JP6385862B2 - Solar power system - Google Patents

Description

  Embodiments described herein relate generally to a photovoltaic power generation system.

  In recent years, attention has been paid to the introduction of a photovoltaic power generation system into a detached house, an apartment house, an office building, etc., to generate photovoltaic power, due to recent attention to renewable energy.

  In a solar power generation system, a solar cell module is configured by connecting a plurality of solar cells that convert solar energy into electric energy in series. The solar cell module is connected to the main circuit in the house and an external system, and supplies power to a load installed in the house and performs reverse power flow to the external system. The solar cell module is connected to a PCS (Power Conditioning System) by a cable. The PCS is installed on the wall surface of the building and performs output control for converting the power generated by the solar cell module into appropriate power. Further, an interconnection relay is installed between the solar cell module and the external system, and the PCS controls switching of the interconnection relay between ON and OFF. By switching ON and OFF of the interconnection relay, it is possible to switch interconnection and disconnection to the external system of the solar cell module.

  The PCS software may need to be updated due to circumstances such as the addition of a solar cell module or a load in the house. Since the PCS cannot perform output control during the update, it is desirable to perform the update at night, avoiding the daytime when solar power is generated. However, at night when power generation is not performed, the PCS controls the interconnection relay to be turned off, so the PCS cannot receive power necessary for the update from the external system. Therefore, workers manually updated the PCS. Specifically, the interconnection relay is manually turned on, and the USB or SD card in which the update program is written is directly inserted into the PCS attached to the wall of the building. As a result, the power supply from the external system was updated.

JP 2013-529051 A

  In recent years, it has been proposed to use a micro inverter (MIC) that can be attached to the back surface of a panel of a solar cell module in place of the PCS. When there are a plurality of solar cell modules, the MIC can be attached to each solar cell module, so that each solar cell module can be individually controlled. As with the PCS, the MIC may need to be updated. However, it is difficult for the worker to manually update the MIC of the solar cell module installed on the roof and attached to the back surface.

  The present embodiment has been made in view of the above-described problems, and an object thereof is to provide a highly convenient solar power generation system that can easily update software of a micro inverter.

  The photovoltaic power generation system of the present embodiment includes a solar cell module, an interconnection relay that switches between interconnection and disconnection with respect to an external system of the solar cell module, and is attached to the solar cell module and connected to the interconnection relay. A micro-inverter that performs output control of the solar cell module and switching control of the interconnection relay, the micro-inverter receives a software update notice of the micro-inverter from the outside, and is designated as the software update notice At this time, the interconnection relay is controlled to link the solar cell module to the external system, and the software is updated using the power supplied from the external system.

It is a figure showing the whole solar power generation system composition concerning a 1st embodiment. It is a figure which shows the structure of the surface and back surface of a solar cell module. It is a block diagram which shows the structure of a microcontroller. It is a flowchart which shows operation | movement of the micro inverter at the time of software update. It is a figure which shows the whole structure of the solar energy power generation system which concerns on the modification of 1st Embodiment. It is a figure which shows the structure of the solar energy power generation system which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the microcontroller in the solar energy power generation system which concerns on 3rd Embodiment. It is a figure which shows the operation | movement at the time of the software update of a microcontroller. It is a figure which shows the operation | movement at the time of the update error generation | occurrence | production of a microcontroller.

  Hereinafter, a solar power generation system according to an embodiment will be described with reference to the drawings.

1. First embodiment 1-1. Configuration FIG. 1 is a block diagram showing a configuration of a photovoltaic power generation system 100 according to the first embodiment. The photovoltaic power generation system 100 converts DC power generated by the solar cell module 20 into AC power and supplies it to a main circuit (not shown) in the house via a distribution board (not shown), or an external power system. (Hereinafter referred to as “external system 200”). An interconnection relay 50 is installed between the solar cell module 20 and the external system 200, and the interconnection and disconnection of the solar cell module 20 to the external system 200 are performed by switching the interconnection relay 50 ON and OFF. Can be switched.

