DC power output device, wireless power transmission system, and photovoltaic power generation system

Abstract

To provide a DC power output device that can prevent damage to a DC power supply circuit when an input to the DC power supply circuit connected in parallel is attenuated.SOLUTION: A DC power output device includes a plurality of DC power supply circuits, a protection circuit having a plurality of protection elements that can be selectively connected between positive output portions and negative output portions of the DC power supply circuits for all or some of the plurality of DC power supply circuits, and a connection circuit having an input portion to which the plurality of DC powers output from the protection circuit are input and an output portion that outputs one or more DC powers to be supplied to one or more power supply targets.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power receiving device of a wireless power transmission system, a DC power output device such as a photovoltaic power generation device, a wireless power transmission system, and a photovoltaic power generation system. [Background technology]

[0002] Conventionally, there is known a wireless power transmission power receiving device that transmits power via radio waves such as microwaves. For example, Patent Document 1 discloses a power receiving device including a plurality of rectifier circuits (DC power supply circuits) that rectify signals received by a plurality of antennas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-213313 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a power receiving device for wireless power transmission, an asymmetrical connection in which multiple rectifier circuits (DC power supply circuits) are asymmetrically connected in parallel may be used to increase efficiency. When using such an asymmetrical connection of multiple rectifier circuits, if the input (electrical energy) input to one of the multiple rectifier circuits connected asymmetrically attenuates, the output voltage of the other rectifier circuit may be applied to the one rectifier circuit, which may cause damage to the rectifier circuit. Note that a similar problem may occur not only in a power receiving device having multiple rectifier circuits, but also in a photovoltaic power generating device (DC power output device) having multiple photoelectric conversion elements (DC power supply circuits) such as solar cells. [Means for solving the problem]

[0005] A DC power output device according to one embodiment of the present invention includes a plurality of DC power supply circuits, a protection circuit having a plurality of protection elements that can be selectively connected between positive output portions and negative output portions of the DC power supply circuits for all or some of the plurality of DC power supply circuits, and a connection circuit having an input portion to which the plurality of DC powers output from the protection circuit are input and an output portion that outputs one or more DC powers to be supplied to one or more power supply targets.

[0006] In the DC power output device, the plurality of DC power supply circuits may have an asymmetric parallel connection section in which a first power supply circuit in which a plurality of DC power supply circuits are connected in series and a second power supply circuit in which a smaller number of DC power supply circuits than the first power supply circuit are connected in series or which is composed of a single DC power supply circuit are connected in parallel, and the bypass diode may be connected to the DC power supply circuit included in the second power supply circuit in the asymmetric parallel connection section.

[0007] In the DC power output device, the protection element may be a bypass diode, wherein each of the DC power supply circuits has a diode connected between the positive output section and the negative output section, and a threshold voltage of the bypass diode may be lower than a breakdown voltage of a diode of the DC power supply circuit.

[0008] The DC power output device may further include a control unit that controls connection of the protection element connected between the positive output unit and the negative output unit of the DC power supply circuit. Here, the control unit may control connection of the protection element based on connection information between the multiple input units and the one or multiple output units in the connection circuit. The control unit may also receive control information from an external device such as a server, a management device, or a center device, and control connection of the protection element based on the control information.

[0009] The DC power output device may include a plurality of DC control circuits connected to a plurality of output sections of the connection circuit, wherein the DC control circuit may have at least one circuit selected from the group consisting of a maximum power point tracking (MPPT) control circuit, a DC-DC conversion circuit, and a rectifier circuit.

[0010] In the DC power output device, the DC power output device may be a power receiving device of a wireless power transmission system, and the multiple DC power supply circuits may be multiple rectifier circuits connected to multiple antennas that constitute a receiving antenna device of the wireless power transmission system.

[0011] A wireless power transmission system according to another aspect of the present invention includes the power receiving device and a power transmitting device that transmits a power transmission signal to the power receiving device.

[0012] In the DC power output device, the DC power output device may be a photovoltaic power generation device of a photovoltaic power generation system, and the multiple DC power supply circuits may be multiple power supply circuits each connected to a photovoltaic cell (photoelectric conversion element) such as a solar cell.

[0013] A photovoltaic system according to yet another aspect of the present invention includes the photovoltaic device described above.

