Power supply system and solar power generation system

Abstract

A solar power generation roller shade device 10 comprises a power source 24, a power supply port 22, a power supply unit 26, and a control unit 28. When a power receiving apparatus 50 is connected to the power supply port 22, the control unit 28 performs first negotiation with the power receiving apparatus 50 on the basis of power that can be supplied from the power source 24 at that time point, and the control unit 28 controls the power supply unit 26 so as to supply power to the power receiving apparatus 50 at a first power supply voltage which has been determined in the first negotiation. When the power that can be supplied from the power source 24 decreases after the first negotiation and the power supply at the first power supply voltage cannot be maintained, the control unit 28 performs second negotiation with the power receiving apparatus 50 on the basis of power that can be supplied from the power source 24 at that time point, and the control unit 28 controls the power supply unit 26 so as to supply power to the power receiving apparatus 50 at a second power supply voltage which has been determined in the second negotiation.

Description

Power supply system and solar power generation system

[0001] The present disclosure relates to a power supply system and a solar power generation system.

[0002] Conventionally, a roll screen device provided with solar cells on a screen portion has been known. For example, Patent Document 1 discloses a roll screen device provided with a power supply port for outputting power generated by solar cells to the outside, and capable of charging a portable terminal such as a smartphone through the power supply port.

[0003] Japanese Patent Application Laid-Open No. 2024-51874, Japanese Patent Application Laid-Open No. 2011-179193, Japanese Patent Application Laid-Open No. 2017-85750

[0004] In a power supply system that uses natural energy such as sunlight as described above, since the power generation amount is unstable, it is a problem to perform stable power supply.

[0005] The present disclosure has been made in view of such problems, and an object thereof is to provide a power supply system capable of performing stable power supply even under an unstable power generation situation.

[0006] In order to solve the above problems, a power supply system according to an aspect of the present disclosure includes a power source that outputs power generated by natural energy, a power supply port to which a power receiving device can be connected, a power supply unit that supplies power from the power source to the power receiving device connected to the power supply port, and a control unit that controls the power supply power of the power supply unit. When a power receiving device is connected to the power supply port, the control unit performs a first negotiation with the power receiving device based on the available power of the power source at that time, and controls the power supply unit to supply power to the power receiving device at a first power supply voltage determined by the first negotiation. When the available power of the power source decreases after the first negotiation and it becomes impossible to maintain power supply at the first power supply voltage, the control unit performs a second negotiation with the power receiving device based on the available power of the power source at that time, and controls the power supply unit to supply power to the power receiving device at a second power supply voltage determined by the second negotiation.

[0007] This is a schematic front view of the solar power generation roller screen device according to the first embodiment. This is a functional block diagram of the solar power generation roller screen device according to the first embodiment. This is a flowchart illustrating the operation of the control unit when a power receiving device is connected to the power supply port. This is a flowchart illustrating the operation of the control unit after power supply is started by the first negotiation. This is a flowchart illustrating the operation of the control unit after power supply is resumed by the second negotiation. This is a schematic diagram illustrating the solar power generation system according to the second embodiment. This is a schematic cross-sectional view of the solar cell roller screen. This is a schematic diagram illustrating the solar power generation system according to the third embodiment. This is a schematic cross-sectional view of the solar cell glass.

[0008] The present disclosure will be described below with reference to the drawings, based on preferred embodiments. The following configurations are illustrative for the purpose of understanding the present disclosure, and the scope of the present disclosure is determined solely by the attached claims. Identical or equivalent components and members shown in each drawing are denoted by the same reference numerals, and redundant descriptions are omitted where appropriate. In addition, the dimensions of members in each drawing are shown enlarged or reduced as appropriate for ease of understanding. Furthermore, some members that are not important for describing the embodiments are omitted in each drawing.

[0009] [First Embodiment] Here, as a power supply system utilizing natural energy, we will describe a solar power generation roller screen device which is a power supply system that utilizes solar energy. Figure 1 is a schematic front view of the solar power generation roller screen device 10 according to the first embodiment. The solar power generation roller screen device 10 shown in Figure 1 is configured to supply power generated from solar energy to smartphones and personal computers.

[0010] The solar power generation roller screen device 10 is used by being installed in an opening in a building. In the example shown in Figure 1, the opening in the building is formed by frame materials such as vertical mullions (vertical frames) 101, 102 and horizontal transoms (horizontal frames) 103, 104. A glass panel (not shown) is placed on the exterior side of the opening in the building. The glass panel may be attached to the mullions 101, 102 and transoms 103, 104 by predetermined support means such as structural sealant. The solar power generation roller screen device 10 is placed on the interior side of the opening in the building.

[0011] The solar power generation roll screen device 10 comprises a screen section 12, a winding drum 14 that suspends and holds the screen section 12 and winds it up, and a bottom rail 16 provided at the lower end of the screen section 12. A tubular motor (not shown) for rotating the winding drum 14 is arranged inside the winding drum 14. The screen section 12 can be raised and lowered by driving the tubular motor.

[0012] The screen section 12 is made up of a flexible rectangular sheet-like body. The bottom rail 16 applies force in a direction that pulls the screen section 12 downwards and also applies tension to the screen section 12 to improve its flatness.

[0013] The screen portion 12 comprises a fabric layer and a plurality of solar cells 18 provided on the fabric layer. The fabric layer may be made of fibers such as polypropylene, polyethylene, or polyester, or plastics (synthetic resins). In another embodiment, the screen portion 12 may not have a fabric layer and may be a skeleton type made of, for example, an ETFE film.

