KR101365398B1 - Earthquake disaster prevention system built-in switchgear and control method thereof - Google Patents

Abstract

Disclosed are a switchboard comprising an earthquake disaster prevention system and a control method thereof capable of preventing overvoltage generated by voltage imbalance and maintaining normal voltage when disconnection of a neutral line is generated in the switchboard and of preventing a disaster by automatically blocking the power of a building when an emergency is generated by the earthquake. The switchboard comprising the earthquake disaster prevention system comprises a power supply device, an earthquake sensing sensor, and a neutral line recovery device. The power supply device comprises a main breaker and a mold case current breaker (MCCB). The earthquake sensing sensor senses the intensity of the earthquake. The neutral line recovery device reduces image high-harmonics by operating a zigzag transformer when over current flows in the neutral line of the power supply device. When the voltage imbalance is sensed by sensing the voltage imbalance for each phase of power supplied from the power supply device, the neutral line recovery device the power imbalance as the short-circuit of the neutral line and recovers the neutral line by connecting one end of an inductance to the recovered neutral line. The neutral line recovery device calculates a current progress level based on the intensity of the earthquake sensed in the earthquake sensing sensor. When the current progress level is over a predetermined danger progress level, the neutral line recovery device outputs a power blocking signal. [Reference numerals] (210) Short-circuit detector; (220) Current detector; (230) Controller; (240) Neutral line recovery device; (250) Alarm generator; (260) Alarm release signal input unit; (300) Earthquake sensing sensor

Description

Switchgear with high earthquake disaster prevention system (high pressure panel, low pressure panel, electric control panel, distribution panel) and control method {Earthquake disaster prevention system built-in switchgear and control method}

The present invention relates to a switchgear with a built-in earthquake disaster prevention system and a control method thereof, and more particularly, to prevent overvoltage caused by voltage unbalance and maintain a steady voltage when a neutral line (N) break occurs in the switchgear. The present invention relates to a switchgear with a built-in earthquake disaster prevention system and its control method that automatically prevents disasters such as fire by automatically cutting off power distributed to buildings in case of an emergency caused by an earthquake.

In general, in power systems, the 22.9kv-y power distribution system directly powers large customers, such as factories and buildings, from substations through three-phase four-wire distribution lines, or through small transformers or homes through secondary transformers. It is a method of supplying power to the power switchboard.

Such a cabinet panel is equipped with an image harmonic filter for removing image harmonics.

Harmonics are frequencies that are integer multiples, such as 2, 3, and 4 times the fundamental frequency, and are called distortion or distortion waves, and especially high frequency orders such as 3, 6, 9, etc. The high frequency component corresponding to the multiple of 3 is called image harmonic.

Due to the characteristics of the distribution system in Korea, which adopts three-phase four-wire system, unbalanced current flows in the neutral wire due to the mixing of single-phase and three-phase loads.In recent years, computers, LED lighting devices, copiers, office equipment, uninterruptible power supply More image harmonics flow through the neutral due to the increase in nonlinear loads such as UPS. Since the phase harmonics of three phases have in-phase values, up to three times the image harmonics flow by being superimposed on a neutral line as if three single-phase power sources are connected in parallel. When excessive image harmonics flow in the neutral line, it causes obstacles such as overheating of the neutral conductor, deterioration of the distribution transformer, voltage distortion, communication line noise, and malfunction of electrical and electronic equipment.

Therefore, various methods have been proposed in the switchgear for attenuating such excessive image harmonics. Among them, three phase lines and a zig-zag connection transformer (zig-zag transformer) connected to the neutral line are used to make the image impedance small. The typical device is to prevent the image harmonics from flowing to the load system and to absorb the image harmonics by absorbing it into the zigzag connection transformer.

Conventional technology for a switchgear to which an image harmonic filter using a zigzag connection transformer is applied is disclosed in Korean Patent Application Publication No. 10-0795037 (Invention: Image Harmonic Reduction Device with Overload Protection Function) (hereinafter, " Technology 1 "and Korean Patent Office Patent Registration No. 10-0849463 (name of the invention: image harmonic reduction device equipped with an overload protection device) (hereinafter referred to as" prior art 2 ") have.

