KR102111299B1 - Two-channel circuit breaker system - Google Patents

Abstract

The present invention, in the two-channel circuit breaker system of the switchboard, includes a CT sensor that senses an external accident by sensing an overcurrent of a line connected to a load, and an arc sensor that senses an internal accident by sensing the occurrence of arc inside the switchboard. A sensor unit; A circuit breaker control unit including an accident current relay outputting an operation signal when detecting an external accident of the CT sensor, and an arc relay outputting an operation signal when detecting an internal accident of the arc sensor; And a circuit breaker composed of two channels of an open operation circuit that is cut off and driven by the operation signal of the arc relay and a delay circuit for delaying the operation time of the accident current relay by a predetermined time. It is characterized in that the circuit breaking time due to an external accident is delayed rather than the circuit breaking time due to an internal accident.

Description

2-channel circuit breaker system of switchboard {TWO-CHANNEL CIRCUIT BREAKER SYSTEM}

The present invention relates to a two-channel circuit breaker system of a switchboard, and relates to a two-channel circuit breaker system of a switchboard in which a selective blocking function can be performed according to the type of an accident current.

The switchboard is a device that is regularly put and managed by switches, instruments, and relays (relays) for the operation or control of power plants or substations, the operation of electric motors, etc., and distributes power to each switchboard. The distribution panel receives power from the switchboard through the trunk line and supplies power to the terminal loads, electricity use equipment, etc. In general, the switchboard receives 22.9KV of extra high voltage from the KEPCO side and receives power by stepping down to a high voltage of 3.3KV or 6.6KV in the substation room, and stepping down with three-phase four wires from the transformer to 690V, 440V, 380V or Supply 220V power.

The switchboard is installed for receiving or distributing high-voltage or special high-voltage electricity in a power plant, substation, switchgear, or the like. As an example, the switchboard receives power from different substations in a substation in case of a power outage in a major facility such as a hospital, and receives power through different lines. Therefore, it is operated by two-way power receiving method to supply power, and there have been many construction examples in which an emergency generator is additionally installed and operated.

It is most important that facilities such as hospitals, power plants, substations, etc., where multiple switchboards are installed, can supply power stably even in an emergency. In particular, in the distribution panel for distributing power, there is a risk of numerous accidents caused by natural factors such as short circuit, discharge, fire, and condensation due to deterioration. Electrical safety accidents occurring from the switchboard can cause astronomical damage, not only malfunction of the switchboard device itself, but also malfunction of numerous electric and electronic devices in the field and loss of a factory due to fire. Therefore, the switchboard must quickly separate the failure section from the electrical system when an electrical fault occurs in the power system. For this, it is essential to detect a line in which an electrical fault has occurred and to quickly cut off the line in which an electrical fault has occurred.

Circuit breakers are installed in the distribution panel and distribution panel in the building to block the current flowing into the load before an accident occurs due to overcurrent, overload, or short circuit. The biggest power of these circuit breakers is that they can safely cut off electricity at high speed. Currently, the breaking time of domestic and foreign circuit breakers is on average about 10ms ± 2ms, and recently, ultra-high-speed circuit breakers capable of breaking within one cycle of an accident current have been developed. When it is applied to the system, it is possible to reduce the burden on the system by quick blocking.

However, such a fast interruption time (1-cycle clearing) causes an increase in DC when the fault current is asymmetric, so that the fault current above the rated cutoff current blocked by the actual breaker is forced to be blocked. Therefore, the conventional ultra-high-speed shut-off system causes side effects that degrade the electrical durability of the breaker contact.

On the other hand, when an accident occurs due to an arc in the device of the switchboard while the circuit breaker is applied to the switchboard and the system, it is required to cut off the accident current as quickly as possible before inducing sudden heat and pressure. In view of this, in the event of an arc inside the switchboard, a conventional ultra-high-speed cut-off operation is preferable, and in the case of an overcurrent such as a load line outside the switch-board, the ultra-high cut-off rather deteriorates the durability of the circuit breaker, so a delayed cut-off operation to some extent is desirable.

