KR20200127406A - Apparatus and method for arc detection and removal of photovoltaic cells for fire prevention - Google Patents

Abstract

The present invention relates to a device for arc detection and removal of a solar connection board for fire prevention. The device for arc detection and removal of a solar connection board for fire prevention comprises: a sensor unit detecting an arc generated from wiring of a plurality of solar cell strings; a serial arc processing unit connected in series to the wiring of the plurality of solar cell strings; a parallel arc processing unit connected in parallel to the wiring of the plurality of solar cell strings; and a control unit controlling to cut off the wiring connected in series through the serial arc processing unit when the arc is detected through the sensor unit and controlling to cut off both ends of the wiring connected in parallel by controlling the parallel arc processing unit when the arc is still detected through the sensor unit after the wiring connected in series is cut off.

Description

Apparatus and method for arc detection and removal of photovoltaic cells for fire prevention {Apparatus and method for arc detection and removal of photovoltaic cells for fire prevention}

The present invention relates to arc detection and removal technology, and more particularly, to an apparatus for arc detection and removal of a solar panel for fire prevention and a method therefor.

The solar panel is a device for concentrating the electricity of the solar power module, and it concentrates less than 100kW of power.

Photovoltaic cells produce DC electricity with (+) and (-), and one electricity usually produces 32~40V, 9A level of electricity at maximum. Like the series connection of the corresponding battery, 15~17 solar cells are connected in series to form high-voltage electricity of 480~540V, 9A (approximately 4.3~5 kW) and wired to the solar junction box.This high voltage series solar module consists of Is called a string. The solar junction box is configured to hold up to 20 such solar cell strings.

Korean Patent Laid-Open Patent No. 2018-0058992 published on June 04, 2018 (Name: Solar panel protection device using quick cut-off function)

An object of the present invention is to provide an apparatus and method for detecting and removing arcs that cause frequent fires of a solar panel for collecting electricity from a solar module in solar power generation.

An apparatus for detecting and removing arcs from a solar panel for fire prevention according to a preferred embodiment of the present invention for achieving the above object is a sensor unit that detects arcs generated from wiring of a plurality of solar cell strings. Wow, a series arc processing unit connected in series to the wiring of a plurality of solar cell strings, a parallel arc processing unit connected in parallel to the wiring to the plurality of solar cell strings, and when the arc is detected through the sensor unit, the series Controls to cut off the serially connected wiring through the arc processing unit, and if the arc is still detected through the sensor unit after blocking the serially connected wiring, the wiring in which the arc is detected through the parallel arc processor It includes a control unit that controls to short-circuit both ends of.

The control unit is characterized in that after shorting both ends of the parallel connected wiring, when the arc is removed, the shorted ends are restored to restore insulation performance between both ends of the parallel connected wiring.

The sensor unit may include at least one of a sensor detecting an arc through flash, a sensor detecting an arc through radio waves (RF), and a sensor detecting an arc through a current harmonic signal.

In the apparatus for detecting and removing arcs according to an embodiment of the present invention, a warning message notifying that an arc has occurred is sent to the manager device after blocking the wiring connected in series or shorting both ends of the wiring connected in parallel. It further includes a communication unit for transmitting.

A method for detecting and removing arcs of a solar panel for fire prevention according to a preferred embodiment of the present invention for achieving the above object is to monitor whether an arc occurs in wiring connected to a plurality of solar cell strings. Steps and, as a result of the monitoring, when an arc is detected, blocking a wiring connected in series to a plurality of solar cell strings, and checking whether the arc is still detected after blocking the wiring connected in series And, if the arc is still detected as a result of the check, shorting both ends of the wiring connected in parallel to the plurality of solar cell strings.

In the method for detecting and removing arcs of a solar panel according to an embodiment of the present invention, when both ends of the parallel connected wiring are short-circuited and the arc is removed, the insulation performance between both ends of the parallel connected wiring is improved. And returning both ends shorted to recover.

