JP2015198508A - Photovoltaic power generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photovoltaic power generation device which suppresses a power loss, improves workability, secures safety in system cooperation and further attains improvement in maintainability.SOLUTION: In the photovoltaic power generation device, a plurality of AC modules 51 outputting AC power and AC set cables 52 connecting the AC modules 51 in parallel with each other are installed on the roof. An AC pull box 53 is installed on the roof or in the vicinity thereof, and the plurality of AC set cables 52 are connected to the AC pull box 53. An AC collector box 55 is installed for collecting AC power into a house, and a connection from the AC pull box 53 to the AC collector box 55 is performed by an AC cable 54. The AC modules 51 are fixed onto the roof by a fixing rail 43 mounted in a water stream direction on the roof. On the fixing rail 43, a duct part 42 is provided in which the AC set cables 52 can be accommodated.

Description

  Embodiments described herein relate generally to a solar power generation apparatus using an AC module with AC output.

  In recent years, many photovoltaic power generation apparatuses have been installed as distributed power sources connected to an electric power system. A solar power generation device installed in a house includes a plurality of solar cells to form a solar battery module, and the plurality of solar battery modules are connected in series and in parallel to be fixed on a roof of a house. Each solar cell module outputs DC power and combines the DC power output by the plurality of solar cell modules.

  A series circuit in the solar cells constituting the solar cell module is called a substring, and a combination of a plurality of solar cell modules in series is called a string. A backflow prevention diode is connected in series between the strings, and a plurality of strings are connected in parallel in a connection box.

  A power conditioner for grid connection is connected to the connection box via two plus and minus output cables. The power conditioner receives the DC power of the solar cell module, converts the DC power to AC power by turning on / off the transistor switching element, and connects the AC power to the power system.

  By the way, in the solar power generation device, when the shadow of the obstacle is applied to the solar cell module, the solar cell module that is shaded does not generate power and the output voltage of the string is lowered. As described above, since the string is connected to the backflow prevention diode, the voltage of the shaded string loses to the voltage of the unshadowed string, and the generated power is transferred to the power conditioner in the shaded string. Cannot be output.

  Further, when the substring of each solar cell module is shaded, current from other substrings is forced to flow from the negative electrode of the solar cell toward the positive electrode. Therefore, the internal resistance increases in the shaded substrings, and when the current continues to flow, the solar cells included in these substrings generate heat. As a result, there is a possibility that the resin material around the solar battery cell is deteriorated and a failure occurs in the solar battery module.

  In order to correct such inconvenience, a solar power generation apparatus that employs an AC module that outputs AC power instead of DC power and has a bypass circuit in a substring has been proposed (for example, Patent Document 1). . The AC module is a module in which a micro inverter is fixed to the back side or the vicinity of the solar cell module.

  The micro inverter is a small inverter having a capacity of about 200 W corresponding to the power generation output of one solar cell module, and has a circuit for adjusting a DC voltage and a circuit for converting DC to AC. The circuit configuration of such a micro inverter is the same as that of a power conditioner of about 3 kW or more.

  Here, the AC module will be described with reference to FIGS. FIG. 18 is a configuration diagram of an AC module. The AC module 10 shown in FIG. 18 includes a plurality of solar cells 2 and a solar cell module bus bar 3 that connects the solar cells 2 in series. In the solar cell module 1, a terminal box 5 is fixed on the back side, and a micro inverter is incorporated in the terminal box 5. The terminal box 5 houses the bypass diode 4 and is electrically and mechanically connected to the solar cell output cable 6 and fixed to the back side of the solar cell module 1. A solar cell output cable terminal 7 is provided at the end of the solar cell output cable 6.

  FIG. 19 is a circuit diagram in the terminal box 5. As shown in FIG. 19, the series circuit of the solar cells 2 is divided into three equal parts, and three substrings are provided. Each substring is connected to the input terminal 8 through the solar cell module bus bar 3, and connects the bypass diode 4 and the output terminal 9. When any one of the three substrings or two substrings do not output voltage due to the influence of the shadow, there is a bypass diode 4 connected to a position that bypasses the substring that does not output voltage. Conduct.

  In this way, the bypass diode 4 bypasses the substring that no longer outputs voltage, so that one substring does not output voltage due to the influence of the shadow, and the DC output voltage of the entire solar cell 2 decreases to two thirds. Alternatively, even if the two substrings do not output voltage due to the influence of the shadow and the DC output voltage of the entire solar battery cell 2 drops to one third, the AC module 10 can output AC power. In addition, since the electric current does not flow from the other substrings to the shaded substring by the function of the bypass diode 4, the solar cell 2 included in the shaded substring does not generate heat, and the resin There is no fear that the AC module 10 will fail due to material deterioration.

JP 2006-41440 A

  In general, AC modules are connected to each other in parallel with cables and fixed on the roof. The installation position of the AC module on the roof depends on the direction and size of the roof. Different. Therefore, it is necessary to select and arrange the number of cables and the length according to the installation position of the AC module. In particular, the length of the cable often varies greatly depending on the roof.