In the disclosed prior art 1, a plurality of circuit breakers are connected to the switchgear, and three phases (A, B, C) and the neutral wire (N) of the power supply pass through the distribution panel breaker, and each phase line (A, B) of the connection transformer of the image harmonic reduction device. , C) and the neutral wire (N), but the neutral wire (N) through the interruption switch, the circuit is cut off when the connection transformer rises above a certain set temperature, and again if the temperature of the connection transformer is lowered below a certain temperature Operate overload protection to automatically restore the circuit.

In addition, the disclosed prior art 2 is configured to be connected to the three-phase line (R, S, T) and the neutral line (N) of the power supply passing through the switchgear, respectively, the three-phase line (R, inputted from the distribution panel to the image harmonic reduction device) S, T) is provided with a magnetic contactor at the input terminal, the coil constituting the magnetic contactor is configured to be connected to a temperature switch built in the image harmonic reduction device, the three-phase line (R, It is configured to open and close the magnetic contactor connecting S, T).

The conventional technology 2 configured as described above includes a temperature switch inside the image harmonic reducing device, and connects an input terminal of the three-phase lines R, S, and T introduced into the reducing device to an electromagnetic contactor connected to the temperature switch, thereby reducing the inside of the reducing device. When the temperature rises or falls below a certain temperature, the temperature switch is turned on / off accordingly to open or connect the switch of the magnetic contactor connected to the three-phase wires R, S, and T. It can be isolated or energized to prevent burnout of the abatement device due to overload and to operate the whole system stably without opening and closing of the neutral wire.

Korean Patent Registration No. 10-0795037 (Title: Image Harmonic Reduction Device with Overload Protection Function) Korean Patent Registration No. 10-0849463 entitled "Image Harmonic Reduction Device with Overload Protection Device"

However, although the conventional techniques as described above can reduce the image harmonics flowing to the neutral line to some extent, when the neutral wire is disconnected due to the image harmonics or overheating, the countermeasure against the neutral wire disconnection is not taken at all, so the overvoltage It caused a problem that the load device was burned out.

In addition, the conventional switchgear as described above has been used in a state where the seismic design is not applied, there was also a problem that caused damage to people and property loss due to secondary damage such as fire caused by a short circuit during an earthquake.

Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art,

The problem to be solved by the present invention is to prevent overvoltage caused by voltage unbalance and to maintain a steady voltage when a neutral line (N) disconnection occurs in the switchgear to attenuate excessive image harmonics generated in the neutral line The present invention provides a switchgear with an earthquake disaster prevention system and a control method thereof.

Another problem to be solved by the present invention is a switchgear with a built-in earthquake disaster prevention system that detects the current flowing in the neutral wire and operates the jig-zag transformer when excessive current (over the reference value) flows to reduce the image harmonics To provide a control method.

Another problem to be solved by the present invention is to provide a switchgear with a built-in earthquake disaster prevention system and control method to prevent disasters such as fire by automatically cutting off the power distributed into the building in the event of an earthquake emergency There is.

The switchgear embedded with the earthquake disaster prevention system according to the present invention for solving the above problems,

A power supply having a main breaker and a distribution breaker (MCCB);

An earthquake detection sensor for detecting the intensity of the earthquake;

When excessive current flows through the neutral line of the power supply, the jig-zag transformer is operated to reduce image harmonics, and the phase voltage unbalance of the power supplied from the power supply is detected. Determine and connect one end of the inductance to the neutral for recovery, recover the disconnected neutral, calculate the current magnitude based on the seismic intensity detected by the earthquake detection sensor, and calculate the current magnitude based on the predetermined risk magnitude. It is characterized in that it comprises a neutral line recovery device for outputting a power interruption signal if the class is higher.

Neutral recovery device in the above,

A current detector for detecting a current flowing in the neutral line;

A disconnection detector for detecting whether the neutral line is disconnected;

A controller for generating control signals for image harmonic reduction and neutral line recovery according to the current detection value and the disconnection detection value output by the current detector and the disconnection detector;

And a neutral line recoverer for reducing image harmonics flowing through the neutral line or restoring the neutral line in accordance with a control signal generated by the controller to maintain a single phase voltage balance.

The disconnection detector in the above,

The voltage of the neutral wire and each phase is measured, and when the voltage between the neutral wire and each phase is unbalanced, the disconnection detection value is output to the neutral wire and transmitted to the controller.

In the above controller,

The current value detected by the current detector is compared with the reference set value, and when the detected current value exceeds the reference set value, it is determined that the image harmonics have risen, and a control signal for reducing the image harmonics is generated. .