The step of checking whether the arc is detected may include using at least one of a sensor that detects an arc through a flash, a sensor that detects an arc through a radio wave (RF), and a sensor that detects an arc through a current harmonic signal. It characterized in that it detects.

In the method for detecting and removing arcs of a solar connection panel according to an embodiment of the present invention, after the step of blocking the wires connected in series or shorting both ends of the wires connected in parallel, the arc is It characterized in that it further comprises the step of transmitting a report notifying that the occurrence has occurred to the manager device.

According to the present invention, fire can be prevented through arc detection and removal of the solar power junction box.

1 is a view for explaining a solar cell string and a solar connection board according to an embodiment of the present invention.
2 is a view for explaining the cause of arc generation according to an embodiment of the present invention.
3 is a block diagram illustrating an apparatus for detecting and removing an arc of a solar panel according to an embodiment of the present invention.
4 is a flowchart illustrating a method for detecting and removing an arc of a solar panel according to an embodiment of the present invention.

Prior to the detailed description of the present invention, terms or words used in the present specification and claims described below should not be construed as being limited to their usual or dictionary meanings, and the inventors shall use their own invention in the best way. In order to explain, based on the principle that it can be appropriately defined as a concept of terms, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all the technical spirit of the present invention, and various equivalents that can replace them at the time of application It should be understood that there may be water and variations.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this case, it should be noted that the same components in the accompanying drawings are indicated by the same reference numerals as possible. In addition, detailed descriptions of known functions and configurations that may obscure the subject matter of the present invention will be omitted. For the same reason, some components in the accompanying drawings are exaggerated, omitted, or schematically illustrated, and the size of each component does not entirely reflect the actual size.

First, according to an embodiment of the present invention, an apparatus for detecting and removing an arc of a solar panel for preventing fire will be described. 1 is a view for explaining a solar cell string and a solar connection board according to an embodiment of the present invention. 2 is a view for explaining the cause of arc generation according to an embodiment of the present invention. 3 is a block diagram illustrating an apparatus for detecting and removing an arc of a solar panel according to an embodiment of the present invention.

Referring to FIG. 1, a solar connection panel 20 is a facility in which photovoltaic electricity generated by a photovoltaic cell string 10 is concentrated. The solar connection panel 20 is also a facility that frequently causes fire when an electrical accident occurs, and is characterized by being burned out once a fire starts.

Since the current of the solar cell string 10 is at most 9A, even if an arc occurs, the circuit breaker cannot directly protect against an arc accident because it does not fall within the overcurrent operating range of the circuit breaker (MCCB). In addition, in the case of a parallel arc, even if the circuit breaker blocks the main line, since the solar cell string 10 continues to supply energy, the arc may not be removed and a fire may be caused.

Referring to Figure 1, the arc can be divided into a series arc (ar_d) and parallel arc (ar_p). The series arc (ar_d) may be generated by a defect in the connection process of the (+) and (-) lines of the solar cell string 10. Specifically, the series arc ar_d may be caused by loose bolting (fastening), faulty converters (breaking, bad wires, damage, etc.), converter separation fuse, and contact failure between fuse connections.

Referring to FIG. 2, a parallel arc ar_p may be generated by contamination of a solar contact terminal or insulation failure. Specifically, the parallel arc ar_p may be generated by a short circuit due to contamination due to infiltration of the wiring terminal block, contamination of the wiring terminal block, and contamination of the solar cell string 10 between the wirings of the solar cell string 10.

The arc relay 100, which is an apparatus for detecting and removing arcs according to an embodiment of the present invention, detects serial arcs and parallel arcs generated in a solar junction box by analyzing light (light), radio waves, and current signals, and Eliminate the series arc and parallel arc.

A conventional solar panel is equipped with a circuit breaker (MCCB). The overcurrent relay of the circuit breaker is an equipment to protect the overheating of the converter and prevents fire by performing a cut-off operation when several minutes have elapsed for 200% of the rated current. However, an arc accident occurs at a current lower than the rated current, but generates high heat, and the overcurrent relay of an existing circuit breaker cannot recognize and protect it. Moreover, the existing solar panel does not have an arc detection facility. Therefore, the arc relay 100 according to the embodiment of the present invention detects the occurrence of a series arc (ar_d) using a sensor, separates the solar cell string 10 from the solar connection panel 20, and separates the main converter ( For example, it is disconnected from the inverter 30).