  Therefore, it is realistic to select a cable to be actually wired from standard products having a predetermined length. However, when selecting a cable to be actually used from standard products, it does not make sense as a cable if the length is insufficient, so there is no choice but to select a longer cable and there will be an extra cable length. I don't get it.

  For this reason, there arises a problem that wasteful power loss occurs as much as the extra length of the cable occurs. Moreover, since the extra length of the cable is generated, a space for placing the extra length must be secured. Therefore, when the installation work of the AC module is performed, the extra cable length becomes an obstacle, and there is a problem that the installation work of the AC module becomes difficult.

  Furthermore, when the AC module is fixed to the roof, the fixing rail is not directly opened in the AC module itself, but the fixing rail is directly above the roof path plate and roofing material along the direction of the water flow of the roof. The AC module is attached to the fixed rail. Therefore, when wiring the cable pulled out from the AC module, even if you try to pass the cable horizontally across the fixed rail at an arbitrary position, there is a fixed rail. I can't. As a result, the degree of freedom of the cable wiring configuration is reduced, and from this point of view, improvement in the workability of the AC module installation work is required.

  The AC output AC module can be installed in units of one sheet, and can be easily expanded because the installation location is not selected. Therefore, if the installation work of the AC module becomes troublesome, these advantages cannot be utilized. Therefore, conventionally, in a solar power generation apparatus using an AC module, it is an urgent task to improve workability.

  Furthermore, now that attention is focused on distributed power sources, the needs for photovoltaic power generation devices are diversifying and the level is also high. Therefore, in the photovoltaic power generation apparatus, it is expected to further improve the grid connection safety and maintenance.

  Embodiments according to the present invention have been proposed to solve the above problems, and in a solar power generation apparatus including an AC module of AC output, power loss is suppressed, workability is improved, and grid interconnection is achieved. It aims at obtaining the photovoltaic power generation device which secured safety | security of this, and also aimed at the improvement of maintainability.

In order to achieve the above object, an embodiment of the present invention relates to a photovoltaic power generation including an AC module that outputs AC power, an AC assembly cable that connects the AC modules in parallel, and an AC current collection box that collects AC power. The apparatus is characterized by having the following components (1) to (4).
(1) A plurality of the AC modules and the AC assembly cables are installed on the roof.
(2) Install an AC pull box on or near the roof.
(3) Connect the plurality of AC cable pairs to the AC pull box.
(4) Connect the AC pull box to the AC current collection box with an AC cable.

The block diagram of the whole structure of 1st Embodiment. The block diagram which shows the connection structure from the AC module in 1st Embodiment to the AC current collection box. The top view of the AC module in 1st Embodiment. The figure which shows the example of the driving | running permission conditions of the AC module in 1st Embodiment. The circuit diagram of the AC module in a 1st embodiment. (A) is sectional drawing of the water flow direction at the time of fixing an AC module to a roof in 1st Embodiment, (B) is a top view at the time of fixing an AC module to a roof in 1st Embodiment. (A) is sectional drawing of the water flow direction at the time of fixing an AC module to a roof in 2nd Embodiment, (B) is a top view at the time of fixing an AC module to a roof in 2nd Embodiment. (A) is sectional drawing of the water flow direction at the time of fixing an AC module to a roof in 3rd Embodiment, (B) is a top view at the time of fixing an AC module to a roof in 3rd Embodiment. The perspective view of the conductor bus bar in other embodiments. The top view of the conductor bus-bar in other embodiment. The circuit diagram of the AC module in other embodiments. The circuit diagram of the AC module in other embodiments. The circuit diagram of the AC module in other embodiments. The circuit diagram of the AC module in other embodiments. The circuit diagram of the AC module in other embodiments. The circuit diagram of the AC module in other embodiments. The circuit diagram of the AC module in other embodiments. The top view of the conventional AC module. The circuit diagram of the conventional AC module.

  Hereinafter, an embodiment of a solar power generation device according to the present invention will be specifically described with reference to the drawings. Each of the following embodiments is a solar power generation device using an AC module. Therefore, the same components as those in the prior art shown in FIGS. 18 and 19 are denoted by the same reference numerals and description thereof is omitted.

[First Embodiment]
The first embodiment will be described with reference to FIGS.
[Constitution]
FIG. 1 is a block diagram showing the overall configuration of the first embodiment, FIG. 2 is a block diagram showing a connection configuration from an AC module to an AC current collection box, and a configuration example for connecting the AC module to a low-voltage distribution line Show.

  As shown in FIG. 1 and FIG. 2, the first embodiment includes a plurality of AC modules 51 (enlarged view within a chain line), a plurality of AC assembled cables 52, an AC pull box 53, and an AC current collection box. 55. The AC module 51 and the AC assembly cable 52 are installed on the roof, and the AC current collection box 55 is installed in the house. A housing distribution board 65 is connected to the AC current collection box 55 and connected to the power system.