The neutral-

A first switch operating according to a control signal for reducing image harmonics;

A zig-zag transformer that operates during the operation of the first switch to reduce an electric current flowing through a neutral line to remove image harmonics;

It characterized in that it comprises a second switch for maintaining the balance of the single-phase voltage by connecting each phase and the recovery neutral (N).

In the method for reducing the image harmonics and recovering them in the case of neutral disconnection,

Detecting electric current flowing through the neutral line when electric power is supplied;

Comparing the detected current with a reference set value to determine whether image harmonics increase, and when the image harmonics increase, operating the zig-zag transformer to reduce image harmonics;

Determining whether an image harmonic is increased by detecting a current flowing through a neutral line after the jig-zag transformer operation, and operating the circuit breaker when the image harmonic is not reduced;

Measuring a voltage of a neutral wire and each phase, and detecting whether the neutral wire is disconnected by the voltage unbalance of the neutral wire and each phase;

If it is determined that the neutral wire is disconnected, operating the neutral wire restorer to recover the disconnected neutral wire;

Checking whether the neutral line is normally restored after the neutral line restorer is operated, and operating a breaker when the neutral line is not normally restored;

Determining whether an earthquake is detected when the neutral wire is not disconnected as a result of detecting whether the neutral wire is disconnected, and calculating a current magnitude of magnitude when the earthquake is detected;

If the calculated current magnitude rank is greater than or equal to the degree of danger, automatically operating a breaker to cut off power;

Generating an alarm after the breaker operation or after the image harmonics are normally reduced or after the neutral line is normally restored;

And releasing an alert when an alarm release request is generated after the alarm is generated.

According to the present invention, even when a neutral line (N) disconnection occurs in the switchgear, there is an advantage of preventing the occurrence of overvoltage and maintaining a normal voltage.

In addition, according to the present invention, when a current flowing through a neutral line is detected to increase an image harmonic, an image harmonic wave flowing in a neutral line can be attenuated by operating a jig-jag trans.

In addition, according to the present invention there is an advantage that can prevent the disaster, such as fire by automatically cutting off the power distributed into the building in the event of an emergency by the earthquake.

1 is a block diagram of a switchgear embedded with an earthquake disaster prevention system according to the present invention.
FIG. 2 is a circuit diagram of an embodiment of the neutral conductor recovery apparatus of FIG. 1. FIG.
Figure 3 is a flow chart showing a control method of the switchboard with a built-in earthquake disaster prevention system according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

1 is a circuit diagram of a switchgear incorporating an earthquake disaster prevention system according to a preferred embodiment of the present invention, a power supply device 100 including a main breaker 101 and a distribution breaker (MCCB) and an earthquake detection sensor ( 300) and the neutral line recovery device 200.

Here, the power supply device 100 is supplied with power through a three-phase four-wire (R, S, T, N), and the detailed operation of the main breaker 101 or the switchgear breaker (MCCB) included therein is a general distribution panel. Since the operation is the same, specific description of the corresponding part will be omitted below.

The earthquake detection sensor 300 serves to detect the strength of the earthquake, and is generally buried in the ground to detect vibrations caused by the earthquake, and converts the vibration into an electrical signal to transmit the neutral line recovery device 200. .

The neutral wire recovery device 200 reduces the image harmonics by operating a zig-zag transformer when excessive current flows through the neutral wire N provided in the power supply device 100, and phase of power supplied from the power supply device. When the voltage unbalance is detected, if the voltage unbalance is detected, it is judged as a neutral wire disconnection, and one end of the inductance is connected to the recovery neutral wire to prevent the occurrence of overvoltage and maintain a steady voltage through the recovery of the disconnected neutral wire. This function prevents the load from burning out.

In addition, the neutral line recovery device 200 calculates the current magnitude based on the seismic intensity detected by the earthquake detection sensor 300 based on a predetermined criterion, and when the current magnitude is greater than or equal to a preset risk level, a power cutoff signal. It also performs the function of printing.

The neutral line recovery device 200 includes: a current detector 220 for detecting a current flowing through the neutral line; A disconnection detector (210) for detecting whether the neutral is disconnected; A controller 230 generating control signals for reducing image harmonics and restoring neutral lines according to the current detection value and the disconnection detection value output by the current detector 220 and the disconnection detector 210; In accordance with a control signal generated by the controller 230 includes a neutral recovery device 240 to maintain the balance of the single-phase voltage by reducing the image harmonics flowing to the neutral line or to recover the neutral line.

