KR101208468B1 - Device for prevention disaster in cabinet panel - Google Patents

Abstract

PURPOSE: A disaster preventing apparatus of a cabinet panel is provided to stably recover a neutral line by including a neutral line recovering device in parallel. CONSTITUTION: A current detector(220) detects a current flowing in a neutral line. A disconnection detector(210) detects the disconnection of the neutral line. A controller(230) generates a control signal for reducing zero harmonic and recovering a neutral line. A neutral line recovering device(240) maintains the balance of a single phase voltage by recovering the disconnected neutral line. An alarm generator(250) gives an alarm about the increase of zero harmonic or the disconnection of a neutral line. A memory(260) stores abnormal state information outputted from the controller. [Reference numerals] (210) Disconnection detector; (220) Current detector; (230) Controller; (240) Neutral line recovering device; (250) Alarm generator; (260) Memory; (270) Alarm release signal input unit

Description

Device for prevention disaster in cabinet panel

The present invention relates to a disaster prevention apparatus for a distribution system, and more particularly, to prevent the occurrence of overvoltage and to maintain a normal voltage when a neutral line (N) error occurs in the distribution panel. Relates to a device.

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 electricity, and it is the distribution system that is used at this time.

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 distribution panel to attenuate such excessive image harmonics. Among them, three image lines are used to reduce the image impedance by using a zigzag connection transformer (zig-zag transformer) connected to three phase lines and a neutral line. A typical device is to prevent the image harmonics from the neutral line to the load system and to absorb the image harmonics by absorbing it to the zigzag connection transformer. As described above, the image harmonic filter using the zigzag connection transformer can efficiently attenuate the third-order harmonics, which are the most generated orders.

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

In the disclosed prior art 1, a plurality of circuit breakers are connected to the distribution panel, and three phases (A, B, C) of the power supply and the neutral wire (N) pass through the distribution panel breaker, and each phase line (A, B, C) and the neutral wire (N), but the neutral wire (N) through a cutoff switch, the circuit is cut off when the connection transformer rises above a certain set temperature, and again the temperature of the connection transformer is lowered below a certain temperature It operates to provide overload protection that automatically restores the ground circuit.

In addition, the disclosed prior art 2 includes a three-phase line R (R, S, T) which is connected to three-phase lines R, S, T and a neutral line N of a power source passing through the entire distribution, , S, T), and a coil constituting the electromagnetic contactor is connected to a temperature switch incorporated in the image harmonic reduction device, and the three-phase line R , S, T) of the electromagnetic contactor is opened and closed.

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 above or below a certain temperature, the temperature switch is turned on / off to separate the image harmonic reduction device from the main circuit by opening or connecting a switch of the magnetic contactor connected to the three-phase line (R, S, T). Or it is energized to prevent the burnout of the abatement device due to overload, and to operate the entire system stably without the opening and closing of the neutral wire.

Registered Patent Publication No. 10-0795037 (Invention name: Image Harmonic Reduction Device with Overload Protection) 2. Registered Patent Publication No. 10-0849463 of Korea Patent Office (Invention name: Image Harmonic Reduction Device equipped with overload protection device)

However, the prior art as described above has the advantage of reducing the image harmonics flowing to the neutral line to some extent, but if an abnormality occurs in the neutral line due to image harmonics or overheating (for example, the neutral wire break), the countermeasure against the neutral line abnormality Since no over voltage was formed, the load device was burned out due to the overvoltage.

Accordingly, the present invention has been proposed to solve all the problems occurring in the prior art as described above,

The problem to be solved by the present invention is to provide a disaster prevention apparatus for the distribution panel to prevent the occurrence of overvoltage and to maintain a normal voltage when a neutral line (N) abnormality occurs in the distribution panel.

Another problem to be solved by the present invention is to provide a disaster prevention apparatus for the entire distribution to detect the current flowing in the neutral wire, and to operate the jig-zag transformer when excessive current (over the reference value) flows to reduce the image harmonics have.

Another problem to be solved by the present invention is to detect the neutral wire disconnection, when the neutral wire disconnection is detected to recover the neutral wire to prevent the overvoltage caused by the neutral wire disconnection and to maintain the normal voltage To provide a device.

Another problem to be solved by the present invention is to provide a neutral wire recovery device in parallel to seek stability in the neutral wire recovery, disaster prevention of the overall distribution to operate the breaker automatically if the neutral wire is not restored by the parallel neutral wire recovery device To provide a device.

Disaster prevention device of the overall distribution according to the present invention for solving the above problems,

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

Detects the neutral state abnormality of the power supply device, if a neutral line abnormality is detected, attempts to recover the neutral line first, and if the overcurrent flows in the neutral line even after the neutral line recovery, attempts to recover the neutral line as the secondary, and recovers the neutral line to the secondary. It is characterized in that it comprises a neutral line recovery device that automatically operates the breaker when an overcurrent flows in the neutral line even after the attempt.