  A micro inverter (MIC) 12 is attached to the solar cell module 20. FIG. 2 is a diagram illustrating an installation example of the solar cell module 20 and the MIC 12. The solar cell module 20 is formed by connecting a plurality of solar cells 22 in series to form a single panel. The solar battery cell 22 converts the energy of sunlight incident on the light receiving surface into electric energy. The solar cell module 20 is fixed on a gantry (not shown) and installed on the roof of a house. At this time, it is installed so that the light receiving surface of the solar battery cell 22 faces upward. Here, the surface on which the light receiving surface of the solar cell module 20 is disposed is the front surface, and the surface facing the surface is the back surface.

  The MIC 12 is attached to the back surface of the solar cell module 20 and is connected to the solar cell module 20 by a cable. The MIC 12 used here is a combination of a power conversion function and a maximum power point tracking (MPPT) function. For the power conversion function, the MIC 12 includes a DC / DC converter 13, a transformer 14, a rectifier 15 and a DC / AC converter 16, and converts the current generated by the solar cell module 20 from direct current to alternating current. The MIC 12 includes a microcontroller (MCU: Micro Control Unit) 18 as a control device that realizes a power conversion function and an MPPT function. The MIC 12 is connected to the DC / DC converter 13 and the DC / AC converter 16 via the control IC 17. The MCU 18 is an electronic circuit including a memory 35 (see FIG. 3), and implements a power conversion function and an MPPT function by executing software stored in the memory 35. Furthermore, the MCU 18 is also connected to the interconnection relay 50 and controls switching of the interconnection relay 50 between ON and OFF.

  The MCU 18 is connected to the gateway 40 by wire or wireless. The gateway 40 is a monitoring device for the photovoltaic power generation system 100 and has a wireless communication function. The gateway 40 collects information necessary for the operation of the photovoltaic power generation system 100 from the outside via a network. For example, the gateway 40 communicates with the terminal device 44 possessed by the management company of the photovoltaic power generation system 100, receives data necessary for operations such as maintenance and repair of the photovoltaic power generation system 100 from the management company, and sends it to the MCU 18. Send. The data received from the management company includes an MCU 18 software update program.

  Further, the gateway 40 transmits a software update notice of the MCU 18 to the MCU 18. The software update notice of the MCU 18 includes at least the designation of the time for performing the software update of the MCU 18. The time for performing the software update may be determined by the management company and transmitted to the gateway 40 together with the update program. The time for performing the software update can be set to an arbitrary time. However, since the MIC 12 cannot perform the output control operation during the update, it is preferable to specify a time when the solar power generation is not performed or the power generation amount is small. For example, the power generation amount by the solar cell module 20 is predicted, and the time when the predicted power generation amount becomes a predetermined value or less may be set as the time for performing the update. Further, for example, a sunset time when the power generation amount becomes zero is acquired in advance, and the sunset time may be set as the update execution time.

  Or the resident (henceforth "user") of the house in which the solar power generation system 100 was installed may determine the time which performs software update. The gateway 40 can communicate with a terminal device 42 owned by the user, for example, a PC, a tablet terminal, a smartphone, a mobile phone, or the like. For example, when the gateway 40 receives an update program from the management company, the gateway 40 may transmit an update notification to the terminal device 42 of the user and accept an input for specifying the update time from the user. For example, when the date on which the update notification is received is cloudy or rainy when the amount of power generation cannot be expected, the user may specify the time so that the update is performed even during the day.

  FIG. 3 is a block diagram showing the configuration of the MCU 18. In addition to the memory 35 described above, the MCU 18 includes a transmission / reception unit 32, a timer unit 31, a control unit 33, and the like. In the present embodiment, the transmission / reception unit 32 receives a software update program and a software update notice from the gateway 40. In addition, when an update program and a software update notice are received, a reception confirmation signal, an update end notification signal, and the like are transmitted to the gateway 40. The control unit 33 refers to the timer unit 31 and turns on the interconnection relay 50 at the designated software update time so as to receive power supply from the external system 200. Further, the received update program is written in the memory 35 to update the software.