On the other hand, when a parallel arc (ar_p) occurs, even if the circuit breaker is operated, the arc is continuously maintained with the energy of the solar cell string 10 regardless of the circuit breaker, and thus a fire is inevitable. Therefore, the arc relay 100 according to an embodiment of the present invention removes the parallel arc by shorting the wiring of the solar electric string 10 when a parallel arc ar_p occurs.

Then, in more detail, it will be described for the arc relay 100 according to an embodiment of the present invention. 2 and 3, the arc relay 100 according to an embodiment of the present invention includes a sensor unit 110, a serial arc processing unit 120, a parallel arc processing unit 130, a communication unit 140, and a control unit 140. ).

The sensor unit 110 is for detecting an arc by monitoring a wiring portion connected to the plurality of solar cell strings 10. The sensor unit 110 may detect an arc through light (light), an arc through radio waves (RF), or detect an arc through a current harmonic signal. When detecting an arc through light (light), the sensor unit 110 may be an optical fiber sensor. When an arc occurs, a flash is generated like an arc welding rod, and the sensor unit 110 generates a signal by detecting the generated flash, and transmits the signal to the controller 140. In the case of detecting an arc through radio waves (RF), when an arc occurs, radio waves (RF) in a specific frequency range among the 20 to 200 MHz band are generated, and the sensor unit 110 passes the radio waves through a band-pass filter. After receiving by, the arc can be detected by adjusting the intensity of this radio wave. In the case of detecting an arc through a current harmonic signal, when an arc occurs, a current signal of a high frequency component appears in addition to the DC current supplied from the existing solar cell, and the sensor unit 110 detects the corresponding harmonic current to detect the arc. can do.

The series arc processing unit 120 is for removing the series arc generated in the wiring of the solar cell string. The series arc processing unit 120 is connected in series to the wiring of the solar cell string. When a serial arc occurs, the serial arc processing unit 120 blocks wiring connected in series under the control of the controller 150. The series arc processing unit 120 may be a circuit breaker made of a switch or a relay connected in series to the wiring of the solar cell string. That is, when an arc is detected under the control of the controller 150, the serial arc processing unit 120 removes the serial arc by opening the corresponding wiring.

The parallel arc processing unit 130 is for removing the parallel arc generated in the wiring of the solar cell string. The series arc processing unit 120 is connected in parallel to wirings of a plurality of solar cell strings. As soon as the series arc processing unit 120, that is, the circuit breaker is opened, all of the series arc is removed, but the parallel arc may be maintained regardless of the series arc processing unit 120. Therefore, if an arc is still detected through the sensor unit 110 after blocking the wiring connected in series, it is recognized that a parallel arc has occurred. The parallel arc processor 130 removes the parallel arc by shorting both ends of the wire in which the parallel arc is detected. When both ends of the wire causing the parallel arc are shorted, the voltage at both ends of the arc causing the arc becomes “0”V. In the absence of a voltage across the arc, the arc is eliminated because no more plasma material is created that activates the parallel arc. After removing the parallel arc, the parallel arc processor 130 returns the shorted ends to restore insulation performance between both ends of the wiring. Accordingly, the parallel arc processing unit 130 may be a relay or switch capable of causing a short circuit and recovering.