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 the image harmonics flowing to the neutral line or restoring the disconnected neutral line in accordance with the control signal generated by the controller to maintain the equilibrium of the single-phase voltage.

The disconnection detector in the above,

The neutral line voltage and the ground voltage are measured, and when the neutral line voltage and the ground voltage are detected, a disconnection detection value is output to a neutral line and transmitted to the controller.

Neutral recovery device in the above,

An alarm generator for generating an alarm for an increase in image harmonics or a disconnection of a neutral wire according to an alarm control signal generated by the controller;

A memory for storing abnormal state information output from the controller;

And an alarm release signal input unit configured to generate an alarm release signal and transmit it to the controller when an alarm release switch for alarm release is operated by an administrator after an alarm is generated by the alarm generator.

Neutral recovery machine in the above,

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 second switch connecting the respective phases to the restoring neutral wire (N) to maintain the balance of the single phase voltage through a first neutral recovery operation;

When the neutral line recovery is not performed even after the second switch operation, it characterized in that it comprises a third switch for performing the neutral line recovery operation by connecting each phase to the recovery neutral line (N) through an inductance.

According to the present invention there is an advantage that can prevent the occurrence of overvoltage and maintain a normal voltage when a neutral line (N) abnormality occurs in the overall distribution.

In addition, according to the present invention, by detecting the current flowing in the neutral wire, if the excessive current (over the reference value) flows by operating the zig-zag transformer can also reduce the image harmonics.

In addition, according to the present invention by providing a neutral wire restorer in parallel, it is possible to seek stabilization in the recovery of the neutral wire, and even if the neutral wire is not restored by the parallel neutral wire recovery device to automatically operate the breaker to minimize the problem occurring over the neutral wire There are advantages to it.

1 is a block diagram of a disaster prevention apparatus of the overall distribution according to the present invention,
FIG. 2 is a circuit diagram of an embodiment of the neutral line recoverer of FIG. 1.

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 block diagram of a disaster prevention apparatus in the overall distribution according to a preferred embodiment of the present invention, it is composed of a power supply device 100, the neutral line recovery device 200.

Here, the power supply device 100 includes a main circuit breaker 101 and a distribution circuit breaker (MccB), and serves to supply power to the rear end by receiving power through a three-phase four-wire type (R, S, T, N). Do it. Detailed operation of the main circuit breaker 101 or the switchboard circuit breaker (MccB) is the same as the operation of the general distribution panel, a detailed description thereof will be omitted below.

Neutral recovery unit 200 detects the neutral state abnormality of the power supply device 100, and when a neutral line abnormality is detected, attempts to restore the neutral line first, and when the overcurrent occurs in the neutral line even after the neutral line recovery, the secondary line recovers the neutral line. And attempts to automatically operate the circuit breaker when an overcurrent flows in the neutral wire even after the secondary wire neutral recovery is attempted.

The neutral line recovery device 200 includes a current detector 220 for detecting a current flowing in 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 is provided a neutral recovery device 240 to maintain the balance of the single-phase voltage to reduce the image harmonics flowing in the neutral line or to recover the disconnected neutral line.

Here, the disconnection detector 210 measures the neutral voltage and the ground voltage, and when the neutral voltage and the ground voltage are detected, outputs a disconnection detection value through neutral disconnection and transmits the detected disconnection value to the controller 230.

In addition, the neutral wire recovery device 200 includes an alarm generator 250 for generating an alarm for an increase in image harmonics or a disconnection of a neutral wire according to an alarm control signal generated by the controller 230; A memory 260 for storing abnormal state information output from the controller 230; After the alarm is generated by the alarm generator 250, if the alarm release switch for the alarm is operated by the administrator further comprises an alarm release signal input unit 270 for generating an alarm release signal to pass to the controller 230 . The warning release switch is a switch operated by an administrator to release the warning generator after taking a follow-up action on an abnormal condition that occurred, and when the warning release switch is operated, the controller 230 recognizes this and turns off the warning generator 250. Will dismiss the warning.

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; A second switch (M2) for connecting the respective phases (R, S, T) and the recovery neutral line (N) to maintain the balance of the single-phase voltage through a primary neutral line recovery operation; When the neutral line recovery is not performed even after the second switch M2 is operated, a third switch that connects the phases with the recovery neutral line N through inductances L4 to L6 to perform the neutral line recovery operation as a secondary. M3).

Disaster prevention device of the distribution panel according to the present invention configured as described above, the electric power supplied from the Korea Electric Power is supplied from the power supply device 100 through the primary transformer, a three-phase four-wire type through the Y-wire method through the secondary transformer When power is supplied to the load, if the image harmonics are excessively flowed on the neutral line (N) among the power lines supplied to the load side, or if the disconnection of the neutral line is detected, an error occurs in the power supplied to the load, and the load device is burned out. There is a concern.

