KR20200130532A - Connection box for solar module that can shut off arc and reverse current and maintain temperature - Google Patents

Abstract

A connection box for a solar module capable of blocking arc and reverse current and maintaining a temperature, comprises: a DC blocking unit (210) for confirming a peak value of a DC current from the solar module (100) to provide a DC current less than a peak value to an inverter (300) through an MOV (220) when the DC current less than the peak value is received, and to block the DC current by turning-off a switch not to supply the DC current to the inverter when the DC current greater than the peak value is received; an MOV (220) to discharge moment arc generated when the DC blocking unit (210) is turned-off and an over current generated and back-flown from the inverter (300) to a ground line when the moment arc and the over current are received; a peltier device (230) provided therein with one side heated by an electric energy through a body of the connection box (200) and an opposite side being cooled; a first temperature sensor (240) to measure an internal temperature of the connection box (200); a second temperature sensor (250) to measure an external temperature of the connection box (200); and an internal temperature controller (260) for comparing the external temperature measured by the second temperature sensor (250) with the internal temperature measured by the first temperature sensor (240) to supply a forward current to the peltier device (230) when the internal temperature is greater than the external temperature beyond a reference value, and to supply a reverse current to the peltier device (230) when the external temperature is greater than the internal temperature beyond a reference value.

Description

Connection box for solar module that can shut off arc and reverse current and maintain temperature.

In the present invention, when a DC current is generated in each solar module, a MOV is mounted on the DC cut-off part of the junction box that receives it and supplies it to the inverter, so that the moment that occurs when the DC cut-off part is OFF, the arc is blocked from being provided to the inverter, It relates to a junction box for a solar module capable of blocking an arc and reverse current that can be protected by blocking overcurrent flowing back from the inverter from flowing back to the DC cut-off unit and maintaining temperature.

Recently, due to the seriousness of the problem of depletion of fossil fuels such as coal and oil and environmental pollution, various models for alternative energy have been proposed. Among them, power generation or heating using solar energy can reduce energy dependence on fossil fuels and create a pollution-free environment, and as a result of active research in various countries around the world, solar power generation systems are increasing.

The photovoltaic power generation system converts light energy incident from the sun into electrical energy to produce power, a photovoltaic module that converts light energy into direct current electrical energy, and a photovoltaic module located between the photovoltaic module and the inverter. It consists of a junction box that collects the DC power generated from and an inverter that converts and stores DC power into AC power.

In particular, in the case of the junction box, when an error of the internal DC circuit breaker occurs due to the temperature that is converted according to the surrounding environment or season, or when the circuit breaker is turned off due to an overload or abnormal voltage flowing from the solar module, an instant arc caused by the operation of the circuit breaker It is provided as a problem to damage the inverter.

Korean Patent Publication No. 10-2019-0020506 (2019.03.04)

The problem to be solved by the present invention is that when a DC current is generated in each photovoltaic module, the MOV is mounted on the DC cut-off part of the junction box that receives it and supplies it to the inverter, so that the moment when the DC cut-off part is OFF, the arc is generated. It is related to a junction box for a solar module capable of blocking arc and reverse current that can be protected by blocking what is provided to the inverter and preventing the overcurrent flowing back from the inverter from flowing back to the DC blocking unit and maintaining temperature.

Another problem of the present invention relates to a junction box for a solar module capable of blocking arcs and reverse currents capable of maintaining the internal temperature of the junction box within a certain range according to the surrounding environment and season, and maintaining the temperature.

