Power supply device, power supply system and control method

Abstract

To provide "a power supply device, a power supply system and a control method", which achieve efficient supply of power to a plurality of connected devices.SOLUTION: A power supply device 1 includes: a power supply part 21 capable of supplying power to a plurality of connected devices DV; and a control part 20 having a function for performing negotiation before supply of power to the devices DV is started and determining distribution of power supplied to the respective devices DV within a range which does not exceed an upper limit value. The control part 20 re-determines distribution of power supplied to the plurality of connected devices DV by reflecting reduction of power requested in a request when the request of reduction of power supplied to the device DV is received after supply of power is started according to distribution based on negotiation.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 in particular, is suitable for use in a power supply device configured to be able to supply power to a plurality of devices simultaneously, a power supply system including the power supply device, and a control method using the power supply device. [Background technology]

[0002] Conventionally, there is known a power supply device that is configured to be connectable to a plurality of devices and can supply power to each of the plurality of devices. In particular, USB PD (Power Delivery), which is a charging standard for USB-TypeC, can supply a large amount of power. Taking advantage of this, a power supply device that is compatible with USB PD, has a plurality of connectors, and is configured to be able to supply power to a plurality of devices connected to the plurality of connectors has become widespread.

[0003] With regard to a power supply device capable of supplying power to each of a plurality of devices, 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, and 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. Patent Document 1 enables appropriate active distribution of the total power output of the power supply device.

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

[0005] [Patent Document 1] JP 2018-206394 A [Patent Document 2] JP 2019-109898 A Summary of the Invention [Problem to be solved by the invention]

[0006] Here, when power is supplied from a power supply device to a plurality of connected devices, as suggested in Patent Document 1, the allocation of power to be supplied to each device is usually determined, and power is supplied according to the determined allocation. In a power supply device capable of supplying power to a plurality of devices and communicating with each device, the following processing has been conventionally performed for power allocation. Note that a device compatible with USB PD corresponds to this type of power supply device. That is, when supplying power to a plurality of connected devices, negotiation is performed between the power supply device and the devices before starting to supply power to the devices. Then, the power supply device determines the power allocation according to the result of the negotiation. Thereafter, the power supply device does not change the allocation unless the power supply is reset once, such as when a device is plugged in or unplugged, or the power of a device is turned on / off, and negotiation is performed again. On the other hand, after the supply of power to a plurality of devices is started, each device transmits a request to the power supply device and requests a change in the power supply for itself when a situation arises in which the supply of power for itself should be changed. The above processing has been performed.

[0007] The conventional technology in which the above processing is performed has the following problems. For example, assume that a first device and a second device are connected to a power supply device, and power is supplied according to allocation based on negotiation. In this situation, if a situation arises in which the second device needs to reduce the power supply, the second device transmits a request to reduce the power, and the power supply device reduces the power supplied to the second device in accordance with the request. In this case, the power supply device has a surplus in power supply capacity by the amount of the reduction in the power supplied to the second device, but this state continues, which is a factor that hinders efficient power supply.

[0008] The present invention has been made to solve such problems, and aims to realize an efficient supply of power to multiple connected devices using a power supply device that is capable of supplying power to multiple devices and communicating with each of the devices. [Means for solving the problem]

[0009] In order to solve the above-mentioned 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, and 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 communicating with the devices and negotiating before starting to supply power to the devices when supplying power to the plurality of devices, and determining an allocation of power to be supplied to each of the devices within a range in which the total of the power to be supplied does not exceed an upper limit. Then, when the control unit starts supplying power to each of the plurality of connected devices according to the allocation based on the negotiation, and then receives a request from one device to reduce the power to be supplied to that device, the control unit redetermines the allocation of power to be supplied to the plurality of connected devices, reflecting the reduction in power requested in the request. Effect of the Invention

[0010] According to the present invention configured as described above, after starting power supply according to the allocation based on negotiation, if one of the multiple connected devices requests a reduction in the power supply, the allocation of power to be supplied to the multiple connected devices is redetermined to reflect the reduction in power requested in the request. Therefore, it is possible to determine a new power allocation without waiting for the next negotiation to be performed, and efficient power supply is possible. In other words, according to the present invention, an efficient power supply to multiple connected devices is realized for a power supply device that can supply power to multiple devices and communicate with each device. [Brief description of the drawings]