[0014] In addition, some or all of the programs used for the control may be trained models created by machine learning. Effect of the Invention

[0015] According to the present invention, in a DC power output device having a plurality of DC power supply circuits, damage to the DC power supply circuits connected in parallel can be avoided when the input to the DC power supply circuits is attenuated. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a power supply system according to an embodiment. [Diagram 2]FIG. 2 is an explanatory diagram illustrating an example of a schematic configuration of a wireless transmission system including a power receiving device connected to the power supply system according to the embodiment. [Diagram 3] FIG. 3 is a circuit diagram illustrating an example of a rectifier circuit of the power receiving device according to the embodiment. [Figure 4] FIG. 4 is a circuit diagram showing an example of a parallel connection of a plurality of rectifier circuits. [Diagram 5] FIG. 5 is an explanatory diagram showing an example of a connection of a plurality of rectifier circuits in which damage to rectifier diodes is likely to occur. [Figure 6] FIG. 6 is an explanatory diagram showing an example of an input power distribution of the rectifier circuit group. [Figure 7] FIG. 7 is an explanatory diagram showing another example of the input power distribution of the rectifier circuit group. [Figure 8] FIG. 8 is an explanatory diagram showing an example of the principle of preventing damage to a rectifier circuit using a bypass diode according to an embodiment. [Figure 9] FIG. 9 is an explanatory diagram illustrating an example of a bypass diode-connected circuit in a power receiving device according to an embodiment. [Figure 10] FIG. 10 is a circuit diagram showing an example of a rectenna array unit and a bypass diode-connected circuit in a power receiving device according to an embodiment. [Figure 11] FIG. 11 is a block diagram showing an example of the configuration of a photovoltaic power generation system according to an embodiment. [Figure 12] FIG. 12 is a circuit diagram showing an example of a power supply circuit group and a bypass diode-connected circuit in a photovoltaic power generation device of a photovoltaic power generation system according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A system according to an embodiment described herein is, for example, a power supply system that can avoid damage to a rectifier circuit (DC power supply circuit) connected in parallel in a rectenna array unit of a wireless power transmission (WPT) power receiving device when the input to the rectifier circuit (DC power supply circuit) is attenuated. Note that, in the following embodiment, a case will be described in which the DC power supply circuit in the power supply system is a rectifier circuit in a rectenna array unit of a wireless power transmission (WPT) power receiving device, but the DC power supply circuit in the power supply system may be another type of DC power supply circuit, such as a power supply circuit connected to a photocell (photoelectric conversion element) such as a solar cell in a photovoltaic power generation system such as a solar power generation system.

[0018] FIG. 1 is a block diagram showing an example of a configuration of a power supply system 10 according to an embodiment. The power supply system 10 of this embodiment includes a power receiving device (hereinafter also referred to as a "WPT power receiving device") 22 which is a direct current power output device for wireless power transmission (WPT). The power supply system 10 may include a direct current control circuit between the WPT power receiving device 22 and a plurality of power supply targets 90(1) to 90(m). The direct current control circuit may be a circuit having at least one circuit of, for example, an MPPT (maximum power point tracking) control circuit, a DC-DC conversion circuit, and a rectifier circuit. The DC-DC conversion circuit is, for example, a step-down converter, a step-up converter, or a step-up / step-down converter.

[0019] The WPT power receiving device 22 has a rectenna array section 220 having a plurality of rectennas, a bypass diode connection circuit 230 as a protection circuit, and a DC connection circuit 223. The rectenna array section 220 outputs n sets (e.g., 16 sets) of DC power to n sets (e.g., 16 sets) of positive connection lines 231 and negative connection lines 232. The n sets of positive connection lines 231 and negative connection lines 232 (2×n connection lines) are connected to the DC connection circuit 223 via the bypass diode connection circuit 230.

[0020] Bypass diode connection circuit 230 is a protection circuit that prevents damage to the rectifier circuits of rectenna array section 220. As described below, bypass diode connection circuit 230 has bypass diodes as multiple protection elements that can be selectively connected between the positive output section and the negative output section of the rectifier circuits for all or some of the multiple rectifier circuits of rectenna array section 220. Note that bypass diode connection circuit 230 may be a protection circuit that has protection elements other than bypass diodes.

[0021] 1 may include a control unit 240 that controls the connection of the bypass diodes connected between the positive output unit and the negative output unit of each of the multiple rectifier circuits in the bypass diode connection circuit 230. The control unit 240 controls the connection of the bypass diodes in the bypass diode connection circuit 230 based on, for example, connection information between the multiple input units 224, 225 and one or more output units 226, 227 in the DC connection circuit 223.