(AC module)
The AC module 51 is a single-phase three-wire electric system with a voltage of 100 V / 200 V, and outputs AC power. When each phase of the single-phase three-wire is U, O, and W, and O is a neutral wire, the AC between UO is 100V, the AC is 100V, and the UW is 200V. Further, the AC module 51 individually monitors the failure and transmits the monitoring result to the AC current collection box 55. The configuration of the AC module related to the circuit configuration of the AC module 51 and the connection structure with the AC cable assembly will be described later.

  Further, as shown in FIG. 3, in the vicinity of one corner portion on the surface side of the AC module 51 (near the upper right corner portion in FIG. 3), the length of the AC module 51 is about 15 times longer. One light emitting display 69 having a thickness is attached. The light emitting display 69 emits the light emission color indicating that the AC module 51 is in failure and the light emission color indicating that the AC module 51 is operating in a different color, and The operating state can be discriminated visually.

(AC cable)
The AC assembly cable 52 is a cable for connecting the AC modules 51 in parallel to each other. In order to collect electric power from the AC module 51, the AC cable pair 52 connects Us, Os, and Ws. The AC assembly cable 52 includes a current collecting trunk line having a conductor having a thickness that takes into account the magnitude of the current to flow and the temperature rise due to exhaust heat.

(AC pull box)
The AC pull box 53 is installed on or near the roof. The AC pull box 53 collectively connects a plurality of AC cable sets 52 via connectors 27 and 29, and collects and outputs to a single-phase three-wire, that is, three AC cables 54 of U, O, and W. The AC cable 54 connects the AC pull box 53 to the AC current collection box 55.

(Connection configuration from AC module to AC collector box)
As described above, the AC output of the AC module 51 is collected in the AC pull box 53 via the AC set cable 52, and then finally enters the AC current collection box 55 via the AC cable 54.

  Here, an electrical connection configuration from the AC module 51 to the AC current collection box 55 will be described with reference to FIG. The portions indicated by U, O, and W at the left end of FIG. 2 are connectors 25, respectively, and are connected to the AC cable set 52 from the AC module 51. The connector 25 has three poles U, O, and W, and the O pole is a ground potential.

  As shown in FIG. 2, the AC cable group 52 is divided by a connector 27 and includes two stages of AC cable groups 52 a and 52 b. The AC group cable 52 a collects the AC outputs of the three AC modules 51, and the AC group cable 52 a is connected to the AC group cable 52 b via the connector 27.

  The AC group cable 52 b collects the AC outputs of the nine AC modules 51 and connects them to the AC pull box 53 via the connector 29. A terminal block 31 is disposed in the AC pull box 53 and a terminal block 33 is disposed in the AC current collection box 55, and the terminal blocks 31 and 33 are connected by an AC cable 54. The connectors 25, 27, and 29 are color-coded or have different connector shapes so that each pole of the AC single-phase three-wire is correctly wired.

  That is, in the present embodiment, the AC power output from one AC module 51 becomes the output of nine AC modules 51 at the connector 27, and further becomes the output of 27 AC modules 51 at the connector 29. Finally, an AC pull box 53 having three connectors 29 outputs 81 AC modules 51.

(AC current collector box)
Returning to FIG. 1, the configuration of the AC current collection box 55 will be described. The AC current collection box 55 is provided with an emergency stop button 60 at a position where it can be operated from the outside. The emergency stop button 60 is a button for disconnecting the interconnecting contactor 56 and transmitting an emergency stop command to all the AC modules 51, and the number of installations is arbitrarily set.

  In addition, the AC current collection box 55 accommodates the interconnection contactor 56 and the control device 57. The interconnection contactor 56 functions as an interconnection point switch with the power distribution line system. The interconnection contactor 56 sends the output AC power to the residential distribution board 65 via the AC cable 63 and the distributed power source breaker 64.

(Control device)
The control device 57 is a device that disconnects and turns on an interconnection point switch for system interconnection, and communicates with all AC modules 51 via the AC cable 54 and the AC assembly cable 52. When the communication with the AC module 51 becomes impossible, the control device 57 extracts the internal information of the AC module 51 by another wired or wireless communication system, and sends it to the display operation device 61 described later. , Display the status at that time. Furthermore, the control device 57 excludes the AC module 51 in which communication has failed, and restarts the sound AC module 51.

  The control device 57 includes a calculation control unit 58, and the calculation control unit 58 includes a determination unit 58A and an operation permission unit 58B. As described above, the AC module 51 individually performs failure monitoring and transmits the monitoring result to the control device 57 (described in paragraph 0025), but the determination unit 58A receives the monitoring result from the AC module 51, and the AC module 51 Determine operational health. The driving permission unit 58B gives driving permission to the AC module 51 based on the determination result of the determination unit 58A.

The driving permission unit 58B gives driving permission to the AC module 51 when the determination result of the determination unit 58A is the AND condition of the following (1) to (5) (see FIG. 4).
(1) The total number of AC modules 51 is not abnormal.
(2) The communication of all the AC modules 51 is normal.
(3) The total number of AC modules 51 does not have grid connection protection operation.
(4) There is no stop command from the host server to the control device 57.
(5) All emergency stop buttons 60 are OFF.