[0014] In the first embodiment shown in Figure 1, a plurality of square solar cells 18 are arranged in a matrix, but the size, shape, and arrangement method of the solar cells 18 are not particularly limited, and any size, shape, and arrangement is possible. For example, a plurality of rectangular solar cells may be arranged in the vertical direction of the screen portion 12. Generally, matrix arrangement is frequently used for crystalline silicon solar cells. In another embodiment, perovskite or the like may be coated or printed on the entire surface of the light-receiving surface. The solar cells 18 are configured to convert solar energy into electricity by utilizing the photovoltaic effect. In the solar power generation roll screen device 10 according to this first embodiment, the plurality of solar cells 18 function as a power source.

[0015] Each solar cell 18 has positive and negative extraction electrodes. The positive extraction electrodes formed on each solar cell 18 are connected to each other by a positive electrode ribbon wire (not shown). Similarly, the negative extraction electrodes formed on each solar cell 18 are connected to each other by a negative electrode ribbon wire (not shown). Multiple solar cells 18 are connected to each other in this way by positive electrode ribbon wires and negative electrode ribbon wires. The wiring configuration can be series or parallel, and is not limited to this.

[0016] At the lower end of the screen section 12, a positive lead wire and a negative lead wire (not shown) are connected to the positive ribbon wire and the negative ribbon wire, respectively. The positive lead wire and the negative lead wire are led out from the lower end of the screen section 12. The lower end of the screen section 12 is embedded within the bottom rail 16.

[0017] The bottom rail 16 may be a hollow rod-shaped body. The outer cross-section perpendicular to the longitudinal direction of the bottom rail 16 may be rectangular or circular. The hollow rod-shaped body may be constructed by combining two or more divided members, for example, by fitting them together.

[0018] The bottom rail 16 houses a power supply board 20 for controlling the power generated by multiple solar cells 18 and supplying power to external power receiving devices 50 such as smartphones. Positive and negative lead wires, which are drawn out from the lower end of the screen section 12, are connected to this power supply board 20. Details of the power supply board 20 will be described later.

[0019] The power supply board 20 is provided with a power supply port 22 to which a power receiving device 50 can be connected. When the cable 52 to which the power receiving device 50 is connected is inserted into the power supply port 22, power can be supplied from the power supply board 20 to the power receiving device 50.

[0020] Figure 2 is a functional block diagram of the solar power generation roller screen device 10 according to the first embodiment. Each functional block shown in Figure 2 can be realized hardware-wise using electronic elements and mechanical parts, including the CPU of a computer, and software-wise using computer programs, etc. However, here, the functional blocks that are realized through the cooperation of these are depicted. Therefore, it will be understood by those skilled in the art that these functional blocks can be realized in various forms by combinations of hardware and software.

[0021] The solar power generation roller screen device 10 comprises a power supply 24 and a power supply board 20. The power supply 24 comprises a plurality of solar cells 18 provided on the screen portion 12 of the solar power generation roller screen device 10. The maximum output of the power supply 24 may be, for example, around 120W to 200W.

[0022] The power supply board 20 is housed within the bottom rail 16 of the solar power generation roller screen device 10. The power supply board 20 is provided with a power supply port 22, a power supply unit 26 that supplies power from a power source 24 to a power receiving device 50 connected to the power supply port 22 via a cable 52, and a control unit 28 that controls the power supplied to the power supply unit 26 (power supply voltage and power supply current). Power is supplied to the power supply unit 26 from the power source 24 via a power supply line 30. The control unit 28 is configured to detect the power supplied from the power source 24 to the power supply unit 26. The control unit 28 is also configured to communicate with the power receiving device 50 via the power supply port 22.

[0023] In this first embodiment, the power supply port 22 is a USB port compliant with the USB Type-C (registered trademark) standard. Furthermore, the power supply port 22, the power supply unit 26, and the control unit 28 are compatible with USB PD (USB Power Delivery), which is one of the power supply standards compatible with the USB Type-C standard. Conventional standards had low power supply capabilities, with a maximum of 2.5W (5V / 500mA) for USB 2.0, a maximum of 4.5W (5V / 900mA) for USB 3.0, and a maximum of 7.5W (5V / 1500mA) for USB BC1.2, and could only supply power to small digital devices such as smartphones. However, the USB PD standard can supply a large amount of power, up to 240W (48V / 5A), and can supply power to large digital devices such as laptops that consume a lot of power. To provide power according to the USB PD standard, the cable 52 connected to the power supply port 22 and the powered device 50 also comply with the USB PD standard.

[0024] When a powered device 50 is connected to the power supply port 22 via cable 52, a negotiation in accordance with the USB PD standard is performed between the control unit 28 of the power supply board 20 and the powered device 50. "Negotiation" is "a process in which devices confirm each other's conditions (rules) while communicating." In this connection negotiation (hereinafter referred to as the first negotiation), the control unit 28 sends power supply capacity information of the power supply unit 26 to the powered device 50 based on the available power supply from the power supply 24 at the time of the negotiation. The power supply capacity of the power supply unit 26 is the combination of power supply and power supply current that the power supply unit 26 can provide. The power supply capacity of the power supply unit 26 changes depending on the available power supply from the power supply 24. For example, suppose the power supply unit 26 supports four combinations of power supply voltage and power supply current: (1) 5V / 3A, (2) 9V / 3A, (3) 15V / 3A, and (4) 20V / 3A. In this case, if the power generation of the solar cell 18 is large and the power that can be supplied from the power source 24 is 60W or more, all combinations (1) to (4) are provided to the power receiving device 50. If the power generation of the solar cell 18 decreases and the power that can be supplied from the power source 24 decreases to, for example, 45W, the combination (4) 20V / 3A cannot be provided because it requires 60W, so the power supply unit 26 provides the three combinations (1) to (3) to the power receiving device 50.