[0022] The DC connection circuit 223 has, for example, multiple pairs (m pairs) of positive input sections 224 and negative input sections 225 to which multiple DC powers from the rectenna array section 220 are input via the bypass diode connection circuit 230, and multiple pairs of positive output sections 226 and negative output sections 227 that output DC powers to multiple (m pieces) power supply targets 90(1) to 90(m).

[0023] The DC connection circuit 223 may be a passive circuit or an active circuit. The number of pairs of the positive output part 226 and the negative output part 227 of the DC connection circuit 223 may be one pair. The DC connection circuit 223 may be a switching circuit that can switch the connection state between multiple pairs (n pairs) of the positive input part 224 and the negative input part 225 and multiple pairs (m pairs) of the positive output part 226 and the negative output part 227, for example.

[0024] The m sets of positive output parts 226 and negative output parts 227 of the DC connection circuit 223 output m sets of DC power to the m sets of positive connection lines 233 and negative connection lines 234. The m sets of positive connection lines 233 and negative connection lines 234 (2×m connection lines) are respectively connected to the power supply targets 90(1) to 90(m).

[0025] The power supply targets 90(1) to 90(m) are not limited to specific devices. For example, the power supply targets 90(1) to 90(m) are terminal devices (e.g., user devices, IoT devices, etc.) that have a communication function of a mobile communication system, and IoT devices such as sensors that do not have a communication function of a mobile communication system.

[0026] 2 is an explanatory diagram showing an example of a schematic configuration of a wireless power transmission system 800 including a WPT power receiving device 22 connected to a power supply system 10 according to an embodiment. The wireless power transmission system 800 includes a power transmitting device 80 that transmits radio waves of a power transmission signal, and a WPT power receiving device (DC power source) 22 that receives the radio waves transmitted from the power transmitting device 80 and outputs DC power. The radio waves for wireless power transmission are, for example, microwaves or millimeter waves.

[0027] The power transmitting device 80 has an antenna device 81 consisting of an array antenna in which a plurality of antenna elements (hereinafter also referred to as "antennas") are arranged two-dimensionally. The array antenna of the power transmitting device 80 may be an array in which a plurality of antennas are arranged one-dimensionally or three-dimensionally.

[0028] The WPT power receiving device 22 has an antenna device 221 consisting of an array antenna in which a plurality of antennas 221a are arranged two-dimensionally. The array antenna of the WPT power receiving device 22 may be an array in which a plurality of antennas 221a are arranged one-dimensionally or three-dimensionally. The WPT power receiving device 22 also has a rectifier circuit group 222 consisting of a plurality of rectifier circuits (DC power sources) provided to correspond to the plurality of antennas 221a of the antenna device 221. A combination of one set of antenna 221a and rectifier circuit is also called a rectenna. The above-mentioned rectenna array section 220 includes the antenna device 221, the plurality of antennas 221a, and the rectifier circuit group 222.

[0029] Fig. 3 is a circuit diagram showing an example of a rectifier circuit 2220 constituting the rectifier circuit group 222 of the WPT power receiving device 22 according to the embodiment. In Fig. 3, each of the multiple rectennas 2210 of the WPT power receiving device 22 has an antenna 221a which is an input power source (high frequency signal source) and a rectifier circuit 2220. The rectifier circuit 2220 has a DC cut capacitor 2221, an input filter 2222, a rectifier diode 2223, an output filter 224, and a capacitor 2225 of output capacitance.

[0030] The power receiving signal output from the antenna 221a is input to the input filter 2222 after the DC component is cut by the DC cut capacitor 2221. The input filter 2222 passes a fundamental component of a predetermined frequency out of the high-frequency power receiving signal. The rectifier diode 2223 half-wave rectifies the high-frequency power receiving signal (fundamental component) that has passed through the input filter 2222, and outputs a positive voltage pulsating current to the output filter 2224. The output filter 2224 is, for example, an LC low-pass filter, and passes a DC component out of the pulsating current rectified by the rectifier diode 2223. The output capacitance capacitor 2225 reduces the pulsation (ripple) of the output voltage that has passed through the output filter 2224, and smoothes the output voltage. The DC power rectified by the rectifier circuit 2220 is output from a positive terminal 2226 and a negative terminal 2227.