[0011] [Figure 1] 2 is a block diagram showing an example of a functional configuration of a power supply device according to an embodiment; FIG. [Diagram 2] FIG. 2 is a diagram showing a state of power supply by a power supply device. [Diagram 3] 4 is a flowchart showing an operation example of the power supply system. [Figure 4] FIG. 1 is a diagram used to explain a conventional problem. [Diagram 5] FIG. 1 is a diagram used to explain a conventional problem. [Figure 6] 4 is a flowchart showing an operation example of the power supply system. [Figure 7] FIG. 11 is a diagram illustrating the relationship between the upper limit of power supply and power distribution. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of a functional configuration of a power supply device 1 according to this embodiment, together with a first device 2 and a second device 3 connected to the power supply device 1. A power supply system 4 is configured 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 2 are connected via a USB Type-C cable 5 (hereinafter referred to as the "first cable 5"), and the power supply device 1 and the second device 3 are connected via a USB Type-C cable 6 (hereinafter referred to as the "second cable 6").

[0013] The power supply device 1 according to the present 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 that complies with USB PD (Power Delivery) and has a function of supplying power according to USB PD. In particular, the power supply device 1 has two (a plurality of) power supply device first connectors 8 and power supply device second connectors 9, and can simultaneously supply power to two devices DV connected to the power supply device first connector 8 and the power supply device second connector 9, respectively. Note that the device DV means a device that can be a target of power supply by the power supply device 1. The device DV that receives the power supply charges a specified battery or supplies power to a load. Hereinafter, the connection of the device DV to the power supply device first connector 8 or the power supply device second 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 power supply device first connector 8 and the power supply device second connector 9 are receptacles compatible with USB Type-C, and are configured to 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 power supply device first connector 8 (a line used to supply power to the device DV connected to the power supply device first connector 8) is referred to as a first power supply line 10. Also, the power supply line corresponding to the power supply device second connector 9 (a line used to supply power to the device DV connected to the power supply device second connector 9) is referred to as a second power supply line 11. Also, the CC line corresponding to the power supply device first connector 8 (a communication line used to communicate with the device connected to the power supply device first connector 8) is referred to as a first CC line 12. Also, the CC line corresponding to the power supply device second connector 9 (a communication line used to communicate with the device connected to the power supply device second connector 9) is referred to as a second CC line 13.

[0015] The first device 2 is an electronic device. There is no limitation on the type of electronic device of the first device 2. The first device 2 is, for example, a notebook computer, a tablet terminal (including a smartphone), a portable game console, or a wearable terminal (but is not limited to these).

[0016] The second device 3 is an electronic device. As with the first device 2, the second device 3 may be of any type as an electronic device, but in this embodiment, the type of the second device 3 is a smartphone. A user who boards a vehicle equipped with the power supply device 1 can connect his or her smartphone to the power supply device 1 and charge the smartphone.

[0017] 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.

[0018] The control unit 20 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 20 executes processes through cooperation between hardware and software, such as the processor reading and executing a program stored in a predetermined memory.

[0019] 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 communication between the power supply device 1 and the device DV is appropriately performed by the communication unit 22, and detailed description of the communication itself will be omitted. The control unit 20 includes a function of communicating with each of the devices DV connected to the power supply device 1 via the communication unit 22.

[0020] 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 from an in-vehicle battery 23, which is an external power source. Under the control of the control unit 20, the power supply unit 21 converts the voltage of the in-vehicle battery 23, which is an external power source, to an appropriate voltage and supplies the 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 the vehicle.

[0021] The control unit 20 has a function of controlling the power supplied by the power supply unit 21. That is, the control unit 20 can control the power supply unit 21 to supply power of a specific voltage value and a specific maximum current value (upper limit of current) to each of the devices DV connected to the power supply device 1. Note that, regarding the supplied power, the current value basically varies depending on the circumstances of the device DV, but cannot exceed the maximum current value set on the power supply device 1 side. Hereinafter, when the term "current" is used in relation to the power supplied by the power supply device 1, it means "current equal to or lower than the maximum current value" unless otherwise specified. Furthermore, when the term "current value" is used in relation to the power supplied by the power supply device 1, it means "maximum current value" (upper limit of current value) unless otherwise specified. Furthermore, regarding the power supplied by the power supply device 1, a combination of a voltage value and a current value may be referred to as a "power-related value".