As a prior art, Korean Patent Publication No. 10-2010-0138004 (hereinafter, abbreviated as Prior Patent 1) discloses a circuit breaker that improves a breaker breaking time when an instantaneous current occurs. Korean Patent Publication No. 10-2004-0067473 (hereinafter abbreviated as Patent 2) discloses a time delayed automatic trip circuit. Prior Patent 1 can be seen as an invention related to an ultra-high-speed circuit breaker that improves the breaking speed when the load power is cut off. Prior Patent 2 proposes a time-delayed automatic trip circuit to improve the reliability of the trip operation by controlling the trip operation not to occur for an abnormal voltage that occurs instantaneously, such as an instantaneous power failure or an instantaneous voltage drop.

Prior patent 2 is for the purpose of applying a delayed trip circuit to the circuit breaker so that the blocking operation does not occur with respect to the instantaneous voltage, but rather a switchboard in which instantaneous arcing or instantaneous overcurrent should not be determined as a malfunction of the tripping operation. It is difficult to apply to the system.

In summary, an accident current blocking function and an optional blocking function for protecting the device in the event of an arc in the device are required, and for this purpose, a switchboard that can selectively perform a blocking operation for each type of accident occurring in the switchboard The system is in demand.

Patent Publication No. 10-2010-0138004 Patent Publication No. 10-2004-0067473

Therefore, the present invention performs ultra-fast shut-off in the case of an internal accident of the switchboard that causes rapid heat and pressure, such as the occurrence of arc inside the device, and relatively delayed shut-off in the case of an external accident occurring in the load line outside the switchboard to ensure safety of the power system. It is intended to provide a 2-channel circuit breaker system of the switchboard that can preserve the durability of the circuit breaker and the circuit breaker.

In order to achieve the above object, the present invention, in the two-channel circuit breaker system of the switchboard, the CT sensor to sense the external accident by sensing the overcurrent of the line connected to the load, and the internal accident by sensing the occurrence of arc inside the switchboard A sensor unit including an arc sensor for sensing; A circuit breaker control unit including an accident current relay outputting an operation signal when detecting an external accident of the CT sensor, and an arc relay outputting an operation signal when detecting an internal accident of the arc sensor; And a circuit breaker composed of two channels of an open operation circuit that is cut off and driven by the operation signal of the arc relay and a delay circuit for delaying the operation time of the accident current relay by a predetermined time. It is characterized in that the circuit breaking time due to an external accident is delayed rather than the circuit breaking time due to an internal accident.

Preferably, the arc sensor detects the arc discharge of the switchboard with an infrared image of a medium wavelength, compares the measured luminance value of the infrared image with a set first reference value, and counts a luminance value exceeding the first reference value. 2 Compare the reference value and judge whether the switch panel has an arc.

Preferably, the arc sensor is an infrared image sensor, and the imaging speed is set to 1000 frames or more and 2000 frames or less, so that the speed of the arc occurrence determination is greater than 0 [count of luminance values exceeding the first reference value] / less than 1000 sec. Can be.

Preferably, the circuit breaker control unit interlocks the accident current relay when the arc relay is operated.

Preferably, the circuit breaker delays the operation signal of the accident current relay in the range of 3 to 5 cycles of the accident current by the operation delay circuit, and the open operation circuit is within 1 cycle of the accident current during operation of the arc relay. It is cut off and driven, so that the cutoff driving region of the accident current is different by the two-channel control of the open operation circuit or the operation delay circuit.

According to the present invention, the relay corresponding to each accident is operated by the circuit breaker control unit according to the configuration of the sensor detecting the internal accident and the external accident and the type of the detected accident. The circuit breaker is composed of 2-channels having a differential blocking time according to each accident route, so that a quick switch-off in an internal accident and a delayed cut-off in an external accident are provided to provide an excellent switchboard system for system safety and circuit breaker durability. Can be.

1 is a block diagram of a two-channel circuit breaker system of a switchboard according to an embodiment of the present invention.
Figure 2 shows a two-channel circuit breaker system of the switchboard associated with the arc sensor.
Figure 3 shows the arc detection process of the two-channel circuit breaker system of the arc sensor and the switchboard.
4 shows the cycle of the accident current and the cut-off driving area of the circuit breaker.

Hereinafter, the present invention will be described in detail with reference to the contents described in the accompanying drawings. However, the present invention is not limited or limited by the exemplary embodiments. The same reference numerals in each drawing denote members that perform substantially the same function.

