KR20210046322A - A diode that prevents backflow to protect direct and parallel converter connections that track the maximum power point of two solar modules - Google Patents

Abstract

The present invention relates to a serial/parallel converter connection device for tracking the maximum power point of two solar modules. An internal circuit of the serial/parallel converter connection device for tracking the maximum power point of the two solar modules equipped with a diode preventing backflow of a high voltage and high current input and output from the serial/parallel converter connection device is protected. The serial/parallel converter connection device for tracking the maximum power point of two external solar modules, as well as the string, connection panel, and inverter are to be protected.

Description

{A diode that prevents backflow to protect direct and parallel converter connections that track the maximum power point of two solar modules}

The present invention measures the voltage for each serial/parallel converter connecting device that tracks the maximum power point of two solar modules, and when the value measured through the control unit is input to the inverter through the connection panel, the input voltage is less than the MPPT lower limit value. , When a problem occurs in any one of the connection devices on the string according to the control program for the upper and lower limit values of the inverter MPPT set in the connection panel when the serial/parallel converter connection device that tracks the maximum power point of each solar module 2 By connecting two solar modules in series through the switching part of the connection device in which the problem occurs, the connection panel controls the problem connection device on the string so that the input voltage to the inverter is within the MPPT setting range. The serial/parallel converter connecting devices that track the maximum power points of the two solar modules are connected in series.The internal circuits and components are stably protected from the power produced by the devices, and the power produced by the devices is output. The present invention relates to a reverse flow prevention diode installed to prevent the high voltage on the string to which the serial/parallel converter connection devices are connected to track the maximum power point of two other photovoltaic modules from flowing back to the device during the process.

The lifetime of each and every battery cell constituting a solar module is not the same. When each of these battery cells fails, the power generation efficiency of the entire or an assembly including the failed cells is significantly lowered. In addition, heat generation of the faulty cell may cause secondary failure of the entire panel.

Photovoltaic (PV) is a power generation method that directly converts infinite, pollution-free solar energy into electrical energy. When solar radiation is irradiated to the PN junction where the p-type and n-type semiconductors of a solar cell are bonded. (solar radiation) Generates electrons with negative (-) charge free to move in n-type semiconductors and holes with positive charge in p-type semiconductors to prevent the movement of electrons across the pn junction. Accordingly, a built-in electric field is generated, and voltage and potential are generated according to the fluctuations of positive and negative charges. In a solar cell, a photovoltaic power is generated between the two electrodes (+) and (-) due to the photovoltaic effect at the p-n junction to generate a DC current and a DC voltage.

A typical conventional technology is disclosed in Korean Patent No. 10-1880944 (2018.07.17), the name of the invention "solar connection panel reverse power prevention device". 3 is a schematic block diagram of a photovoltaic power generation system including a device for preventing reverse power on a solar connection panel according to the present invention, and a circuit for checking the state of the diode 12 for preventing reverse power in the connection panel 6 according to the present invention. It is a configuration diagram.

The solar power generation system includes a solar cell string 4 in which a plurality of solar cell strings 2 are arranged in which a plurality of solar cell modules 2a are arranged for solar power generation. It includes a connection panel 6 for merging DC power output from the battery strings 2, and an inverter 16 for converting DC power supplied from the connection panel 6 into AC power. The AC power converted by the inverter 16 is provided to the switchboard and is configured to be transmitted to various loads.

The connection panel 6 is a means for merging DC power output from the plurality of solar cell strings 2 and outputting it to the inverter 16, which is connected in series to the output terminal of the solar cell string 2 as shown in FIG. A power fuse (8), a reverse power prevention diode (12) connected to the power fuse (8) to prevent reverse power, and a current transformer (10) connected to the reverse power prevention diode (12) to detect current in the line ) And other circuits. According to the present invention, the connection panel 6 is connected between each solar cell string 2 and the inverter 16, and prevents damage to the solar cell module 2a in the solar cell string 2 due to reverse voltage and reverse current. The diodes 12 for preventing reverse power for each solar cell string 2 are provided for each solar cell string 2, but the individual state of the diode for preventing reverse power 2 can be immediately grasped with the naked eye according to the characteristics of the gist of the present invention. It is provided with a diode individual state check unit 14 for preventing reverse power.