In addition, the neutral wire recovery device 200 preferably further includes an alarm generator 250 for alarming the disconnection of the neutral wire according to the alarm generation control signal output by the controller 230.

In addition, the neutral line recovery device 200 generates an alarm release signal and transmits it to the controller 230 when an alarm release switch for alarm release is operated by an administrator after an alarm is generated by the alarm generator 250. Preferably, the alarm cancellation signal input unit 260 is further included. The alarm release signal input unit 260 is provided with an alarm release switch as is well known. Here, the controller 230 may automatically cut off the single-phase power supplied to the load if the alarm release request does not occur within a predetermined time after the alarm occurs. For this purpose, the single-phase power circuit breaker is supplied to the input terminal to which the single-phase power is supplied. It is preferable to have a.

The disconnection detector 210 measures the voltage of the neutral line and each phase, and when the voltage between the neutral line and each phase is unbalanced, outputs the disconnection detection value to the neutral line disconnection and transmits it to the controller 230.

The controller 230 compares the current value detected by the current detector 220 with a reference setting value. If the detected current value exceeds the reference setting value, the controller 230 determines that the image harmonics have increased, And transmits the generated control signal to the neutral line recoverer 240. [

It is preferable that the controller 230 is implemented by a microcomputer, a microprocessor, a central processing unit, a microcontroller, or the like capable of storing controllable programs and controlling the overall operation of the neutral ray restoring apparatus 200 according to the stored programs Do.

As shown in FIG. 2, the neutral ray recoverer 240 includes a first switch M1 operated according to a control signal for reducing image harmonics; A zig-zag transformer (L1 to L6) which operates during the operation of the first switch (M1) to reduce the current flowing through the neutral line to remove image harmonics; It includes a second switch (M2) for connecting each phase (R, S, T) and the recovery neutral (N) to maintain the balance of the single-phase voltage.

In the switchgear equipped with the neutral wire recovery function according to the present invention configured as described above, the power supplied from KEPCO is supplied through a primary transformer, and then, three-phase four-wire power is supplied through a Y-connection method.

At this time, excessive harmonics in the neutral lead to overheating of the neutral conductor, performance degradation of the distribution transformer, voltage distortion, communication line noise, and malfunction of electrical and electronic equipment.If the neutral is disconnected, the voltage supplied to each phase Depending on the capacity of the load, this causes an accident that the load is burned out due to an abnormal voltage (overvoltage) on the light load side.

In order to prevent such an accident in advance in the present invention, the neutral line recovery device 200 detects the state of the neutral line at all times, and when the image harmonics are excessively flowed in the neutral line or the disconnection of the neutral line is immediately detected, the image harmonics are simultaneously reduced. By restoring to a neutral or other neutral, it compensates for the voltage imbalance between phases and prevents overvoltage from flowing to the light load side, so that a stable voltage is always maintained.

In more detail, when power is supplied to the switchgear, the current detector 220 detects a current flowing in the neutral wire and transmits a current detection value to the controller 230. In this case, it is preferable to use a general CT as the current detection method.

The controller 230 compares a preset reference value (reference current value) to determine the current detected value and the amount of the image harmonics, and if the current detected value is equal to or lower than the reference set value, the image harmonics are not excessive If the current detection value is greater than the reference setting value, it is determined that the image harmonics are excessively flowing in the neutral line, and the control signal for reducing the image harmonics .

As shown in FIG. 2, when the control signal for reducing image harmonics is transmitted from the controller 230, the neutral restorer 240 operates with the first switch M1 turned on to be connected to each phase. The secondary inductance (L1 ~ L3) is connected to the secondary side inductance (L4 ~ L6) in a zigzag manner to form a zig-zag transformer, which reduces the image harmonics flowing in the neutral line. Here, the operation of the zig-zag transformer is disclosed in detail in the prior art document described in the technology that is the background of the invention, and it is obvious to anyone skilled in the art. Is omitted.

Through this process, excessive image harmonics flowing in the neutral line are reduced, and then the controller 230 continuously compares the current detection value detected by the current detector 220 with the reference set value, when the current detection value is smaller than the reference set value. It is determined that the image harmonics flowing in the neutral line is reduced, and the jig-zag transformer is released by operating the first switch M1 provided in the neutral line recoverer 240 in an off state.