The objects and effects of the present invention may be naturally understood or more apparent by the following description, and the objects and effects of the present invention are not limited only by the following description. In addition, in the description of the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

1 is a block diagram of a two-channel circuit breaker system 1 of a switchboard according to an embodiment of the present invention. Referring to FIG. 1, the 2-channel circuit breaker system 1 of the switchboard includes a sensor unit 10, a smart control unit 30, a management control unit 50, a circuit blocking control unit 40, and a circuit breaker 60. It can contain.

The sensor unit 10 may include a CT sensor 1031 and an arc sensor 1033. The sensor unit 10 may sense an external accident by sensing an overcurrent of a line connected to a load, and sense an internal accident by sensing an arc generated inside the switchboard. The external accident detection of the sensor unit 10 may be performed through the CT sensor 1031, and the internal accident detection of the sensor unit 10 may be performed through the arc sensor 1033.

The CT sensor 1031 is a CURRENT TRANSFORMER and detects overcurrent. The CT sensor 1031 can detect the overcurrent of the load line. The measured value of the CT sensor 1031 may be received by the accident current relay 401.

The arc sensor 1033 detects the occurrence of arc in the containment device inside the switchboard. The arc sensor 1033 may detect an arc generated in the switchboard in advance by monitoring an electrical contact area, such as a disconnection part of a containment device or a cable connection part.

Figure 2 shows a two-channel circuit breaker system of the switchboard associated with the arc sensor 1033. In this embodiment, the arc sensor 1033 does not use a plurality of sensors, and an infrared image sensor is used as the arc sensor 1033 to detect the occurrence of arc in the switchboard in advance.

Referring to FIG. 2, an arc-sensing configuration may be an arc sensor 1033, a correction voltage generator 1037, a smart control unit 30, and a management control unit 50. The arc sensor 1033 may detect arc discharge of the switchboard with an infrared image of a medium wavelength. The arc sensor 1033 is an infrared image sensor, and the image capturing speed is set to 1000 frames or more and 2000 frames or less, and the speed of the arc occurrence determination of the smart control unit 30 exceeds 0 [count of luminance values exceeding the first reference value] It may be less than / 1000 sec. Hereinafter, the arc sensor is an embodiment implemented by the infrared image sensor 1033, and the reference numbers of the arc sensor and the infrared image sensor may be collectively referred to as 1033.

Note that in this embodiment, an infrared image sensor other than an infrared sensor is used as the arc sensor 1033. The infrared sensor has an infrared detection function at the position where the sensor is attached. In light of this, the switchboard has a considerable interior space, and a number of mechanical devices for distributing power therein are stored. Therefore, in order to detect arc generation with an infrared sensor, the sensors must be arranged in all of a plurality of mechanical devices that need to detect arc generation. Monitoring systems that require the installation of multiple infrared sensors can be costly and place a significant burden on data processing. Therefore, in this embodiment, the arc is sensed by an image sensing method.

Meanwhile, it is common for a general visual camera to have a detection speed of 1/30 second or 1/60 second. Such a general visual camera has a problem in that it is impossible to acquire an arc occurring instantaneously as a frame. Therefore, in this embodiment, a medium-wavelength infrared image sensor 1033 is used for image sensing, and the frame rate is set to 1000 frames or more and 2000 frames or less. When the infrared image sensor 1033 according to the present embodiment is set to the frame rate range, it is possible to acquire the instantaneous occurrence of the arc as a frame. When the infrared image sensor 1033 detects arc generation at a rate of 1000 frames, the time for generating the alarm may be within (number of counts) / 1000 [seconds]. The counting process is described in the luminance analysis of the smart control unit 30 which will be described later, and in this embodiment, it is possible to detect an arc with a short reaction time of about 0.001 second.

The infrared image sensor 1033 is provided inside the switchboard with a resolution of 80x80 pixels. In more detail, the infrared image sensor 1033 is disposed at the center of the rear of the switchboard to monitor the containment machines inside the switchboard.

Meanwhile, when the arc sensor is implemented as the infrared image sensor 1033 according to the present embodiment, information obtained during monitoring may be arc size and image data. At this time, it is possible to recognize the color temperature from the image data. That is, as the color temperature can be obtained from the image data, it is possible to simultaneously detect the deterioration state of the arc generating area in addition to the arc generation. While the general deterioration sensor detects the heat around the attached surface, the infrared image sensor 1033 according to the present embodiment has an advantage of accurately checking the displacement portion of the temperature from the image as it detects deterioration from the color temperature of the image.