The diodes 12 for preventing reverse power installed in the junction panel 6 are capable of generating photovoltaic power only during the daytime, and due to the characteristics of customer demand, reverse voltage and reverse voltage, which may include surges, are other factors. Ryu is approved from time to time and plays a role in preventing this. However, if it can be determined as in the present invention whether the reverse power prevention diode 12 is normal or if it is a failure, as in the present invention, as well as determining whether to replace the reverse power prevention diode 12 or not, the solar cell string 2 It is possible to easily determine whether or not a malfunction or defect.

In the present invention, a reverse power prevention diode individual state check unit 14 is provided in the connection panel 6, but each of the reverse power prevention diodes 12, which is one for each solar cell string 2, is provided.

This prior art relates to a photovoltaic connection panel reverse power prevention device, and a connection panel 6 that combines DC power output from a plurality of solar cell strings 2 in a photovoltaic power generation system and provides it to an inverter 16 And, the connection panel 6 is connected between each solar cell string 2 and the inverter 16, and reverse power prevention diode 12 for preventing damage to the solar cell module 2a due to reverse voltage or reverse current. ), but each connected in parallel to each reverse power prevention diode 12, and a diode operation monitoring circuit unit 14a including an operation status indicator lamp (L1) and a diode failure including a failure status indicator lamp (L2). A diode individual state check unit 14 for preventing reverse power, which is a monitoring circuit unit 14b, is configured in the connection panel 6, and the diode operation monitoring circuit unit 14a and the diode failure monitoring circuit unit 14b are input/output of the reverse power prevention diode. By comparing the voltage value (VA) (VB) of the stage, the current status of each reverse power prevention prevention diode 12 is displayed on and off the operation status display lamp (L1) and the fault status display lamp (L2). 6) It allows you to immediately grasp the site.

Existing photovoltaic connection panel reverse power prevention devices including diodes that control strings made up of strings of more than 16 modules control overvoltage and overcurrent at an early stage and cannot expect fire prevention effects. In addition, since it is a system that controls strings and handles high voltages, it is difficult to control, resulting in a high cost and lowering efficiency. In the process of stably protecting the internal circuits and parts of the serial/parallel converter connection device that tracks the maximum power point of the two solar modules and outputting the power produced by the serial/parallel converter connection devices, another solar module 2 This is to protect two solar modules by initially preventing the high voltage on the string to which the serial/parallel converter connecting devices that track the maximum power point of the field are connected and flowing back to the device.

The present invention is invented to solve the above problems,

The serial/parallel converter connection device that tracks the maximum power point of the two solar modules is connected in series and parallel to maximize the power of the two solar modules. The power generated by the device is connected to the high voltage on the string. In the case of shading on a part of the module that occurs during the process, the cell may be damaged due to hot spots due to current concentration. In order to stably protect the internal circuits and components of the connection device, a reverse flow prevention diode is installed in the serial/parallel converter connection device that tracks the maximum power point of two solar modules.

It is desirable to install a reverse flow prevention diode in the serial/parallel converter connection device that tracks the maximum power point of two solar modules to prevent reverse flow of input and output voltage and current.

With this configuration, it is possible to control fire from overvoltage at the beginning by simply changing the configuration by adding a diode that prevents reverse flow to the serial/parallel converter connecting device that tracks the maximum power point of two solar modules.

In addition, the present invention is a means for solving the above problems, and the reverse flow prevention device of the above configuration tracks the anode of the output diode of the output unit of the switching unit 500 and the maximum power point of each of the two solar modules. The output part and the input part of the serial/parallel converter connection devices 101, 102, 103 ... are connected to the high voltage backflow prevention diode cathode.