  In addition, when the determination unit 58A that has received the result of the failure monitoring of the AC module 51 determines that a failure has occurred in the AC module 51, the operation permission unit 58B does not grant the operation permission to the AC module 51, The operation permission is given to the other AC modules 51 by excluding them. At this time, the control device 57 transmits a stop command to the AC module 51 whose operation is not permitted. The control device 57 has a communication input / output device 59. The communication input / output device 59 is connected to the display operation device 61 via the communication cable 70.

(Display operation device)
The display operation device 61 is connected to the upper Internet 68 via the network connection device 62. The display operation device 61 displays the operation status and failure status of each AC module 51, the position of the failed AC module 51 on the roof, the status of the system, etc., and performs operations such as changing the set value.

As the display screen contents of the display operation device 61, for example,
(1) Grid interconnection protection operation item (2) Grid interconnection protection setting value (3) Generated power (4) Generated power amount (5) Voltage rise suppression operation in progress (6) Voltage rise suppression operation time (7) Operation terminal Communication status of tablet (8) Communication status of upper internet 68 (9) Software version information (10) Emergency stop button 60 issuance (11) Location of failed AC module 51

In addition, as an operation screen content, for example,
(1) Change / confirmation of grid connection protection setting value (2) Change / confirmation of voltage rise suppression setting value (3) Change / confirmation of other setting items.

(Residential distribution board)
Next, the configuration of the residential distribution board 65 will be described. The residential distribution board 65 is provided with a current detector 66, an earth leakage breaker ELB, a load switch CB, two contactors CTT connected in series for safety, and a contracting current limiter SB.

  Among these, the current detector 66 measures the reverse power flow to the power distribution line system, or controls the distributed power source so that the reverse power flow from the distributed power source where the reverse power flow cannot be performed under a contract with the power company does not occur. . The AC power output from the AC module 51 is connected to a load device in the house via the load switch CB of the residential distribution board 65. An electricity meter 67 is connected to the contracting current limiter SB, and the residential distribution board 65 is connected to the power distribution line via the electricity meter 67 and is connected.

(AC module circuit configuration)
Next, the circuit configuration of the AC module 51 will be described with reference to FIG. FIG. 5 is an example of a circuit diagram of a micro inverter fixed to the AC module 51, and is an example in which a DC / AC conversion circuit is configured for each of the three substrings of the solar cell module 1.

  In FIG. 5, the micro inverter includes an input capacitor 11, a reactor 12, a switching element 13, a diode 14, a capacitor 15, a switching element 16, a reactor 17, an input capacitor 18, an obstruction noise elimination filter 19, a surge voltage elimination element 20 and the like. Consists of a control circuit that does not.

  When the switching element 13 is turned ON / OFF at a high speed, the AC module 51 causes the current of the reactor 12 to be intermittently connected, so that a counter electromotive voltage is generated at both ends, and this voltage charges the capacitor 15 via the diode 14. The DC voltage charged in the capacitor 15 is converted into an AC waveform by the switching element 16, harmonics are removed by the reactor 17 and the capacitor 18, and AC power is output through the circuit of the obstacle noise elimination filter 19 and the surge voltage elimination element 20. To do.

(Connection structure between AC module and AC cable)
Next, a connection structure between the AC module and the AC cable assembly will be described with reference to FIG. As shown in FIG. 6, the AC module 51 is integrally attached with a solar cell frame 35 serving as a roof material around the AC module 51.

  The AC module 51 serves as a roofing material and an AC module function, and is a building material type AC module having fire resistance that can be used as a roofing material. A solar cell surface glass 36 is installed on the AC module 51. The solar cell surface glass 36 fixes solar cells (not shown in FIG. 4).

  An inverter box 37 is fixed on the back side of the solar cell surface glass 36. In this inverter box 37, a micro inverter having the circuit configuration shown in FIG. An output cable 38 is connected to the inverter box 37 and a terminal 39 is provided at the end thereof. A current collecting cable 40 is connected to the terminal 39. The current collecting cable 40 extends from the AC assembly cable 52.

  Further, the AC module 51 forms a substantially L-shaped fitting portion 35 b on the side surface portion of the solar cell frame 35. A fixed rail 43 is disposed in the gap between the solar cell frames 35 adjacent to the left and right. The fixed rail 43 is a member for fixing the AC module 51 to the roof base plate 41, and is installed directly above the roof path plate 41 along the direction of water flow of the roof. The fitting portion 35b of the solar cell frame 35 is fitted into the fixed rail 43 from the left and right.

  A duct portion 42 is disposed above the fixed rail 43. The duct part 42 has an opening in the upper part and has a space for accommodating the AC cable assembly 52. Through holes 42 a and 35 a for passing the current collecting cable 40 are formed on the side surfaces of the duct portion 42 and the solar cell frame 35.

  In the first embodiment as described above, the AC assembly cable 52 is accommodated in the duct portion 42, and the current collecting cable 40 extending from the AC assembly cable 52 is connected to the through hole 42 a on the duct portion 42 side and the solar cell frame 35. From the through hole 35a on the side, it passes through the outside of the duct part 42. Then, the AC cables 51 connected to each other in parallel are connected to the terminal 39 by connecting the current collecting cable 40 that has come out of the duct portion 42. Thereafter, the fitting portion 35b of the solar cell frame 35 is fitted into the fixed rail 43, and in this state, the fixed rail 43 is fixed to the roof base plate 41 with the fixing screw 44.