The correction voltage generator 1037 may apply a negative voltage to the infrared image sensor 1033. The correction voltage generator 1037 may reduce the pixel noise value of the infrared image sensor and offset the noise level to zero. The initial value of the negative voltage may be input from the main processor 307, and the initial value may be corrected according to big data analysis of the management control unit 50. The correction voltage generator 1037 offsets the basic noise level by reducing the overall signal level, and the FPGA 301, which will be described later, offsets the pixel values of the image to set each of the noise and pixels as initial values.

The smart control unit 30 compares the luminance value of the infrared image measured by the arc sensor 1033 with the set first reference value, counts the luminance value exceeding the first reference value, and compares the set second reference value to generate the arc of the switchboard Can determine whether The first reference value is for detecting a pixel whose luminance value exceeds a certain value in an infrared image measured by the arc sensor 1033. The second reference value is for checking the number of pixels whose luminance value exceeds a certain value. The first reference value and the second reference value may be input from the user.

The management control unit 50 according to the present embodiment continuously accumulates luminance values, initial negative voltage values for reducing noise levels, first reference values, and second reference values as monitoring data as monitoring information of the smart control unit 30. The accumulated big data may be used to correct the reference value by grasping the error range with the luminance of the infrared pixel according to the temperature change when the switchboard is in operation, taking into account the operation information of the switchboard.

The smart control unit 30 may include an FPGA 301, a comparator 303, a counter 305, a memory 306, a main processor 307, a reference value register 308, and a signal generator 309.

The FPGA 301 may arrange pixel values of the infrared image captured by the arc sensor 1033 in units of frames, and output luminance values in units of pixels. The FPGA 301 reads each pixel value from the infrared image sensor 1033 and sets the initial value again. The FPGA 301 rearranges the read pixel values in units of frames and outputs luminance values in units of pixels. The output information may be stored in the memory 306. The memory 306 may temporarily store data read from the infrared image sensor 1033. The memory 306 according to the present embodiment may include a database for storing image data captured by the infrared image sensor 1033 as well as temporary storage. As an image data storage device, a memory 306 for storing real-time image information for a predetermined period may be provided in the smart control unit 30 or the management control unit 50.

The FPGA 301 receives the image pixel value in the state where the arc sensor 1033 is blocked and transmits it to the smart control unit. At this time, the smart control unit 30 receives the image pixel value in the state where the arc sensor 1033 is blocked. The error value table for making it 0 can be stored in the memory 306 and an error value is input to each pixel to offset the reference state to 0. In the process of offset adjustment, the infrared image sensor 1033 is controlled to a signal-free state by closing the shutter in front of the fish eye lens. The FPGA 301 receives each pixel value in the no-signal input state of the infrared image sensor 1033.

The memory 306 may store pixel values received by the FPGA 301 in a signalless input state of the infrared image sensor 1033. In the memory 306, an image pixel value in a blocked state and an error value table for making each pixel value 0 may be stored. Referring to the error value table stored in the memory 306, the FPGA 301 inputs an error value to offset the pixel reference state of the initial state to 0 level.

The comparator 303 is a Magnitude comparator, and can compare the luminance value output from the FPGA 301 with the first reference value. The main processor 307 may be understood as a central control device that controls each block of the smart control unit 30 as a whole. A first reference value and a second reference value may be set in the main processor 307. The first reference value and the second reference value are registered in the reference value register 308, and the registered data information can be accumulated and corrected as big data through the management control unit 50.

The comparator 303 compares the first reference value set in the main processor 307 with the luminance value output by the FPGA 301 being large or small. In addition, the comparator 303 may compare the number of counts exceeding the first reference value with the second reference value.

The counter 305 may count the luminance value exceeding the first reference value in the comparator 303. The signal generator 309 generates an arc generation danger signal when the number of counts exceeding the first reference value by the comparator 303 is greater than or equal to the second reference value, and transmits it to the management control unit 50.

The smart control unit 30 according to the present embodiment is defined as a configuration for expressing a function of storing an image of the infrared image sensor 1033 and performing the process of arc detection, where the smart control unit 30 is provided. It is not limited. The FPGA 301 of the smart control unit 30, the comparator 303, the counter 305, the memory 306, the main processor 307, the reference value register 308 or the signal generator 309 is an infrared image sensor 1033 It may be arranged in a modular manner or may be provided on a server separated from the infrared image sensor 1033.