[0025] When the power receiving device 50 receives power supply capacity information from the control unit 28, it sends the power request information (requested voltage / current information), which is the voltage and current information required by the power receiving device 50, to the control unit 28. For example, if the power supply unit 26 sends four voltage / current combinations: (1) 5V / 3A, (2) 9V / 3A, (3) 15V / 3A, and (4) 20V / 3A, and the required voltage / current combination is 15V and 3A, the power receiving device 50 requests (3) 15V / 3A from the control unit 28. Upon receiving the request power information from the power receiving device 50, the control unit 28 controls the power supply unit 26 so that the power supply voltage is 15V and the power supply current is 3A. As a result, power supply from the power supply unit 26 to the power receiving device 50 begins. In another embodiment, the power receiving device 50 may first send the required power information (required voltage and current information), which is the voltage and current information required by the power receiving device 50, to the control unit 28, and then receive power supply capacity information from the control unit 28.

[0026] In the case of commercial power, the available power supply is stable, so it is almost impossible for power to be interrupted to the receiving equipment after power supply has started. However, in the case of a solar power generation roller screen device 10 according to this first embodiment, where the power supply 24 is a solar cell 18, the available power supply from the power supply 24 is unstable. For example, at the start of power supply, it may be possible to supply 60W, but then the sunlight may dim and the available power supply from the power supply 24 weakens, making it impossible to supply 60W, and thus the power supply to the receiving equipment 50 may stop. Therefore, in the solar power generation roller screen device 10 according to this first embodiment, we propose a method that enables stable power supply even under unstable power generation conditions.

[0027] The operation of the control unit 28 in the solar power generation roller screen device 10 according to this first embodiment will be described below with reference to the flowcharts in Figures 3 to 5.

[0028] Figure 3 is a flowchart illustrating the operation of the control unit 28 when a powered device 50 is connected to the power supply port 22. To briefly explain the flowchart, when a powered device 50 is connected to the power supply port 22, the control unit 28 performs a first negotiation with the powered device 50 based on the available power supply from the power source 24 at that time. The control unit 28 then controls the power supply unit 26 to supply power to the powered device 50 at the first power supply voltage determined by the first negotiation.

[0029] First, the control unit 28 determines whether or not the power receiving device 50 is connected to the power supply port 22 (S10). That is, the control unit 28 determines whether or not the cable 52 connected to the power receiving device 50 is inserted into the power supply port 22. If it is determined that the power receiving device 50 is not connected to the power supply port 22 (N in S10), this process is terminated.

[0030] If the control unit 26 determines that a powered device 50 is connected to the power supply port 22 (Y in S10), it performs a first negotiation with the powered device 50 based on the available power supply from the power supply 24 at that time (S12). In the first negotiation, the control unit 28 detects the available power supply from the power supply 24 (S14). Next, the control unit 28 transmits power supply capability information to the power supply board 20 (S16). This power supply capability information is set based on the available power supply from the power supply 24. Here, it is assumed that the power supply unit 26 supports four combinations of power supply voltage and power supply current: (1) 5V / 3A, (2) 9V / 3A, (3) 15V / 3A, and (4) 20V / 3A. If the available power supply from the power supply 24 is 60W or more, all combinations (1) to (4) are transmitted to the powered device 50 as power supply capability information. If the power supply from power source 24 is 45W or more and less than 60W, the three combinations (1) to (3) are transmitted to the power receiving device 50 as power supply capacity information. If the power supply from power source 24 is 27W or more and less than 45W, the two combinations (1) and (2) are transmitted to the power receiving device 50 as power supply capacity information. If the power supply from power source 24 is 15W or more and less than 27W, the combination (1) is transmitted to the power receiving device 50 as power supply capacity information. If the power supply from power source 24 is less than 15W, the process is terminated.

[0031] Upon receiving power supply capacity information from the control unit 28, the power receiving device 50 sends information on the requested power (i.e., requested voltage and requested current) to the control unit 28. Specifically, the power receiving device 50 selects one combination of power supply voltage and power supply current from those received from the control unit 28 and sends it to the control unit 28 as requested power information.

[0032] The control unit 28 determines whether or not it has received power request information from the power receiving device 50 (S18). If it has not received power request information from the power receiving device 50 (N in S18), it waits for reception. If it has received power request information from the power receiving device 50 (Y in S18), the power supply unit 26 sets the received requested voltage as the first power supply voltage and controls the power supply unit 26 to start supplying power at the first power supply voltage (S20). Through the above process, the power supply unit 26 starts supplying power to the power receiving device 50 at the first power supply voltage. In another embodiment, when the power receiving device 50 is plugged into the power supply port 22, the control unit 28 identifies the power request of the power receiving device 50 (requested voltage and requested current), detects the available power from the power supply 24, and if the available power is equal to or greater than the requested power, it may start supplying power to the power receiving device 50 with the requested voltage as the first power supply voltage.

[0033] Figure 4 is a flowchart illustrating the operation of the control unit 28 after power supply is initiated by the first negotiation. To summarize this flowchart, if the available power supply of the power source 24 decreases after the first negotiation and the control unit 28 can no longer maintain power supply at the first power supply voltage, it performs a second negotiation with the power receiving device 50 based on the available power supply of the power source 24 at that time. The control unit 28 then controls the power supply unit 26 to supply power to the power receiving device 50 at the second power supply voltage determined by the second negotiation.