  Further, the duct portion 42 is placed on the upper portion of the fixed rail 43, and the duct portion 42 is fixed to the fixed rail 43 with a fixing screw 45. At this time, the fixing screw 45 passes through the fitting portion 35b and the fixing rail 43 of the solar cell frame 35, thereby fixing the duct portion 42, the solar cell frame 35, and the fixing rail 43 to the roof base plate 41. Finally, a lid 46 is fitted on the upper part of the duct portion 42 as a cover member.

  As described above, in the first embodiment, the AC assembly cable 52 is first accommodated in the duct portion 42, the AC assembly cable 52 is connected to the inverter box 37 via the current collecting cable 40 and the terminal 39, and then The fitting portion 35 b and the duct portion 42 of the solar cell frame 35 are fixed to the base plate 41 together with the fixed rail 43. As a result, the AC module 51 integrally attached to the solar cell frame 35 is fixed to the roof.

[Action]
In the first embodiment having the above configuration, it is possible to perform grid connection operation in which the AC power of the AC module 51 is synchronized with the AC voltage waveform of the power system. In addition, the AC power of the AC module 51 can be operated independently by synchronizing the phases of the output voltages of the AC modules 51 with each other by a signal from an external or internal free-running oscillator.

  In such an AC module 51, the voltage applied to both ends of the three bypass diodes 4 from the series circuit of the solar cells 2 is converted into an AC voltage by an inverter circuit individually connected in parallel by the bypass diode 4. To generate a commercial AC waveform. When this configuration is used, the series circuit of the solar cells 2 in the solar cell module 1 is divided into three substrings, and the DC output power of each substring is converted into AC power and then synthesized. AC output power is obtained from the module 51.

[effect]
(1) Improvement of power generation efficiency According to the first embodiment as described above, maximum power tracking can be performed in units of substrings in the solar cell module 1. Therefore, in the AC module 51, even if the substring is shaded, the DC voltage is hardly lowered to the lower limit value necessary for conversion from DC to AC by performing maximum power tracking in units of substrings. . As a result, the possibility that the inverter circuit that converts direct current to alternating current becomes inoperable is reduced.

  In the AC module 51 described above, even if a large shadow is applied, the influence can be suppressed as much as possible, and the power generation efficiency can be improved. In addition, as described in the next stage, no extra length cable is generated, so that it is possible to avoid the occurrence of power loss, and this also improves the power generation efficiency.

  The merit of the AC module 51 is that it can be connected to a commercial power system independently, and therefore only a sound AC module 51 can be used as a power source when a part of the AC module 51 fails. Therefore, in the present embodiment in which power loss is suppressed as much as possible, even if there is only one AC module that can be operated, it is possible to obtain a sufficient amount of power generation, and the above advantages can be fully extracted.

(2) Improvement of workability In the present embodiment, as shown in FIG. 2, the AC pull box 53 is connected to the AC pull box 53 via the connectors 27 and 29, so that the two-stage AC assembled cables 52 a and 52 b are connected. The closer the AC set cable 52b is to the pull box 53, the larger the energization current, and the cross-sectional size of the cable increases.

  In the present embodiment, the AC pull box 53 for connecting a plurality of AC cable pairs 52 is always installed at or near the roof. Therefore, the connection of the AC cable set 52 is based on the position of the AC pull box 53. The order and the installation position of the AC module 51 can be efficiently planned.

  Therefore, it becomes easy to determine the number of steps and the length of the AC cable group 52 in advance according to the installation position of the AC module 51 on the roof, and the selection and arrangement of the length of the AC cable group 52 are simplified. Therefore, the length and the number of steps of the AC cable assembly 52 accommodated in the duct portion 42 can be determined in advance at the same time as the setting of the fixed rail 43, and no extra cable length is generated. This eliminates the need for a place for the extra length, improves efficiency in terms of economy and space, and improves the workability of the AC module 51 installation work.

  In addition, in the first embodiment, the AC cable assembly 52 is accommodated in the duct portion 42. Therefore, when the AC cable assembly 52 is to be extended in the horizontal direction from the duct portion 42 at an arbitrary position, the AC cable assembly 52 is fixed to the field plate 41. Thus, the fixed rail 43 does not collide with the AC group cable 52, and the AC group cable 52 can be passed in the horizontal direction. Therefore, the degree of freedom of the wiring configuration of the AC assembly cable 52 is remarkably increased, and the workability of the AC module installation work is greatly improved.

(3) Improvement of maintainability In the first embodiment, if the lid 46 is removed, the AC cable 52 housed in the duct portion 42 appears immediately, so that the maintenance work of the AC cable 52 is easy. It is. Furthermore, the duct module 42 and the solar cell frame 35 are removed from the fixed rail 43 by removing the fixing screw 45, and the AC module 51 can be removed from the roof by removing the current collecting cable 40 of the AC assembly cable 52 from the terminal 39. Is possible. At this time, since the fixed rail 43 remains attached to the roof by the fixing screw 44, the work is easy even when the AC module 51 is reattached, and the work efficiency can be improved.