[0031] The DC connection circuit 223 in the WPT power receiving device 22 of this embodiment has a parallel connection section in which the rectifier circuits 2220(1) and 2220(2) of the multiple rectennas 2210(1) and 2210(2) are connected in parallel, as shown in FIG. 4. In the multiple rectifier circuits 2220(1) and 2220(2) connected in parallel in this manner, the output voltages of the rectifier circuits 2220(1) and 2220(2) are equal to each other during normal operation, and the other rectifier circuits appear as loads to the rectifier circuits 2220(1) and 2220(2). Here, if the output voltage of some of the multiple rectifier circuits 2220(1) and 2220(2) becomes too large, the output voltage of the rectifier circuit of the rectifier circuit of the multiple rectifier circuits 2220(1) and 2220(2) may exceed the breakdown voltage of the rectifier diode of the other rectifier circuits connected in parallel and be applied to the other rectifier circuits, which may damage the rectifier diode.

[0032] Furthermore, in the DC connection circuit 223 of the WPT power receiving device 22 of this embodiment, when aiming to improve the efficiency of power output of wireless power transmission by a flexible connection method of the multiple rectifier circuits 2220, an asymmetric connection of the multiple rectifier circuits 2220 may be used as exemplified in Fig. 5. In the example of Fig. 5, three rectifier circuits 2220(1)-2220(3) are connected in series to configure a series rectifier circuit, and the series rectifier circuits 2220(1)-2220(3) are connected in parallel to a single rectifier circuit 2220(4) to configure an asymmetric connection section of the rectifier circuit. In this asymmetric connection of rectifier circuits, for example, if the input power situation (wireless power reception situation) of the antenna device 221 of the WPT power receiving device 22 changes and the input power to the single rectifier circuit 2220(4) on the right side of the figure attenuates, the output voltage of the series rectifier circuits 2220(1)-2220(3) on the left side of the figure will be applied to the single rectifier circuit 2220(4), which may result in damage to the rectifier diode of the rectifier circuit 2220(4).

[0033] 6 and 7 are explanatory diagrams showing an example of the input power distribution of the rectifier circuit group 222 of the WPT power receiving device 22. In FIG. 6 and FIG. 7, the rectifier circuit group 222 has a total of 16 rectifier circuits 2220(1,1)-2220(4,4) arranged four by four in the horizontal and vertical directions. The rectifier circuit group 222 has a configuration in which four sets of series-connected rectifier circuit units 2220(1,1)-2220(4,1), 2220(1,2)-2220(4,2), 2220(1,3)-2220(4,3), and 2220(1,4)-2220(4,4) are fixed to a parallel connection, and output a single DC power as a whole. The density of the illustrated portion of the rectifier circuits 2220(1,1)-2220(4,4) in FIG. 6 and FIG. 7 represents the magnitude of the input power from the corresponding antenna. In the example of Fig. 6, the rectifier circuits in the center have a larger input power, and the rectifier circuits in the peripheral areas have a smaller input power. Also, in the example of Fig. 7, the rectifier circuits in the upper right corner have a larger input power, and the rectifier circuits in the lower left corner have a smaller input power. In this way, if the input power to each of the multiple rectifier circuits 2220(1,1)-2220(4,4) changes depending on the power transmission status or power reception status, the rectifier circuits with reduced input power may be damaged.

[0034] Therefore, in this embodiment, a bypass diode is inserted between the positive output portion and the negative output portion of a rectifier circuit whose input power has been reduced in an asymmetric connection portion, etc. of the rectifier circuit group 222, thereby preventing damage to the rectifier circuit whose input power has been reduced.

[0035] FIG. 8 is an explanatory diagram showing an example of damage prevention of the rectifier circuit 2220 using a bypass diode in the WPT power receiving device 22 according to the embodiment. FIG. 8 shows an example of the asymmetric connection of the rectifier circuit shown in FIG. 5 described above. In FIG. 8, the bypass diode 23 is inserted between the positive output part (positive output terminal) and the negative output part (negative output terminal) of the rectifier circuit 2220(4) in which the input power on the right side of the drawing has decreased. 0 More specifically, a bypass diode 23 is inserted in the positive output section (positive output terminal) of the rectifier circuit 2220(4). 03 is connected to the anode of the bypass diode 23 and the negative output part (negative output terminal) of the rectifier circuit 2220(4). 0 Connect the cathode of 3.

[0036] In addition, when the rectifier circuit 2220(4) to be bypassed has a rectifier diode 2223 (see FIG. 3), the bypass diode 23 0 3 is a threshold voltage V that is smaller than the breakdown voltage of the rectifier diode 2223 of the rectifier circuit 2220(4) to be bypassed. T It is preferable to have

[0037] The above-mentioned predetermined threshold voltage V T Bypass diode with 23 0 According to 3, when the input power to the rectifier circuit 2220(4) is attenuated and the DC power output from the series rectifier circuits 2220(1) to 2220(3) on the left side of the figure is applied to the rectifier circuit 2220(4), the current of the applied DC power can be bypassed (diverted) so as not to flow through the rectifier diode 2223 of the rectifier circuit 2220(4), thereby preventing damage to the rectifier diode of the rectifier circuit 2220(4).