The communication unit 140 is for communication with other devices, including a manager device (not shown), and performs communication through various communication connection methods. The communication unit 140 may communicate by selecting any one of communication functions of various communication connection methods. The communication unit 210 may be implemented as one module or a plurality of modules. For example, the communication unit 140 is a broadband mobile communication method that accesses a network through a base station according to standards such as WCDMA, LTE, and LTE-A, and a wireless local area network (WLAN) method using Wi-Fi (wireless fidelity). Accordingly, it is possible to use a wireless near-field communication method that performs communication by connecting to a network (NW) through an access point (AP). As another example, the communication unit 140 may communicate using an Industrial Scientific and Medical equipment (ISM) band. The communication unit 140 may use, for example, communication standards such as Bluetooth, Zigbee, and infrared (IrDA), and communication standards equivalent to or improved or improved from these. The improved or improved communication standard may typically exemplify BLE (Bluetooth Low Energy) 4.0, and iBeacons may be exemplified as a communication standard accordingly. The communication unit 140 may include an RF transmitter that up-converts and amplifies a frequency of a transmitted signal, and an RF receiver that amplifies a received signal with low noise and down-converts a frequency. The communication unit 140 may convert the report received from the control unit 150 into a wireless signal and transmit it through a wireless channel.

The controller 150 may perform a data processing function of controlling the general operation of the arc relay 100 and a signal flow between the internal blocks 110 to 140 of the arc relay 100 and processing data. The control unit 150 may be a central processing unit (CPU), a graphic processing unit (GPU), a digital signal processor (DSP), or the like. The operation of the control unit 150 will be described in more detail below.

Next, a method for detecting and removing the arc of the solar panel for fire prevention will be described. 4 is a flowchart illustrating a method for detecting and removing an arc of a solar panel according to an embodiment of the present invention.

Referring to FIG. 4, the control unit 150 of the arc relay 100 monitors a wiring portion connected to the plurality of solar cell strings 10 through the sensor unit 110 in step S110. During monitoring, the control unit 140 determines whether an arc is detected through the sensor unit 110 in step S120.

The sensor unit 110 may detect an arc through light (light), an arc through radio waves (RF), or detect an arc through a current harmonic signal.

When detecting an arc through light (light), the sensor unit 110 may be an optical fiber sensor. When an arc occurs, a flash is generated like an arc welding rod, and the sensor unit 110 generates a signal by detecting the generated flash, and transmits the signal to the controller 140.

In the case of detecting an arc through radio waves (RF), when an arc occurs, radio waves (RF) in a specific frequency range among the 20 to 200 MHz band are generated, and the sensor unit 110 passes the radio waves through a band-pass filter. After receiving by, the arc can be detected by adjusting the intensity of this radio wave.

In the case of detecting an arc through a current harmonic signal, when an arc occurs, a current signal of a high frequency component appears in addition to the DC current supplied from the existing solar cell, and the sensor unit 110 detects the corresponding harmonic current to detect the arc. can do.

If the arc is detected in step S120, the control unit 150 proceeds to step S130, and if the arc is not detected in step S120, the control unit 150 continues the monitoring of step S110.

In this case, when an arc is detected, the control unit 150 blocks the wiring connected in series through the serial arc processing unit 120 connected in series to the wiring of the solar cell string in step S130.

The series arc processing unit 120 may be a circuit breaker connected in series to the wiring of the solar cell string. When an arc is detected under the control of the controller 150, the series arc processing unit 120 cuts off the series arc processing unit 120, that is, a circuit breaker, to remove the series arc. Subsequently, the control unit 150 transmits a report informing that the arc has occurred and removed in step S140 to the administrator's device through the communication unit 140.

On the other hand, as soon as the series arc processing unit 120, that is, the breaker is opened, all of the series arc is removed, but the parallel arc can be maintained irrespective of the series arc processing unit 120.

Therefore, the controller 150 of the present invention checks whether an arc is still detected through the sensor unit 110 in step S150 after blocking the wiring connected in series.

If an arc is still detected as a result of the check in step S150, the process proceeds to step S160, and if the arc is not detected as a result of the check in step S150, the process returns to step S110 to continue monitoring.

As a result of the confirmation in step S150, if the arc is still detected, since parallel arc has occurred, the controller 150 removes the parallel arc in step S160. A more detailed description of step S160 is as follows.

