JPH09201061A - Photovoltaic power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photovoltaic power generation system which reduces the labor of an installation operation, which is extended easily and which can restrain the temperature rise of a solar cell. SOLUTION: Every solar cell module 11 is formed in a panel shape, and a plurality of solar cell modules are used to obtain a prescribed electric power. An inverter 12 is installed at every solar cell module 11, and the DC output of every solar cell module 11 is input to the inverter 12 via a diode 13 for reverse-current prevention. The solar cell module 11, the inverter 12 and the diode 13 for reverse-current prevention are constituted integrally, and a photovoltaic power generation module 10 is constituted. The AC output of the inverter 12 at the photovoltaic power generation module 10 is supplied to a link control protective module 15 provided with a switch used to divide the photovoltaic power generation module 10 via a power line 14. The output of the link control protective module 15 is suppled to a distribution line 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar power generation system that operates in parallel with each other or with other power sources.

[0002]

2. Description of the Related Art In recent years, small-scale power generation systems using natural energy such as solar power generation and wind power generation have been attracting attention, and solar power generation systems are becoming popular mainly for residential use. FIG. 6 is a schematic configuration diagram of a solar power generation system that has been conventionally used. In FIG. 6, 1A and 1B are solar cell modules that receive sunlight to generate power, and a plurality of solar cell modules 1A and 1B ( For example, about 100 solar cells are arranged side by side in a rectangular frame, and the cells are connected in series to form a panel. The DC output generated by the solar cell modules 1A and 1B thus configured is supplied to the inverter 3 via the connection box 2. The junction box 2 is composed of backflow prevention diodes 2A and 2B and a switch 2C that prevent direct current from flowing back to the solar cell modules 1A and 1B from another power supply system. The inverter 3 converts the input DC into AC and is connected to another power supply system via the switch 4. Reference numeral 5 denotes an interconnection protection device. The interconnection protection device 5 detects an abnormality such as a power failure in another power supply system during interconnection, and disconnects the solar power generation system from the other power supply system. It is for.

[0003]

However, the conventional photovoltaic power generation system has many components, requires a lot of time for installation, and has a problem of high cost in the case of a small capacity system. Further, when adding a solar cell module, if the total output of the solar cell module becomes larger than the output of the inverter, it is necessary to add the inverter or replace the inverter with a larger output. For this reason, there is also a problem that the expansion cannot be easily performed. In addition, there is a problem that the temperature of the solar cell that receives sunlight rises and the power generation efficiency decreases when the sunlight is strong such as in summer.

The present invention has been made in view of the above circumstances, and saves the trouble of installation and facilitates the addition, and
An object of the present invention is to provide a photovoltaic power generation system capable of suppressing a temperature rise of a solar cell.

[0005]

In order to achieve the above-mentioned object, the present invention provides a solar power generation module by incorporating an inverter in the lower surface of a panelized solar cell module. It is characterized in that an AC output is directly obtained from the photovoltaic module.

A second aspect of the invention is characterized in that the inverter is provided with a parallel operation function so that a plurality of photovoltaic modules are operated in parallel.

A third aspect of the invention is characterized in that the solar power generation module and another power supply system are operated in parallel via an interconnection control protection device.

According to a fourth aspect of the present invention, a heat recovery device with a heat rectifying function is provided on the lower surface of the solar cell module, and the heat recovery device efficiently recovers the heat generated by solar radiation and suppresses the temperature rise of the solar cell module. The feature is that the recovered heat is used at the same time as the power generation efficiency is improved.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention. In FIG. 1, 11 is the solar cell module shown in FIG.
Is a panel, and a plurality of solar cell modules are used to obtain a predetermined electric power. Each of these solar cell modules 11 is provided with an inverter 12,
The DC output of the solar cell module 11 is input to the inverter 12 via the diode 13 for backflow prevention. The inverter 12 is provided with a function that enables parallel operation, which will be described later. Then, the solar cell module 11, the inverter 12, and the backflow prevention diode 1 are provided.
The solar power generation module 10 is configured by integrally configuring 3 and 3.

Inverter 1 of photovoltaic module 10
The AC output of 2 has a function of connecting to a connection point with another power supply system via the power line 14 and oscillating a synchronization signal for parallel operation,
It is supplied to the interconnection control protection module 15 that has a function of detecting an abnormality in another power supply system and a switch (contactless switch) that separates the other power supply system from the photovoltaic power generation module 10. It The output of the interconnection control protection module 15 is supplied to the distribution line 16. A control line 17 shown by a broken line in the drawing is provided between the inverter 12 of the photovoltaic power generation module 10 and the interconnection control protection module 15 so as to exchange control signals.