Meanwhile, the disconnection detector 210 operates to detect whether the neutral line N is disconnected, and transmits the detected disconnection detection value to the controller 230.

For example, the disconnection detector 210 measures the voltages of the neutral line and each phase, and compares the result of measuring the voltages of the neutral line and each phase to determine whether the voltage of each phase is balanced or unbalanced. Here, the method of measuring the voltage of the neutral wire and each phase is implemented in the same way as the method of measuring by using a general voltage meter for measuring the voltage of both ends, a detailed description thereof will be omitted.

Here, the preferred embodiment of the present invention has been described as measuring the neutral wire and the voltage of each phase in the disconnection detector 210 and comparing the same to determine the disconnection of the neutral wire. However, in this case, the configuration of the disconnection detector 210 may be complicated. In another embodiment of the present invention, the disconnection detector 210 measures only the neutral wire and the voltage of each phase and transmits the voltage to the controller 230, and the controller 230 may programmatically compare the phase voltage and determine whether the neutral is disconnected. Do.

On the other hand, if the voltage unbalance is confirmed by the disconnection detector 210, it is determined that there is a neutral fault (contact failure and / or disconnection), and the disconnection fault information is included in the neutral disconnection detection value and provided to the controller 230. Here, the neutral disconnection fault information may be referred to as a high signal (5V), and when the disconnection of the neutral wire is not detected, the neutral disconnection detection value may be referred to as a low signal (0V).

The controller 230 analyzes the disconnection detection value provided from the disconnection detector 210 with a built-in control program, and when it is determined that the disconnection is not the neutral disconnection (when a low signal is input), the neutral recoverer 240 does not operate. On the contrary, when it is determined that the wire is disconnected (when a high signal is input), a control signal for neutral wire recovery is generated in the neutral wire restorer 240.

As shown in FIG. 2, the neutral restorer 240 includes a neutral neutral N for recovery internally, and when the control signal for neutral recovery is transmitted by the controller 230, the second switch M2. The operation will connect the recovery neutral (N) and the coil (inductance) (L1 ~ L3) for each phase. That is, the recovery neutral line (N) is to always recover the disconnected neutral wire by connecting the three phases to the recovery neutral wire in the case of neutral disconnection in the state that is always present. Here, the neutral wire connection can be easily connected by using a magnet switch or the like.

When the neutral wire restorer 240 operates and recovers the disconnected neutral wire, the unbalance of single phase voltages that may occur due to the neutral wire disconnection may be maintained in an equilibrium state as before, and thus, the power supply device 100 may Even if the neutral wire is disconnected, the overvoltage is prevented from flowing to the light load side and maintains the normal voltage as in the prior art, thereby preventing the problem of damage to the electric device due to the overvoltage as in the past.

Meanwhile, as is well known, the controller 230 immediately drives the alarm generator 250 after the breaker is operated due to an increase in image harmonics or an increase in image harmonics, or when it is determined that the neutral wire is disconnected. The alarm generator 250 is driven to alert the image harmonics increase or breaker operation or neutral wire disconnection. In the present invention, the alarm is generated using a visual alarm and / or an audio alarm method.

When the administrator recognizes this in the state of a visual or audible alarm, a follow-up action is promptly taken, thereby preventing various accidents that may occur due to image harmonic increase or breaker operation or disconnection of the neutral line.

In addition, the administrator can release the alarms as needed. For example, when the alarm release switch provided in the alarm release signal input unit 260 is operated, the alarm release signal input unit 260 generates an alarm release signal and transmits it to the controller 230.

When the alarm release signal is transmitted, the controller 230 stops the operation of the alarm generator 250 to release the alarm.

In addition, the present invention, after performing the alarm for the disconnection of the neutral wire, if the alarm is not requested to be released within a predetermined time period automatically cuts off the power (single phase power) supplied to the load, the accident that may occur due to the neutral disconnection This is prevented in advance. Although not shown in the drawing, it is assumed that a power breaker is provided at the input terminal of the single-phase power.

In addition, the present invention is to detect the neutral disconnection through the disconnection detector 210 in the state in which the neutral recovery device 240 is operated by the neutral disconnection, the neutral recovery device due to the neutral disconnection If the voltage unbalance is detected despite the operation of the 240, the controller 230 automatically operates the main breaker 101 using the control signal, cuts off the single-phase load power, or cuts off the main breaker and the single-phase load power. It is blocked at the same time to prevent the load equipment from being burned out.