  In this specification, “MCU 18 software update” may be described as “MIC 12 software update”, but as described above, the MCU 18 constitutes the MIC 12 and the two are synonymous.

1-2. Operation The operation of the above-described photovoltaic power generation system 100 will be described with reference to the flowchart of FIG. 4 in addition to FIGS. Here, an example will be described in which the MCU 18 receives a software update notice during the day when the normal output control operation of the solar cell module 20 is performed, and performs software update at night when power generation is not performed.

  During the day when power is generated by the solar cell module 20, the MCU 18 controls the interconnection relay 50 to ON. The current generated by the solar cell module 20 is converted from direct current to alternating current through the DC / DC converter 13, the transformer 14, the rectifier 15 and the DC / AC converter 16 of the MIC 12, and supplied to the main circuit in the house, or A reverse power flow is made to the external system 200. In addition, the MIC 12 executes the MPPT function.

  The transmission / reception unit 32 of the MCU 18 receives the software update notice from the gateway 40 (step S01). The software update notice includes a command to perform software update at night time t1. For example, when sunset occurs and the power generation amount = 0 (step S02: Yes), the control unit 33 of the MCU 18 turns off the interconnection relay 50 (step S03). The control unit 33 of the MCU 18 refers to the timer unit 31 and turns on the interconnection relay 50 at time t1 (step S04: Yes) (step S05). As a result, the MCU 18 can be updated by receiving power supply from the external system 200. The transmission / reception unit 32 of the MCU 18 receives the update program from the gateway 40, and the control unit 33 writes the update program in the memory 35 and performs the update (step S06). When the update is completed, the control unit 33 of the MCU 18 turns off the interconnection relay 50 (step S07), disconnects from the external system 200, and ends the update.

1-3. Operational Effect (1) As described above, the solar power generation system 100 of the present embodiment includes the solar cell module 20, the interconnection relay 50 that switches the interconnection and disconnection of the solar cell module 20 with respect to the external system 200, the solar An MIC 12 that controls output control of the battery module 20 and switching of the interconnection relay 50 is provided. The MIC 12 is attached to the solar cell module 20 and connected to the interconnection relay 50. The MCU 18 provided in the MIC 12 receives the software update notice of the MIC 12 from the outside, controls the interconnection relay 50 at the time designated in the software update notice, and links the solar cell module 20 with the external system 200, Software is updated using power supplied from the system 200.

  The solar cell module 20 is often installed on the roof of a building, and it is difficult to manually operate the MIC 12 at night when the interconnection relay 50 is OFF to turn on the interconnection relay 50. In this embodiment, the software update notice is received in advance, and the software update can be easily performed by turning on the interconnection relay 50 at a designated time so as to receive power supply from the external system 200. It is possible to provide a highly convenient solar power generation system 100.

(2) The photovoltaic power generation system 100 of the present embodiment further includes a gateway 40 that is connected to the MIC 12 and transmits a software update notice and a software update program to the MIC 12. In addition, by transmitting data necessary for the update from the gateway 40 that is a monitoring device of the photovoltaic power generation system 100 to the MIC 12, it is necessary for an operator to directly write data to the MIC 12 installed on the roof using an SD card or the like. The convenience can be further improved.

(3) The software update notice of the MIC 12 may include, for example, the time when the predicted power generation amount by the solar cell module 20 is equal to or less than a predetermined amount as the software update time designation.

  By designating the time period during which power generation is not performed or the amount of power generation is low as the software update time, it is possible to prevent the update operation from reducing the power generation amount, and the highly reliable photovoltaic power generation system 100 is provided. Can be provided.

(4) The software update notice may include, for example, a software update time designated by the user. Since the software update can be performed according to the convenience of the user, the solar power generation system 100 with a high degree of freedom can be provided.