The main control units of the inverter 12 and the interconnection control protection module 15 are integrated into a microcomputer and integrated into one chip. The solar power generation modules 10 are operated in parallel with each other or with other power supply systems, and the output of the solar power generation module 10 is increased. The control, the control and protection of the inverter, the abnormality detection of the other power supply system, and the disconnection of the solar power generation module 10 are automatically performed. Thereby, the solar power generation module 10
By connecting the interconnection control protection module 15 to the solar power generation module 10 and another power supply system in parallel, the solar power generation system can be easily installed and expanded.

In the solar power generation system configured as described above, the solar cell module 11 sends direct current to the output when it receives sunlight. This DC output is input to the inverter 12 via the backflow prevention diode 13. The inverter 12 receives the synchronization signal from the interconnection control protection module 15 and creates a switching signal (ON / OFF signal) synchronized with this signal. With this switching signal, switching elements such as a transistor and a thyristor that form the inverter 12 are turned on and off to output an alternating current synchronized with another power supply system.

Here, a schematic block configuration provided with a parallel operation function of the inverter 12 will be described with reference to FIG. FIG.
15A and 15B are interconnection control protection module 1
In the PLL control unit and the protection setting / abnormality detection unit provided in 5, the system frequency is input to the PLL control unit 15A, and the system frequency and the system voltage are input to the protection setting / abnormality detection unit 15B. The PLL control unit 15A outputs a synchronization signal for parallel operation of the inverter 12 from the system frequency, and the protection setting / abnormality detection unit 15B outputs a system abnormality signal.

The synchronization signal output from the PLL control unit 15A is input to the PWM signal generation unit 22 including a microcomputer and a memory via the interconnection / single changeover switch 21. The output signal of the PWM signal creation unit 22 is the inverter 12
Is input to the ON / OFF signal generating unit 23. On the other hand, the inverter output voltage and output current are
After being D-converted, the signal is input to the output control unit 25 composed of a microcomputer, and the signal output from this output control unit 25 is turned on.
・ OFF signal generator 23 supplies this ON / OFF signal
The signal generator 23 uses the PWM signal and the ON / OFF signal generated by the PWM signal generator 22 to drive the inverter 1
Two control signals are created.

Reference numeral 26 denotes a protection setting unit, which is the protection setting unit 26.
The inverter output voltage and current, and the output voltage and current from the solar cell module 11 are input to. The output of the protection setting unit 26 is input to the abnormality detection unit 27. A system abnormality signal from the protection setting / abnormality detecting unit 15B is also input to the abnormality detecting unit 27, and the abnormality detecting unit 27 sends an abnormality detecting signal from them to turn off the contactless switch 28. In addition, 29 is an oscillator for independent operation, and 30 is a transmission interface. Connections to other photovoltaic modules are made via the transmission interface 30.

Using the apparatus constructed as described above,
The parallel operation function of the inverter can be easily performed, and the DC output voltage and current of the solar cell module 11 and the AC output voltage and current of the inverter 12 are detected to change the ON / OFF time of the switching element. , Output can be controlled. In addition to these, there is a function of detecting a failure of the inverter 12 such as an abnormality of a switching element and stopping the inverter 12, and further,
It has a function to automatically operate and stop the inverter 12 by the DC output voltage of the solar cell module 11, and a function to receive the grid connection abnormality signal from the grid connection control protection module 15 and disconnect the photovoltaic power generation module 10 from the grid. ing. Each control described above is performed by a control unit in which a microcomputer, a memory, an ON / OFF signal generation unit, a module protection setting unit, and a transmission interface unit are integrated into one chip.

When only the photovoltaic power generation module 10 is operated in parallel, the reference photovoltaic power generation module 10 is used.
Is set, and a synchronizing signal is generated by the inverter 12 of the module 10 to be distributed to other photovoltaic modules.

Next, the interconnection control protection module 15 will be described. This module 15 detects the voltage, current, and frequency of another power supply system, creates a synchronization signal synchronized with the frequency and phase of the system by PLL (phase locked loop) control, and detects system abnormalities such as power failure. To do. The synchronization signal and the system abnormality signal are transmitted to the photovoltaic power generation module 10 through the control line (communication line) 17 or the power line that transmits the power generation output.

The above control is performed by the control unit in which the microcomputer, the memory, the PLL control unit, the interconnection protection setting unit, and the transmission interface unit are integrated into one chip as described above.

FIG. 3 is a schematic block diagram showing a second embodiment of the present invention. In FIG. 3, 10A and 10B are solar power generation modules installed in plural, and these solar power generation modules 10A and 10B are respectively installed. Inverter 12
A and 12B and backflow prevention diodes 13A and 13B are provided, and the direct current outputs of the solar cell modules 11A and 11B are input to the inverters 12A and 12B via the backflow prevention diodes 13A and 13B. There is.

