JP2018133992A - Photovoltaic power generating system, connection method for cable way between solar cell modules, and release method for cable way between solar cell modules - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that power generation output of a solar cell array connecting solar cell modules may become high voltage of DC hundreds V and if a building in which such a solar cell array is installed is on fire, since the solar cell array is generating high voltage in the daytime, there is risk that a fire fighter may get electric shock during water discharge work or the like for firefighting, although a system in which a device for reducing the output voltage of the solar cell array in the case of fire is integrated is being advocated as countermeasures, a dedicated apparatus such as fire detection means may be required and further, a wiring construction may be complicated.SOLUTION: A photovoltaic power generation system comprises: a plurality of cable way switches between a plurality of solar cell modules installed in a cable way between the solar cell modules; and connection control means for controlling connection between solar cell modules in a state of a system power source. The connection control means controls a cable way switch between solar cell modules on a first stage and then successively controls cable way switches between solar cell modules on next and subsequent stages in a dizzy chain manner.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a solar power generation system using an electric circuit switch that opens and closes an electric circuit between solar cell modules connected in series, and the electric circuit switch and the solar cell module.

Generally, a solar power generation system is a solar cell having a configuration in which a plurality of solar cell modules are arranged in series on a roof of a building such as a factory or an office building or a roof of a house and connected in series. Each of the array and the solar cell string includes a connection box that collects DC power generated by the array, a power conditioner that converts the collected DC power into AC power, and the like. The input voltage to the power conditioner is a high voltage of a level from several hundreds of volts DC to over 1000 volts in some cases.
When a building with such a solar power generation system is in a fire, even if the AC power source in the building, that is, the commercial power system is shut off during fire extinguishing activities, Since the voltage is generated, there is a concern about firefighters' electric shocks during fire fighting and water discharge activities.

For such a problem, for example, Patent Document 1 proposes a solar power generation system in which a relay interlocked with a fire detection means is provided between solar cell modules.
The conventional photovoltaic power generation system in Patent Document 1 includes a fire detection means including a fire alarm and an adapter device, and transmits a fire detection signal detected by the fire alarm to the electric shock prevention circuit via the adapter device via the power conditioner. The electric shock prevention circuit releases the connection between the solar cell string formed by connecting a plurality of solar cell modules in series and the power conditioner, and connects the electric shock prevention resistor to both ends of the solar cell string to connect the short circuit current. The voltage across the solar cell string is lowered to a voltage level that does not cause an electric shock by passing a current close to. Further, it is disclosed that the connection with the power conditioner and the connection of the electric shock prevention resistor may be in units of individual solar cell modules instead of units of solar cell strings.

JP 2014-68509 A

In such a conventional solar power generation system, in order to enable the interruption of the electric circuit, an adapter device for transmitting a fire detection signal from the fire alarm and the fire alarm to the electric shock prevention circuit via the power conditioner; It was necessary to construct a dedicated solar power generation system equipped with a fire detection means consisting of
In addition, wiring from the control unit provided in the power conditioner to each electric shock prevention circuit installed in each solar cell string is necessary, and wiring work takes time and effort. Further, when the electric shock prevention circuit is installed in units of solar cell modules, the number of wires in the whole greatly increases, making the wiring work more complicated and requiring more labor and time.
In addition, in the case of a configuration in which an electric shock prevention resistor is connected to both ends of the solar cell string, it is possible that the electric shock prevention resistor may be disconnected (disconnected) due to the use of a destruction device in a fire fighting activity. There was a concern that a high voltage would be generated at both ends, resulting in another risk of electric shock.

  The present invention has been made to solve the above-described problems, and does not require the construction of a dedicated system for controlling each electric shock prevention circuit in conjunction with a fire alarm or the like. It is an object of the present invention to provide a solar power generation system capable of avoiding the fear of electric shock in fire fighting activities without requiring complicated wiring work and electric shock prevention resistance.

  A photovoltaic power generation system according to the present invention includes a plurality of inter-solar cell module circuit switches installed in a circuit between solar cell modules, and a connection control unit that controls connection of solar cell strings. Controls the circuit switch between the solar modules in the first stage according to the command, controls the circuit switch between the solar modules in the next stage according to the switching control output of the circuit switch between the solar modules in the first stage, and sequentially controls the subsequent It is configured as described above.

  Since the present invention is configured as described above, it is possible to cut off the electric circuit between the solar cell modules without interlocking with a fire alarm or the like, and the daisy chain system is also used for the wiring work to each electric circuit switch. Because of the configuration that can be adopted, it is possible to implement more easily. In addition, in the event of a fire, the construction is such that the electric circuit is interrupted so as to keep the voltage low enough to avoid an electric shock without using an anti-electric shock resistance, so that more effective safe fire extinguishing activities are possible. Can also be obtained.

It is a general block diagram of a solar power generation system. It is a general block diagram of a solar cell module. It is a figure which shows an example of the voltage-power characteristic and voltage-current characteristic of a solar cell module. 1 is a system configuration diagram of a photovoltaic power generation system according to Embodiment 1 of the present invention. It is a system block diagram of the solar energy power generation system concerning Embodiment 2 of this invention. It is a system block diagram of the solar energy power generation system concerning Embodiment 3 of this invention. It is a system block diagram of the solar energy power generation system concerning Embodiment 4 of this invention. It is the figure which extracted a part of system configuration | structure of the solar energy power generation system concerning Embodiment 5 of this invention. It is a schematic block diagram of the solar cell module concerning Embodiment 6 of this invention. It is a system block diagram of the solar energy power generation system using the solar cell module concerning Embodiment 6 of this invention.

  Hereinafter, embodiments of a photovoltaic power generation system, an inter-solar cell module circuit switch and a solar cell module according to the present invention will be described in detail with reference to the drawings.

Embodiment 1 FIG.
1 is a general configuration diagram of a photovoltaic power generation system, FIG. 2 is a general configuration diagram of a solar cell module, and FIG. 3 is a graph of (a) voltage-power characteristics and (b) voltage-current characteristics of a solar cell module. It is a figure which shows an example, respectively.
First, the general configuration and operation outline of a photovoltaic power generation system will be described with reference to FIG.
In general, the photovoltaic power generation system includes a solar cell array 1, a connection box 2, and a power conditioner 3. The solar cell array 1 is installed, for example, on the roof of a house, the roof of a building, or the ground. The solar cell array 1 has a configuration in which a plurality of solar cell modules 11a, 11b,..., 11n are connected in series with solar cell strings 1-1, 1-2,. Although it is general, only one solar cell string may be used. The outputs of the solar cell strings 1-1, 1-2,..., 1-m are connected to each DC switch 21 in the connection box 2 for each string, and the output of the connection box 2 is connected to the power conditioner 3. The

Each of the solar cell array 1, that is, the solar cell strings 1-1, 1-2,..., 1-m, receives sunlight to generate electric power and generate DC power. The junction box 2 collects the DC power from each solar cell string into one output and sends it to the power conditioner 3, and the power conditioner 3 converts the input DC power into AC power. The output of the power conditioner 3 is connected to the commercial power system 31 via the distribution board 30. Further, it is also connected to each electrical device in the house, that is, a load 32 via a branch breaker (not shown) in the distribution board 30. AC power from the solar power generation system is supplied to the load 32 and consumed.
When the generated power is low during cloudy weather or rainy weather, or when power generation is not possible at night or the like, power is supplied from the commercial power system 31 to the load 32 via the distribution board 30 (power purchase). On the contrary, when the generated power is larger than the total power consumed at the load 32 in the house at that time, the surplus power flows backward to the commercial power system 31 via the distribution board 30. (Power sale).