With this configuration, when a serial/parallel converter connecting device that tracks the maximum power point of two solar modules in a set of two modules uses a series/parallel switching switching unit to operate two modules in series/parallel. The serial/parallel converter connection device 102, which tracks the maximum power point of the second solar module two, is output to the anode of the reverse flow prevention diode, and the second solar module 2 The voltage drawn from the serial/parallel converter connection device 101 that tracks the maximum power point of the first two solar modules input to the OUT terminal of the serial/parallel converter connection device 102 that tracks the maximum power point of the field and When overvoltage and overcurrent flow in the process of collecting current, the reverse current on the serial/parallel converter connection device 103 side is controlled by the reverse flow prevention diode cathode and tracks the maximum power point of two third solar modules. The series/parallel converter that tracks the maximum power point of two solar modules because the voltage and current are controlled by preventing the input to the serial/parallel converter connecting device 102 that tracks the maximum power point of two solar modules. It can protect the internal circuit of the connection device and control the fire in the early stage.

In order to protect the serial/parallel converter connection device that tracks the maximum power point of two solar modules, a reverse flow prevention diode is installed. This is not only in clear weather, but also in low/high voltage due to sunrise, sunset, rain, and cloudy weather. Its purpose is to provide a technology that enables stable solar power generation by controlling it. This prevents fire at the beginning and protects the internal circuit of the serial/parallel converter connection device, which tracks the maximum power point of each of the two solar modules, and the inverter and the string connection panel. It relates to a reverse flow prevention diode for protecting a tracking serial/parallel converter connection device.

A brief description of the drawings of the embodiments illustrated for the present invention is as follows.
1 is a circuit diagram showing an entire configuration in which a reverse flow prevention diode is installed to protect a serial/parallel converter connection device that tracks the maximum power point of two solar modules according to the present invention,
2 is a block diagram showing the configuration of a reverse flow prevention diode for protecting a serial/parallel converter connection device that tracks the maximum power point of two solar modules according to the present invention,
3 is a view showing the overall configuration of the solar connection panel reverse power prevention device disclosed in a typical prior art,

1 Hereinafter, an embodiment according to the present invention will be described with reference to the accompanying drawings. In addition, in the following description, terms indicating a specific direction or position (e.g., terms including'top','bottom','side', and'edge') are used as necessary, but the use of these terms Is to facilitate understanding of the invention with reference to the drawings, and the technical scope of the invention is not limited by the meaning of these terms. In addition, the following description is essentially merely an illustration, and the present invention is not intended to limit its applications or uses. The size of each component may be exaggerated for the sake of explanation, and does not mean a size that is actually applied.

In order to solve the failure of the entire solar power plant due to the above overvoltage and overcurrent, a reverse flow prevention diode 800 may be applied. To this end, as in the embodiment of the present invention, the anode of the high voltage reverse flow prevention diode 800 connected to the series/parallel switching switching unit 500 of the serial/parallel converter connecting device that tracks the maximum power point of two solar modules. This problem can be solved through. The internal circuit of the serial/parallel converter connection device in which the overvoltage and overcurrent generated from the serial/parallel converter connection device tracking the maximum power point of any two solar modules not specified above track the maximum power point of each solar module two The reverse flow prevention diode 800 to protect the inverter and the serial/parallel switching switching unit 500 installed in the serial/parallel converter connection device that tracks the maximum power point of the two solar modules consisting of two modules It can be initially prevented by using the connected diode 800.

1 to 2 show a backflow prevention device 800 according to the present embodiment. Referring to FIG. 1, the backflow prevention device 800 includes each (+), (-) input terminal 100 of module 1 and module 2 according to an embodiment, and each of module 1 and module 2 (+), ( -) The voltage/current detection unit 200 applied to the control unit 300 by sensing the voltage/current input from the input terminal 100, and a signal output from the voltage/current detection unit 200 are received and a control signal is directly received. By converting the input voltage/current applied from the control unit 300 output to the parallel switching switching unit 500, each of the (+) and (-) input terminals 100 of the module 1 and module 2 into a low square wave voltage It is composed of a switching rectifier 400 that outputs a low output to the serial/parallel switching switching unit 500, and a serial/parallel switching switching unit 500 that is turned on/off by the control unit 300, respectively. When overvoltage and overcurrent flow in the process of collecting output and incoming voltage and current to the OUT terminal of the serial/parallel converter connecting device that tracks the maximum power point of two solar modules, a fuse or PTC to prevent fire at the beginning. (700) controls overvoltage and overcurrent, and prevents reverse current from flowing into the OUT terminal of the serial/parallel converter connection device that tracks the maximum power point of each of the two solar modules. It is composed of a reverse flow prevention diode 800 and a communication unit 600 that monitors them in a serial/parallel converter connecting device that tracks the maximum power point.