On the other hand, as another feature of the present invention detects an earthquake in the switchgear, when the magnitude of progress is more than the dangerous degree of class automatically cut off the power, to prevent accidents such as fire caused by the earthquake in advance.

For example, the controller 230 digitizes the electrical signal sensed by the earthquake detection sensor 300 and converts it back to earthquake intensity, and calculates the current magnitude of the earthquake in preparation for the following magnitude. Here, earthquake intensity is the intensity of vibration that appeared in a place, and it is a numerical expression that expresses the feeling of a person or the degree of shaking of an object or structure around it. Therefore, if an electrical signal (digital signal) is corresponded to each earthquake intensity in advance, the earthquake intensity can be immediately known when an electrical signal is detected from the earthquake detection sensor 300 using the earthquake detection sensor 300. In addition, the magnitude of magnitude can be easily calculated by the magnitude of the magnitude of seismic intensity by using the method of matching the magnitude of magnitude with the magnitude of seismic intensity.

In this way, the current progress rank is calculated and the current progress rank is checked to see if it is greater than or equal to the preset risk progress class to automatically cut power. Here, in the present invention, the risk magnitude class is set to Ⅶ. Therefore, the calculated current progress class and the risk progress class are compared, and when the current progress class is more than the above risk progress class (for example, in the range of Ⅶ Ⅶ ⅩⅡ), the breaker power is automatically cut off by operating the breaker. . This prevents the risk of fire that may occur due to power distribution during an earthquake.

3 is a flowchart illustrating a control method of a switchgear incorporating an earthquake disaster prevention system according to a preferred embodiment of the present invention, showing a process performed by the controller 230 of the switchgear as shown in FIG.

As shown therein, detecting power flowing in the neutral line (S101 to S103) when electric power is supplied; Determining whether the image harmonics increase by comparing the detected current with a reference set value, and when the image harmonics increase, operating the jig-zag transformer to reduce the image harmonics (S105 to S107); Determining whether the image harmonics are increased by detecting a current flowing in the neutral line after the jig-zag transformer operation, and operating the circuit breaker when the image harmonics are not reduced (S121 to S123); Measuring a voltage of a neutral wire and each phase, and detecting whether the neutral wire is disconnected by the voltage unbalance of the neutral wire and each phase (S109); If it is determined that the disconnection of the neutral is detected, operating the neutral restorer to recover the disconnected neutral (S111 to S113); Checking whether the neutral wire is normally restored after the neutral wire restorer is operated, and operating a breaker when the neutral wire is not normally restored (S125 to S127); Determining whether an earthquake is detected when the neutral wire is not disconnected as a result of detecting whether the neutral wire is disconnected, and calculating current magnitude of magnitude when an earthquake is detected (S129 to S131); When the calculated current magnitude rank is greater than or equal to the degree of danger magnitude, automatically operating a breaker to cut off power (S133 to S135); Generating an alarm after the breaker operation or after the image harmonics are normally reduced or after the neutral line is normally restored (S115); When the alarm release request is generated after the alarm occurs, the step (S117 ~ S119) to release the generated alarm.

In the switchgear control method equipped with the neutral wire recovery function according to the present invention, when power is first supplied to the motor control panel through the three-phase four-wire system in step S101, the current flowing through the neutral wire is detected through the current detector in step S103. Done. Thereafter, the detected current value is compared with a preset reference set value to determine the amount of image harmonics, and when the detected current value is larger than the reference set value, it is determined that the image harmonics are excessively flowing in the neutral line and the jig-zag By operating the transformer, the image harmonics flowing in the neutral line are reduced (S105 to S107).

After the jig-jag transformer is operated as described above, the process proceeds to step S121 to check whether the image harmonics have decreased normally. That is, after operating the zig-zag transformer, the current flowing through the neutral line is detected again and compared with the preset reference set value. When the detected current value is larger than the reference set value, it is determined that the image harmonics are not normally reduced. In order to prevent a fire or the like from occurring due to the increase of the image harmonics, the breaker operation control signal is automatically generated (S123). The breaker operation control signal generated as described above is transmitted to each breaker (LBS, AISS, MCCB, etc.) to perform a power interruption operation.

After generating the circuit breaker operation control signal, go to step S115 to drive the alarm generator 250 to generate an alarm for an image harmonic increase visually and visually, and when the alarm generated by the administrator is requested to release the alarm generator 250. ) Is stopped to release the generated alarm (S115 to S119).