[0038] Fig. 9 is an explanatory diagram showing an example of the bypass diode connection circuit 230 in the WPT power receiving device 22 according to the embodiment. In Fig. 9, one or more bypass diodes built into the bypass diode connection circuit 230 are respectively connected between the positive output terminal and the negative output terminal of the rectifier circuit 2220 to be bypassed. For example, appropriate terminals, that is, the positive output terminal and the negative output terminal of the rectifier circuit 2220 to be bypassed are selected according to the DC connection status in the downstream DC connection circuit 223, and the bypass diodes are connected in parallel to the positive connection line 231 and the negative connection line 232 corresponding to the selected positive output terminal and the negative output terminal.

[0039] In FIG. 9, when the number of rectifier circuits built in the rectifier circuit group 222 is n, and the number of each of the positive connection line 231 and the negative connection line 232 connected to the rectifier circuit group 222 is n, the number of multiple bypass diodes used for connection in the bypass diode connection circuit 230 is a maximum of n. The number of bypass diodes built in the bypass diode connection circuit 230 is not particularly limited, and may be, for example, greater than the number of bypass diodes used for connection. In addition, all or some of the multiple bypass diodes built in the bypass diode connection circuit 230 may have different threshold voltages. For example, multiple bypass diodes with different bypass voltages (threshold voltages) may be built in the bypass diode connection circuit 230, and an appropriate diode may be selected depending on the connection situation. In this case, for the convenience of increasing the number of selectable bypass diodes, the number of bypass diodes built in the bypass diode connection circuit 230 may be greater than n.

[0040] 9, the control unit 240 may control the connection of the bypass diode connected between the positive output portion and the negative output portion of each of the multiple rectifier circuits. The control unit 240 may control the connection of the bypass diode in the bypass diode connection circuit 230 based on connection information between the multiple input portions 224, 225 and one or more output portions 226, 227 in the DC connection circuit 223, for example.

[0041] FIG. 10 is a circuit diagram showing an example of the rectenna array section 220 and the bypass diode connection circuit 230 in the WPT power receiving device 22 according to the embodiment. FIG. 10 shows an example in which the number of the rectifier circuits 2220(1) to 2220(4) built into the rectenna array section 220 is four, but the number of the rectifier circuits 2220 may be two or three, or may be five or more. FIG. 10 also shows an example in which the number of the bypass diodes 23 built into the bypass diode connection circuit 230 is four. 0 3(1),23 0Although the number of bypass diodes in 3(2) is two, the number of bypass diodes may be one, three or four.

[0042] In FIG. 10, the bypass diode 23 0 3(1),23 0 A switch 23 is connected between the anode of the first rectifier 2220(1) to the positive connection line 231 of the plurality of rectifier circuits 2220(1) to 2220(4). 0 4(1), 23 0 4(2). Also, a bypass diode 23 0 3(1),23 0 A switch 23 is connected between the cathode of the first rectifier 2220(1) to the negative connection line 232 of the plurality of rectifier circuits 2220(1) to 2220(4). 0 5(1), 23 0 Article 5(2) is provided.

[0043] 1st set of switches 23 0 4(1) and switch 23 0 5(1) are linked together to form a first bypass diode 23 0 3(1) is turned off (disconnected), or the first bypass diode 23 0 The second set of switches 23 can be used to switch the connection destinations (positive connection line 231 and negative connection line 232) of the second set of switches 23. 0 4(2) and switch 23 0 5(2) are connected together to form a second bypass diode 23 0 3(2) is turned off (disconnected), or the second bypass diode 23 0 The connection destination of 3(2) (the positive connection line 231 and the negative connection line 232) can be switched.

[0044] Switch 23 0 4(1), Switch 23 0 5(1), Switch 23 0 4(2) and switch 23 0 5(2) Bypass diode 23 0 3(1),23 03(2) The switching of the insertion (connection) of each of the positive connection line 231 and the negative connection line 232 can be controlled by the control unit 240 described above.

[0045] Although the above describes a case where the DC power output device is the power receiving device 22 of a wireless power transmission system and the multiple DC power supply circuits are each the rectifier circuit 2220, the DC power output device and the multiple DC power supply circuits are not limited to the configurations exemplified above. For example, the DC power output device may be a photovoltaic device of a photovoltaic power generation system, and the multiple DC power supply circuits may be multiple power supply circuits each connected to a photovoltaic cell (photoelectric conversion element) such as a solar cell.