[0022] 1, the first device 2 includes a first device connector 25 that is compatible with 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 a power supply device first connector 8 of the power supply device 1 are connected via a first cable 5. The first device 2 also includes a first device battery 26 that is a secondary battery.

[0023] As shown in FIG. 1, the first device 2 includes a first device control unit 27, a first device communication unit 28, and a first device charging unit 29 as functional blocks.

[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 the processor reading and executing a program stored in a predetermined memory.

[0025] The first device communication unit 28 has 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 2 and the power supply device 1 is appropriately performed by the first device communication unit 28, and a detailed description of the communication itself will be 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 that opens and closes the first power supply line 10, and other elements (e.g., necessary switches and necessary capacitors). The first device charging unit 29 receives power from the power supply unit 21 of the power supply device 1 via the first power supply line 10. Under the control of the first device control unit 27, the first device charging unit 29 charges the first device battery 26 by adjusting the voltage / current, adjusting the timing of power supply, and performing other necessary processes related to charging.

[0027] Although not shown in the figure, the first device 2 includes a load that receives power from the first device battery 26.

[0028] As described above, the second device 3 is a smartphone. As shown in Fig. 1, the second device 3 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 power supply device second connector 9 of the power supply device 1 are connected via a second cable 6. The second device 3 also includes a second device battery 31 built therein, which is a secondary battery.

[0029] As shown in FIG. 1, the second device 3 includes, as functional blocks, a second device control unit 32, a second device communication unit 33, a second device charging unit 34, and a main body control unit 35.

[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 processes through cooperation between hardware and software, such as the processor reading and executing a program stored in a predetermined memory.

[0031] The second device communication unit 33 has 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 3 and the power supply device 1 is appropriately performed by the second device communication unit 33, and detailed description of the communication itself will be 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 switch element that opens and closes the second power supply line 11, and other elements (e.g., necessary switches and necessary capacitors). The second device charging unit 34 receives power from the power supply unit 21 of the power supply device 1 via the second power supply line 11. Under the control of the second device control unit 32, the second device charging unit 34 charges the second device battery 31 by adjusting the voltage / current, adjusting the power supply timing, and performing other necessary processes related to charging.

[0033] The main body control unit 35 includes a processor. The main body control unit 35 controls each unit of the second device 3 based on the OS (Operating System) of the second device 3, which is a smartphone, applications running on the OS, and other programs. The main body control unit 35 can communicate with the second device control unit 32. The main body control unit 35 can also communicate with the second device control unit 32 and control the second device charging unit 34 via the second device control unit 32. Hereinafter, the control of the second device charging unit 34 by the main body control unit 35 via the second device control unit 32 may be expressed simply as "the main body control unit 35 controls the second device charging unit 34." In this embodiment, the main body control unit 35 controls the second device charging unit 34 via the second device control unit 32, but the main body control unit 35 may directly control the second device charging unit 34.

[0034] Although not shown in the figure, the second device 3 includes a load that receives power from the second device battery 31.

[0035] Next, an example will be given of the operation of the power supply system 4 when a plurality of devices DV are connected to the power supply unit 1 and the power supply unit 1 starts supplying power to the plurality of devices DV.

[0036] In the following, it is assumed that the second device 3 is connected to the power supply device 1. When the second device 3 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 3 and negotiates to determine the power-related value of the power to be supplied to the second device 3. In this negotiation, the control unit 20 receives a desired power-related value (voltage value and current value) from the second device control unit 32. Hereinafter, the power-related value desired by the device DV is referred to as a "desired power-related value." In this example, it is assumed that the desired power-related value of the second device 3 is 9V, 3A, or 27W. In addition, in this example, it is assumed that the control unit 20 has determined the power-related value of the power to be supplied to the second device 3 to be 9V, 3A (27W). Hereinafter, the determined power-related value of the power to be supplied to the device DV is referred to as a "determined power-related value." Thereafter, the control unit 20 controls the power supply unit 21 to supply power to the second device 3 according to the determined power-related values ​​(9 V, 3 A in this example). Figure 2A shows the state at this time.