In the junction box for a solar module capable of blocking arc and reverse current and maintaining temperature according to the present invention, a DC current having a peak value within a standard is determined by checking the peak value of the DC current received from the solar module 100. When introduced, it is provided to the inverter 300 through the MOV 220, and when a DC current higher than the reference peak value is introduced, the switch is turned off so that it is not supplied to the inverter 300 to block the DC current, and ; A MOV 220 for discharging through the ground line when the DC cut-off unit 210 is turned off and the overcurrent which is generated from the inverter 300 and the overcurrent which is generated from the inverter 300 is introduced; A Peltier element 230 that penetrates the body of the junction box 200 and heats one side thereof by electric energy and cools the other side; A first temperature sensor 240 for measuring the internal temperature of the junction box 200; A second temperature sensor 250 for measuring the external temperature of the junction box 200; The difference between the internal temperature measured by the first temperature sensor 240 and the external temperature measured by the second temperature sensor 250 is compared, and when the internal temperature is higher than the external temperature by more than the reference, forward current is supplied to the Peltier element 230. And, when the external temperature is higher than the internal temperature by more than the standard, it is characterized in that it supplies a reverse current to the Peltier element 230 and includes an internal temperature control unit 260.

Preferably, the solar module 100 is characterized in that an SPD (lightning protector) is installed in each solar module 100.

Preferably, the DC cut-off unit 210 is characterized in that it is a switch-type circuit breaker that is located ON in the case of a normal DC current and moves to OFF in the case of a DC current above the reference.

Preferably, the junction box 200 is characterized in that it further comprises a communication unit 270 for transmitting information on the current state of the DC blocking unit 210 and the temperature inside the junction box to an external management center.

Preferably, the inverter 300 includes a current conversion unit 310 for converting the DC current of each solar module 100 provided from the junction box 200 into an AC current; It characterized in that it comprises an ESS (320) for receiving and storing the AC current converted by the current conversion unit 310.

The junction box for a solar module according to the present invention prevents the arc from being provided to the inverter at the moment that occurs when the DC cutoff part is turned off by attaching a MOV to each DC cutoff part, and the overcurrent flowing back from the inverter flows back to the DC cutoff part. It has the effect of blocking the arc and reverse current that can be protected by blocking the current.

In addition, there is an advantage in that the internal temperature of the junction box can be maintained within a certain range by supplying forward or reverse current to the Peller element according to the difference between the internal and external temperatures of the junction box.

1 is a schematic diagram of a power system including a junction box for a solar module capable of blocking arc and reverse current and maintaining temperature according to the present invention.
Figure 2 is a block diagram of a junction box for a solar module according to the present invention.
3 is a block diagram of an inverter according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION The following detailed descriptions are embodiments in which the present invention may be practiced and refer to the accompanying drawings, which are illustrated as examples of the embodiments. These examples are described in detail sufficient for those skilled in the art to practice the present invention. It is to be understood that the various embodiments of the present invention are different from each other but need not be mutually exclusive. For example, specific shapes, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the present invention in relation to one embodiment. In addition, it should be understood that the location or arrangement of individual components within each described embodiment may be changed without departing from the spirit and scope of the present invention.

Therefore, the detailed description to be described below is not intended to be taken in a limiting sense, and the scope of the present invention is limited only by the appended claims, along with all scopes equivalent to those claimed by the claims, if appropriately described. In the drawings, like reference numerals refer to the same or similar functions over several aspects. In addition, terms used in the present invention should be defined based on the meaning of the term and the overall contents of the present invention, not just the name of the term.

In the present invention, when a part "includes" a certain component in the whole, it means that other components may be further included rather than excluding other components unless otherwise stated.

Referring to FIG. 1, the junction box 200 for a solar module capable of blocking arc and reverse current having a disaster prevention function according to the present invention and maintaining a temperature is generated when a DC current is generated in each solar module 100 This is provided and supplied to the inverter 300.

In the solar module 100, a plurality of PV (solar light) elements are connected in series to convert sunlight into electrical energy to generate a direct current and provide it to the junction box 200. Each solar module 100 is equipped with an SPD 110 (lightning protector) to discharge the lightning current flowing into the solar module 100 to the ground through a ground line.