[0046] Fig. 11 is a block diagram showing an example of the configuration of a photovoltaic power generation system 50 according to an embodiment. The photovoltaic power generation system 50 of this embodiment is, for example, a solar power generation system, and includes a photovoltaic power generation device 52 that is a photovoltaic DC power output device that receives light such as sunlight and generates power. The photovoltaic power generation system 50 may include a DC control circuit between the photovoltaic power generation device 52 and a plurality of power supply targets 90(1) to 90(m). The DC control circuit may be, for example, a circuit having at least one circuit of an MPPT (maximum power point tracking) control circuit, a DC-DC conversion circuit, and a rectifier circuit. The DC-DC conversion circuit is, for example, a step-down converter, a step-up converter, or a step-up / step-down converter.

[0047] The photovoltaic power generation device 52 has a photovoltaic cell output section 520 having a plurality of power supply devices each connected to a photoelectron (photoelectric conversion element) such as a solar cell, a bypass diode connection circuit 530, and a DC connection circuit 523. The photovoltaic cell output section 520 outputs n sets (e.g., 16 sets) of DC power to n sets (e.g., 16 sets) of positive connection lines 531 and negative connection lines 532. The n sets of positive connection lines 531 and negative connection lines 532 (2×n connection lines) are connected to the DC connection circuit 523 via the bypass diode connection circuit 530.

[0048] The bypass diode connection circuit 530 is a protection circuit that prevents damage to the power supply circuit of the photovoltaic cell output section 520. As described later, the bypass diode connection circuit 530 has a plurality of bypass diodes that can be selectively connected between the positive output section and the negative output section of the power supply circuit for all or part of the plurality of power supply circuits of the photovoltaic cell output section 520.

[0049] 11 may include a control unit 540 that controls the connection of the bypass diodes connected between the positive output unit and the negative output unit of each of the multiple power supply circuits in the bypass diode connection circuit 530. The control unit 540 controls the connection of the bypass diodes in the bypass diode connection circuit 530 based on connection information between the multiple input units 524, 525 and one or more output units 526, 527 in the DC connection circuit 523, for example.

[0050] The DC connection circuit 523 is connected to the bypass diode connection circuit 530 via, for example, Photocell Output The power supply unit 520 has multiple sets (m sets) of positive input units 524 and negative input units 525 to which multiple DC powers are input from the power supply unit 520, and multiple sets of positive output units 526 and negative output units 527 that output DC power to multiple (m sets) of power supply targets 90(1) to 90(m).

[0051] The DC connection circuit 523 may be a passive circuit or an active circuit. The number of pairs of the positive output part 526 and the negative output part 527 of the DC connection circuit 523 may be one pair. The DC connection circuit 523 may be a switching circuit that can switch the connection state between multiple pairs (n pairs) of the positive input part 524 and the negative input part 525 and multiple pairs (m pairs) of the positive output part 526 and the negative output part 527, for example.

[0052] The m sets of positive output parts 526 and negative output parts 527 of the DC connection circuit 523 output m sets of DC power to the m sets of positive connection lines 533 and negative connection lines 534. The m sets of positive connection lines 533 and negative connection lines 534 (2×m connection lines) are respectively connected to the power supply targets 90(1) to 90(m).

[0053] 11, the power supply targets 90(1)-90(m) are not limited to specific devices. For example, the power supply targets 90(1)-90(m) are terminal devices (e.g., user devices, IoT devices, etc.) having a communication function of a mobile communication system, and IoT devices such as sensors not having a communication function of a mobile communication system.

[0054] FIG. 12 is a circuit diagram showing an example of a power supply circuit group 500 and a bypass diode-connected circuit 530 in a photovoltaic device 52 of a photovoltaic system 50 according to an embodiment. In FIG. 12, the power supply circuit group 500 has a plurality of power supply circuits 5220(1)-5220(4) to which photovoltaic cells (photoelectric conversion elements) such as solar cells are respectively connected. Note that FIG. 12 shows an example in which the number of the power supply circuits 5220(1)-5220(4) built into the power supply circuit group 500 is four, but the number of the power supply circuits 5220 may be two or three, or may be five or more. Also, FIG. 12 shows an example in which the number of the bypass diodes 53 built into the bypass diode-connected circuit 530 is four. 0 3(1),53 0 Although the number of bypass diodes in 3(2) is two, the number of bypass diodes may be one, three or four.