Next, an example of a general configuration and characteristics of the solar cell module will be described with reference to FIGS. 2 and 3.
The solar cell module 11 illustrated in FIG. 2 has a configuration in which 60 solar cells 11C are arranged and all of them are connected in series. Further, 20 solar cells connected in series are set as a set (cluster), and a bypass diode 11D is connected in parallel for each cluster. The bypass diode 11D cannot generate the above-mentioned power generation current in other normal solar cells when some of the solar cells cannot generate power due to falling leaves or shadows on the surface of the solar cell module. It has a role of bypassing and flowing the cluster including the abnormal solar battery cell, thereby avoiding an abnormal temperature rise in the abnormal solar battery cell and effectively utilizing the generated current in the normal solar battery cell. In addition, the electric power generated by each solar battery cell can be taken out by connecting an output cable to the positive electrode (+) and the negative electrode (−) of the solar battery module 11.
FIG. 3A is an example of a voltage-power characteristic diagram of the solar cell module, and FIG. 3B is an example of a voltage-current characteristic diagram of the solar cell module. Depending on the amount of solar radiation from the sun, the output power (generated power) value of the solar cell module and the output current (generated current) value of the solar cell module greatly increase or decrease, but the output voltage (generated voltage) is low current. Then, it can be seen that a certain level is generated even in low solar radiation, for example, a value of DC 25 V or more is generated in the case of an open voltage.

Next, the solar power generation system according to Embodiment 1 of the present invention will be described.
FIG. 4 is a system configuration diagram of the photovoltaic power generation system according to Embodiment 1 of the present invention. In FIG. 4, the photovoltaic power generation system 100 includes a plurality of solar cell module circuit switches for connecting the solar cell array 1, the junction box 2, and the power conditioner 3 to each solar cell module in the solar cell string. 4 and a connection control device 5 serving as a connection control means for outputting a command indicating whether or not to allow connection to each solar cell string, that is, a connection control command.
The solar cell array 1 is composed of solar cell strings 1-1,..., 1-m, and each solar cell string includes a plurality of solar cell modules 11a, 11b,..., 11n-1, 11n connected in series. It becomes the composition. Here, the electric circuit switch 4 between solar cell modules is each arrange | positioned in the middle of the electric circuit between the two solar cell modules connected in series.

The electric circuit switch 4 between the solar cell modules includes an electric circuit switching relay 41 as an opening / closing means for opening and closing the electric circuit, and a control output relay 42 as an output means for outputting an opening / closing control output to the electric circuit switch between the solar cell modules in the next stage. It is configured.
In the first-stage solar cell module circuit switch 4a disposed between the solar cell modules 11a and 11b, one end of the contact of the circuit switch relay 41a is connected to the output cable from the positive electrode (+) side of the solar cell module 11a. The other end of the connection is connected to the output cable from the negative electrode (−) side of the solar cell module 11b. Further, one end of the contact of the control output relay 42a is connected to the other end side of the contact of the electric circuit switching relay 41a, and the other end is used as the switching control output terminal O, so that the switching control of the electric circuit switch 4b between the solar cell modules in the next stage is performed. The input terminal I is connected via a signal line. The coil of the electric circuit switching relay 41a and the coil of the control output relay 42a are connected in parallel, one end side thereof is connected to one end of the contact of the electric circuit switching relay 41a, and the other end side is used as the switching control input terminal I. The switching control output terminal O is connected via a signal line.
The solar cell module circuit switches 4b,..., 4n-1 after the second stage are also connected in the same manner. However, each switching control input terminal I is connected to the switching control output terminal O of the preceding solar cell module circuit switch, and the switching control output terminal O of the final photovoltaic module switch 4n-1 is the next switching control output terminal O. Since there is no electric circuit switch between the solar cell modules of the stage, it is not connected to anything.

The connection control device 5 includes a system voltage monitoring unit 50, a plurality of interconnection permission relays 52a as a connection command unit corresponding to each solar cell string, 52m, and a plurality of independent changeover switches 51a as a self-sustained operation permission unit. , 51m. The input of the system voltage monitoring means 50 is connected between the phases of the commercial power system 31, and the output of the system voltage monitoring means 50 is connected to each coil of the interconnection permission relays 52a, ..., 52m. Further, the connection permission relays 52a,..., 52m have one end connected to the output terminal N on the lowest potential side of the corresponding solar cell string, and the other end connected to the NC terminals of the independent switching switches 51a,. Connected to the system operation side). In addition, the independent switches 51a,..., 51m are connected in parallel to the switching control input terminal I of the first-stage solar cell module circuit switch 4a in the corresponding solar cell string, with the COM terminal serving as the switching control output terminal O. The other end side of the coil of the electric circuit switching relay 41a and the control output relay 42a is connected to the output terminal N of the solar cell string corresponding to the NO terminal (self-supporting operation side) and the NC terminal (interconnection operation side), respectively. Connected to the other end of the contacts of the system permission relays 52a, ..., 52m.
Further, the output terminal P on the maximum potential side and the output terminal N on the lowest potential side of the solar cell strings 1-1, ..., 1-m are connected to the input side of the DC switches 21a, ..., 21m in the connection box 2, respectively. Is done.

  In addition, in this configuration, it is realized by arranging the inter-solar cell module circuit switch in the middle of the electric circuit between the solar cell modules and wiring the control lines for transmitting control signals in a daisy chain from the first stage to the last stage. In addition, there is no need for a special dedicated device that works with the fire detection means. Therefore, it is possible to easily modify the present configuration by adding necessary devices to the existing photovoltaic power generation system and performing simple wiring work.

Next, the operation of the first embodiment will be described.
First, the operation during normal interconnection operation will be described. It is assumed that the self-supporting changeover switch 51a is switched to the state where the COM terminal and the NC terminal are connected, that is, to the connected operation side. Moreover, if the system voltage monitoring means 50 in the connection control apparatus 5 is monitoring the voltage between phases of the commercial power system 31, and the voltage is normal, that is, if the photovoltaic power generation system can be connected, the connection permission relay 52a Assume that the contact is driven to the ON state. This state means that the open / close control input is ON (closed instruction) when viewed from the solar cell inter-module electric circuit switch 4a. Here, when the sun rises and the amount of solar radiation increases in the morning, each solar cell module 11a, 11b, ..., 11n of the solar cell string 1-1 starts a power generation operation, and the power generation amount increases. come. Then, the current generated by the solar cell module 11a at the first stage (lowest potential side) is supplied from the positive electrode (+) of the solar cell module 11a to the coil of the electric circuit switching relay 41a of the inter-solar cell module circuit switch 4a and the control output relay 42a. The path from the COM terminal of the self-standing changeover switch 51a in the connection control device 5 to the NC terminal (connected operation side), the contact of the connection permission relay 52a, and the negative electrode (−) of the solar cell module 11a through the coil of It flows in. If this current is equal to or greater than the operating currents of the electric circuit switching relay 41a and the control output relay 42a, both the contacts of the electric circuit switching relay 41a and the contacts of the control output relay 42a are closed. That is, the electric circuit between the solar cell module 11a and the solar cell module 11b is closed.