[0037] 2A, a first device 2 is newly connected to the power supply device first connector 8. The operation of the power supply system 4 when the first device 2 is newly connected to the power supply device first connector 8 will be described below.

[0038] Fig. 3 is a flowchart showing the operations of the power supply device 1, the first device 2, and the second device 3. The flowchart FA shows a control method by the power supply device 1, the flowchart FB shows a control method by the first device 2, and the flowchart FC shows a control method by the second device 3. At the start of the flowchart shown in Fig. 3, as shown in (A) of Fig. 2, only the second device 3 is connected to the power supply device 1, and power of 9 V and 3 A is being supplied from the power supply device 1 to the second device 3.

[0039] As shown in the flow chart FA, the control unit 20 of the power supply device 1 monitors whether or not the device DV is connected to the power supply device first connector 8 (step SA1). In this example, it is assumed that the first device 2 is connected to the power supply device first connector 8 during the monitoring in step SA1. When it is detected that the first device 2 is connected to the power supply device first connector 8 (step SA1: YES), the control unit 20 and the first device control unit 27 of the first device 2 negotiate according to the protocol (step SA2, step SB1). In this negotiation, the control unit 20 accepts 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 2 is 45 W at 15 V and 3 A.

[0040] Next, the control unit 20 executes an allocation determination process based on the desired power related value (step SA3). The allocation determination process is a process for determining the allocation of power to be supplied to the multiple connected devices DV (in this example, the first device 2 and the second device 3). The allocation determination process of step SA3 will be described in detail below.

[0041] Here, the power supply device 1 is preset with an upper limit of power that can be simultaneously supplied to all connected devices DV (hereinafter referred to as "supply power upper limit"). The total value of power simultaneously supplied to each device DV cannot exceed this supply power upper limit. Hereinafter, the total value of power supplied to all connected devices DV is referred to as "total supply power". The supply power upper limit is appropriately set taking into consideration that power (power source) is supplied from the vehicle battery 23. In this example, the supply power upper limit is "60 W". In this way, when the supply power upper limit is 60 W, the power supply device 1 cannot supply 45 W of power to the first device 2 and 27 W of power to the second device 3. This is because the total supply power (45 W + 27 W = 72 W) exceeds the supply power upper limit (60 W).

[0042] In the allocation determination process of step SA3, the control unit 20 determines the allocation of the power to be supplied to each of the first device 2 and the second device 3 in accordance with the following conditions. <Condition R1> The total supply power value is equal to or less than the supply power upper limit value and is as close to the supply power upper limit value as possible. <Condition R2> The power distribution to each of the first device 2 and the second device 3 is as close as possible to the desired power-related value of each of these devices DV. However, the voltage value of the supplied power is not allowed to exceed the voltage value of the desired power-related value.

[0043] 2A, when the first device 2 is connected, the power supplied to the second device 3 is 9V, 3A, or 27W. The desired power-related value of the first device 2 is 15V, 3A. In this case, if the power-related value of the power supplied to the first device 2 is not changed and the power-related value of the power supplied to the second device 3 is set to the desired power-related value, the total supplied power value (27W+45W=72W) will exceed the upper supply power limit value (60W). Therefore, the control unit 20 does not allocate in this way, but instead allocates, for example, as follows:

[0044] That is, the control unit 20 does not change the power-related value of the power supplied to the first device 2, and determines the power-related value of the power supplied to the second device 3 to be 15V, 2.2A, or 33W. By determining in this manner, the conditions R1 and R2 are satisfied. That is, with regard to the condition R1, the total supply power value (33W+27W) is equal to or less than the upper supply power limit value (60W) and is as close as possible to the upper supply power limit value (60W). Also, with regard to the condition R2, the distribution (15V, 2.2A) of the first device 2 and the distribution (9V, 3A) of the second device 3 are as close as possible to the desired power-related value (15V, 3A) of the first device 2 and the desired power-related value (9V, 3A) of the second device 3, respectively.