[0034] First, the control unit 28 detects the available power supply of the power supply 24 (S30). The control unit 28 determines whether the available power supply of the power supply 24 is equal to or greater than the first power supply (available power supply ≥ first power supply) (S32). The first power supply is the product of the first power supply voltage and the current flowing through the power receiving device 50. If the available power supply of the power supply 24 is equal to or greater than the first power supply (Y in S32), the power supply at the first power supply voltage can be maintained, and the process is terminated.

[0035] On the other hand, if the available power supply of the power supply 24 is less than the first power supply power (N in S32), it is not possible to maintain power supply at the first power supply voltage. In this case, the control unit 28 according to this first embodiment performs a second negotiation (S34). This second negotiation is a new negotiation that resets all the results of the first negotiation. In the USB PD standard, a new negotiation is not performed unless the cable 52 is inserted into or removed from the power supply port 22, and power supply remains stopped. According to the control unit 28 according to this first embodiment, power supply can be resumed by performing a second negotiation without inserting or removing the cable 52 from the power supply port 22.

[0036] In the second negotiation, the control unit 28 first requests information on the requested voltage and requested current (i.e., requested power) from the power receiving device 50 (S36). Upon receiving the request, the power receiving device 50 sends the requested voltage and requested current information to the control unit 28. The control unit 28 determines whether or not it has received the requested voltage and requested current information from the power receiving device 50 (S38). If it has not received the requested voltage and requested current information from the power receiving device 50 (N in S38), it waits for reception. For example, if the power receiving device 50 has a built-in battery, the power supply request from the power receiving device 50 stops when the battery is fully charged. Then, when the power receiving device 50 is used and power is consumed, a power supply request is made again. On the other hand, when the control unit 28 receives information on the requested voltage and requested current from the power receiving device 50 (Y in S38), it determines whether the power supplyable from the power supply 24 at that time is equal to or greater than the power requested by the power receiving device 50 (product of the requested voltage and the requested current) (supplyable power ≥ requested power) (S40).

[0037] If the power supply capacity of the power supply 24 is equal to or greater than the power requested by the power receiving device 50 (Y in S40), the control unit 28 sets the requested voltage as the second power supply voltage and controls the power supply unit 26 to start power supply at the second power supply voltage (S42). On the other hand, if the power supply capacity of the power supply 24 is less than the power requested by the power receiving device 50 (N in S40), the control unit 28 sets the maximum voltage that can be set under the available power supply capacity as the second power supply voltage and controls the power supply unit 26 to start power supply at the second power supply voltage (S44). For example, if the power receiving device 50 requests 20V / 3A but the available voltage is 50W, the control unit 28 sets 15V, which is the maximum voltage that can be set under the available power supply capacity, as the second power supply voltage. Also, for example, if the power receiving device 50 requests 15V / 3A but the available voltage is 20W, the control unit 28 sets 5V, which is the maximum voltage that can be set under the available power supply capacity, as the second power supply voltage.

[0038] Thus, according to the control unit 28 of this first embodiment, even if the available power supply of the power supply 24 decreases after the first negotiation and power supply stops, the control unit 28 can automatically perform a second negotiation without inserting or removing the cable 52, and restart power supply at a supply voltage corresponding to the available power supply of the power supply 24 at that time. This avoids a state where power supply remains stopped, and enables stable power supply even under unstable power generation conditions.

[0039] The flowchart shown in Figure 4 represents the process after power supply has started following the first negotiation, but it is also executed repeatedly after the second negotiation has been performed. In this case, the first power supply power in S32 is replaced with the second power supply power (the product of the second power supply voltage and the current flowing through the power receiving device 50). By repeating the flowchart shown in Figure 4, even if the power supply stops because the second power supply voltage cannot be maintained, the second negotiation can be automatically executed again to resume power supply.

[0040] Figure 5 is a flowchart illustrating the operation of the control unit 28 after power supply is resumed following the second negotiation. In summary, if the second power supply voltage is less than the voltage requested by the powered device 50 during the second negotiation, the control unit 28 changes the second power supply voltage to approach the voltage requested by the powered device 50 in accordance with the increase in the available power of the power supply 24 after the second negotiation. The processing shown in the flowchart in Figure 5 may be performed alternately with the processing shown in the flowchart in Figure 4.

[0041] First, the control unit 28 determines whether the second power supply voltage determined in the second negotiation is equal to the requested voltage of the power receiving device 50 (requested voltage = second power supply voltage) (S50). If the second power supply voltage is equal to the requested voltage (Y in S50), the power supply unit 26 is able to supply the power required by the power receiving device 50, and the process ends. The case where the second power supply voltage is equal to the requested voltage (Y in S50) corresponds to the case where power supply is started with the requested voltage as the second power supply voltage (S42) in the flowchart of Figure 4.

[0042] On the other hand, if the second power supply voltage is different from the required voltage (N in S50), the control unit 28 detects the available power supply from the power supply 24 (S52). The case where the second power supply voltage is different from the required voltage (second power supply voltage ≠ required voltage) means that the second power supply voltage is less than the required voltage, which corresponds to the case in the flowchart of Figure 4 where power supply is started with the maximum voltage that can be set under the available power supply as the second power supply voltage (S44). In this case, the power supply unit 26 is not able to supply the power required by the power receiving device 50.