The management control unit 50 may transmit arc generation information of the smart control unit 30 by communicating with at least one of a main management center (SCADA), an intelligent electronic device (IED), or a manager's smartphone. The smart control unit 30 may detect the occurrence of an arc without heat generation with only the infrared image data.

The management control unit 50 collects the luminance value of the smart control unit 30 and the operation information of the switchboard as big data, and an artificial intelligence-based machine learning algorithm is built in to perform information classification, analysis, and processing of the big data to perform the first operation. The reference value and the second reference value can be corrected.

3 shows the arc detection process of the arc sensor 1033 and the two-channel circuit breaker system of the switchboard. Referring to FIG. 3, the process of processing the smart controller 30 of the signal detected by the arc sensor 1033 includes setting an offset (S10), comparing a first reference value (S30), counting (S40), and second It may include a reference value comparison step (S50), and an alarm signal generation step (S60).

In the setting of the offset (S10), the noise level is reduced by applying a negative voltage from the correction voltage generator 1037 (S101), correcting the initial value of the pixel (S103) and the FPGA 301 is offset. It may include the step of loading the pixel value (S105). The step of setting the offset (S10) may be performed in the FPGA 301, and the related contents are omitted as described above.

The first reference value comparison step (S30) is a step of comparing the luminance value of the pixel and the first and second threshold values, which are performed by the above-described comparator 303.

In the counting step S40, when the luminance value of the pixel exceeds the first threshold in the first reference value comparison step S30, the count value is +1. The counting step S40 is performed at the counter 305 described above.

The second reference value comparison step S50 is a step of comparing whether the count value counted in the count step S40 exceeds a second reference value. The second reference value comparison step S50 may be performed in the above-described comparator 303.

The alarm signal generation step S60 is a step of generating an alarm output signal when the count value counted in the second reference value comparison step S50 exceeds the second reference value. The alarm signal generation step S60 may be performed in the signal generator 309 described above.

In another embodiment of the present invention, the arc sensor 1033 may be provided as an image sensor that combines a visual monitoring image as well as an arc detection function. More specifically, in this embodiment, the arc sensor 1033 may be provided as an image sensor using a fisheye lens for real-time image monitoring of internal containment machines of the switchboard.

4 shows the cycle of the accident current and the cut-off driving area of the circuit breaker 60. Referring to FIG. 4, it can be seen that the DC component rapidly increases in the event of an arc occurring inside the switchboard, and then returns to a normal state over time. Here, in the 2-channel circuit breaker system of the switchboard according to the present embodiment, the driving area of the circuit breaker 60 is divided based on the cycle of the accident current. When the P1 section is determined to be an internal accident from the sensor unit 10, the circuit breaker 60 may be a blocking area to be operated. When the P2 section is determined to be an external accident from the sensor unit 10, the circuit breaker 60 may be a blocking area to be operated. The operation of the circuit breaker 60 according to the determination of the accident type of the internal accident and the external accident may be performed through the circuit blocking control unit 40.

The circuit breaker control unit 40 may include an accident current relay 401 and an arc relay 403. The accident current relay 401 outputs an operation signal when an external accident of the CT sensor 1031 is detected. The arc relay 403 outputs an operation signal when detecting an internal accident of the arc sensor 1033. In the embodiments of FIGS. 1 to 3, the sensor unit 10 detects an accident current, but it is described above that it is divided into an internal accident and an external accident. Particularly, in the case of an internal accident, it will be said that an arc occurrence requires a rapid blocking operation. Thus, the two-channel circuit breaker system of the switchboard according to the present embodiment is an arc relay 403 channel for operating the circuit breaker 60 in the case of an internal accident, and a circuit breaker 60 for operating the circuit breaker 60 in the case of an external accident. It consists of a channel of the fault current relay 401.

In addition, the circuit breaker 60 is also connected to the 2-channel of the circuit breaker control unit 40, and the open operation circuit 603 is driven to be cut off in case of an internal accident and the 2-channel of the operation delay circuit 601 to delay the cutoff time in case of an external accident. It can be composed of.