[0045] Although the conditions R1 and R2 are given as conditions that the control unit 20 follows when determining the distribution of the power supply, the conditions are not limited to these. In particular, when there are conditions specified in the protocol, the control unit 20 naturally determines the distribution according to the conditions. In addition, 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 to exchange various information. The above also applies to the redistribution process described later.

[0046] In this example, in the allocation determination process, the control unit 20 determines the power-related value of the power supplied to the first device 2 (i.e., the determined power-related value for the first device 2) to be 15 V, 2.2 A, or 33 W, as shown in (B) of Figure 2, and further determines the power-related value of the power supplied to the second device 3 (i.e., the determined power-related value for the second device 3) to be 9 V, 3 A.

[0047] As shown in the flowchart FA, after the allocation determination process of step SA3, the control unit 20 notifies the first device control unit 27 of the determined power-related values ​​(15V, 2.2A) determined for the first device 2, and notifies the second device control unit 32 of the determined power-related values ​​(9V, 3A) determined for the second device 3 (step SA4). Next, the control unit 20 starts supplying power to the first device 2 and the second device 3 according to the allocation determined in the allocation determination process (step SA5). Specifically, the control unit 20 controls the power supply unit 21 to supply power corresponding to the determined power-related values ​​related to the first device 2 to the first device 2, and to supply power corresponding to the determined power-related values ​​related to the second device 3 to the second device 3.

[0048] As shown in the flowchart FB, in response to the notification in step SA4, the first device control unit 27 controls the first device charging unit 29 to start charging the first device battery 26 based on the power supplied from the power supply device 1.

[0049] As shown in the flowchart FC, in response to the notification in step SA4, the second device control unit 32 controls the second device charging unit 34 to start charging the second device battery 31 based on the power supplied from the power supply device 1.

[0050] As described above, the control unit 20 of this embodiment has the function of, when supplying power to multiple devices DV, communicating with the devices to negotiate before starting to supply power to the devices DV, and determining the allocation of power to be supplied to each of the devices DV within a range in which the total power supplied does not exceed an upper limit value.

[0051] Next, an operation of the power supply system 4 when a situation arises in which the power supply unit 1 is supplying power to a plurality of devices DV and a supply power needs to be reduced in a certain device DV will be described.

[0052] Prior to describing the operation, a conventional problem regarding the supply of power to a plurality of devices by a power supply device will be described. FIG. 4 is a diagram used to describe the conventional problem. As shown in FIG. 4(A), a first device X2 and a second device X3 are connected to a power supply device X1, and power is supplied to the first device X2 and the second device X3 according to allocation based on negotiation. Specifically, as in FIG. 2(B), it is assumed that 15V, 2.2A, or 33W of power is supplied to the first device X2, and 9V, 3A, or 27W of power is supplied to the second device X3. It is also assumed that the upper limit of the power supply of the power supply device X1 is 60W.

[0053] Fig. 5(A) is a diagram showing the relationship between the upper limit of power supply and the distribution of power in this situation. As shown in Fig. 5(A), in this situation, the total power supply is equal to the upper limit of power supply, and efficient power supply is achieved.

[0054] Incidentally, the conventional power supply device X1 does not change the power allocation unless the power supply is reset once and negotiation is performed again, for example, when a device is plugged in or unplugged, or when the power of the device is turned on / off.

[0055] In this situation, if circumstances arise in which the second device X3 needs to reduce the power supply, the second device X3 transmits a request to the power supply device X1 to request a reduction in power. In this example, the request is to reduce the power from 9V, 3A to 5V, 3A. In response to the request, the power supply device X1 reduces the power supplied to the second device X3 from 9V, 3A to 5V, 3A (see (B) of FIG. 4). As a result, the following events occur.

[0056] FIG. 5B is a diagram showing the relationship between the upper limit value of the power supply after the power is reduced based on the request and the distribution of power. When the power supply to the second device X3 is reduced based on the request, the determined power-related value for the second device X3 becomes 15W (5V, 3A). As a result, as shown in FIG. 5B, the power supply capacity of the power supply device X1 has a surplus of 12W due to the reduction in the power supply to the second device X3. This surplus is the power that the power supply device X1 can originally supply, and the state in which this surplus occurs can be said to be a state in which efficient power supply is not realized. The state in which the surplus occurs will not be resolved unless the power supply is reset once, such as when a device is plugged in or unplugged, or when the power of a device is turned on / off, and negotiation is performed again.