  In addition, closing the contact of the control output relay 42a means that the switching control output to the next-stage solar cell module electric circuit switch 4b is turned ON (closed instruction), thereby the solar cell module 11b, the solar A closed circuit is formed by the coil of the electric circuit switching relay 41b, the coil of the control output relay 42b, and the contact of the control output relay 42a in the electric circuit switch 4b between the battery modules, and the generated current of the solar cell module 11b flows there. Thereby, the contact of the electric circuit switching relay 41b and the contact of the control output relay 42b in the electric circuit switch 4b between the solar cell modules are closed. That is, the electric circuit between the solar cell module 11b and the next-stage solar cell module is closed. In this way, the electric circuit between the solar cell modules arranged in series in the solar cell string is closed in order from the lowest potential side, and finally the electric circuit between the solar cell modules on the maximum potential side is closed and finally In the state where the electric circuit between all the solar cell modules of the solar cell string 1-1 is closed, that is, the solar cell string 1-1 is connected, and the DC power by the solar cell string 1-1 is DC open / closed in the connection box 2. Is input to the device 21a.

  The operation is the same in other solar cell strings, and the junction box 2 inputs DC power from all the solar cell strings, collects them into one, and supplies them to the power conditioner 3 as the generated power of the solar cell array 1. send. The power conditioner 3 converts the DC power from the connection box 2 into AC power. The AC power is consumed by a load such as an electric appliance in the house, and if there is a surplus, it is reversely flowed to the commercial power system 31. The above is the operation during the interconnection operation.

  Here, the specifications and performance required by the electric circuit switching relay 41 and the control output relay 42 in the electric circuit switch 4 between the solar cell modules will be described in detail. As a solar cell module that can be used in this embodiment, for example, a solar cell module having a nominal maximum output of 200 W, a nominal maximum output operating voltage of 25 V, a nominal maximum output current of 8 A, and a nominal open-circuit voltage of DC 32 V is raised. As shown in FIGS. 3 (a) and 3 (b), the solar cell module generally increases or decreases its output power value and output current value due to the increase or decrease of the amount of solar radiation, but the output voltage is the output current even during low solar radiation. If there is little, it will become a high voltage value, and DC25V or more is possible as an open circuit voltage (output voltage when output current = 0). Therefore, if a relay with a rated coil voltage of DC 24V is used as the electric circuit switching relay 41, the operating voltage is generally equal to or lower than DC 21V, so that it can be driven by the power generation voltage of one solar cell module during low solar radiation. is there. Moreover, if the contact rating is a DC400V / DC25A level relay, the coil power consumption can be expected to be 2 W or less, and the relay can be driven even in the low solar radiation where the generated power of the solar cell module is only a few W. Since the control output relay 42 has a smaller capacity for contact opening / closing compared to the electric circuit opening / closing relay 41, a smaller relay having a coil power consumption of 0.2 W can be used.

  Moreover, even if the power conditioner is activated and the generated voltage of the solar cell module is reduced by taking out a large current as the generated current from the solar cell module, the relay characteristics change from the closed state to the open state. The return voltage to be switched is about 10% of the rated voltage. For example, if the relay has a rated voltage of DC 24V, the return voltage is DC 5V or more. Therefore, once the relay is turned ON, the power generation voltage of the solar cell string stops the operation of the power conditioner. Even when such a low voltage drops to about 50 V or less, it is possible to continue the closing of the electric circuit between the solar cell modules by the electric circuit opening / closing relay and the closing instruction (opening / closing control output ON) to the next stage by the control output relay. A stable connection of solar cell strings is possible.

  Next, the operation when a fire occurs during the interconnected operation will be described. By shutting off the commercial power system at the time of fire extinguishing activity, that is, in a power failure state, the system voltage monitoring means 50 in the connection control device 5 detects a phase voltage abnormality (power failure) of the commercial power system 31, and the contact of the interconnection permission relay 52a Is turned off. Therefore, from the positive electrode (+) of the solar cell module 11a, via the coil of the electric circuit switching relay 41a of the electric circuit switch 4a between the solar cell modules and the coil of the control output relay 42a, the self-standing changeover switch 51a in the connection control device 5 is switched. Since the current path from the COM terminal to the NC terminal (connected operation side), the contact of the connection permission relay 52a, and the negative electrode (−) of the solar cell module 11a is cut off, the contact of the electric circuit switching relay 41a, the control output Both contacts of the relay 42a are opened. That is, the electric circuit between the solar cell module 11a and the solar cell module 11b is opened.

  Further, the opening of the contact of the control output relay 42a means that the opening / closing control output to the next-stage solar cell module electric circuit switch 4b is turned OFF (opening instruction), thereby the solar cell module 11b, the solar Since the current path by the contact of the coil of the electric circuit switching relay 41b, the coil of the control output relay 42b and the control output relay 42a in the electric circuit switch 4b between the battery modules is interrupted, the generated current of the solar cell module 11b does not flow there. . Thereby, the contact of the electric circuit switching relay 41b and the contact of the control output relay 42b in the electric circuit switch 4b between the solar cell modules are opened. That is, the electric circuit between the solar cell module 11b and the next-stage solar cell module is opened. In this way, the electric circuit between the solar cell modules connected in series in the solar cell string sequentially opens from the lowest potential side, and finally the electric circuit between the solar cell modules on the maximum potential side opens, With time, all the electric circuits of the respective solar cell modules in the solar cell string are opened.

  The same operation is performed in the other solar cell strings, and all the electric circuits between the solar cell modules forming the solar cell array 1 are opened. Therefore, even in the daytime, i.e., when there is solar radiation, only a voltage of about 32 VDC is generated as an open voltage for each solar cell module, and there is no high voltage that may cause an electric shock. Fire extinguishing and water discharge activities can be performed.

  In the above description, an example is shown in which the system voltage monitoring means 50 in the connection control device 5 issues an instruction to shut off the electric circuit between the solar cell modules by shutting off the commercial power system when a fire occurs. A disaster monitoring unit may be used instead of the voltage monitoring unit 50. In other words, as a disaster monitoring means, as long as it has a function of taking out an alarm output from a fire alarm installed in a building and issuing an instruction to cut off the electric circuit between each solar cell module based on the alarm output, As in the description above, the high voltage generated by the solar cell strings can be divided into a safe low voltage by a device having a simple configuration and simple wiring work, and the risk of electric shock in the fire fighting activity can be reduced. Further, both the system voltage monitoring means and the disaster monitoring means may be provided, and an instruction to cut off the electric circuit between the solar cell modules may be issued when at least one of a system power failure or a fire alarm occurs.