1-4. Modified Example FIG. 5 shows a modified example of the present embodiment. In the above-described embodiment, the solar power generation system 100 including one solar cell module 20 is shown. However, the disclosure of the present embodiment can be applied to the solar power generation system 100 including a plurality of solar cell modules 20. It is. In the case of using a plurality of solar cell modules 20, MICs 12 are attached to the individual solar cell modules 20, the plurality of MICs 12 are connected in parallel, and a main circuit (not shown) in the house or an external system is connected via the interconnection relay 50. Connect to 200. That is, although not shown in FIG. 5, the solar cell module 20 is connected to each MIC 12.

  When the solar power generation system 100 includes a plurality of MICs 12, the output control of the individual solar cell modules 20 is performed by the MICs 12 attached to each. On the other hand, since there is only one interconnection relay 50 for the plurality of MICs 12, it is not necessary for all the MICs 12 to control switching of the interconnection relays 50 between ON and OFF. In addition, when communicating with the gateway 40 to receive a software update notice or update program, if all the MICs 12 communicate with the gateway 40 individually, the amount of communication becomes enormous and the line may be burdened. is there.

  Therefore, for example, one MIC 12A of the plurality of MICs 12 may be a parent device, and only the MIC 12A of the parent device may control ON / OFF switching of the interconnection relay 50 and may communicate with the gateway 40. . Of course, it is necessary to update the software for all MICs 12. Therefore, when the master unit receives data such as a software update notice or update program from the gateway 40, the master unit may sequentially transfer the data to the MIC 12 of the adjacent slave unit using a so-called bucket relay system. As a result, it is possible to prevent the communication amount from increasing and placing a burden on the line.

  Similarly, from the viewpoint of preventing the burden on the line, the update execution times may be made different without simultaneously updating the software for the plurality of MICs 12. For example, an ID that is an identifier may be attached to each of the plurality of MICs 12. The software update notice may include the ID of each MIC 12 and the update execution time that is different for each ID. Each MIC 12 that has received the software update notice performs software update at the update execution time corresponding to its own ID.

  Alternatively, after the software update is completed with one MIC 12, the next MIC 12 may perform the software update. In this case, for example, a time zone having a certain range may be designated as the update execution time in the software update notice. Then, within that time, it is preferable that communication is performed between the MIC 12A of the parent device and the MIC 12 of the child device to complete the update sequentially. That is, the MIC 12A of the parent device transmits a software update start command to the MIC 12 of one child device. When the MIC 12 of the slave unit completes the update, a completion notification is transmitted to the MIC 12A of the master unit. The MIC 12A of the parent device that has received the completion notification transmits a software update start command to the MIC 12 of the next child device. By repeating this, the software update time of the MIC 12 does not overlap, and the burden on the line can be further prevented.

  The above-described aspect is, of course, an example, and the update aspect is not limited to a specific one. For example, when the communication line between the gateway 40 and the MIC 12 has a margin, the gateway 40 may communicate with all the MICs 12 individually. Further, the update may be performed on all MICs 12 at the same time.

2. Second Embodiment A photovoltaic power generation system 100 according to a second embodiment will be described with reference to FIG. In the following embodiments, only points different from the above-described embodiment will be described, and the same parts as those in the above-described embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

  In the second embodiment, a control power supply 60 dedicated for updating is installed between the interconnection relay 50 and the external system 200. The control power supply 60 is directly connected to the MIC 12 and can directly supply the power of the external system 200 to the MIC 12 regardless of whether the interconnection relay 50 is ON or OFF.

  With such a configuration, when the MIC 12 receives the software update notice from the gateway 40 and the solar cell module 20 is disconnected from the external system 200 at the update time specified in the software update notice, Even when the system relay 50 is OFF, the software can be updated using the power supplied from the control power supply 60. As a result, there is no need for control to turn on the interconnection relay 50 even at night when the interconnection relay 50 is turned off, and the software update can be easily performed and the highly convenient solar power generation system 100 is provided. can do.

