the supplied power are referred to as "determined power-related values". Thereafter, the control unit 20 controls the power supply unit 21 to supply power to the second device DV2 according to the determined power-related values (in this example, 9V, 3A). Figure 2(A) shows the state at this time.

[0036] And after the state shown in Figure 2(A) is reached, assume that a new first device DV1 is connected to the first source-side connector 8. Hereinafter, the operation of the power supply system 4 when the new first device DV1 is connected to the first source-side connector 8 will be described.

[0037] Figure 3 is a flowchart showing the operations of the power supply device 1, the first device DV1, and the second device DV2. The flowchart FA shows the control method by the power supply device 1, the flowchart FB shows the control method by the first device DV1, and the flowchart FC shows the control method by the second device DV2. At the start point of the flowchart shown in Figure 3, as shown in Figure 2(A), only the second device DV2 is connected to the power supply device 1, and power of 9V, 3A (27W) is being supplied from the power supply device 1 to the second device DV2.

[0038] As shown in flowchart FA, the control unit 20 of the power supply device 1 monitors whether a device DV is connected to the first source-side connector 8 (step SA1). In this example, it is assumed that the first device DV1 is connected to the first source-side connector 8 during the monitoring of step SA1. When it detects that the first device DV1 is connected to the first source-side connector 8 (step SA1: YES), the control unit 20 executes voltage-related special processing (step SA2). Hereinafter, the voltage-related special processing will be described. In the following description, when a device DV is connected to the power supply device 1, in the case where a new device DV is newly connected, the newly connected device is referred to as a "new device", and the device that was connected before the new device was connected is referred to as an "already connected device".

[0039] In the voltage-related special processing, the control unit 20 reduces the voltage value of the power supplied to the already connected second device DV2 to the "corresponding voltage" within the "limit period". The value of this corresponding voltage is the value to which the voltage value of the already connected device should shift before negotiating with each device DV when a new device DV is newly connected to the power supply device 1. Note that the reason why the voltage of the power supplied to the already connected device is reduced to the corresponding voltage in response to the connection of the new device is to prevent the total power supplied to each device DV from exceeding the power supply upper limit value even for an instant due to the connection of the new device DV. The specific value of the corresponding voltage is determined by the corresponding protocol. However, a configuration in which the value of the corresponding voltage is set independently for product protection may also be used. In this embodiment, it is assumed that the value of the corresponding voltage is "5V". The corresponding voltage corresponds to the "first voltage". Also, the limit period is the upper limit value of the length of the period required for the voltage to reach the corresponding voltage after detecting the connection of the new device DV. That is, the control unit 20 causes the voltage of the power supplied to the already connected device to reach the corresponding voltage before the limit period elapses after detecting the connection of the new device. The limit period is determined by the corresponding protocol or set independently.

[0040] Then, when reducing the voltage value of the power supplied to the connected device to the corresponding voltage, the control unit 20 according to this embodiment executes the following special processing. That is, the control unit 20 gradually reduces the voltage of the power supplied to the connected device to the corresponding voltage (first voltage). More specifically, the control unit 20 reduces the voltage of the power supplied to the connected device to a "relay voltage" greater than the corresponding voltage, maintains the state of the relay voltage for a predetermined period, and then reduces it to the corresponding voltage. The relay voltage corresponds to the "second voltage".

[0041] FIG. 4 is a diagram showing the transition of the voltage value of the power supplied to the second device DV2 when the control unit 20 executes voltage-related special processing for the second device DV2 in this embodiment. In FIG. 4, the horizontal axis indicates the passage of time from left to right. Hereinafter, the voltage-related special processing executed by the control unit 20 for the second device DV2 will be described with reference to FIG. 4. As shown in FIG. 4, assume that the control unit 20 detects the connection of the first device DV1 at timing T1. Then, the control unit 20 starts to lower the voltage of the power supplied to the second device DV2. Next, when the voltage of the power supplied to the second device DV2 reaches the relay voltage at timing T2, the control unit 20 stops lowering the voltage. Next, the control unit 20 maintains the state where the voltage of the power supplied is the relay voltage during the residence period. The residence period is a period predetermined as the period for maintaining the state where the voltage value is the relay voltage. The length of the residence period is preset in consideration of the length of the deadline period.