  In the first embodiment, the display operation device 61 connected to the control device 57 displays the failure status of the AC module 51 and the position of the failed AC module 51 on the roof. The worker can actually go up to the roof after preparing sufficient replacement parts and tools for the AC module 51 to be confirmed by removing it from the roof.

  Furthermore, the light emitting display 69 attached to the surface side of the AC module 51 has a light emission color indicating that the AC module 51 is in failure and a light emission color indicating that the AC module 51 is operating soundly. , Emitting light in different colors. Therefore, the worker who has gone up to the roof can easily determine the operating state of the AC module 51 visually only by looking at the light emission color of the light emitting display 69. Therefore, the worker can immediately find the AC module 51 to be confirmed, and can quickly perform the maintenance work.

(5) Improvement of operability Furthermore, since the display operation device 61 can be connected to the upper internet 68, the driving information is sent to the upper server, or the driving and display software is downloaded from the upper server and updated. Is also possible and convenient.

(6) Improvement of safety In the first embodiment, the emergency stop button 60 is provided at a position that can be operated from the outside of the AC current collection box 55. All the AC modules 51 can be stopped immediately at the same time that the contactors 56 are disconnected to achieve grid connection protection. Therefore, even when a fire or the like occurs and the firefighter tries to enter the house from the roof, there is no risk of electric shock to the AC module 51 during the power generation operation, and emergency safety can be ensured.

[Second Embodiment]
[Constitution]
The second embodiment will be described with reference to FIG. The second embodiment has a configuration similar to that of the first embodiment, and is characterized in that a conductor bus bar 71 is used in place of the AC cable assembly 52. The conductor bus bar 71 is a member made of copper or aluminum whose surface is covered with an insulating resin. A current collecting cable 40 is connected to the conductor bus bar 71.

  In addition, in 1st Embodiment shown in FIG. 6, although the fixing screw 45 has penetrated the fixing rail 43 and has shown the state which has reached the roof path board 41, 2nd implementation shown in FIG. In the embodiment, the fixing screw 45 has a configuration in which the duct portion 42 and the solar cell frame 35 are fixed only to the fixed rail 43 without reaching the path plate 41.

[Action and effect]
In the second embodiment as described above, by using the conductor bus bar 71, the wiring connection work can be further simplified as compared with the wiring connection and distribution work between the AC module 51 and the AC assembly cable 52. Sex is further improved.

[Third Embodiment]
[Constitution]
A third embodiment will be described with reference to FIG. The third embodiment is similar to the second embodiment in that the conductor bus bar 71 is used, but is characterized in the arrangement position of the duct portion 42. That is, in the third embodiment, the duct portion 42 is disposed below the fixed rail 43 rather than above. For this reason, the duct part 42 is located in the upper part of the roof base plate 41. FIG. In addition, the point which forms the through-holes 42a and 35a for letting the current collection cable 40 pass in the side surface of the duct part 42 and the solar cell frame 35 is the same as that of 1st Embodiment shown in FIG.

  In the third embodiment, after the pair of conductor bus bars 71 are accommodated in the duct portion 42, the duct portion 42 is disposed on the roof base plate 41, and the current collecting cable 40 extending from the conductor bus bar 71 is connected to the duct portion 42. From the through hole 42a on the 42 side and the through hole 35a on the solar cell frame 35 side, it goes out of the duct portion 42. The AC modules 51 are connected to each other by connecting the current collecting cable 40 taken out of the duct portion 42 to the terminal 39.

  Thereafter, the fixed rail 43 is placed on the duct portion 42, the fitting portion 35b of the solar cell frame 35 is fitted into the fixed rail 43, and the fixed rail 43 is fixed to the roof base plate 41 with the fixing screw 44 in this state. Further, the fixed rail 43 is placed on the upper part of the duct portion 42, and the solar cell frame 35 is fixed to the fixed rail 43 with a fixing screw 45. Finally, the lid 46 is sandwiched and fixed.

[Action and effect]
In the third embodiment described above, the duct portion 42 is disposed below the fixed rail 43 rather than above, and the conductor bus bar 71 is housed therein, so that the fixed rail 43 and the lid 46 are connected to the conductor bus bar 71 with the cover. Thus, there is no possibility that rainwater or the like enters the vicinity of the conductor bus bar 71 in the duct portion 42. Therefore, excellent safety can be obtained.

[Other Embodiments]
In addition, said embodiment is shown as an example in this specification, Comprising: It does not intend limiting the range of invention. In other words, the present invention can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope of the invention and in the scope equivalent to the invention described in the claims and equivalents thereof. Embodiments are included.

(1) In the conductor bus bar 72 shown in FIG. 9, the portion from which a part of the coating is removed is in electrical contact with the current collecting cable 49 via the terminal 48 and fixed with screws.
(2) In the conductor bus bar 73 shown in FIG. 10, the current collecting cable 40 and the terminal 39 are electrically connected to the bus bar-shaped current collecting trunk line 73 a, and the whole is covered with the insulating coating 50.
In these embodiments, the connection structure between the AC module 51 and the conductor bus bars 72 and 73 can be further simplified, and further improvement in workability can be expected.