In addition, when the image harmonics are normally reduced after the jig-zag transformer is operated after the increase of the image harmonics, the alarm generator 250 is moved to step S115 to generate an alarm for the increase of the image harmonics visually. After the alarm is issued by the administrator is requested to stop the operation of the alarm generator 250, it is to release the generated alarm (S115 ~ S119).

For example, if the image harmonics are normally decreased after operating the jig-zag transformer after increasing the image harmonics, only the alarm for the image harmonics is increased. It will generate an alarm for the increase in image harmonics.

On the other hand, if the image harmonics do not flow excessively to the neutral line, the flow advances to step S109 to detect whether the neutral wire is disconnected through the disconnection detector. Here, the method of detecting whether the neutral wire is disconnected is detected in the same manner as the operation of the switchgear equipped with the neutral wire recovery function, and thus detailed description is omitted in order to avoid duplicated materials.

When it is determined that the neutral wire is disconnected as a result of checking whether the neutral wire is disconnected (S111), the neutral wire restorer 240 is driven to recover the disconnected neutral wire (S113). For example, if the neutral wire (N) of the power supply line is disconnected and the neutral wire (N) is disconnected, one end of the inductance is connected to the neutral wire to restore the neutral wire, so that the voltage balance for each phase is achieved, and the load device connected to the single phase power that may be generated from the neutral wire disconnection. Will prevent damage.

After operating the neutral wire restorer, go to step S125 to check whether the neutral wire is normally restored. If the neutral wire is not restored normally, that is, the neutral wire is detected again through the disconnection detector to detect the neutral wire. When it is detected, the control unit 100 moves to step S127 to automatically generate a breaker operation control signal in order to prevent various problems caused by the disconnection of the neutral wire (S127). The breaker operation control signal generated as described above is transmitted to each breaker (LBS, AISS, MCCB, etc.) to perform a power interruption operation.

After generating the circuit breaker operation control signal, the control unit moves to step S115 to drive the alarm generator 250 to generate an alarm for neutral wire disconnection in an audiovisual manner, and when the alarm generated by the administrator is requested to be released, the alarm generator 250. The driving of the vehicle is stopped and the generated alarm is released (S115 to S119).

In addition, if the neutral wire is normally restored after operating the neutral wire restorer with the neutral wire breakage (checked through phase voltage unbalance detection), go to step S115 to drive the alarm generator 250 to generate an alarm for the neutral wire break in audio and visual directions. When the alarm is requested to be released by the administrator, the alarm generator 250 stops driving, thereby releasing the generated alarm (S115 to S119).

For example, if the neutral wire is normally restored after the disconnection of the neutral wire, only the alarm for the neutral wire is generated, and if the neutral wire is not restored normally after the neutral wire, the breaker is operated to generate an alarm for the neutral wire.

On the other hand, in the present invention, if it is determined that the neutral line is not disconnected as a result of the determination in step S111, the movement to step S129 to detect the earthquake through the earthquake detection sensor. After the earthquake is detected, go to step S131, the electrical signal detected by the earthquake detection sensor is converted into a digital signal, and then converted back to the earthquake intensity. Calculate the current progression class in preparation.

Thereafter, go to step S133 to check whether the current magnitude of progress calculated is greater than or equal to the preset risk magnitude in order to automatically cut off power. Here, in the present invention, the risk magnitude class is set to Ⅶ. Therefore, the calculated current progress class and the risk progress class are compared, and if the current progress class is above the above-mentioned risk progress class (for example, in the range of Ⅶ Ⅹ Ⅹ Ⅱ), go to step S135 and operate the circuit breaker automatically. Power off. This is to prevent the risk of fire that may occur due to power distribution during an earthquake.

After the breaker operation control signal is generated by the earthquake detection to go to step S115 to drive the alarm generator 250 to generate an alarm for the earthquake detection in audio and visual, after the alarm generated by the administrator is requested, the alarm generator The driving of the 250 is stopped to release the generated alarm (S115 to S119).

That is, according to the present invention, when the neutral wire of the power supply is disconnected, the automatic recovery is automatically performed by the neutral wire for recovery, thereby preventing phase voltage unbalance caused by the neutral wire disconnection, thereby preventing the electric load on the light load side from being burned out. do. In addition, if a neutral wire break occurs, an alarm is generated immediately so that the manager can recognize it, and afterwards, the manager can quickly take follow-up actions, thereby preventing an accident such as a system failure that may occur later due to the wire break. will be.