[0042] The control unit 20 starts to lower the voltage of the power supplied to the second device DV2 at timing T3 when the elapsed time from timing T2 becomes the residence period. Next, when the voltage of the power supplied to the second device DV2 reaches the corresponding voltage at timing T4, the control unit 20 stops lowering the voltage. Note that the residence period is determined so that timing T4 arrives before the expiration of the deadline period starting from timing T1 (before timing T5 arrives in FIG. 4(A)), and the processing related to the voltage drop by the control unit 20 is executed. The above is the voltage-related special processing executed by the control unit 20 for the second device DV2.

[0043] As described above, in this embodiment, when a new device DV is connected, the control unit 20 gradually reduces the voltage of the power supplied to the device DV that has already been connected to obtain a corresponding voltage (first voltage). More specifically, the control unit 20 reduces the voltage of the power supplied to the device DV that has already been connected to a "relay voltage" that is greater than the corresponding voltage, maintains the state of the relay voltage for a predetermined period, and then reduces it to the corresponding voltage. This achieves the following effects.

[0044] Figure 4(B) shows how the voltage of the already-connected device drops when a new device is connected in the conventional case where the technology according to this embodiment is not applied. As shown in Figure 4(B), conventionally, after the connection detection timing (timing T1), the control unit of the power supply device drops the voltage of the power supplied to the already-connected device toward the corresponding voltage and stops the drop when the corresponding voltage is reached. In the case of this configuration, the voltage of the power supplied to the already-connected device is steeply dropped, and there is a possibility that problems may occur due to this voltage drop. As an example, in some cases, an error may occur in the already-connected device in response to a sudden voltage drop, or the device may execute error handling for error prevention in response to a sudden voltage drop. In this case, problems may occur due to the error or error handling. Based on this, according to the configuration of this embodiment, when a new device is connected during the connection of the already-connected device, the voltage of the power supplied to the already-connected device is not steeply decreased toward the corresponding voltage, but is gradually decreased to reach the corresponding voltage. Therefore, it is possible to suppress the occurrence of problems caused by the voltage drop of the power supplied to the already-connected device.

[0045] Here, in the present embodiment, in the voltage-related special processing, instead of gently reducing the voltage drop amount per unit time, a residence period during which the voltage drop does not occur is provided, and the voltage value is decreased step by step. As a result, it is possible to prevent the lengthening of the period during which the voltage drop is continuously performed, that is, the period during which the voltage continuously fluctuates, and to decrease the voltage until the corresponding voltage is reached. Thereby, it is possible to suppress the problems that may occur due to the lengthening of the period during which the voltage continuously fluctuates.

[0046] Note that the value of the relay voltage is determined in advance from the viewpoint of suppressing the occurrence of problems as much as possible. As an example, the value of the relay voltage is set to a value between 6.8 V and 8 V. Further, when a new device is newly connected, if the voltage of the power supplied to the already connected device is equal to or lower than the relay voltage, the control unit 20 does not execute the voltage-related special processing, and drops the voltage of the power supplied to the existing device toward the corresponding voltage. Further, the control unit 20 sets the voltage of the power supplied to the new device immediately after the new device is connected to the corresponding voltage.

[0047] Now, as shown in FIG. 3, after executing the voltage-related special processing and setting the voltage value of the power supplied to the second device DV2 to the corresponding voltage (5 V in the present embodiment), the control unit 20 negotiates with the first device control unit 27 of the first device DV1 according to the protocol (step SA3, step SB1). In this negotiation, the control unit 20 receives a desired power-related value from the first device control unit 27. In this example, it is assumed that the desired power-related value of the first device DV1 is 45 W of 15 V and 3 A. At the same time, the control unit 20 negotiates with the second device control unit 32 of the second device DV2 according to the protocol (step SA4, step SC1). In this negotiation, the control unit 20 receives a desired power-related value from the second device control unit 32. In this example, it is assumed that the desired power-related value of the second device DV2 is 27 W of 9 V and 3 A.

[0048] Next, the control unit 20 executes a distribution determination process based on the desired power related values of the first device DV1 and the second device DV2 (step SA5). The distribution determination process is a process of determining the distribution of the power supplied to a plurality of connected devices DV (in this example, the first device DV1 and the second device DV2). Hereinafter, the distribution determination process in step SA5 will be described in detail. As described above, the power supply device 1 has a supply power upper limit value set to 60W. When the supply power upper limit value is 60W in this way, the power supply device 1 cannot supply 45W of power to the first device DV1 and 27W of power to the second device DV2. This is because the total supply power value (45W + 27W = 72W) exceeds the supply power upper limit value (60W).