The open operation circuit 603 is cut off and driven by the operation signal of the arc relay 403. The operation delay circuit 601 delays the operation signal of the accident current relay by a predetermined time to delay the cutoff driving time of the open operation circuit 603. In this case, the circuit breaker control unit 40 may interlock the accident current relay 401 when the arc relay 403 operates. Accordingly, a channel in which the circuit breaker 60 is driven is formed without going through the operation delay circuit 601 when an internal arc occurs. On the other hand, it has been described above that the breakdown of the ultra-high speed in the event of an accident current in the load line rapidly consumes the durability of the breaker. In order to improve the above problems, the circuit breaker control unit 40 drives and controls the open circuit 603 of the circuit breaker through the operation delay circuit 601 through the accident current relay 401 when an external accident occurs.

The accident current relay 401 and the arc relay 403 may be configured separately and independently. When the arc relay 403 is configured alone, the circuit may be configured by interlocking the general fault current relay 401.

The operation delay circuit 601 of the circuit breaker 60 delays the operation signal of the accident current relay 401 in the range of 3 to 5 cycles of the accident current. Referring to FIG. 4, the blocking driving region by the operation delay circuit 601 may be P2. Even in the case of breaking of the load line that does not require ultra-high-speed breaking, the breaker should be operated within 100ms when an accident current occurs. Therefore, the operation delay circuit 601 considers the safety of the system by setting the clearing section of the general accident in the range of 3 to 4 cycles, but does not overload the durability of the circuit breaker. On the other hand, the open operation circuit 603 is cut off and driven within one cycle of the accident current when the arc relay 403 is operated. Referring to FIG. 4, the blocking driving region by the open operation circuit 603 may be P1.

Although the present invention has been described in detail through exemplary embodiments above, those skilled in the art to which the present invention pertains understand that various modifications are possible within the limits of the embodiments described above without departing from the scope of the present invention. will be. Therefore, the scope of rights of the present invention should not be limited to the described embodiments, but should be determined by any modified or modified form derived from the claims and equivalent concepts as well as the claims described below.

1: 2-channel circuit breaker system of switchboard 10: sensor unit
1031: CT sensor 1033: Arc sensor
30: smart control unit 1033: infrared image sensor
1037: correction voltage generator 301: FPGA
303: comparator 307: main processor
308: Reference value register 305: Counter
309: signal generator 40: circuit breaker control
401: accident current relay 403: arc relay
50: management control unit 60: circuit breaker
601: operation delay circuit 603: open operation circuit

Claims (5)

A sensor unit including a CT sensor that senses an external accident by sensing an overcurrent of a line connected to a load, and an arc sensor that senses an internal accident by sensing an arc generated inside the switchboard;
A circuit breaker control unit including an accident current relay outputting an operation signal when detecting an external accident of the CT sensor, and an arc relay outputting an operation signal when detecting an internal accident of the arc sensor; And
A circuit breaker composed of two channels of an open operation circuit which is cut off and driven by the operation signal of the arc relay, and an operation delay circuit that delays the operation time of the accident current relay by a predetermined time to delay the cut off driving time,
The circuit breaker,
The operation delay circuit delays the operation signal of the accident current relay to a range of 3 to 5 cycles of the accident current, and the open operation circuit is cut off and driven within 1 cycle of the accident current during operation of the arc relay, and the open operation Circuit or the operation of the delay circuit of the operation delay circuit is different from the interruption driving region of the accident current,
The sensor unit detects the internal accident and the external accident of the switchboard,
The circuit breaker,
When an internal arc occurs, a channel that is driven without going through an operation delay circuit is formed, and when an external accident occurs, it is driven and controlled by the open operation circuit of the breaker through the operation delay circuit through the accident current relay, and based on the cycle of the accident current The circuit breaker 2-channel circuit breaker system, characterized in that the drive region of the circuit breaker is divided.
According to claim 1,
The arc sensor,
It detects the arc discharge of the switchboard with the infrared image of the medium wavelength, compares the measured luminance value of the infrared image with the set first reference value, counts the luminance value exceeding the first reference value and compares the set second reference value to compare the A two-channel circuit breaker system in a switchboard, characterized in that it determines whether an arc has occurred.
According to claim 2,
The arc sensor,
It is an infrared image sensor, and the video shooting speed is set to 1000 frames or more and 2000 frames or less,
The 2-channel circuit breaker system of the switchboard, characterized in that the speed of the arc occurrence determination is greater than 0 [count of luminance values exceeding the first reference value] / 1000 sec.
According to claim 1,
The circuit breaker control unit,
A two-channel circuit breaker system of a switchboard, characterized in that when the arc relay operates, the accident current relay is interlocked.
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