Next, the operation when the photovoltaic power generation system is operated independently as an emergency power source will be described.
A general power conditioner has a function of self-sustained operation as an emergency power source. When a disaster such as an earthquake occurs and the commercial power system goes out of power for a long time, Even in the state where the interconnection is not performed, it is possible to output the AC power supplied to the load in the house by the input of the generated voltage from the solar cell strings.
In the photovoltaic power generation system 100 according to the present embodiment, in normal operation (interconnection operation), when a power failure of the system is detected, the connection between the solar cell modules is released, so there is no input to the power conditioner 3. It becomes a state. When it is desired to perform a self-sustained operation in such a state, the self-supporting changeover switch 51a in the connection control device 5 is switched to a state where the COM terminal and the NO terminal are connected, that is, the self-sustained operation side. In other words, an operation of outputting a second connection control command for permitting independent operation is performed. Assuming that there is a sufficient amount of solar radiation and that each of the solar cell modules 11a, 11b,..., 11n of the solar cell string 1-1 is generating power, the current generated by the solar cell module 11a at the first stage (lowest potential side) However, from the positive electrode (+) of the solar cell module 11a via the coil of the electric circuit switching relay 41a of the electric circuit switch 4a between the solar cell modules and the coil of the control output relay 42a, the independent switching switch 51a in the connection control device 5 It flows through a route that extends from the COM terminal to the NO terminal (self-supporting operation side) and the negative electrode (−) of the solar cell module 11a. As a result, both the contact of the electric circuit switching relay 41a and the contact of the control output relay 42a are closed. That is, the electric circuit between the solar cell module 11a and the solar cell module 11b is closed, and the opening / closing control output to the next-stage inter-solar cell module electric circuit switch 4b is turned ON (closed instruction).

Similarly, the electric circuit between the solar cell modules is closed, and all the solar cell modules are connected in the solar cell string 1-1. The same operation is performed in other solar cell strings, and the generated power of each solar cell string is input to the connection box 2 and collected into one, and then sent to the power conditioner 3. Receiving this generated power, the power conditioner 3 can carry out a self-sustaining operation.
In the present embodiment, the power source for driving the coil of the electric circuit switching relay 41 and the coil of the control output relay 42 in each electric circuit switch 4 between the solar cell modules is supplied from each solar cell module, not from the commercial power system. Therefore, if there is solar radiation, the solar cell modules can be connected even during a system power failure, which is suitable for carrying out independent operation.

Since the first embodiment is configured as described above, an electric circuit between solar cell modules is usually automatically connected with an increase in the amount of solar radiation by adding a device with a simple configuration and a simple wiring work. In the event of a fire, there is an effect that the fireworks can be safely extinguished by immediately shutting off the electric circuit between the solar cell modules when a fire breaks out.
Furthermore, instead of increasing the current by connecting resistors to lower the voltage, the series connection between the solar cell modules is divided to a sufficiently low voltage level, so it is possible to avoid electric shock with higher reliability. It has become.
In addition, by setting the specifications of the electric circuit switch suitable for the characteristics of the solar cell module, even if the generated power of the solar cell module decreases during low solar radiation, the connection state of the electric circuit is maintained and stable solar cell strings It is possible to continue supplying the power generation output.
Moreover, since the electric circuit switch between solar cell modules operates using the generated electric power of the solar cell module, it does not require a special power supply device and can be realized with an inexpensive and simple configuration.
In addition, since the connection control device is provided with a self-sustained operation permission means, in a long-time power outage state such as a disaster, even if a system voltage is not generated, the solar cell modules of the solar cell strings are connected and operated independently. Can be implemented.

Embodiment 2. FIG.
In the solar power generation system in Embodiment 1, it was set as the structure which inputs the output of the solar cell string formed by connecting the electric circuit between each solar cell module directly to a connection box. The photovoltaic power generation system according to Embodiment 2 further includes means for opening and closing an electric circuit between the solar cell strings and the connection box.
FIG. 5 is a system configuration diagram of the photovoltaic power generation system according to the second embodiment. The configuration and operation of the second embodiment will be described below with reference to FIG.
In addition to the system voltage monitoring means 50, the plurality of interconnection permission relays 52a,..., The plurality of independent switching switches 51a,..., The connection control device 6 includes each solar cell string and a DC switch in the connection box. A plurality of strings relays 63a as a string opening / closing means for opening and closing the electric circuit between them, a plurality of strings connection permission relays 62a for controlling the opening and closing of each string relay, and a second self-supporting interlocking with the self-standing changeover switch 51a,. It is comprised by the changeover switch 61a.

  Next, the above connection will be described with a portion related to the solar cell string 1-1 as a representative. One end of the contact point of the string relay 63a is connected to the output terminal P on the maximum potential side of the solar cell string 1-1, and the other end is connected to the input side of the DC switch 21a in the connection box 2. That is, it is inserted in the middle of the electric circuit between the solar cell string 1-1 and the junction box 2. One end of the coil of the strings relay 63a is connected to one end of the contact of the strings relay 63a, and the other end is connected to one end of the contact of the strings connection permission relay 62a and the COM terminal of the second changeover switch 61a. The other end of the contact of the string connection permission relay 62a is connected to the NO terminal of the second self-supporting changeover switch 61a together with the control output relay 42n- of the inter-solar cell module circuit switch 4n-1 in the last stage in the solar cell string 1-1. 1 is connected to the other end of the contact, that is, the opening / closing control output O to the next stage. The coil of the strings connection permission relay 62a is connected to the output of the system voltage monitoring means 50 in the same manner as the coil of the connection permission relay 52a. Since other configurations are the same as those of the first embodiment (FIG. 4), description thereof is omitted.

Next, the operation of the second embodiment will be described.
First, the operation during normal interconnection operation will be described. When the self-supporting changeover switch 51a is switched to the state where the COM terminal and the NC terminal are connected, that is, to the connected operation side, the second changeover switch 61a that is interlocked is also connected to the COM terminal and the NC terminal. In other words, the COM terminal and the NO terminal are open. Moreover, the system voltage monitoring means 50 in the connection control device 6 monitors the interphase voltage of the commercial power system 31, and if it is normal, the contact of the connection permission relay 52a and the contact of the strings connection permission relay 62a are driven to the ON state. . Here, when the sun rises and the amount of solar radiation increases in the morning, each solar cell module 11a, 11b, ..., 11n of the solar cell string 1-1 starts a power generation operation, and the power generation amount increases. come. Thereby, as described above, the electric circuit switching relay and the control output relay of each solar cell module electric circuit switch are closed, and the solar cell strings 1-1 are fully connected. And the control output relay 42n-1 of the electric circuit switch 4n-1 between the solar cell modules of the last stage will also be in the closed state. Thereby, the solar cell module 11n in the final stage, the coil of the strings relay 63a in the connection control device 6, the contact of the strings connection permission relay 62a, the contact of the control output relay 42n-1 of the inter-solar cell module circuit switch 4n-1 Is formed, and the generated current of the solar cell module 11n flows there. Accordingly, the contacts of the strings relay 63a in the connection control device 6 are closed. That is, the electric circuit between the solar cell strings 1-1 and the junction box 2 is closed. The same operation is performed in the other solar cell strings, and the generated power of each solar cell string is input to the connection box 2 via the respective string relay 63 and collected in the connection box 2, and then to the power conditioner 3. Supply operation is performed.

  When a fire occurs during the interconnection operation, the contact of the interconnection permission relay 52a of the connection control device 6 is opened by the system voltage monitoring unit 50, as in the first embodiment. The electric circuit switch between the solar cell modules sequentially cuts off the electric circuit between the solar cell modules, and all the connections are released. Therefore, even if it is in the state of solar radiation, it will be in a state where only a voltage of about DC32V, which is an open circuit voltage, is generated for each solar cell module, and the risk of electric shocks of firefighters in fire fighting and water discharge activities should be reduced. Can do.