The junction box 200 has a DC cut-off unit 210 corresponding to each solar module 100 installed therein to receive a DC current generated from the solar module 100, and the DC cut-off unit 210 A MOV 220 is installed at the rear end.

The DC blocking unit 210 checks the peak value of the DC current received from the photovoltaic module 100, and when the DC current having a peak value within the standard is introduced, it is provided to the inverter 300 through the MOV 220, When a DC current higher than the reference peak value is introduced, the switch is turned off so that it is not supplied to the inverter 300 to block the DC current. At this time, it is preferable that the DC cut-off unit 210 is a switch-type circuit breaker that is located at ON in the case of a normal DC current and moves to OFF in the case of a DC current above the reference.

The MOV 220 discharges through the ground line when an instantaneous arc generated when the DC cut-off unit 210 is turned off and an overcurrent generated from the inverter 300 and flowing backward are introduced. That is, when a DC current higher than the reference peak value flows into the DC circuit breaker by the MOV 220, the switch is turned OFF to release the momentary arc to the ground line to block the momentary arc supplied to the inverter 300. In addition, when overcurrent occurs due to aging of the ESS 320 of the inverter 300, the overcurrent flowing back from the ESS 320 is discharged to the ground line, and the overcurrent is supplied to the DC circuit breaker. It is possible to prevent damage by blocking it.

In addition, the junction box 200 is provided with a Peltier element 230 in which one side is heated by electric energy through the body and the other side is cooled. In addition, a first temperature sensor 240 for measuring the internal temperature is mounted inside the junction box 200, and a second temperature sensor 250 for measuring the external temperature is mounted outside the junction box 200, The difference between the internal temperature measured by the first temperature sensor 240 and the external temperature measured by the second temperature sensor 250 is compared, and when the internal temperature is higher than the external temperature by more than the reference, forward current is supplied to the Peltier element 230. And, when the external temperature is higher than the internal temperature by more than the standard, a reverse current is supplied to the Peltier element 230 and the internal temperature control unit 260 is installed.

In the summer when the internal temperature of the junction box 200 is higher than the external temperature by the internal temperature control unit 260, a forward current is supplied to the Peltier element 230 to lower the internal temperature of the junction box 200, and the internal temperature is reduced. In winter when the temperature is lower than the outside temperature, the internal temperature of the junction box 200 can be increased by supplying a reverse current to the Peltier element 230.

In addition, the junction box 200 is provided with a communication unit 270 that transmits information about the current state of the DC blocking unit 210 and the temperature inside the junction box to an external management center. In the external management center by the communication unit 270, it is possible to take action if the DC blocking unit 210 of the access box is turned off.

The inverter 300 receives the DC current generated from each of the plurality of solar modules 100 passing through the DC blocking unit 210 of the junction box 200, converts it into AC current, and stores it. The inverter 300 is provided with a current conversion unit 310 and ESS 320.

The current conversion unit 310 converts the DC current of each solar module 100 provided from the junction box 200 into an AC current. The current conversion unit 310 converts the DC current output from the solar module 100 into the AC current used in the ESS 320 by performing the MPPT algorithm.

The ESS 320 receives and stores the AC current converted by the current converter 310.

It looks at the operation process of the solar module junction box capable of blocking the arc and reverse current of the present invention and maintaining the temperature.

First, when a DC current is generated based on sunlight in each solar module 100 installed in the field, it is provided to the junction box 200. At this time, when a lightning strike is introduced into the solar module 100, the lightning current is discharged to the ground through the ground line of the SPD (lightning protector).

The DC current generated by the solar module 100 is supplied from the junction box 200 to the DC blocking unit 210 installed corresponding to each solar module 100, and the DC blocking unit 210 is When a DC current having a peak value within the standard is introduced by checking the peak value of the current, the DC current is provided to the inverter 300 through the MOV 220 as it is. In addition, when a DC current higher than the reference peak value is introduced, the switch is turned off so that it is not supplied to the inverter 300 to block the DC current.