In addition, according to the present invention, when the earthquake is detected in the switchgear and the detected earthquake intensity is higher than the degree of dangerous magnitude, the breaker is automatically operated to prevent an accident such as fire that may occur due to power distribution during an earthquake. .

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. Of course, such modifications are within the scope of the claims.

100 ... Power supply
200 ... Neutral Line Recovery Device
210... Disconnection detector
220 ... Current detector
230 ... Controller
240 ... Neutral Line Restore
300 ... Earthquake detection sensor

Claims (6)

In the switchgear,
A power supply having a main breaker and a distribution breaker (MCCB);
An earthquake detection sensor for detecting the intensity of the earthquake;
When excessive current flows through the neutral line of the power supply device, the zig-zag transformer is operated to reduce the current flowing through the neutral line, reduce the image harmonics to maintain the equilibrium of single phase voltage, and phase of the power supplied from the power supply device. When the voltage unbalance is detected, if the voltage unbalance is detected, it is judged as a neutral wire disconnection, and one end of the inductance is connected to the recovery neutral wire to restore the disconnected neutral wire, and the earthquake intensity detected by the seismic sensor is based on a predetermined criterion. A switchgear with a built-in earthquake disaster prevention system, comprising a neutral line recovery device for calculating a magnitude of magnitude and outputting a power cutoff signal when the current magnitude of magnitude is greater than or equal to a preset risk magnitude. The apparatus according to claim 1,
A current detector for detecting a current flowing in the neutral line;
A disconnection detector for detecting whether the neutral line is disconnected;
A controller for generating control signals for image harmonic reduction and neutral line recovery according to the current detection value and the disconnection detection value output by the current detector and the disconnection detector;
Built-in earthquake disaster prevention system comprising an image harmonics reduction and neutral line recovery device to reduce the image harmonics flowing to the neutral line or to restore the neutral line in accordance with the control signal generated by the controller to maintain the equilibrium of the single-phase voltage One switchboard. The method according to claim 2, wherein the disconnection detector,
And measuring the voltage of the neutral wire and each phase, and if the voltage between the neutral wire and each phase is unbalanced, outputting a disconnection detection value through neutral disconnection and transmitting the detected disconnection system to the controller. 3. The apparatus of claim 2,
Comparing the current value detected by the current detector with a reference set value, and when the detected current value exceeds the reference set value, it is determined that the image harmonic is increased and generates a control signal for reducing the image harmonic. Switchgear with an earthquake disaster prevention system. The method according to claim 2, The neutral line recovering device,
A first switch operating according to a control signal for reducing image harmonics;
A zig-zag transformer that operates during the operation of the first switch to reduce an electric current flowing through a neutral line to remove image harmonics;
A switchgear with a built-in earthquake disaster prevention system, characterized in that it comprises a second switch for connecting each phase and the recovery neutral (N) to maintain a single phase voltage balance. In the method for reducing the image harmonics, recovering when the neutral wire breaks, and cut off the power distribution by detecting an earthquake,
Detecting electric current flowing through the neutral line when electric power is supplied;
Comparing the detected current with a reference set value to determine whether image harmonics increase, and when the image harmonics increase, operating the zig-zag transformer to reduce image harmonics;
Determining whether an image harmonic is increased by detecting a current flowing through a neutral line after the jig-zag transformer operation, and operating the circuit breaker when the image harmonic is not reduced;
Measuring a voltage of a neutral wire and each phase, and detecting whether the neutral wire is disconnected by the voltage unbalance of the neutral wire and each phase;
If it is determined that the disconnection of the neutral wire is detected, operating the neutral wire restorer to recover the disconnected neutral wire;
Checking whether the neutral line is normally restored after the neutral line restorer is operated, and operating a breaker when the neutral line is not normally restored;
Determining whether an earthquake is detected when the neutral wire is not disconnected as a result of detecting whether the neutral wire is disconnected, and calculating a current magnitude of magnitude when the earthquake is detected;
If the calculated current magnitude rank is greater than or equal to the degree of danger, automatically operating a breaker to cut off power;
Generating an alarm after the breaker operation or after the image harmonics are normally reduced or after the neutral line is normally restored;
If the alarm release request after the alarm occurs, the control method of the switchgear with a built-in earthquake disaster prevention system comprising the step of releasing the generated alarm.

Images