[0049] In the distribution determination process of step SA3, the control unit 20 determines the distribution of the power supplied to each of the first device DV1 and the second device DV2 according to the following conditions. <Condition R1> Make the total supply power value equal to or less than the supply power upper limit value and as close as possible to the supply power upper limit value. <Condition R2> Make the distribution to each of the first device DV1 and the second device DV2 as close as possible to the respective desired power related values of these devices DV. However, ensure that the voltage value of the supply power does not exceed the voltage value of the desired power related value.

[0050] In this example, the desired power related value of the first device DV1 is 45W at 15V, 3A, and the desired power related value of the second device DV2 is 27W at 9V, 3A. In this case, if the power related value of the power supplied to the first device DV1 is set to 15V, 3A and the power related value of the power supplied to the second device DV2 is set to 9V 3A, the total supply power value (27W + 45W = 72W) will exceed the supply power upper limit value (60W). Therefore, the control unit 20 does not make such a distribution and makes, for example, the following distribution.

[0051] That is, the control unit 20 determines that the power-related value of the power supplied to the first device DV1 is 33 W at 15 V and 2.2 A, and determines that the power-related value of the power supplied to the second device DV2 is 27 W at 9 V and 3 A. By making such a determination, conditions R1 and R2 are satisfied. That is, regarding condition R1, the total power supply value (33 W + 27 W) is equal to or less than the power supply upper limit value (60 W), and is as close as possible to the power supply upper limit value (60 W). Also, regarding condition R2, each of the distribution of the first device DV1 (15 V, 2.2 A) and the distribution of the second device DV2 (9 V, 3 A) is as close as possible to each of the desired power-related values of the first device DV1 (15 V, 3 A) and the desired power-related value of the second device DV2 (9 V, 3 A).

[0052] Note that when determining the distribution of the power supply, conditions R1 and R2 are cited as the conditions that the control unit 20 follows, but the conditions are not limited to these. In particular, when there are conditions defined by the protocol, the control unit 20 naturally determines the distribution in accordance with the said conditions as well. Also, in the distribution determination process, the control unit 20 may communicate with the first device control unit 27 and the second device control unit 32 and exchange various information. In this example, in the distribution determination process, as shown in Fig. 2(B), the control unit 20 determines that the power-related value of the power supplied to the first device DV1 (that is, the determined power-related value for the first device DV1) is 33 W at 15 V and 2.2 A, and further determines that the power-related value of the power supplied to the second device DV2 (that is, the determined power-related value for the second device DV2) is 9 V and 3 A.

[0053] As shown in flowchart FA, after the distribution determination process of step SA5, the control unit 20 notifies the first device control unit 27 of the determined power-related value (15V, 2.2A) for the first device DV1, and notifies the second device control unit 32 of the determined power-related value (9V, 3A) for the second device DV2 (step SA6). Next, the control unit 20 starts supplying power to the first device DV1 and the second device DV2 according to the distribution determined in the distribution determination process (step SA7). Specifically, the control unit 20 controls the power supply unit 21 to supply power corresponding to the determined power-related value for the first device DV1 to the first device DV1, and supply power corresponding to the determined power-related value for the second device DV2 to the second device DV2.

[0054] As shown in flowchart FB, in response to the notification in step SA6, the first device control unit 27 controls the first device charging unit 29 and starts charging the first device battery 26 based on the supplied power from the power supply device 1 (step SB2). As shown in flowchart FC, in response to the notification in step SA6, the second device control unit 32 controls the second device charging unit 34 and starts charging the second device battery 31 based on the supplied power from the power supply device 1 (step SC2).

[0055] As described above, when supplying power to a plurality of devices DV, the control unit 20 according to the present embodiment communicates with the devices and negotiates before starting the power supply to the devices DV, and has a function of determining the distribution of the power to be supplied to each of the devices DV within a range where the total power to be supplied does not exceed the upper limit value.