When the switch of the DC cut-off unit 210 is turned off and an instantaneous arc is generated and provided to the MOV 220, the MOV 220 discharges the instantaneous arc to the ground line to block the instantaneous arc from being supplied to the inverter 300. .

Then, the DC current provided to the inverter 300 is integrated into the AC current in the current conversion unit 310 and then stored in the ESS 320. And, when an over-output current is generated in the ESS 320 and flows back to the junction box 200, the MOV 220 of the junction box 200 releases the over-output current through the ground line, so that the over-output current is prevented from the DC blocking unit ( 210) is blocked.

On the other hand, the internal temperature control unit 260 of the junction box 200 is the internal temperature measured by the first temperature sensor 240 located inside the junction box 200 and the second located outside the junction box 200. By comparing the difference between the external temperature measured by the temperature sensor 250, in the summer when the internal temperature is higher than the external temperature above the standard, forward current is supplied to the Peltier element 230 to lower the internal temperature of the junction box 200, In winter, when the internal temperature is lower than the external temperature by more than the standard, the internal temperature of the junction box 200 can be increased by supplying a reverse current to the Peltier element 230.

As described above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and the technical idea and the following by those of ordinary skill in the art to which the present invention pertains. It goes without saying that various modifications and variations are possible within the equivalent range of the claims to be described in.

100: solar module 110: SPD
200: junction box for solar module 210: DC cut-off part
220: MOV 230: Peltier element
240: first temperature sensor 250: second temperature sensor
260: internal temperature control unit 270: communication unit
300: inverter 310: current converter
320: ESS

Claims (5)

When a direct current is generated in each solar module 100, in the connection for a solar module that receives it and supplies it to the inverter 300,
The junction box,
When a DC current having a peak value within the standard is introduced by checking the peak value of the DC current received from the solar module 100, it is provided to the inverter 300 through the MOV 220, and a DC current higher than the reference peak value A DC cut-off unit 210 for blocking the DC current by turning off the switch so that it is not supplied to the inverter 300 when the flow is introduced;
A MOV 220 for discharging through a ground line when an instantaneous arc generated when the DC cut-off unit 210 is turned off and an overcurrent that is reverse flowed from the inverter 300 flows in;
A Peltier element 230 through which one side of the junction box 200 is heated and the other side is cooled by electric energy;
A first temperature sensor 240 for measuring the internal temperature of the junction box 200;
A second temperature sensor 250 for measuring the external temperature of the junction box 200;
The difference between the internal temperature measured by the first temperature sensor 240 and the external temperature measured by the second temperature sensor 250 is compared, and when the internal temperature is higher than the external temperature by more than the reference, forward current is supplied to the Peltier element 230. And, when the external temperature is higher than the internal temperature above the standard, a reverse current is supplied to the Peltier element 230, and an internal temperature control unit 260 is included for the solar module capable of blocking arc and reverse current and maintaining the temperature. Access box.
The method according to claim 1, The solar module 100, each solar module 100, characterized in that the SPD (110) is installed to block arc and reverse current and a solar module connection box capable of maintaining temperature.
The method according to claim 1, wherein the DC cut-off unit 210 is a switch-type circuit breaker that is located at ON in the case of a normal DC current and moves to OFF in the case of a DC current above the standard. Junction box for optical module.
The arc according to claim 1, wherein the junction box 200 further comprises a communication unit 270 for transmitting information on the current state of the DC blocking unit 210 and the temperature inside the junction box to an external management center. And junction box for solar modules that can block reverse current and maintain temperature.
The method according to claim 1, wherein the inverter 300 comprises: a current conversion unit 310 for converting the DC current of each solar module 100 provided from the junction box 200 into an AC current; A connection box for a solar module capable of blocking arc and reverse current and maintaining temperature, characterized in that it comprises an ESS 320 that receives and stores the alternating current converted by the current conversion unit 310.

Images