[0043] The control unit 28 determines whether the available power has increased compared to the time of the second negotiation (S54). Here, "increase in available power" means an increase in available power that allows the power supply voltage to be raised by one step. For example, suppose that in the second negotiation, the power requested by the power receiving device 50 was 20V / 3A, but the available voltage at that time was 50W, so the second power supply voltage could not be raised to 20V and was set to 15V. In this case, if the available voltage has increased to 60W or more, the power supply voltage can be raised by one step from 15V to 20V.

[0044] When it is determined in S54 that the available power has increased (Y in S54), the control unit 28 raises the second power supply voltage by one step and starts power supply (S56). On the other hand, when it is determined in S54 that the available power has not increased (N in S54), the process ends.

[0045] By performing the process of the flowchart shown in FIG. 5, even if the second power supply voltage is determined to be lower than the required voltage in the second negotiation, the second power supply voltage can be gradually changed so as to approach the required voltage of the power receiving device 50 in accordance with an increase in the available power of the power supply 24 thereafter. For example, in S44 of the flowchart in FIG. 4, even if the required voltage is 20 V and the second power supply voltage is determined to be 5 V, if the available power of the power supply 24 increases to, for example, 60 W or more thereafter, the second power supply voltage can be increased step by step as 5 V → 9 V → 15 V → 20 V, and power supply at the required voltage of the power receiving device 50 can be realized.

[0046] Although not shown in FIG. 5, when there is available power that can satisfy the required power, the required voltage may be directly provided to the power receiving device 50 without going through steps. For example, if the required voltage was 20 V but due to low available power only a power supply voltage of 5 V could be provided, and then immediately the power supply voltage of 20 V can be provided, instead of increasing the power supply voltage step by step, the required voltage of 20 V may be provided linearly (directly). On the other hand, when the available power rapidly decreases with respect to the required power, the power supply voltage is gradually decreased to a voltage at which power supply is possible according to the available power, but here too, the power supply voltage may be decreased linearly (directly) to the power supply possible voltage.

[0047] In the above, the solar power generation roll screen device 10 using solar energy has been described, but the technology of the present disclosure can also be applied to other power generation systems using solar energy. Further, the technology of the present disclosure can also be applied to other power generation systems using natural energy such as a wind power generation system and a geothermal power generation system.

[0048] [Second Embodiment] Conventionally, a solar cell roll screen having solar cell cells provided on a screen portion and a solar cell glass having solar cell cells provided on a glass panel are known (see, for example, Patent Documents 2 and 3).

[0049] It is desirable to effectively utilize the electric power generated by the solar cell roll screen and the solar cell glass as described above.

[0050] In view of such problems, the present disclosure has been made, and an object thereof is to provide a solar power generation system capable of effectively utilizing the electric power generated by a solar cell roll screen or a solar cell glass.

[0051] In order to solve the above problems, the solar power generation system of the present disclosure includes a plurality of solar cell roll screens and / or solar cell glasses, and is arranged for each of the plurality of solar cell roll screens and / or solar cell glasses, and a solar cell roll screen device and / or And a plurality of power transmission / reception devices for transmitting and receiving the electric power generated by the solar cell glass, and a load device for receiving the electric power from the plurality of power transmission / reception devices connected in parallel.

[0052] FIG. 6 is a schematic diagram for explaining a solar power generation system 1010 according to the second embodiment. As shown in FIG. 6, the solar power generation system 1010 includes a plurality (here, four) of solar cell roll screens 1012. The four solar cell roll screens 1012 are horizontally arranged and attached to an opening of a building. A peri cover 1020 is disposed below the solar cell roll screen 1012. A power receiving coil 1022 is disposed on the upper surface of the peri cover 1020 or in the vicinity thereof.

[0053] FIG. 7 is a schematic cross-sectional view of the solar cell roll screen 1012. The solar cell roll screen 1012 includes a screen portion 1011 and a holding portion 1013 that suspends and holds the screen portion 1011.

[0054] The holding unit 1013 includes a winding drum 1014 for winding up the screen unit 1011. A tubular motor (not shown) for rotating the winding drum 1014 is located inside the winding drum 1014. The screen unit 1011 can be raised and lowered by driving the tubular motor.

[0055] The screen section 1011 is configured as a rectangular sheet-like body that can be rolled up. The upper end of the screen section 1011 in the longitudinal direction is connected to the winding drum 1014, and a bottom rail 1015 is provided at the lower end. The bottom rail 1015 applies force in a direction that pulls the screen section 1011 downward, and also applies tension to the screen section 1011 to improve its flatness.

[0056] The screen portion 1011 comprises a fabric layer and a plurality of solar cells 1016 provided on the fabric layer. The fabric layer may be made of fibers or plastics (synthetic resins) such as PVC (polyvinyl chloride), polypropylene, polyethylene, or polyester. In another embodiment, the screen portion 1011 may not have a fabric layer and may be a skeleton type made of, for example, an ETFE film.

[0057] The solar cell 1016 may be square in plan view and may be arranged in a matrix. However, the size, shape, and arrangement method of the solar cell 1016 are not particularly limited, and any size, shape, and arrangement is possible. For example, multiple rectangular solar cells in plan view may be arranged in the vertical direction of the screen portion 1011. In general, matrix arrangement is frequently used in crystalline silicon solar cells. In another embodiment, the entire surface of the light-receiving surface may be coated or printed with perovskite or the like. The solar cell 1016 is configured to convert light energy into electricity by utilizing the photovoltaic effect.