[0057] As described above, in the past, when the power supply to a device is reduced based on a request, surplus power (power that is not supplied even though it can be supplied) occurs, which hinders efficient power supply. In order to solve the above-mentioned conventional problems, the power supply system 4 according to this embodiment executes the following process.

[0058] 6 is a flowchart showing the operations of the power supply device 1, the first device 2, and the second device 3. The flowchart FD shows a control method by the power supply device 1, the flowchart FE shows a control method by the first device 2, the flowchart FF shows a control method by the second device control unit 32 of the second device 3, and the flowchart FG shows a control method by the main body control unit 35 of the second device 3. The start point of the flowchart of FIG. 6 is a point after the processing of the flowchart of FIG. 3 is completed. Therefore, at the start point, as shown in FIG. 2B, the first device 2 and the second device 3 are connected to the power supply device 1, and 15V, 2.2A power is supplied to the first device 2, and 9V, 3A power is supplied to the second device 3.

[0059] Fig. 7(A) is a diagram showing the relationship between the upper limit of power supply and the distribution of power in this state. Fig. 7(A) has the same content as Fig. 5(A). In this state, the upper limit of power supply and the total power supply match, realizing an efficient power supply.

[0060] At the start of the flowchart in FIG. 6, the charging rate of the second device battery 31 of the second device 3 is assumed to be below 80%. Here, the main body control unit 35 has the following functions. That is, regarding the charging of the second device battery 31, when the charging rate is lower than 80%, the main body control unit 35 controls the second device charging unit 34 to charge the second device battery 31 at 9V. Note that there are cases where power of 9V or more is not supplied due to circumstances on the power supply side (source side), and in this case, the main body control unit 35 charges the second device battery 31 at a lower voltage. Then, when the charging rate becomes 80% or more from a state lower than 80%, the main body control unit 35 executes necessary processing and then controls the second device charging unit 34 to charge the second device battery 31 at 5V. The main body control unit 35 has the above functions. In this way, the function of reducing the charging voltage when the charging rate of the battery becomes equal to or higher than a threshold is widely implemented not only in smartphones but also in many electronic devices.

[0061] 6, the main body control unit 35 monitors whether the charging rate of the second device battery 31 is 80% or more (step SG1). When it detects that the charging rate is 80% or more (step SG1: YES), the main body control unit 35 communicates with the second device control unit 32 and requests that a "request to reduce the supply power" be sent to the control unit 20 of the power supply device 1 (step SG2). In this example, the request requests that the power-related values ​​of the supply power be reduced from 9V, 3A to 5V, 3A.

[0062] As described above, the second device 3 (first device) has a function of receiving power to charge the second device battery 31 (battery), and a function of transmitting a request depending on the state of the second device battery 31.

[0063] As shown in a flow chart FF, the second device control section 32 transmits a request in response to a request from the main body control section 35 (step SF1).

[0064] As shown in the flow chart FD, the control unit 20 of the power supply device 1 receives a request (step SD1). Next, the control unit 20 executes a reallocation process based on the received request (step SD2). The reallocation process is a process for re-determining the allocation of power to be supplied to the first device 2 and the second device 3. In the reallocation process, the control unit 20 re-determines the allocation of power according to the following conditions: <Condition R1'> Within the range where the total supply power value does not exceed the upper limit of the supply power value, the power reduction for the second device 3 is allocated to the first device 2. Furthermore, the total supply power value after allocation is made as close as possible to the upper limit of the supply power value. <Condition R2'> The allocation to the first device 2 is as close as possible to the desired power-related value of the first device 2 (45W at 15V, 3A in this example). However, the voltage of the allocated power does not exceed the voltage related to the desired power-related value. Furthermore, the allocation to the second device 3 is as close as possible to the "power-related value reflecting a power reduction based on a request" (15W at 5V, 3A in this example). However, the voltage of the allocated power does not exceed the voltage related to the "power-related value reflecting a power reduction based on a request". Hereinafter, the "power-related value reflecting the power reduction based on the request" will be referred to as the "requested power-related value."