(3) The number of installed contactors and emergency stop buttons and the installation location can be selected as appropriate. For example, a connected contactor or an emergency stop button may be provided in the AC pull box 53. In addition, a DC contactor can be installed in the AC pull box 53 in order to stop the operation of the AC module 51. Thereby, the worker near the roof can control the AC module 51 from the AC pull box 53, and the working efficiency of the worker is improved.

(4) Although the AC module 51 is a building material type AC module, it may be an AC module made of a member different from the roofing material.
(5) The number of stages of the AC assembly cable 52 or the conductor bus bars 72 and 73 can be changed as appropriate, and the power may be collected in three or more stages.

(6) The AC pull box 53 receives power from a plurality of connectors instead of one, and a plurality of AC cables 52 can be connected.
(7) The fixed rail for fixing the AC module 51 to the roof and the duct portion 42 that accommodates the AC cable assembly 52 or the conductor bus bars 72 and 73 may be integrated, and the arrangement direction thereof is the roof. The direction is not limited to the water flow direction and may be a direction orthogonal to the water flow direction.
(8) The member that closes the opening provided in the upper portion of the duct portion 42 is not limited to the lid, and may be a tape.

(9) Further, other circuit configurations of the AC module 51 include the following.
(9-a)
The circuit of the AC module 51 shown in FIG. 5 described above is a “non-insulated circuit” that boosts the DC voltage and converts it to AC, but does not have insulation between the DC side of the solar cell module 1 and the AC side of the micro inverter output. It is. On the other hand, it is also possible to use an “insulation circuit” that insulates the DC side of the solar cell module 1 from the AC side of the micro inverter output.

  For example, the circuit example of FIG. 11 shows a substring type micro inverter using the high frequency insulation transformer 23. In the AC module 51 having the circuit configuration of FIG. 11, the voltage charged in the capacitor 11 is converted into a high-frequency voltage by the switching element 13, and the high-frequency voltage is boosted via the high-frequency isolation transformer 23. The boosted high-frequency voltage is rectified by the diode 21 and converted to direct current, and the switching element 16 converts it to a commercial alternating current waveform.

  According to such a circuit configuration, the circuit of the solar battery cell 2 in the solar battery module 1 and the AC circuit can be insulated. Therefore, the direct current outflow to the alternating current circuit can be eliminated in principle. Moreover, it is possible to select the turn ratio of the primary winding and the secondary winding of the high-frequency insulation transformer 23. Therefore, the freedom degree of the combination of a micro inverter and the solar cell module 1 can be raised.

(9-b)
A circuit of a substring type micro inverter using a high frequency isolation transformer usually includes a reverse connection diode in a MOSFET transistor. Therefore, the built-in reverse connection diode can be used as the bypass diode 4 of the solar cell module 1 (see the circuit diagram of FIG. 12).

  In other words, by adopting such a circuit configuration, the bypass diode 4 conventionally required for the solar cell module 1 can be replaced by the function of the reverse connection diode of the switching transistor of the substring type micro inverter. When a current flows, the bypass diode 4 generates a current loss determined by a conduction loss of the diode and generates heat, and may be deteriorated after long-term use. Further, the output voltage is lowered due to the voltage drop when the output current of the solar cell module 1 passes through the diode, and as a result, the output power of the solar cell module may be lost.

  On the other hand, according to the embodiment having a circuit configuration in which the conventional bypass diode 4 is eliminated, the circuit can be simplified, degradation and conduction loss can be suppressed, and cost can be reduced.

(9-c)
FIG. 12 shows a configuration of a system that collectively converts the combined current of the three DC voltage booster circuits into AC. In this configuration, a single inverter circuit that converts direct current to alternating current is used in the micro inverter, and a chopper circuit that does not use a high-frequency isolation transformer is used.

  According to such a circuit configuration, the circuit can be further simplified, and further downsizing and cost reduction can be further promoted.

(9-d)
FIG. 13 shows a configuration in which three DC booster circuits are each insulated by a high-frequency transformer and one inverter circuit that performs DC / AC conversion is used.

  According to such a circuit configuration, when it is necessary to insulate the alternating current side and the solar battery cell 2 side due to the characteristics of the solar battery cell 2, the inverter circuit is provided with the high frequency insulation transformer. By using one common device, the circuit can be simplified, and downsizing and cost reduction can be realized.

(9-e)
FIG. 14 shows a configuration in which three DC booster circuits are each insulated by a high-frequency transformer, and a switching element or diode that bypasses the substring is not used. In this circuit configuration, the reverse connection diode built in the MOSFET transistor is used as the bypass diode 4 of the solar cell module 1 as in the circuit configuration shown in FIG.

  Thereby, deterioration and conduction loss can be suppressed, and simplification and cost reduction of the circuit can be realized.