Both solar power generation modules 10A and 10B are operated in parallel and the solar cell modules 11A and
The solar power generation modules 10A and 10B are provided with collectors 18A and 18B with a heat rectification function to suppress the temperature rise of 11B and to increase power generation efficiency, and are configured to effectively use the recovered heat as hot water. To be done. 19A, 1
9B is a connector installed in the photovoltaic power generation modules 10A and 10B, and these connectors 19A and 19B are for connecting the AC output terminals of the inverters 12A and 12B and the control line 17 for parallel operation. As a result, both electric power generated by the solar power generation modules 10A and 10B is output from the connector 19B and supplied to the load 20. In addition,
Heat recovery is performed by the collectors 18A and 18B with a heat rectification function incorporated in the solar power generation modules 10A and 10B, and hot water is supplied to, for example, a bath.

Now, the collectors 18A and 18B with a heat rectifying function will be described with reference to FIG. A cooling water passage 41 is provided on the lower surfaces of the photovoltaic power generation modules 10A and 10B, and a plurality of heat pipes 42 are inserted between the cooling water passage and the solar cell module 11. Both ends of the heat pipe 42 are connected to the solar cell module 11 respectively.
Is in contact with the cooling water passage 41, and the position on the cooling water side is high. For this reason, the refrigerant that has taken away the heat of the solar cell module 11 and evaporated rises toward the cooling water side, and when cooled by the cooling water and liquefied, this time it descends toward the solar cell module 11 side. By repeating this phenomenon, the cooling water can recover the heat of the solar cell module 11.
Any refrigerant can be used as the refrigerant. 43 is a heat insulating material.

FIG. 5 is a schematic configuration diagram showing a third embodiment of the present invention. The same parts as those of the second embodiment of FIG. 3 are designated by the same reference numerals. In FIG. 5, the photovoltaic power generation module 1
0A and 10B are provided with outlets 31A and 31B for parallel operation of the inverters 12A and 12B, and AC outlet plug 32A of the inverter 12A is inserted into the outlet 31B for parallel operation of the inverters. Inverter 1
The AC output plug 32B of 2B is inserted into an outlet 33A provided in the interconnection control protection module 33. The interconnection control protection module 33 is inserted into an outlet 34 provided in the indoor wiring. In the third mode, signal transmission between the interconnection control protection module 33 and the photovoltaic power generation modules 10A and 10B is performed by using the power line without providing the control line.

[0024]

As described above, according to the present invention,
By simply connecting the photovoltaic power generation module to another power supply system via the interconnection control protection module, the photovoltaic power generation system can be easily operated in parallel with the other power supply system.
Also, when it becomes necessary to add more photovoltaic power generation modules, it becomes possible to operate the photovoltaic power generation modules in parallel by connecting the AC outputs of the multiple photovoltaic power generation modules. Etc. installation,
Removal, relocation, and expansion will become easier, and cost will be reduced. In addition, the heat recovery device built into the photovoltaic power generation module can suppress the temperature rise of the solar cell, which makes it possible to improve the power generation efficiency and effectively use the recovered heat as hot water. There are various advantages such as being possible.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration including a parallel operation function of inverters.

FIG. 3 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a collector having a heat rectification function.

FIG. 5 is a schematic configuration diagram showing a third embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a solar power generation system.

[Explanation of symbols]

 10, 10A, 10B ... Photovoltaic power generation module 11 ... Solar cell module 12, 12A, 12B ... Inverter 13, 13A, 13B ... Backflow prevention diode 14 ... Power line 15 ... Interconnection control protection module 16 ... Distribution line 17 ... Control line

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H02J 3/38 H02J 7/35 K 7/35 H01L 31/04 K

Claims (4)

[Claims] 1. A photovoltaic power generation system characterized in that an inverter is incorporated in the lower surface of a panelized photovoltaic cell module to form a photovoltaic power generation module, and an AC output can be directly obtained from the photovoltaic power generation module. . 2. The solar power generation system according to claim 1, wherein the inverter has a parallel operation function so that a plurality of solar power generation modules are operated in parallel. 3. The solar power generation system according to claim 1, wherein the solar power generation module and another power supply system are operated in parallel via an interconnection control protection device. 4. A heat recovery device with a heat rectifying function is provided on the lower surface of the solar cell module, and the heat recovery device efficiently recovers heat from solar radiation and suppresses temperature rise of the solar cell module to improve power generation efficiency. A solar power generation system characterized by using recovered heat at the same time as raising it.