[0056] As described above, the power supply device 1 according to the present embodiment includes a power supply unit 21 capable of supplying power to a plurality of connected devices DV, and a control unit 20 having functions to control the power supplied by the power supply unit 21, to communicate with the connected devices DV, and, when supplying power to the plurality of devices DV, to communicate with each of the devices DV to negotiate and determine the allocation of power to be supplied to each of the devices DV so that the total amount of power supplied does not exceed an upper limit. When a new device DV is connected while one or more devices DV are already connected, the control unit 20 gradually reduces the voltage of the power supplied to the already connected devices DV to a compatible voltage, and then negotiates with each of the devices DV.

[0057] With this configuration, when a new device is connected while other devices are connected, the voltage of the power supplied to the already connected device is not suddenly reduced to the first voltage, but is gradually reduced until it reaches the first voltage, thereby preventing problems caused by a voltage drop in the power supplied to the device.

[0058] 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.

[0059] For example, in the above embodiment, in the voltage-related special processing, the control unit 20 reduces the voltage of the power supplied to the already connected device to the relay voltage and then to the corresponding voltage. That is, in the above embodiment, the control unit 20 reduces the voltage of the power supplied to the already connected device by one step, maintains that state for a certain period of time, and then reduces the voltage to the corresponding voltage. In this regard, the control unit 20 may be configured to reduce the voltage of the power supplied to the already connected device in two or more steps and then reduce the voltage to the corresponding voltage.

[0060] Furthermore, for example, 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 21 is configured to include an AC / DC converter, and appropriate AC / DC conversion is performed.

[0061] 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.

[0062] The power supply device 1 described above includes connectors (the first source-side connector 8 and the second source-side connector 9). However, the power supply device may be a device that does not include connectors and is integrated with a cable that complies with a standard.

[0063] In the above embodiment, the number of devices DV that the power supply device 1 can charge at one time is two, but the number may be three or more.

[0064] Furthermore, for example, the control unit 20 may be configured to execute various processes in cooperation with an external device in addition to the processes that are described as being executed solely by the control unit 20. As an example, the control unit 20 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.

[0065] 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.

[0066] 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.

[0067] For example, the provision of a program executed by the computer of the power supply device 1 can be included in the embodiments. The provision of a recording medium on which the program is recorded so as to be readable by a computer can also 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 disk 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]

[0068] 1 Power supply device 4 Power Supply System 20 Control Unit 21 Power supply section DV device DV1 First device (device) DV2 Secondary Device (Device)

Claims

1. A power supply unit capable of supplying power to a plurality of connected devices, a control unit having a function of controlling the power supplied by the power supply unit, a function of communicating with the connected devices, and a function of negotiating with each of the devices when supplying power to the plurality of devices and determining the distribution of the power supplied to each of the devices within a range where the total power supplied does not exceed the upper limit value, wherein the control unit, when one or more of the devices are connected and a new device is connected, gradually reduces the voltage of the power supplied to the devices that have already been connected to a first voltage, and then negotiates with each of the devices characterized in that it is a power supply device.

2. wherein the control unit, when one or more of the devices are connected and a new device is connected, reduces the voltage of the power supplied to the devices that have already been connected to a second voltage greater than the first voltage, maintains the second voltage for a predetermined period, then reduces it to the first voltage, and then negotiates with each of the devices characterized in that it is the power supply device according to Claim 1.

3. mounted on a vehicle characterized in that it is the power supply device according to Claim 1 or 2.

4. A power supply system including a power supply device and devices, wherein the power supply device, has a power supply unit capable of supplying power to a plurality of connected devices, a control unit having a function of controlling the power supplied by the power supply unit, a function of communicating with the connected devices, and a function of negotiating with each of the devices when supplying power to the plurality of devices and determining the distribution of the power supplied to each of the devices within a range where the total power supplied does not exceed the upper limit value, wherein the control unit of the power supply device, when one or more of the devices are connected and a new device is connected, gradually reduces the voltage of the power supplied to the devices that have already been connected to a first voltage, and then negotiates with each of the devices characterized in that it is a power supply system.

5. A control method by a power supply device including a power supply unit capable of supplying power to a plurality of connected devices, When one or more of the devices are connected, if a new device is connected, the control unit of the power supply device controls the power supply unit to gradually decrease the voltage of the power supplied to the devices that have already been connected to a first voltage; The control unit of the power supply device communicates with each of the devices to perform negotiation, and determines the distribution of the power supplied to each of the devices within a range where the total power supplied does not exceed the upper limit value. A control method characterized by the above.

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