  In addition, when updating during the day when solar power generation is performed, the MIC 12 can also receive the power supply from the solar cell module 20 instead of the external system 200 and perform the update. However, during the update, there is a possibility that sufficient power supply from the solar cell module 20 may not be received due to a sudden change in weather or the like. In such a case, the update can be maintained by switching to the power supply from the control power supply 60.

3. 3rd Embodiment The solar power generation system 100 which concerns on 3rd Embodiment is demonstrated using FIGS. 7-9. The third embodiment is a modification of the MCU 18 constituting the MIC 12, and can be applied to both the first and second embodiments.

  As shown in FIG. 7, in the third embodiment, the MCU 18 includes two memories 35A and 35B. The two memories 35A and 35B may be of the same type. When one of the memories is used as a main and the other is used as a sub, the main may be a memory having a larger capacity. The two memories 35A and 35B store the same software for realizing the function of the MCU 18.

  In the above-described embodiment, an example in which the update is performed at night in order not to reduce the power generation amount of the solar power generation has been mainly described. However, in this embodiment, by providing two memories 35A and 35B, Updates are possible without reducing the amount of power generated even during the day of power generation.

  The operation at the time of updating the MCU 18 of this embodiment will be described with reference to FIG. Except when performing a software update, MCU18 implement | achieves a power conversion function and a MPPT function using any one memory, and is performing the output control of the solar cell module 20. FIG. Here, a case where the memory 35A is used will be described.

  Similar to the above-described embodiment, when the MCU 18 receives the software update notice from the gateway 40, the MCU 18 receives the update program from the gateway 40 at a designated time and performs the software update. Here, a case will be described in which the time designated in the software update notice is during the day when solar power generation is performed. That is, the MCU 18 uses the memory 35 </ b> A for controlling the solar cell module 20.

  The MCU 18 continues the output control of the solar cell module 20 using the memory 35A. On the other hand, the update program is written to the memory 35B. When the update of the memory 35B is completed, the output control of the solar cell module 20 is switched to the updated memory 35B. Then, the update program is written to the memory 35A. After the update of the memory 35A is completed, the output control of the solar cell module 20 may be performed with the memory 35B as it is. However, when the memory 35B is used as a sub, it may be switched immediately to the memory 35A.

  As described above, in the present embodiment, two memories are provided, and the update can be performed without stopping the output control of the solar cell module 20 even during the day by switching the memory to be updated and the output control of the solar cell module 20. It becomes possible, and the highly flexible solar power generation system 100 can be provided.

  In addition, by providing two memories, when an abnormality occurs when one of the memories is updated and the update is not normally completed, the other memory can be used to perform a recovery operation. This is not limited to daytime or nighttime updates.

  As a cause of the abnormality, when the MCU 18 receives power supply from the external system 200 and performs an update, a disturbance such as an instantaneous voltage drop or a power failure occurs in the external system 200, and the power supply from the external system 200 is received. It may be impossible. Moreover, when MCU18 is receiving the electric power supply from the solar cell module 20 and performing update, it is possible that sufficient solar radiation cannot be obtained for the sudden change of the weather. For example, when the update of the memory 35B is interrupted due to such an abnormality, the memory 35B remains in the middle of rewriting as an update error, and it is difficult to restore the operation.

  Therefore, as shown in FIG. 9, the memory 35B in which the update error has occurred is started up from the Boot side and repaired or reset. Then, by writing the software stored in the memory 35A to the memory 35B, the memory 35B can be restored to the state before the error occurred. Thus, by providing two memories, it is possible to provide a backup when an error occurs, and to provide a highly reliable photovoltaic power generation system 100. When an error occurs in the memory 35A, the memory 35A can be restored using the memory 35B in the same manner.

  In addition, the aspect provided with two memories mentioned above is applicable also when performing software update of PCS in the photovoltaic power generation system 100 provided with PCS instead of MIC12, for example.