[0055] In FIG. 12, bypass diode 53 0 3(1),53 0 A switch 53 is connected between the anode of the power supply circuit 5220(1) to the positive connection line 531 of the power supply circuit 5220(4). 0 4(1), 53 0 4(2). Also, a bypass diode 53 0 3(1),53 0A switch 53 is connected between the cathode of the first rectifier 5220(1) to the negative connection line 532 of the plurality of rectifier circuits 5220(1) to 5220(4). 0 5(1), 53 0 Article 5(2) is provided.

[0056] First set of switches 53 0 4(1) and switch 53 0 5(1) are linked together to form a first bypass diode 53 0 3(1) is turned off (disconnected), or the first bypass diode 53 0 The second set of switches 53 can be used to switch the connection destinations (positive connection line 231 and negative connection line 232) of the second set of switches 53. 0 4(2) and switch 53 0 5(2) are connected together to form a second bypass diode 53 0 3(2) is turned off (disconnected), or the second bypass diode 53 0 The connection destination of 3(2) (positive connection line 531 and negative connection line 532) can be switched.

[0057] Switch 53 0 4(1), Switch 53 0 5(1), Switch 53 0 4(2) and switch 53 0 Bypass diode by 5(2)53 0 3(1),53 0 3(2) The switching of the insertion (connection) of each of the positive connection line 531 and the negative connection line 532 can be controlled by the control unit 240 described above.

[0058] As described above, according to this embodiment, in a DC power output device (WPT power receiving device, photovoltaic power generation device) having multiple DC power supply circuits (rectifier circuits, power supply circuits), damage to the DC power supply circuits can be avoided when the input to the parallel-connected DC power supply circuits (rectifier circuits, power supply circuits) is attenuated.

[0059] Moreover, according to this embodiment, the protection circuit (bypass diode connection circuit) 230 incorporates a smaller number of protection elements (bypass diodes) than the number of the multiple DC power supply circuits (rectifier circuits, power supply circuits), and switches the protection elements connected to the DC power supply circuits (rectifier circuits, power supply circuits) depending on the state of the DC power supply circuits (rectifier circuits, power supply circuits). This makes it possible to reduce the number of protection elements (bypass diodes) compared to the case where protection elements are individually connected to all of the multiple DC power supply circuits (rectifier circuits, power supply circuits), while avoiding damage to the DC power supply circuits and achieving optimal connection of the DC power supply circuits (rectifier circuits, power supply circuits), thereby improving the efficiency of the DC power output device.

[0060] In addition, the present invention can provide a wireless power transmission system and a photovoltaic power generation system that can avoid damage to a DC power supply circuit when the input to the DC power supply circuit (rectifier circuit, power supply circuit) is attenuated, thereby contributing to the achievement of Goal 9 of the Sustainable Development Goals (SDGs), which is to "build resilient infrastructure, promote industry, innovation and infrastructure."

[0061] It should be noted that the process steps and system components described herein may be implemented by various means. For example, these steps and components may be implemented in hardware, firmware, software, or a combination thereof.

[0062] Regarding hardware implementation, means such as processing units used to realize the above steps and components in an entity (e.g., a power receiving device, a power transmitting device, a photovoltaic device, a rectifier circuit, a rectenna, a converter switching unit (switch), a DC-DC converter, various wireless communication devices, a base station device (Node B, Node G), a terminal device, a hard disk drive device, or an optical disk drive device) may be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described in this specification, computers, or combinations thereof.

[0063] Also, for firmware and / or software implementation, the means such as processing units used to realize the above components may be implemented with programs (e.g., codes such as procedures, functions, modules, instructions, etc.) that execute the functions described herein. In general, any computer / processor readable medium tangibly embodying firmware and / or software codes may be used to implement the means such as processing units used to realize the above steps and components described herein. For example, the firmware and / or software codes may be stored in a memory and executed by a computer or processor, for example in a controller. The memory may be implemented within the computer or processor, or may be implemented externally to the processor. Also, the firmware and / or software codes may be stored in a computer or processor readable medium, such as a random access memory (RAM), a read-only memory (ROM), a non-volatile random access memory (NVRAM), a programmable read-only memory (PROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a floppy disk, a compact disk (CD), a digital versatile disk (DVD), a magnetic or optical data storage device, etc. The code may be executed by one or more computers or processors and may cause the computers or processors to perform certain aspects of the functionality described herein.