[0065] In this example, for example, as shown in FIG. 2C, the control unit 20 determines the power-related value of the power to be supplied to the second device 3 to be 15W of 5V, 3A according to the request, and further determines the power-related value of the power to be supplied to the first device 2 to be 45W of 15V, 3A. By determining in this manner, the conditions R1' and R2' are satisfied. That is, with regard to the condition R1', after the power reduced for the second device 3 is allocated to the first device 2, the total supply power value (45W+15W=60W) is equal to or less than the supply power upper limit value (60W) and is as close as possible to the supply power upper limit value (60W). Also, with regard to the condition R2', the allocation (15V, 3A) of the first device 2 and the allocation (5V, 3A) of the second device 3 are as close as possible to the desired power-related value (15V, 3A) of the first device 2 and the requested power-related value (5V, 3A) of the second device 3, respectively.

[0066] Fig. 7B is a diagram showing the relationship between the upper limit of power supply and the distribution of power in this example. As shown in Fig. 7B, in this situation, the total power supply is equal to the upper limit of power supply, and efficient power supply is achieved. This is also clear from a comparison with Fig. 5B. The efficient power supply is achieved by re-determining the distribution of power in response to a request for reducing power, and allocating the reduced power to the first device 2.

[0067] In this example, in the allocation determination process, the control unit 20 determines the power-related values ​​of the power supplied to the first device 2 (i.e., the determined power-related values ​​for the first device 2) to be 15V, 3A, as shown in (C) of Figure 2, and further determines the power-related values ​​of the power supplied to the second device 3 (i.e., the determined power-related values ​​for the second device 3) to be 5V, 3A.

[0068] As shown in the flowchart FD, after the reallocation process of step SD2, the control unit 20 notifies the first device control unit 27 of the determined power-related value determined for the first device 2, and notifies the second device control unit 32 of the determined power-related value determined for the second device 3 (step SD3). Next, the control unit 20 starts supplying power to the first device 2 and the second device 3 in accordance with the allocation determined in the reallocation process (step SD4). Specifically, the control unit 20 controls the power supply unit 21 to supply power corresponding to the determined power-related value related to the first device 2 to the first device 2, and to supply power corresponding to the determined power-related value related to the second device 3 to the second device 3.

[0069] As shown in the flowchart FE, in response to the notification in step SD3, the first device control unit 27 controls the first device charging unit 29 to start charging the first device battery 26 based on the power supplied from the power supply device 1.

[0070] As shown in the flowchart FF, in response to the notification in step SD3, the second device control unit 32 controls the second device charging unit 34 to start charging the second device battery 31 based on the power supplied from the power supply device 1.

[0071] As described above, the control unit 20 of the power supply device 1 in this embodiment starts supplying power to each of the multiple connected devices DV in accordance with the allocation based on negotiation, and then, when a request for reducing the supply power is received from one device DV, the control unit 20 re-determines the allocation of power to be supplied to the multiple connected devices DV to reflect the power reduction requested in the request.

[0072] According to this configuration, after starting the supply of power according to the allocation based on the negotiation, if one of the multiple connected devices DV requests a reduction in the supply power, the allocation of power to be supplied to the multiple connected devices DV is re-determined to reflect the reduction in power requested by the request. Therefore, it is possible to determine a new power allocation without waiting for the next negotiation to be performed, and efficient power supply is possible. In other words, according to the present invention, an efficient power supply to the multiple connected devices DV is realized for a power supply device that can supply power to the multiple devices DV and communicate with each device DV.

[0073] Although one embodiment of the present invention has been described above, the above embodiment is merely one 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.

[0074] In the above-described embodiment, the power supply device 1 is mounted on a vehicle. However, the power supply device 1 does not need 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 performs appropriate AC / DC conversion.

[0075] Furthermore, the functional blocks shown in the above embodiments can be realized by any hardware or by cooperation between any hardware and any software. In other words, these functional blocks are not limited to specific hardware. For example, when a certain functional block is configured by hardware and software, it can have the following configuration. That is, this functional block is configured to include a CPU, RAM, and ROM of a computer. And, this functional block executes processing by the CPU reading a program stored in the ROM or other recording medium into the RAM and executing it.