4). Other Embodiments Although several embodiments of the present invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

12 Micro inverter (MIC)
MIC of 12A master unit
13 DC / DC converter 14 Transformer 15 Rectifier 16 DC / AC converter 17 Control IC
18 MCU
DESCRIPTION OF SYMBOLS 20 Solar cell module 22 Solar cell 31 Timer part 32 Transmission / reception part 33 Control part 35,35A, 35B Memory 40 Gateway 42 User's terminal device 44 Management company's terminal device 50 Interconnection relay 60 Control power supply 100 Solar power generation system 200 External system

Claims (10)

A solar cell module;
An interconnection relay for switching between interconnection and disconnection to the external system of the solar cell module;
A micro inverter that is attached to the solar cell module, connected to the interconnection relay, and performs output control of the solar cell module and switching of the interconnection relay, and
The micro inverter receives a software update notice of the micro inverter from the outside, controls the interconnection relay at a time specified in the software update notice, and links the solar cell module with the external system, A photovoltaic power generation system that uses software supplied from an external system to update software.   The photovoltaic power generation system according to claim 1, further comprising a gateway connected to the micro inverter and transmitting a software update notice of the micro inverter and a software update program to the micro inverter.   The software update notice of the micro inverter includes a software update time, and the software update time is a time when a predicted power generation amount by the solar cell module is equal to or less than a predetermined amount. Solar power system.   The photovoltaic power generation system according to claim 1 or 2, wherein the software update notice of the micro inverter includes a software update time designated by a user. A plurality of the solar cell modules;
A plurality of micro inverters attached to each solar cell module and capable of communicating with each other;
A gateway that is connected to the micro-inverter and transmits a software update notice and software update program of the micro-inverter to the micro-inverter;
5. The device according to claim 2, wherein any one of the plurality of micro inverters receives the software update notice from the gateway as a parent device and sequentially transmits to the other micro inverters serving as child devices. Solar power system.   The solar power generation system according to claim 5, wherein the software update notice includes an ID assigned to each of the plurality of micro inverters and a software update time that is different for each ID. A plurality of the solar cell modules;
A plurality of micro inverters attached to each solar cell module and capable of communicating with each other;
A gateway that is connected to the micro-inverter and transmits a software update notice and software update program of the micro-inverter to the micro-inverter;
Any one of the plurality of micro inverters receives the software update notice from the gateway as a master unit, and updates the other micro inverters serving as slave units at the software update time specified in the software update notice. The solar power generation system according to any one of claims 2 to 4, wherein a start command is sequentially transmitted, and the update start command is transmitted to the next micro inverter after software update is completed by one micro inverter. . A solar cell module;
An interconnection relay for switching interconnection and disconnection between the solar cell module and an external system;
A micro-inverter connected to the solar cell module and the interconnection relay and performing output control of the solar cell module and switching of the interconnection relay;
Provided between the interconnection relay and the external system, connected to the micro inverter, and supplies the power of the external system to the micro inverter even when the solar cell module is disconnected from the external system A control power source,
The micro inverter receives the software update notice of the micro inverter from the outside, and when the solar cell module is disconnected from the external system at the time specified in the software update notice, the micro inverter is supplied from the control power supply. Solar power generation system that uses software to update software. The micro inverter has two memories in which the same software is written,
Upon receiving the software update notice, the micro inverter performs output control of the solar cell module using a first memory at a time specified in the software update notice, and performs the output control on a second memory. After updating the software and completing the update of the second memory, the output of the solar cell module is controlled using the second memory and the software is updated to the first memory. The solar power generation system as described in any one of Claims 1-8. The micro inverter has two memories in which the same software is written,
Upon receiving the software update notice, the micro inverter performs output control of the solar cell module using a first memory at a time specified in the software update notice, and performs the output control on a second memory. When software is updated and an abnormality occurs during the update, the software written in the second memory is restored using the software written in the first memory. The photovoltaic power generation system according to any one of claims 1 to 8, wherein