[0058] The lower end of the screen section 1011 is embedded within the bottom rail 1015. Lead wires 1018 for extracting power generated by the solar cell 1016 are drawn out from the lower end of the screen section 1011. Within the bottom rail 1015, the lead wires are connected to the control board 1019.

[0059] The bottom rail 1015 may be a hollow rod-shaped body. The outer cross-section perpendicular to the longitudinal direction of the bottom rail 1015 may be rectangular or circular. The hollow rod-shaped body may be constructed by combining two or more divided members, for example, by fitting them together.

[0060] A control board 1019 for controlling the power generated by the solar cell 1016 may be housed within the bottom rail 1015.

[0061] The control board 1019 may include an MPPT (Maximum Power Point Tracking) control board, a power supply (power extraction) control board (a user interface board that supplies power via USB-C, DC jack, etc.), and a power supply board. These control boards control the power input via the lead wires 1018.

[0062] The MPPT control board is a control board for tracking the maximum operating point during power generation in real time in response to changes in weather conditions. The power supply (power extraction) control board is a control board for controlling the power supply (extraction) of power generated by the solar cell 1016. The power supply board is a board that controls the supply of power to the outside via the power transmission coil.

[0063] A power transmission coil 1021 is provided within the bottom rail 1015 to output power generated by the solar cell 1016 to a power receiving coil 1022 located on the pericover 1020. The power transmission coil 1021 is positioned opposite the power receiving coil 1022, enabling contactless power supply between them. The contactless power transmission method may be an electromagnetic induction method, a magnetic field resonance method, or a microwave wireless method.

[0064] In the second embodiment shown in Figure 7, since the receiving coil 1022 is provided on the pericover 1020 located below the bottom rail 1015, the transmitting coil 1021 is positioned facing the bottom surface of the bottom rail 1015. However, the position and orientation of the transmitting coil 1028 may be appropriately set according to the arrangement of the receiving coil 1022. The bottom rail 1015 is configured to allow electromagnetic waves to pass through in order to enable power transmission to the receiving coil 1022.

[0065] When the screen section 1011 is lowered and the bottom rail 1015 approaches the upper surface of the pericover 1020, the power generated by the solar cell 1016 is transmitted from the transmission coil 1021 to the receiving coil 1022. On the other hand, when the screen section 1011 is rolled up and the bottom rail 1015 moves away from the upper surface of the pericover 1020, the transmission of power from the transmission coil 1021 to the receiving coil 1022 is stopped. The transmission coil 1021 and the receiving coil 1022 constitute a power transmission and reception device 1024 that transmits and receives power generated by the solar cell roll screen 1012.

[0066] Returning to Figure 6, a power transmission / receiving device 1024, consisting of a power transmission coil 1021 and a power receiving coil 1022, is arranged for each of the four solar cell roller screens 1012. The four power receiving coils 1022 are connected in parallel by a cable 1026. The cable 1026 is connected to a power storage device 1030. The power storage device 1030 is configured to store the power supplied from the cable 1026. The power storage device 1030 is an example of a load device that receives power from multiple power transmission / receiving devices 1024 connected in parallel. The load device may be, for example, a lighting device, an air conditioning fan, or other similar electrical product.

[0067] According to the solar power generation system 1010 of this second embodiment, when the screen portion 1011 of the solar cell roll screen 1012 is lowered and the bottom rail 1015 is close to the upper surface of the pericover 1020, the power generated by the solar cell roll screen 1012 is supplied to the energy storage device 1030 via the power transmission and reception device 1024 and the cable 1026 and stored. Since the power generated by multiple solar cell roll screens 1012 can be stored together in the energy storage device 1030, the generated power can be used effectively.

[0068] When solar cells are movable, as in the solar cell roll screen 1012, routing the wiring becomes difficult, making it not easy to extract the power generated by the solar cells to the outside. As in the solar power generation system 1010 according to this second embodiment, by using a power transmission and receiving device 1024 consisting of a power transmission coil 1021 provided on the bottom rail 1015 of the solar cell roll screen 1012 and a power receiving coil 1022 arranged on the pericover 1020, troublesome wiring is eliminated, and the power generated by the solar cell 1016 can be easily extracted to the outside.

[0069] In the second embodiment described above, the power receiving coil 1022 was provided on the pericover 1020. However, the member on which the power receiving coil 1022 is provided is not particularly limited, as long as it is located near the solar cell roll screen 1012 and is capable of receiving power from the power transmitting coil 1021 of the bottom rail 1015.

[0070] In the second embodiment described above, a power transmission coil 1021 and a power reception coil 1022 were used as the power transmission and reception device 1024. However, instead of these, a magnetic power transmission terminal provided on the bottom rail 1015 of the solar cell roll screen 1012 and a magnetic power reception terminal arranged on the pericover 1020 may be used. A magnetic terminal is a connector that connects using magnetic force. Magnetic terminals are suitable for use as the power transmission and reception device 1024 of the solar cell roll screen 1012 because they can be easily disconnected when the screen section 1011 is rolled up and automatically reconnected by magnetic force when the screen section 1011 is lowered.

[0071] [Third Embodiment] Figure 8 is a schematic diagram illustrating a photovoltaic power generation system 1040 according to the third embodiment. As shown in Figure 8, the photovoltaic power generation system 1040 includes a plurality (in this case, two) of solar cell glass 1042. The two solar cell glass 1042 are each slidable in the left-right direction and constitute a sliding window.