[0076] The above-described power supply device 1 includes connectors (the power supply device first connector 8 and the power supply device second connector 9). However, the power supply device may be a type of device that does not include a connector and is integrated with a cable that complies with a standard.

[0077] In the above embodiment, the control unit 20 re-determines the power allocation based on a request transmitted when the second device 3 reaches a charging rate of 80% or more. In this regard, the type of request that triggers the control unit of the power supply device to re-determine the power allocation is not limited to the type exemplified in this embodiment. As an example, in USB PD PPS (Programmable Power Supply), a device can transmit a request to the power supply device to change the power (naturally including a reduction in power), and this request may be used as the trigger.

[0078] In addition, for example, the control unit 20 may cooperate with an external device to execute various processes described above 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 mounted, or may execute processes in cooperation with an external device that can communicate with the control unit 20 via a network.

[0079] The processing units in the flowcharts of the above embodiments are divided according to the main processing contents in order to make the processing easier to understand. The method of dividing the processing units and their names do not limit the present invention. The processing of each device can be divided into more processing units according to the processing contents. Also, one processing unit can be divided to include more processing. Also, as long as similar processing can be performed, the processing order of the above flowcharts is not limited to the example shown in the figure.

[0080] For example, the embodiment may include the provision of a program executed by the computer of the power supply device 1. The embodiment may also include the provision of a recording medium on which the program is recorded so as to be readable by a computer. The recording medium may be a magnetic or optical recording medium or a semiconductor memory device. Specific examples of the recording medium include portable or fixed recording media such as flexible disks, HDDs (Hard DiSH Drives), CD-ROMs (Compact DiSH Read Only Memory), DVDs (Digital Versatile DiSH), Blu-ray (registered trademark) Discs, magneto-optical disks, flash memories, and card-type recording media. [Explanation of symbols]

[0081] 1 Power supply device 2 First device (device) 3 Second Device (Device) 4. Power Supply System 20 Control section 21 Power supply section DV 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, when supplying power to a plurality of the devices, communicating with the devices to negotiate before starting to supply power to the devices and determining an allocation of power to be supplied to each of the devices within a range in which the total power to be supplied does not exceed an upper limit; The control unit is After starting to supply power to each of the plurality of connected devices in accordance with the distribution based on the negotiation, when a request for reducing the power supplied to one device is received from the one device, the distribution of power to be supplied to the plurality of connected devices is redetermined to reflect the reduction in power requested in the request. A power supply device characterized by:

2. The control unit is The power reduction for the one device is allocated to the devices other than the one device within a range in which the total power supplied does not exceed the upper limit value. The power supply device according to claim 1 .

3. The one device is a device having a function of receiving a power supply to charge a battery and a function of transmitting the request according to the state of the battery. The power supply device according to claim 1 .

4. 4. The power supply device according to claim 1, which is mounted on a vehicle.

5. A power supply system including a power supply apparatus and a device, The power supply device includes: 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, when supplying power to a plurality of the devices, communicating with the devices to negotiate before starting to supply power to the devices and determining an allocation of power to be supplied to each of the devices within a range in which the total power to be supplied does not exceed an upper limit; The control unit of the power supply device After starting to supply power to each of the plurality of connected devices in accordance with the distribution based on the negotiation, when a request for reducing the power supplied to one device is received from the one device, the distribution of power to be supplied to the plurality of connected devices is redetermined to reflect the reduction in power requested in the request. A power supply system comprising:

6. A control method for a power supply device including a power supply unit capable of supplying power to a plurality of connected devices, comprising: a control unit of the power supply device, when supplying power to a plurality of the devices, communicating with the devices and negotiating before starting to supply power to the devices, and determining an allocation of power to be supplied to each of the devices within a range in which the total power to be supplied does not exceed an upper limit value; and when the control unit of the power supplying device receives a request from one device requesting a reduction in power supplied to the one device after starting the supply of power to each of the plurality of connected devices in accordance with the allocation based on the negotiation, redetermining the allocation of power to be supplied to the plurality of connected devices in a manner that reflects the reduction in power requested in the request. A control method comprising:

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