First, the control unit 150 controls the parallel arc processor 130 to short-circuit both ends of the wire where the arc is detected. When both ends of the wire causing the parallel arc are shorted, the voltage at both ends of the arc causing the arc becomes “0”V. In the absence of a voltage across the arc, the arc is eliminated because no more plasma material is created that activates the parallel arc. When the arc is removed after shorting both ends of the wiring, the control unit 150 returns the shorted ends to restore insulation performance between both ends of the wiring.

Next, the control unit 150 transmits a report informing that the arc has occurred and removed in step S170 to the administrator's device through the communication unit 140.

Meanwhile, the method according to the embodiment of the present invention described above may be implemented in the form of a program that can be read through various computer means and recorded on a computer-readable recording medium. Here, the recording medium may include a program command, a data file, a data structure, or the like alone or in combination. The program instructions recorded on the recording medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software. For example, the recording medium includes magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic-optical media such as floptical disks ( magneto-optical media), and hardware devices specially configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions may include not only a machine language such as that produced by a compiler but also a high-level language that can be executed by a computer using an interpreter or the like. These hardware devices may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

The present invention has been described above using several preferred embodiments, but these embodiments are illustrative and not limiting. As such, those of ordinary skill in the art to which the present invention pertains will understand that various changes and modifications can be made according to the equivalence theory without departing from the spirit of the present invention and the scope of the rights presented in the appended claims.

10: solar cell string
20: solar connection panel
110: sensor unit
120: serial arc processing unit
130: parallel arc processing unit
140: communication department
150: control unit

Claims (8)

In the device for arc detection and removal of a solar junction panel for fire prevention,
A sensor unit detecting an arc generated in wiring of a plurality of solar cell strings;
A series arc processing unit connected in series to wirings of a plurality of solar cell strings;
A parallel arc processing unit connected in parallel to wirings to a plurality of photovoltaic cell strings; And
When detecting the arc through the sensor unit,
Controls to block the wiring connected in series through the series arc processing unit,
A control unit configured to short-circuit both ends of the line through which the arc is detected through the parallel arc processor when the arc is still detected through the sensor unit after blocking the wiring connected in series;
Device for arc detection and removal, characterized in that it comprises a. The method of claim 1,
The control unit
When both ends of the parallel connected wire are short-circuited and the arc is removed, the shorted ends are restored to restore insulation performance between both ends of the parallel connected wire. The method of claim 1,
The sensor unit
A sensor that detects arcs through flashes,
A sensor that detects an arc through radio waves (RF) and
Apparatus for arc detection and removal, comprising at least one of sensors for detecting an arc through a current harmonic signal. The method of claim 1,
A communication unit configured to cut off the serially connected wiring or short-circuit both ends of the parallelly connected wiring, and then transmit a warning message indicating that an arc has occurred to a manager device;
An apparatus for arc detection and removal, characterized in that it further comprises. In the method for detecting and removing the arc of the solar panel for fire prevention,
Monitoring whether an arc occurs in a wiring connected to a plurality of solar cell strings;
Blocking wiring connected in series to a plurality of solar cell strings when an arc is detected as a result of the monitoring;
Checking whether the arc is still detected after blocking the wiring connected in series; And
If the arc is still detected as a result of the check, shorting both ends of the wiring connected in parallel to the plurality of solar cell strings;
Method for arc detection and removal comprising a. The method of claim 5,
When both ends of the parallel connected wire are short-circuited and the arc is removed, returning the shorted ends to restore insulation performance between both ends of the parallel connected wire;
Method for arc detection and removal, characterized in that it further comprises. The method of claim 1,
The step of checking whether the arc is detected
A sensor that detects arcs through flashes,
A sensor that detects an arc through radio waves (RF) and
A method for arc detection and removal, characterized in that the arc is detected using at least one of sensors for detecting arc through a current harmonic signal. The method of claim 1,
Transmitting a report notifying that the arc has occurred to a manager device after the step of blocking the wires connected in series or shorting both ends of the wires connected in parallel;
Method for arc detection and removal, characterized in that it further comprises.

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