[0064] The medium may be a non-transitory recording medium. The code of the program may be in any format as long as it can be read and executed by a computer, a processor, or another device or machine, and the format is not limited to a specific format. For example, the code of the program may be any of source code, object code, and binary code, or may be a mixture of two or more of these codes.

[0065] Moreover, the description of the embodiments disclosed herein is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. [Explanation of symbols]

[0066] 10: Power supply system 22: WPT power receiving device 50: Photovoltaic power generation system 52: Photovoltaic device 80: Power transmission equipment 81: Antenna device 90: Power supply target 220: Rectenna Array Section 221: Antenna equipment 221a: Antenna 222: Rectifier circuit group 223: DC connection circuit (switching circuit) 224: Plus input section 225: Minus input section 226: Positive output section 227: Negative output section 230: Protection circuit (bypass diode connection circuit) twenty three 0 3: Protective element (bypass diode) twenty three 0 4: Switch twenty three 0 5: Switch 240: Control section 351: Switch 451(1)~451(n): Input section 452(1)~452(n): Output section 500: Power supply circuit group 520: Photocell output section 523: DC connection circuit 530: Bypass diode connection circuit 53 0 3: Bypass diode 53 0 4: Switch 53 0 5: Switch 540: Control section 800: Wireless power transmission system 2210: Rectenna 2220: Rectifier circuit 2223: Rectifier diode 5220: Power supply circuit

Claims

1. A DC power output device, comprising: an asymmetric parallel connection unit in which a first power supply circuit in which a plurality of DC power supply circuits are connected in series and a second power supply circuit in which a single DC power supply circuit is connected in parallel; a protection circuit connected between the positive output section and the negative output section of the asymmetric parallel connection section; a connection circuit having a plurality of input units to which the plurality of DC powers output from the protection circuit are input and an output unit to output one or more DC powers to be supplied to one or more power supply targets, the DC power supply circuit includes a rectifier diode having a cathode connected to a positive side of the DC power supply circuit and an anode connected to a negative side of the DC power supply circuit, the protection circuit includes a bypass diode having an anode connected to the positive output terminal of the asymmetric parallel connection section and a cathode connected to the negative output terminal of the asymmetric parallel connection section, a threshold voltage of the bypass diode is lower than a breakdown voltage of a rectifier diode of the single DC power supply circuit constituting the second power supply circuit in the asymmetric parallel connection portion; 1. A DC power output device comprising:

2. A DC power output device, comprising: A plurality of DC power supply circuits; a protection circuit having a plurality of protection elements selectively connectable between a positive output portion and a negative output portion of each of the plurality of DC power supply circuits for each of the plurality of DC power supply circuits, and outputting a plurality of DC powers; a connection circuit including a plurality of sets of positive input units and negative input units to which the plurality of DC powers output from the protection circuit are input, and a plurality of sets of positive output units and negative output units to which the plurality of DC powers to be supplied to a plurality of power supply targets are output, the connection circuit being configured with a switching circuit capable of switching a connection state between the plurality of sets of positive input units and negative input units and the plurality of sets of positive output units and negative output units; a plurality of multi-contact switches for switching connections between the protection elements and positive output portions and negative output portions of the plurality of DC power supply circuits in conjunction with each other; a control unit that controls a multi-contact switch of the plurality of circuits so as to switch in conjunction with each other connections of the protection elements connected between the positive output section and the negative output section of the plurality of DC power supply circuits; A DC power output device comprising:

3. 3. The DC power output device according to claim 2, The protection element is a bypass diode.

1. A DC power output device comprising:

4. 4. The DC power output device according to claim 3, each of the plurality of DC power supply circuits has a rectifier diode connected between the positive output section and the negative output section; a threshold voltage of the bypass diode is lower than a breakdown voltage of a rectifier diode of the DC power supply circuit; 1. A DC power output device comprising:

5. 5. The DC power output device according to claim 1, the DC power output device is a power receiving device of a wireless power transmission system, A DC power output device, characterized in that the plurality of DC power supply circuits are a plurality of rectifier circuits connected to a plurality of antennas constituting a receiving antenna device of a wireless power transmission system.

6. The power receiving device according to claim 5 ; a power transmitting device that transmits a power transmission signal to the power receiving device; A wireless power transmission system comprising:

7. 5. The DC power output device according to claim 1, the DC power output device is a photovoltaic power generation device of a photovoltaic power generation system, 13. A DC power output device, wherein the plurality of DC power supply circuits are a plurality of power supply circuits each connected to a photovoltaic cell.

8. A photovoltaic power generation system comprising the photovoltaic power generation device of claim 7.

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