(9-f)
In the circuit configuration shown in FIG. 15, voltages input from three substrings are input to a high-frequency inverter circuit in which the switching elements 13 are combined without the bypass diode 4. And it converts into direct current with the rectifier circuit which combined the diode 21 via the high frequency transformer 23, converts into alternating current with the inverter circuit which combined the switching element 16, and outputs alternating current power.

  In the state where one or more of the substrings of the solar cell module 1 are shaded and the output voltage of the substring cannot be obtained, a reverse voltage is applied to the switching element 13. The reverse voltage is bypassed through a parasitic diode not shown in this figure. The parasitic diode is connected to the switching element 13 in antiparallel, and functions in the same manner as the bypass element in FIG.

  By adopting such a circuit configuration, the bypass diode 4 conventionally required for the solar cell module 1 can be replaced by the function of the reverse connection diode of the switching transistor of the substring type micro inverter. Therefore, the circuit can be simplified and the cost can be reduced by eliminating the conventional bypass diode 4 and suppressing deterioration and conduction loss.

(9-g)
The circuit configuration shown in FIG. 16 is a configuration in which the rectification / inverter circuit including the diode 21 and the switching element 16 in FIG. 15 is combined into one circuit.
(9-h)
FIG. 17 shows a configuration in which the high-frequency transformer 23 is combined into one unit in FIG. Each function is the same as described above.

  By adopting these circuit configurations, the number of parts of the rectification / inverter circuit and the high frequency insulation transformer can be reduced, and the substring type micro inverter can be reduced in size and cost.

DESCRIPTION OF SYMBOLS 1 Solar cell module 2 Solar cell 3 Solar cell module bus bar 4 Bypass diode 5 Terminal box 6 Solar cell output cable 7 Solar cell output cable terminal 8 Input terminal 9 Output terminal 10 AC module 11, 18 Input capacitor 12, 17 Reactor 13 Switching Element 14 Diode 15 Capacitor 16 Switching element 19 Fault noise elimination filter 20 Surge voltage elimination element 23 High frequency insulation transformer 25, 27, 29 Connector 31, 33 Terminal block 35 Solar cell frame 36 Solar cell surface glass 37 Inverter box 38 Output cable 39 Terminal 40 Current collecting cable 41 Field plate 42 Duct portion 43 Fixing rail 44, 45 Fixing screw 46 Lid 51 AC module 52, 52a, 52b AC assembly cable 53 AC pull box 54 63 AC cable 55 AC current collection box 56 Interconnection contactor 57 Control device 58 Arithmetic control unit 58A Judgment unit 58B Operation permission unit 59 Communication input / output device 60 Emergency stop button 61 Display operation device 62 Network connection device 64 Distributed power source breaker 65 House Distribution board 66 Current detector 67 Electric energy meter 68 Upper internet 69 Light emitting display 70 Communication cables 72, 73 Conductor busbar

Claims (12)

In a solar power generation apparatus having an AC module that outputs AC power, an AC cable that connects the AC modules in parallel, and an AC current collection box that collects AC power.
Installing a plurality of the AC module and the AC cable assembly on the roof;
Install an AC pull box on or near the roof,
Connecting the plurality of AC cable pairs to the AC pull box;
A solar power generation apparatus, wherein an AC cable connects the AC pull box to the AC current collection box.   The solar power generation apparatus according to claim 1, further comprising a DC contactor in the AC pull box. Attaching a fixing rail for fixing the AC module to the roof along the water flow direction of the roof,
The solar power generation device according to claim 1, wherein a duct portion capable of accommodating the AC cable assembly is provided in the vicinity of the fixed rail.   The solar power generation apparatus according to claim 3, wherein an opening is formed in an upper surface portion of the duct portion, and a cover member that covers the opening is provided.   5. The photovoltaic power generation apparatus according to claim 3, wherein the AC module is a building material type AC module integrated with a frame serving as a roofing material.   It replaces with the said alternating current assembly cable, and has a copper or aluminum conductor bus bar which coat | covered the surface with the insulating resin, The solar power generation device of any one of Claims 1-5 characterized by the above-mentioned.   The solar power generation device according to claim 6, wherein a cable is connected to the conductor bus bar via a terminal, and the terminal and the cable are covered with an insulating resin together with the conductor bus bar. A control device for controlling the operation of the AC module is provided in the AC current collection box,
The controller is
A determination unit for determining operational soundness of the AC module;
The solar power generation device according to claim 1, further comprising an operation permission unit that gives operation permission to the AC module based on a determination result of the determination unit.   9. The photovoltaic power generation apparatus according to claim 8, wherein the operation permission unit excludes the AC module that the determination unit has determined not to operate soundly and gives operation permission to the AC module.   The sunlight according to any one of claims 1 to 9, wherein an emergency stop button for transmitting an emergency stop command to the AC module is provided in at least one of the AC current collection box and the AC pull box. Power generation device.   The solar power generation device according to any one of claims 1 to 10, wherein a display device that displays an operation state of the AC module is provided in at least one of the AC current collection box and the AC pull box. .   The solar power generation device according to any one of claims 1 to 11, wherein an indicator that indicates an operating state of the AC module is provided in proximity to the AC module.

Images