  Note that the operation in the case of performing an independent operation as an emergency power source will be described. By switching the independent switch 51a to the state where the COM terminal and the NO terminal are connected, that is, to the independent operation side, the second interlocked operation is performed. The changeover switch 61a is also switched to a state where the COM terminal and the NO terminal are connected. If there is solar radiation and each solar cell module can generate electric power, the electric circuit of the first-stage solar cell module circuit switch 4a is closed via the self-supporting changeover switch 51a. The switch also sequentially closes the electric circuit, and finally, the power generation of the solar cell module 11n in the path formed by the contact of the solar cell module 11n, the coil of the strings relay 63a, the second changeover switch 61a, and the control output relay 42n-1. A current flows, and the contacts of the strings relay 63a are closed. That is, the solar cell string 1-1 is connected and the electric circuit with the connection box 2 is closed, and DC power is supplied to the power conditioner 3. Therefore, the second embodiment is also configured to be able to perform independent operation.

In the second embodiment, since the contact of the strings relay 63 is turned on after the connection of the solar cell modules in the solar cell strings is completed as described above, the electric circuit switching in the electric circuit switches between the solar cell modules is performed. At the stage where the relay is closed, a closed circuit is not formed by the solar cell strings, the junction box 2, and the power conditioner 3. Therefore, the contact points of the electric circuit switching relays do not close the electric circuit through which a large current flows, and the last strings When the contact of the relay 63 is closed, a closed circuit is formed and a current flows. That is, it is possible to use a relay with a small maximum switching current as each circuit switching relay, and it is possible to reduce the occurrence of failure / deterioration such as contact welding and wear due to the switching current.
In addition, when the voltage of the solar cell strings decreases during sunset or low sunlight, the solar cell strings and the junction box 2 are stopped by stopping the power conditioner 3 first by setting the operable range of the power conditioner 3. In addition, since it is possible to configure so that the electric circuit switching relay in each electric circuit switch between the solar cell modules is opened after the closed circuit by the power conditioner 3 is opened and the current flow ceases, Since a large current is not opened even during the open circuit operation, it is possible to use a device having a small maximum switching current and to reduce the occurrence of failure / deterioration such as contact welding and wear.

Since the second embodiment is configured as described above, as in the first embodiment, a solar cell module is usually automatically added as the amount of solar radiation increases by adding a device having a simple configuration and performing a simple wiring work. In the event of a fire, the circuit between the solar cell modules can be easily interrupted to enable fire fighters to perform safe fire extinguishing activities.
Also, when starting up, the string relays close after all the circuit switching relays in the circuit switches between the solar cell modules are closed, and when the voltage drops at sunset, the power conditioner is stopped before the circuit switching relays are opened. Because it is possible to configure, the contact of the circuit switching relay does not open and close a large current, the maximum switching current of the contact can be reduced and the occurrence of failure / deterioration can be reduced. On the other hand, an effect of realizing an inexpensive and long-life configuration can be obtained.

Embodiment 3 FIG.
In the photovoltaic power generation system according to the second embodiment, the string relay that opens and closes the electric path between the solar cell strings and the connection box is the open / close control output and the interconnection from the inter-solar cell electric circuit switch located at the final stage of the solar cell strings. It is configured to be opened and closed by a permission relay. In the photovoltaic power generation system according to Embodiment 3, the voltage of the solar cell strings is detected, and the opening and closing of the strings relay is controlled by the voltage level.
FIG. 6 is a system configuration diagram of the photovoltaic power generation system according to the third embodiment. The configuration and operation of the third embodiment will be described below with reference to FIG.
In addition to the system voltage monitoring means 50, the plurality of interconnection permission relays 52a,..., The plurality of independent switches 51a,..., The plurality of strings relays 63a,. And a plurality of voltage monitoring devices 71a,... As string voltage detecting means for controlling the opening and closing of each string relay based on the voltage value.

  Next, the above connection will be described with a portion related to the solar cell string 1-1 as a representative. As with the second embodiment, one end of the string relay 63a is connected to the output terminal P on the maximum potential side of the solar cell string 1-1 and the other end is connected to the input side of the DC switch 21a in the connection box 2. Is done. In the voltage monitoring device 71a, the input end i is connected to the output end P of the solar cell string 1-1, the GND end is connected to the COM terminal side of the self-supporting changeover switch 51a, and the output end o is connected to one end of the coil of the strings relay 63a. . The other end of the coil of the strings relay 63a is connected to the GND end side of the voltage monitoring device 71a. Since other configurations are the same as those of the first embodiment (FIG. 4), description thereof is omitted.

Next, the operation of the third embodiment will be described.
First, the operation during normal interconnection operation will be described. It is assumed that the self-supporting changeover switch 51a is switched to the state where the COM terminal and the NC terminal are connected, that is, to the connected operation side. Moreover, if the system voltage monitoring means 50 in the connection control apparatus 7 is monitoring the voltage between phases of the commercial power system 31, and the voltage is normal, that is, if the photovoltaic power generation system can be connected, the connection permission relay 52a Assume that the contact is driven to the ON state. Here, when the sun rises and the amount of solar radiation increases in the morning, each solar cell module 11a, 11b, ..., 11n of the solar cell string 1-1 starts a power generation operation, and as described above, each solar cell. The electric circuit switching relay and the control output relay of the inter-module electric circuit switch are sequentially closed, and the solar cell strings 1-1 are fully connected.

  The voltage monitoring device 71a connected between the output terminal PN of the solar cell string 1-1 via the self-supporting changeover switch 51a and the interconnection permission relay 52a is a string voltage (inter-PN voltage) of the solar cell string 1-1. When the string voltage becomes equal to or higher than the first predetermined value, a relay drive output as a closing command is output from the output terminal o. As a result, a drive current flows through the coil of the strings relay 63a, and the contacts of the strings relay 63a are closed. That is, the electric circuit between the solar cell strings 1-1 and the junction box 2 is closed. In addition, the relay drive output from the output terminal o of the voltage monitoring device 71a uses the generated power of the solar cell string 1-1, and can operate even during a system power failure. The operation is the same in the other solar cell strings, and the generated power of each solar cell string is input to the connection box 2 via the respective string relay, collected in the connection box 2, and then supplied to the power conditioner 3. Then, the interconnection operation is performed.

  When a fire occurs during the interconnection operation, the contact of the interconnection permission relay 52a of the connection control device 7 is opened by the system voltage monitoring unit 50, as in the first embodiment. The electric circuit switch between the solar cell modules sequentially cuts off the electric circuit between the solar cell modules, and all the connections are released. Further, since the voltage monitoring device 71a is disconnected from the output terminal P-N of the solar cell string 1-1, the contact point of the string relay 63a is also opened. Therefore, even if it is in the state of solar radiation, it will be in a state where only a voltage of about DC32V, which is an open circuit voltage, is generated for each solar cell module, and the risk of electric shocks of firefighters in fire fighting and water discharge activities should be reduced. Can do.