The output terminal of the serial/parallel converter connection device 101 that tracks the maximum power point of the first two solar modules is prevented from reverse flow of the serial/parallel converter connection device 102 that tracks the maximum power point of the second solar module two. It is connected to the cathode of the diode 800. The output terminal of the serial/parallel switching switching unit 500 mounted on the serial/parallel converter connecting device 102 that tracks the maximum power point of the second solar module 2 is used to track the maximum power point of the 2 second solar module. The input terminal of the serial/parallel converter connection device 103 is connected to the anode of the reverse flow prevention diode 800 of the serial/parallel converter connection device 102 and tracks the maximum power point of two third solar modules. It is connected to the cathode of the reverse flow prevention diode 800 of the serial/parallel converter connecting device 102 that tracks the maximum power point of two optical modules. The output terminal of the serial/parallel converter connection device 103 that tracks the maximum power point of two third photovoltaic modules is the serial/parallel converter connection device 104 that tracks the maximum power point of two fourth photovoltaic modules. 800) of the anode and the 4th to the 5th, the 5th to the 6th… Connect the serial/parallel converter connection device that tracks the maximum power point of each two solar modules as much as the number up to the MPP that the inverter accepts, etc.

A serial/parallel converter connection device 101 for tracking the maximum power points of the first two solar modules, the serial/parallel converter connection device 102 for tracking the maximum power points of the second two solar modules, the first 3 A serial/parallel converter connection device 103 that tracks the maximum power point of two solar modules is fastened by a reverse flow prevention diode 800.

In the serial-parallel converter connection device for tracking the maximum power point of two solar modules in a region formed in a shape, a serial-parallel switching switching unit 500 is disposed. A diode 800 is connected to a first switching output-side connection terminal and a second switching output-side connection terminal to the serial/parallel switching switching unit 500.

More specifically, the backflow prevention device of the above-described configuration is employed in a solar power generation system so that the diode 800 tracks the occurrence or damage of fire or the maximum power point of the first two solar modules due to overvoltage and overcurrent. It can be used to prevent damage to the internal circuit of the connection device due to reverse flow of overvoltage and overcurrent from the series/parallel converter connection device 101 to the series/parallel converter connection device 102 that tracks the maximum power point of two second photovoltaic modules. have.

In Fig. 2, the serial/parallel converter connecting device tracking the maximum power point of each of two solar modules is serial/parallel conversion through each of the (+) and (-) input terminals 100 of module 1 and module 2. The maximum voltage produced by the switching unit 500 is within 100V, and the voltage input from each serial/parallel converter connecting device 200 on the string is a high voltage of 500V or more. Therefore, a series/parallel switching switching unit 500 is connected to the anode of the diode 800, and two contact series/parallel switching switching units 500 are connected to the input unit of the diode 800 to prevent the high voltage from flowing back to the internal circuit. This is to prevent. In addition, the serial/parallel switching switching unit 500 is connected to the first input-side connection terminal 21, and the control unit 300 is provided between the first input-side connection terminal 21 and the second input-side connection terminal 22. connected. In addition, the anode of the diode 800 is between the first output-side connection terminal 25 of the series/parallel conversion switching unit 500 and the second output-side connection terminal 23 of the series/parallel conversion switching unit 500. connected.

In the solar power generation system of the above-described configuration, the serial/parallel converter connecting device for tracking the maximum power point of each of the two solar modules includes the (+), (-) input terminals (100) of the module 1 and the module 2, respectively. ), the voltage and current flow to the serial/parallel switching switching unit 500.