[0072] A frame 1050 for attaching the glass to the building is provided around the two solar cell panes 1042. The frame 1050 consists of upper and lower transoms 1051 and 1052 and left and right mullions 1053 and 1054. A power receiving coil 1022 is positioned in the lower transom 1052.

[0073] Figure 9 is a schematic cross-sectional view of the solar cell glass 1042. The solar cell glass 1042 comprises a pair of glass panels 1043 and 1044, a plurality of solar cells 1016 arranged between the pair of glass panels 1043 and 1044, and a frame 1045 surrounding the pair of glass panels 1043 and 1044. The solar cells 1016 may be square in plan view and may be arranged in a matrix. However, the size, shape, and arrangement method of the solar cells 1016 are not particularly limited, and any size, shape, and arrangement are possible.

[0074] The frame 1045 may be made of an aluminum alloy, a resin material such as PVC, or wood. The lower frame 1045a of the frame 1045 is hollow and contains a control board 1019 for controlling the power generated by the solar cell 1016, and a power transmission coil 1021 for outputting the power generated by the solar cell 1016 to a power receiving coil 1022 located in the lower transom 1052. The lower transom 1052 may be configured to allow electromagnetic waves to pass through, or it may be exposed, in order to enable power transmission to the power receiving coil 1022.

[0075] When the solar cell glass 1042 is closed and the transmitting coil 1021 and the receiving coil 1022 are close together, the power generated by the solar cell 1016 is transmitted from the transmitting coil 1021 to the receiving coil 1022. On the other hand, when the solar cell glass 1042 is opened and the transmitting coil 1021 and the receiving coil 1022 are separated, the transmission of power from the transmitting coil 1021 to the receiving coil 1022 is stopped. The transmitting coil 1021 and the receiving coil 1022 constitute a power transmission and reception device 1024 that transmits and receives power generated by the solar cell roller screen 1012.

[0076] Returning to Figure 8, a power transmission and reception device 1024, consisting of a power transmission coil 1021 and a power receiving coil 1022, is positioned for each of the four solar cell glass 1042. The two power receiving coils 1022 are connected in parallel by a cable 1026. The cable 1026 is connected to a power storage device 1030. The power storage device 1030 is configured to store the power supplied from the cable 1026.

[0077] According to the photovoltaic power generation system 1040 of this third embodiment, when the solar cell glass 1042 is closed and the power transmission coil 1021 is close to the power receiving coil 1022, the power generated by the solar cell glass 1042 is supplied to the energy storage device 1030 via the power transmission and reception device 1024 and the cable 1026 and stored. Since the power generated by multiple solar cell glass 1042s can be stored together in the energy storage device 1030, the generated power can be used effectively. Furthermore, if multiple power receiving coils 1022 are provided within the transom 1052, the generated power can be extracted even when the solar cell glass 1042 is open.

[0078] When solar cells are movable, such as in the solar cell glass 1042, routing the wiring becomes difficult, making it difficult to extract the power generated by the solar cells to the outside. As in the photovoltaic power generation system 1040 according to this third embodiment, by using a power transmission and receiving device 1024 consisting of a power transmission coil 1021 provided on the lower frame 1045a of the solar cell glass 1042 and a power receiving coil 1022 arranged on the transom 1052 below, troublesome wiring is eliminated, and the power generated by the solar cell 1016 can be easily extracted to the outside.

[0079] In the third embodiment described above, the power receiving coil 1022 was provided on the lower transom 1052. However, the member on which the power receiving coil 1022 is provided is not particularly limited, as long as it is located near the solar cell glass 1042 and is capable of receiving power from the power transmitting coil 1021 of the lower frame 1045a.

[0080] In the third embodiment described above, a power transmission coil 1021 and a power receiving coil 1022 were used as the power transmission and receiving device 1024. However, instead of these, a magnetic power transmission terminal provided on the lower frame 1045a of the solar cell glass 1042 and a magnetic power receiving terminal arranged on the transom 1052 may be used. Magnetic terminals are suitable for use as the power transmission and receiving device 1024 of the solar cell glass 1042 because they can be easily disconnected when the solar cell glass 1042 is slid open and automatically connected by magnetic force when the solar cell glass 1042 is slid closed.

[0081] In the third embodiment described above, a sliding window was used as an example, but the technology of this disclosure can also be applied to other types of windows, such as projecting windows, outward-opening windows, casement windows, tilt-and-turn windows, vertical-axis rotating windows, and horizontal-axis rotating windows.

[0082] Figure 6 shows a photovoltaic power generation system 1010 using a solar cell roller screen 1012, and Figure 8 shows a photovoltaic power generation system 1040 using solar cell glass 1042. However, a photovoltaic power generation system may be constructed using both the solar cell roller screen 1012 and the solar cell glass 1042.