  In the third embodiment, the connection of the solar cell modules in the solar cell strings is completed as described above, and the voltage of the string relay 63a is increased after the voltage across the solar cell strings 1-1 becomes equal to or higher than the first predetermined value. Since the contact is turned on, the closed circuit by the solar cell strings, connection box, and power conditioner is not yet formed at the stage where the electric circuit switching relay in the electric circuit switch between the solar cell modules is closed. The contact of the electric circuit switching relay does not close the electric circuit through which a large current flows, but a closed circuit is formed when the last string relay contact is closed, and current flows. That is, it is possible to use a relay with a small maximum switching current as each circuit switching relay, and it is possible to reduce the occurrence of failure / deterioration such as contact welding and wear due to the switching current.

  In addition, when the voltage of the solar cell string drops during sunset or low solar radiation, the voltage monitoring device 71a monitors the string voltage (inter-PN voltage), and when the string voltage falls below the second predetermined value, the circuit is opened. As a command, the relay drive output from the output end o of the voltage monitoring device 71a is stopped. As a result, the drive current to the coil of the strings relay 63a is cut off, and the contacts of the strings relay 63a are opened. That is, the electric circuit between the solar cell strings 1-1 and the junction box 2 is opened. By appropriately setting the second predetermined value, the string relay is first opened to stop the current flowing through the solar cell strings, junction box, and power conditioner path, and then each solar cell module circuit switch It is possible to use a relay with a small maximum switching current because it does not open a large current even during the opening operation. In addition, it is possible to reduce the occurrence of failures and deterioration such as contact welding and wear.

Since the third embodiment is configured as described above, as in the first embodiment, a solar cell module is usually automatically added as the amount of solar radiation increases by adding a device having a simple configuration and performing a simple wiring work. In the event of a fire, the circuit between the solar cell modules can be easily interrupted to enable fire fighters to perform safe fire extinguishing activities.
In addition, when starting up, the string relays are closed after all the circuit switching relays in the circuit switch between each solar cell module are closed, and when the voltage drops at sunset, the strings relay is set by appropriately setting the second predetermined value. Since the circuit switching relay can be configured to open after opening the circuit, the contact of the circuit switching relay will not open or close a large current, reducing the maximum switching current of the contact and reducing the occurrence of failure or deterioration. Thus, an effect of realizing an inexpensive and long-life configuration for a long-time opening / closing operation can be obtained.
Furthermore, the maintenance mainly involves checking and replacing the string relay that opens and closes a large current, so that efficient work can be performed.

Embodiment 4 FIG.
In the solar power generation system in Embodiments 1-3, it was set as the structure which uses the direct-current power which a solar cell module generates as it is as a power source which drives the electric circuit switching relay and control output relay in the electric circuit switch between solar cell modules. In the photovoltaic power generation system according to Embodiment 4, the voltage of the DC power generated by the solar cell module is converted to another voltage value by the voltage adjusting means, and the circuit switching relay or the like is driven by the voltage. .
FIG. 7 is a system configuration diagram of a photovoltaic power generation system according to the fourth embodiment. The configuration and operation of the fourth embodiment will be described below with reference to FIG.

An inter-solar cell module circuit switch 8a includes an electric circuit switching relay 41a as an opening / closing unit that opens and closes an electric circuit, a photocoupler 82a as an output unit that outputs an opening / closing control output to an inter-solar cell module circuit switch, and a voltage. A voltage adjustment circuit 83a as an adjustment means, a bypass prevention diode 84a, and the like are included.
One end of the contact of the electric circuit switching relay 41a is connected to the output cable from the positive electrode (+) side of the solar cell module 11a, and the other end is connected to the output cable from the negative electrode (−) side of the solar cell module 11b. . The voltage adjustment circuit 83a has an input terminal i connected to one end of the contact of the electric circuit switching relay 41a, and a GND terminal connected to the anode of the bypass prevention diode 84a. The cathode of the bypass prevention diode 84a is connected as an opening / closing control input terminal I to the opening / closing control output terminal O of the connection control device 5 via a signal line. The output terminal o of the voltage adjustment circuit 83a is connected to one end of the coil of the electric circuit switching relay 41a and one end of the current limiting resistor 85a. The other end of the current limiting resistor 85a is connected to the photodiode anode of the photocoupler 82a. The cathode of the photodiode of the photocoupler 82a is connected to the GND end of the voltage adjustment circuit 83a, that is, the anode of the bypass prevention diode 84a together with the other end of the coil of the electric circuit switching relay 41a. The emitter of the phototransistor of the photocoupler 82a is connected to the other end of the contact of the circuit switching relay 41a, and the collector of the phototransistor of the photocoupler 82a serves as the switching control output terminal O. Is connected to the open / close control input terminal I via a signal line.
Other solar cell module electric circuit switches 8b,..., 8n-1 are also connected in the same manner. Since other configurations are the same as those of the first embodiment (FIG. 4), description thereof is omitted.

Next, an operation of connecting solar cell strings during normal interconnection operation will be described.
The COM terminal and the NC terminal of the self-sustained changeover switch 51a of the connection control device 5 are connected, that is, switched to the grid operation side, the interphase voltage of the commercial power system 31 is normal, and the connection control device 5 It is assumed that the contact of the interconnection permission relay 52a is ON. When the sun rises and the amount of solar radiation increases, each of the solar cell modules 11a, 11b,..., 11n of the solar cell string 1-1 starts the power generation operation, and the power generation amount increases. The power generation voltage of the solar cell module 11a at the first stage (lowest potential side) is applied to the input terminal i-GND terminal of the voltage adjustment circuit 83a, and when the voltage exceeds an operable value, the voltage adjustment circuit 83a performs the voltage adjustment operation. Starts, and outputs a voltage having a predetermined value to the output terminal o. It is assumed that this output satisfies a voltage value and a current value that can drive the electric circuit switching relay 41a. Furthermore, it is assumed that the current value flowing from the output terminal o through the current limiting resistor 85a to the photodiode of the photocoupler 82a is a value sufficient to turn on the phototransistor of the photocoupler 82a. Accordingly, when the voltage adjustment circuit 83a operates and a voltage having a predetermined value is output to the output terminal o, the contact of the electric circuit switching relay 41a is closed, and the phototransistor of the photocoupler 82a is turned on. That is, the electric circuit between the solar cell module 11a and the solar cell module 11b is closed, and the opening / closing control output to the next-stage inter-solar cell module electric circuit switch 8b is turned ON (closed instruction).

By turning on this switching control output, the generated power of the solar cell module 11b is applied to the voltage adjustment circuit 83b in the inter-solar cell module circuit switch 8b, and the contact of the circuit switching relay 41b and the phototransistor of the photocoupler 82b are turned on. To do. That is, the electric circuit between the solar cell module 11b and the next-stage solar cell module is closed. Thus, the electric circuit between the solar cell modules connected in series is closed in order, and finally the electric circuit between all the solar cell modules of the solar cell string 1-1 is closed. That is, the solar cell strings 1-1 are connected, and DC power from all the solar cell modules of the solar cell strings 1-1 is input to the DC switch 21a of the connection box 2.
The same operation is performed in the other solar cell strings, and the generated power of all the solar cell strings is sent to the power conditioner 3 through the connection box 2 to perform the interconnection operation.