When the voltage value flowing through the serial/parallel switching unit 500 due to strong sunlight is greater than or equal to a set value (eg, inverter setting MPP), the first and second switching terminals are changed in parallel, and thus the solar module In the serial/parallel converter connection device that tracks the maximum power points of two modules, the voltage and current supplied from each of the (+) and (-) input terminals (100) of module 1 and module 2 are the maximum of the second photovoltaic module. The diode 800 of the serial/parallel converter connection device 102 tracks the maximum power point of two second photovoltaic modules through the anode of the diode 800 of the serial/parallel converter connection device 102 that tracks the power point. It is output through the cathode. In the meantime, the voltage and current generated by the diode 29 are input through the cathode of the diode 800 of the serial/parallel converter connection device 103 that tracks the maximum power point of the third photovoltaic module. The cathode of the diode 800 of the serial/parallel converter connecting device 103 that tracks the maximum power point of the two solar modules of is connected to the input of the previous step and the output of the next step at the same time. This is a serial/parallel converter connecting device of two solar modules, which prevents voltage and current from flowing into the internal circuit in reverse flow, and it becomes possible to prevent damage to the internal circuit.

In addition, the present invention is not limited to the configuration described in the above-described embodiment, and various modifications are possible. For example, in the above-described embodiment, one diode 800 is configured, but it is also possible to connect two or more diodes in parallel.

The fuse or the PTC 700, the reverse flow prevention diode 800, and the communication unit 600 may be separated from the circuit board inside the serial/parallel converter connecting device that tracks the maximum power points of the two solar modules. To this end, the reverse flow prevention diode 800 may be configured to be detachable. The reverse flow prevention diode 800 may be formed including a detachable portion formed to be detachable from the cable. In the cable, an anode may be connected to a cathode of the reverse flow prevention diode 800.

In addition, although the embodiments have been described above, these are only examples and do not limit the present invention, and those of ordinary skill in the field to which the present invention belongs are illustrated above without departing from the essential characteristics of the present embodiment. It will be seen that various modifications and applications that have not been made are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

100: Each (+), (-) input terminal of module 1 and module 2
101: Serial/parallel converter connection device tracking the maximum power point of two first solar modules
102: Serial/parallel converter connection device tracking the maximum power point of two second solar modules
103: Serial/parallel converter connection device tracking the maximum power point of two third photovoltaic modules
200: voltage/current sensing unit 300: control unit
400: switching rectifier 500: serial/parallel switching unit
600: communication unit 700: fuse or PTC
800: reverse flow prevention diode 900: connection panel

Claims (3)

Each (+), (-) input terminal 100 of the photovoltaic module 1 and module 2 connected to the serial/parallel converter connection device for tracking the maximum power point of the 2 photovoltaic modules;
A voltage measuring unit that measures the (+) and (-) input terminals 100 of the photovoltaic module 1 and module 2;
A control unit receiving a voltage from the voltage measurement unit;
A communication unit for transmitting external and internal control-related signals;
A switching unit receiving a serial/parallel signal from the control unit;
An anode of a high voltage backflow prevention diode receiving output power from a switching unit in a serial/parallel converter connecting device that tracks the maximum power point of two solar modules;
A cathode of the high voltage backflow prevention diode for receiving and outputting power from a serial/parallel converter connection device that tracks the maximum power points of two external photovoltaic modules;
It relates to a high voltage backflow prevention diode for protecting the internal circuit of a serial-parallel converter connection device for tracking the maximum power point of two solar modules including a. The method of claim 1,
Each of the above high voltage reverse flow prevention diode anodes is connected to the output terminal of each series/parallel switching switching , and the cathode of each high voltage reverse flow prevention diode is the output of each series/parallel converter connection device (connector installed at the front end)/input ( It relates to a reverse flow prevention diode for protecting an internal circuit of a serial/parallel converter connection device for tracking the maximum power point of two solar modules, characterized in that it is connected to a connection device installed at the rear end) terminal. The method of claim 1,
There are low-voltage diodes related to the internal circuit of the serial/parallel converter connection device for tracking the maximum power point of the two photovoltaic modules, and the high voltage reverse flow prevention diode that allows the external and internal voltage and current to pass through It relates to a reverse flow prevention diode for protecting an internal circuit of a serial-parallel converter connection device for tracking the maximum power point of two solar modules, characterized in that it consists of.

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