[0083] One aspect of the present disclosure is as follows: (Item 1) A power supply system comprising: a power source that outputs electricity generated from natural energy; a power supply port to which a power receiving device can be connected; a power supply unit that supplies power from the power source to the power receiving device connected to the power supply port; and a control unit that controls the power supplied by the power supply unit, wherein when the power receiving device is connected to the power supply port, the control unit performs a first negotiation with the power receiving device based on the available power supply of the power source at that time, and controls the power supply unit to supply power to the power receiving device at a first power supply voltage determined by the first negotiation; and if the available power supply of the power source decreases after the first negotiation and it becomes impossible to maintain power supply at the first power supply voltage, the control unit performs a second negotiation with the power receiving device based on the available power supply of the power source at that time, and controls the power supply unit to supply power to the power receiving device at a second power supply voltage determined by the second negotiation. (Item 2) The power supply system according to Item 1, wherein the control unit acquires information on the requested voltage and requested current requested by the power receiving device during the second negotiation, and if the available power supply of the power source at that time is equal to or greater than the requested power of the power receiving device, the requested voltage requested by the power receiving device is set as the second power supply voltage. (Item 3) The power supply system according to Item 2, wherein the control unit acquires information on the requested voltage and requested current requested by the power receiving device during the second negotiation, and if the available power supply of the power source at that time is less than the requested power of the power receiving device, the maximum voltage that can be set under the available power supply is set as the second power supply voltage. (Item 4) The power supply system according to Item 3, wherein if the second power supply voltage is set to be less than the requested voltage of the power receiving device during the second negotiation, the control unit changes the second power supply voltage to approach the requested voltage of the power receiving device in accordance with the increase in the available power supply of the power source after the second negotiation.(Clause 5) A photovoltaic power generation system comprising: a plurality of solar cell roller screens and / or solar cell glass; a plurality of power transmission and reception devices arranged for each of the plurality of solar cell roller screens and / or solar cell glass for transmitting and receiving power generated by the solar cell roller screens and / or solar cell glass; and a load device for receiving power from the plurality of power transmission and reception devices connected in parallel. (Clause 6) The photovoltaic power generation system according to Clause 5, wherein the power transmission and reception device comprises: a power transmission coil provided on the bottom frame of the solar cell roller screen and / or the frame of the solar cell glass; and a power receiving coil provided on a member located near the solar cell roller screen and / or the solar cell glass. (Clause 7) The photovoltaic power generation system according to Clause 5, wherein the power transmission and reception device comprises: a magnetic power transmission terminal provided on the bottom frame of the solar cell roller screen and / or the frame of the solar cell glass; and a magnetic power receiving terminal provided on a member located near the solar cell roller screen and / or the solar cell glass.

[0084] The present invention has been described above based on embodiments. These embodiments are illustrative, and it will be understood by those skilled in the art that various modifications and changes are possible within the scope of the claims of the present invention, and that such modifications and changes are also within the scope of the claims of the present invention. Accordingly, the descriptions and drawings herein should be treated as illustrative rather than limiting.

[0085] This disclosure can be used in solar power generation equipment.

[0086] 10 Solar power generation roll screen device, 12 Screen part, 14 Winding drum, 16 Bottom rail, 18 Solar cell, 20 Power supply board, 22 Power supply port, 24 Power supply, 26 Power supply unit, 28 Control unit, 30 Power supply line, 50 Power receiving equipment, 52 Cable, 1010, 1040 Solar power generation system, 1011 Screen part, 1012 Solar cell roll screen, 1014 Winding drum, 1015 Bottom rail, 1016 Solar cell, 1020 Pericover, 1021 Power transmission coil, 1022 Power receiving coil, 1024 Power transmission and receiving device, 1026 Cable, 1030 Energy storage device, 1042 Solar cell glass, 1050 Frame, 1052 Mullion.

Claims

1. A power supply system comprising: a power source that outputs electricity generated from natural energy; a power supply port to which a power receiving device can be connected; a power supply unit that supplies power from the power source to the power receiving device connected to the power supply port; and a control unit that controls the power supplied by the power supply unit, wherein when the power receiving device is connected to the power supply port, the control unit performs a first negotiation with the power receiving device based on the available power supply of the power source at that time, and controls the power supply unit to supply power to the power receiving device at a first power supply voltage determined by the first negotiation; and if the available power supply of the power source decreases after the first negotiation and it becomes impossible to maintain power supply at the first power supply voltage, the control unit performs a second negotiation with the power receiving device based on the available power supply of the power source at that time, and controls the power supply unit to supply power to the power receiving device at a second power supply voltage determined by the second negotiation.

2. The power supply system according to claim 1, wherein the control unit, in the second negotiation, obtains information on the requested voltage and requested current requested by the power receiving device, and if the power supply available at that time is equal to or greater than the power requested by the power receiving device, the requested voltage requested by the power receiving device is set as the second power supply voltage.

3. The power supply system according to claim 2, wherein the control unit, in the second negotiation, obtains information on the requested voltage and requested current requested by the power receiving device, and if the available power supply of the power source at that time is less than the requested power of the power receiving device, the maximum voltage that can be set under the available power supply is set as the second power supply voltage.

4. The power supply system according to claim 3, wherein, in the second negotiation, if the second power supply voltage is less than the voltage requested by the power receiving device, the control unit changes the second power supply voltage to approach the voltage requested by the power receiving device in accordance with the increase in the power supply's available power after the second negotiation.

5. A photovoltaic power generation system comprising: a plurality of solar cell roller screens and / or solar cell glass; a plurality of power transmission and reception devices arranged for each of the plurality of solar cell roller screens and / or solar cell glass, which transmit and receive power generated by the solar cell roller screens and / or solar cell glass; and a load device that receives power from the plurality of power transmission and reception devices connected in parallel.

6. The photovoltaic power generation system according to claim 5, wherein the power transmission and receiving device includes a power transmission coil provided on the bottom frame of the solar cell roll screen and / or the frame of the solar cell glass, and a power receiving coil provided on a member located near the solar cell roll screen and / or the solar cell glass.

7. The photovoltaic power generation system according to claim 5, wherein the power transmission and receiving device includes a magnetic power transmission terminal provided on the bottom frame of the solar cell roll screen and / or the frame of the solar cell glass, and a magnetic power receiving terminal provided on a member located near the solar cell roll screen and / or the solar cell glass.

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