By the way, in Embodiments 1-3, since the coils of the electric circuit switching relay 41 and the control output relay 42 are directly driven by the generated power of the solar cell module, it is difficult to arbitrarily set the relay driving voltage. there were. In the present embodiment, the voltage adjustment circuit 83 drives the electric circuit switching relay 41 and the like. By using a DC / DC step-down switching circuit or the like as the voltage adjustment circuit 83, the input voltage range (output of the solar cell module) Voltage) and output voltage (corresponding to the driving voltage of relays, etc.). Therefore, even if the target solar cell module has a special output voltage specification, an appropriate constant voltage can be supplied to the coil of the relay in the inter-solar cell module circuit switch 8. That is, even if the generated voltage of the solar cell module is in any of a wide range from several tens of volts to 100 V or more, the solar cell module circuit switch 8 can be handled as a standard product.
In the present embodiment, the configuration in which the inter-solar cell module circuit switches 8 are arranged for every solar cell module in the solar cell string, that is, for each solar cell module, has been described as an example. A configuration in which the solar cell module circuit switch 8 is arranged in each solar cell module unit is also possible. That is, if the DC voltage for the two solar cell modules is within the allowable range of the input voltage of the voltage adjustment circuit 83, the solar cell module circuit switch 8 can be arranged for every two solar cell modules. It is possible to reduce the number of solar cell module circuit switches used in the entire solar cell array.
Further, if the output voltage of the voltage adjusting circuit 83 is set to a standard value such as 24 VDC, for example, a large number of standard general-purpose products that are commercially available for the circuit switching relay 41 and the photocoupler 82 that are driven by the output voltage are selected. It becomes selectable, and the electric circuit switch 8 between the solar battery modules can be configured at low cost.

Further, in this embodiment, a photocoupler 82 is used as means for generating an opening / closing control output to the subsequent solar cell module circuit switch, thereby reducing the power consumption of the solar cell module circuit switch 8. A highly reliable output means that is reduced and has no mechanical contact can be configured.
Further, the bypass prevention diode 84 is configured such that when a certain solar cell module cannot generate power for some reason, the generated current of the solar cell module positioned in the preceding stage flows backward from the GND terminal of the voltage adjustment circuit 83 to the input terminal i. This is to prevent the current from flowing to the subsequent solar cell module side, that is, to prevent a bypass current. Although the solar cell module may be partially shaded or fallen on the surface, it may become incapable of generating power. Even in such a case, the bypass prevention diode 84 prevents the bypass current, thereby destroying the voltage regulation circuit 83. Can be prevented.
In addition, since the operation | movement which cancels | releases the connection of a solar cell string when a fire generate | occur | produces during interconnection operation, and the operation | movement in the case of making a solar power generation system operate independently as an emergency power supply, it is the same as Embodiment 1. Is omitted.

Since the fourth embodiment is configured as described above, as in the first embodiment, the solar cell module is usually automatically added with an increase in the amount of solar radiation by adding a device having a simple configuration and a simple wiring work. In the event of a fire, the circuit between the solar cell modules can be easily interrupted to enable fire fighters to perform safe fire extinguishing activities.
In addition, by providing voltage adjustment means in the solar cell module circuit switch, it is possible to handle standard solar cell modules as standard products, and the number of solar cell module circuit switches used in the entire solar cell array. Reduction is possible, and an inexpensive solar power generation system can be configured.
In addition, the structure that prevents bypass currents and the use of parts that do not have mechanical contact parts such as photocouplers can prevent damage and deterioration of the electric circuit switch between solar cell modules and can be used for a long time. It is possible to construct a long-life system.

Embodiment 5. FIG.
In the photovoltaic power generation system according to Embodiment 4, the power generated by the solar cell module is converted to another voltage value by the voltage adjusting means, and the circuit switching relay or the like is driven by the voltage. In the solar power generation system according to the fifth embodiment, a configuration for further stabilizing the connection between the solar cell modules even when the power generation output of the solar cell modules during low solar radiation decreases is added.
FIG. 8 is a diagram illustrating a part of the system configuration of the photovoltaic power generation system according to the fifth embodiment. The configuration and operation of the fifth embodiment will be described below with reference to FIG.

  In FIG. 8, the inter-solar cell module circuit switch 9a has a configuration in which a capacitor 96a that holds the input voltage of the voltage adjustment circuit 83a is added to the inter-solar module circuit switch 8a in the fourth embodiment. The voltage adjustment circuit 83a may originally include a capacitor for holding the input voltage. However, in order to make it easier to understand, FIG. 8 shows the capacitor 96a outside the voltage adjustment circuit 83a.

Next, the operation will be described.
The operation in which each solar cell module starts power generation, the electric circuit of each solar cell module is closed by the electric circuit switch between the solar cell modules, and is connected as a solar cell string is the same as in the fourth embodiment.
When the generated power of each solar cell module decreases due to low solar radiation, a sufficient input voltage to the voltage adjustment circuit 83a in the inter-solar cell module circuit switch 9a cannot be secured, and the output from the output terminal o is not satisfactory. By becoming stable, the operation state of the electric circuit switching relay 41a and the photocoupler 82a also becomes unstable, and the electric circuit with the solar cell module at the next stage and the electric circuit between the solar cell modules after the next stage repeat opening and closing in a short time. There is a concern that motion (chattering) may occur. When chattering occurs, the DC / AC conversion operation of the power conditioner may become unstable, and the contact of the electric circuit switching relay 41a may be worn out, which may lead to early malfunction.
Therefore, it is desirable that the connection of solar cell strings be stable and not chattered, but the output of the solar cell module is always a necessary input to the voltage regulator circuit when the amount of solar radiation is low, especially in the morning and evening sunrise and sunset times. Since it passes through the vicinity of the voltage, the chance of chattering increases.

In the fifth embodiment, when the generated power of the solar cell module decreases due to the low solar radiation state as described above, the operation of the voltage adjustment circuit 83a is made constant by the power stored in the capacitor 96a as the open circuit delay means. It is configured to be able to hold time. That is, even if the power from the solar cell module is reduced, the circuit opening relay 41a and the photocoupler 82a are not turned off immediately, but the circuit opening operation is delayed. If the amount of solar radiation rises again during the delay operation, the generated power of the solar cell module is also recovered, so that the ON / OFF state of the electric circuit switching relay 41a and the photocoupler 82a can be continued. That is, it is possible to reduce chattering when the amount of solar radiation decreases and the output of the solar cell module is in the vicinity of the threshold value (required input voltage of the voltage adjustment circuit).
Further, even when a voltage boosting function is added to the voltage adjustment circuit 83a, it is effective for maintaining the operation of the electric circuit switching relay 41a and the photocoupler 82a when the voltage from the solar cell module is lowered.

The bypass prevention diode 84a also serves as an open circuit delay means, and the stored power of the capacitor 96a passes from the positive electrode (+) side to the negative electrode (−) side of the solar cell module 11a, and the interconnection permission relay 52a, It is prevented from being discharged through a discharge path that passes through the self-supporting changeover switch 51a. That is, the bypass prevention diode 84a also functions as a discharge prevention diode in the present embodiment. In the second-stage and subsequent solar cell module circuit switch 9b, for example, the bypass transistor 84b is connected to the solar transistor 11b and the phototransistor 82a of the photocoupler 82a in the preceding solar cell module circuit switch 9a. Prevents the capacitor 96b from discharging.
Furthermore, since the power consumption can be reduced by using the photocoupler 82 as the output means as in the present embodiment, compared with the case where the control output relay is used, the effect of the open circuit delay means can be increased.

Since the fifth embodiment is configured as described above, the solar cell module is usually automatically and automatically increased with the increase in the amount of solar radiation by the addition of a device having a simple configuration and the simple wiring work as in the first embodiment. In the event of a fire, the circuit between the solar cell modules can be easily interrupted to enable fire fighters to perform safe fire extinguishing activities.
Also, by providing an open circuit delay means in the solar cell module circuit switch, when the generated power of the solar cell module is reduced, the circuit switch relay is opened and the switching control output is turned off for a certain period of time. Therefore, stable solar cell string connection and orthogonal transformation operation of the power conditioner can be obtained. In addition, there is an effect of preventing the contact of the electric circuit switching relay from being worn in a short period of time.
Furthermore, the open circuit delay means includes a configuration that prevents discharge of the capacitor via the solar cell module or the like, and more reliable open circuit delay operation is possible.

Embodiment 6 FIG.
The solar power generation system in Embodiments 1 to 5 is configured to insert an inter-solar cell module circuit switch, which is a separate body from the solar cell module, in the middle of the electrical circuit between the solar cell modules. The solar power generation system in Embodiment 6 is configured using a solar cell module incorporating an electric circuit opening / closing function.
FIG. 9 is a schematic configuration diagram of a solar cell module according to the sixth embodiment, and FIG. 10 is a system configuration diagram of a solar power generation system using the solar cell module according to the sixth embodiment. The configuration and operation of the sixth embodiment will be described below with reference to FIGS.

The solar cell module 33 illustrated in FIG. 9 has the same basic configuration as the solar cell module 11 illustrated in FIG. 2, but the + of the uppermost cell 33Cz among all the solar cells connected in series. Between the pole side and the positive electrode (+) of the solar cell module 33, an electric circuit switching circuit 34 between the solar cell modules is arranged.
The inter-solar cell module circuit switching circuit 34 has the same configuration as that of the inter-solar cell module circuit switch 4a described in the first embodiment. A control output relay 342 is provided as output means for outputting an open / close control output to the battery module.
The contact of the electric circuit switching relay 341 has one end connected to the positive electrode side of the uppermost cell 33Cz and the other end connected to the positive electrode (+) of the solar cell module 33. Further, one end of the contact of the control output relay 342 is connected to the other end of the contact of the electric circuit switching relay 341, and the other end is an external signal output terminal 343 as a signal output end (opening / closing control output end O to the next stage). Connected to. The coil of the electric circuit switching relay 341 and the coil of the control output relay 342 are connected in parallel, one end side thereof is connected to one end side of the contact of the electric circuit switching relay 341, and the other end side is an external signal input terminal 344 as a signal input terminal (previous stage) Open / close control input terminal I).

Next, the structure of the solar power generation system using the solar cell module 33 will be described.
In FIG. 10, the solar cell array 1 is composed of solar cell strings 1-1, ..., 1-m, and each solar cell string includes a plurality of solar cell modules 33a, 33b, ..., 33n-1, 33n. It is the structure connected in series. The other parts are the same as in FIG. Here, the solar cell modules 33a, 33b,..., 33n-1, 33n use the solar cell module inter-circuit circuit circuit switching circuit 34 shown in FIG. As can be seen from FIG. 10, since the configuration of the entire system is the same as that of the first embodiment, the functions of the entire system are also the same. In the present embodiment, since the solar cell module has a built-in electric circuit switching circuit between the solar cell modules, in the wiring work of each solar cell module, via the solar cell module electric circuit switch, which is a separate component. Therefore, it is only necessary to directly connect the solar cell modules to each other, so that work with better workability can be performed.
In addition, in this Embodiment, although the thing of the same structure as the electrical circuit switch 4 between solar cell modules demonstrated in Embodiment 1 was shown as the electrical circuit switching circuit 34 between solar battery modules incorporated in a solar cell module, The solar cell module circuit switch 8 or 9 described in Embodiment 4 or 5 may be used. Further, it can be used in combination with the connection control device 6 or 7 described in the second or third embodiment.

Since the configuration of the sixth embodiment is as described above, as in the first embodiment, a solar cell module is usually automatically added as the amount of solar radiation increases by adding a device having a simple configuration and a simple wiring work. In the event of a fire, the circuit between the solar cell modules can be easily interrupted to enable fire fighters to perform safe fire extinguishing activities.
Moreover, since it was set as the structure which incorporates the electric circuit switching circuit between solar cell modules in a solar cell module, when constructing | assembling the solar cell string which has an electric circuit switching function, the effect that wiring work can be implemented more efficiently is acquired.

1-1 Solar cell string 11 Solar cell module 4 Electric circuit switch between solar cell modules 41 Electric circuit switch relay 42 Control output relay 5 Connection control device 100 Photovoltaic power generation system

Claims (4)

Solar cell strings in which a plurality of solar cell modules are connected in series via an electric circuit;
A plurality of solar cell module circuit switches that are installed in the middle of the circuit and have an opening / closing unit that opens and closes the circuit, and an output unit that outputs an opening / closing control output;
Connection control means for outputting a connection control command for controlling the connection of the solar cell strings,
The electric circuit switch between the solar cell modules in the first stage is based on the connection control command from the connection control means and the generated electric power of at least one solar cell module group connected in series to the front stage side of the electric circuit where it is installed. Open and close its own opening and closing means and output its own opening and closing control output,
The circuit switch between the solar battery modules in the next and subsequent stages is an electric circuit in which the circuit switch between the solar battery modules in the previous stage is installed from the switching control output from the circuit switch between the solar battery modules in the previous stage and the self-installed circuit. A solar power generation system that opens and closes its own opening and closing means and outputs its own opening and closing control output based on the generated power of at least one solar cell module group connected in series until now. Sending a connection command that requires electrical connection between the solar cell modules,
Based on the connection command, close the first serially arranged solar cell module electrical circuit, and transmit the connection command to the next stage,
Based on the transmitted connection command, close the second solar cell module electric circuit arranged in series, and further transmit the transmitted connection command to the next stage,
Thereafter, the connection between the solar cell modules is electrically connected to the plurality of solar cell modules arranged in series by sequentially closing the electric circuit between the solar cell modules based on the sequentially transmitted connection command. Method. When at least one solar cell module group connected in series on the front side of the target electric circuit has a generated power of a predetermined value or more, the target electric circuit is closed based on the transmitted connection command. The method for connecting electric circuits between solar cell modules according to claim 2, wherein the connection command is transmitted to the next stage. Send a release command requesting to release the electrical connection of the electric circuit between the solar cell modules,
Based on the release command, open the first serially arranged solar cell module circuit, and transmit the release command to the next stage,
Based on the transmitted release command, the second series-arranged solar cell module circuit is opened, and the transmitted release command is further transmitted to the next stage,
Thereafter, the electrical connection between the plurality of solar cell modules arranged in series is released by sequentially opening the electric circuit between the solar cell modules based on the sequentially transmitted release command. Electric circuit cancellation method.

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