In order to prevent such an accident in advance, the present invention installs the neutral wire recovery device 200 in the distribution panel, and detects the state of the neutral wire at all times, and immediately performs an alarm when excessive image harmonics flow in the neutral wire or the disconnection of the neutral wire is detected. At the same time, by reducing the image harmonics or restoring to another neutral line, it compensates the voltage imbalance between phases and prevents overvoltage from flowing to the light load side, so that stable voltage is always maintained.

In more detail, when power is supplied to the distribution board, 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 the detected current detection value with a preset reference set value (reference current value) to determine the amount of image harmonics. If the current detection value is equal to or less than the reference set value, the image harmonic is not excessive. If the current detection value is greater than the reference set value, it is judged that the image harmonics are excessively flowing in the neutral line, and the image harmonics decrease and the image harmonic reduction in the neutral line recoverer 240 is determined. Delivers control signals for In addition, the image harmonic increase detection information is stored in the memory 260 and the alarm generator 250 is operated to notify the outside that the image harmonics are increasing.

In addition, as shown in FIG. 2, when the neutral signal recoverer 240 receives a control signal for reducing image harmonics from the controller 230, the first switch M1 operates in an on state, thereby allowing each phase R to operate. , The primary inductance (L1 ~ L3) connected to the (S, T) is connected to the secondary inductance (L4 ~ L6) in a zig-zag method to form a zig-zag transformer, by the jig-zag transformer This reduces the flowing image harmonics. Here, the method of reducing the image harmonics flowing in the neutral line by the zig-zag trance is obvious to anyone skilled in the art, and thus a detailed description thereof will be 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.

Next, 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 determines the disconnection of the neutral by measuring the voltage and / or the ground voltage of the neutral and confirming whether the neutral or the ground voltage is detected.

If it is determined that the neutral wire is disconnected, the neutral wire disconnection information is included in the neutral wire 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 by using a built-in control program (analyze whether the neutral disconnection fault information is a high signal or a low signal), and if it is determined that it is not the neutral disconnection, the image harmonics are reduced. And the neutral line recovery unit 240 is not operated, otherwise, if it is determined that the neutral wire disconnection, the neutral line recovery unit 240 generates a control signal for neutral line recovery.

In addition, the controller 230 stores the neutral disconnection detection information in the memory 260 and simultaneously operates the alarm generator 250 to inform the outside that the neutral disconnection has occurred.

Also, as shown in FIG. 2, the neutral line recoverer 240 includes a neutral line N for recovery internally, and when the control signal for neutral line recovery is transmitted by the controller 230, a second switch ( M2) is operated to connect the recovery neutral (N) and the coil (inductance) (L1 ~ L3) for each phase. That is, the recovery neutral line (N) always recovers the disconnected neutral line by connecting three phases to the recovery neutral line when the neutral line is disconnected in the state where it always exists. Here, the neutral wire connection can be easily connected by using a magnet switch or the like.

When the neutral wire restorer 240 operates to recover 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 neutral wire of the power supply unit 100 may be maintained. Even if the wire is disconnected, it prevents the overvoltage from flowing to the load side and maintains the normal voltage as in the prior art, thereby preventing the problem of damaging the electric equipment due to the overvoltage as before.

On the other hand, the administrator can take a necessary action and operate the alarm release switch to the ON state to input a signal for the alarm release to the controller 230, the controller 230 when the alarm release signal is input the alarm generator 250 Off to clear the alarm.

As another feature of the present invention, if an overcurrent flows in the neutral line N even though the primary neutral line is restored in the same manner as described above (detected through the current detector 220), the controller 230 is the neutral line recoverer 240. A secondary neutral line recovery control signal is generated at.

In the neutral recovery device 240, the third switch M3 operates by the secondary neutral recovery signal, and connects the phases R, S, and T and the inductances L4 to L6 to each phase R. FIG. , S, T) and the neutral wire (N) are connected, and attempts to recover the neutral wire in the second.

For example, the present invention includes a neutral line recoverer in parallel at both ends of a zigzag transformer, and when a neutral line break is detected, the neutral line is first recovered through one neutral line restorer. After the current flowing through the neutral wire is detected to recover the neutral wire first, if the overcurrent flows to the neutral wire, the neutral wire is restored through the second neutral recovery device. In other words, in the worst case, two neutral wire restorers connected in parallel are operated simultaneously to recover the neutral wire and always supply stable power to the load side.

According to the present invention, when the neutral wire is disconnected in the distribution panel, automatic recovery is performed to the recovery neutral wire, thereby preventing phase voltage unbalance caused by the disconnection of the neutral wire, thereby preventing the electric device on the load side from being burned out. In addition, even when the image harmonics increase in the neutral line, the image harmonics can be reduced through the zig-zag transformer, so that the load side can always supply stable power.

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
250... Alarm generator
260 ... Memory
270... Alarm release signal input section

Claims (5)

In the first half of the distribution,
A power supply having a main breaker and a distribution breaker (MCCB);
Detects the neutral state abnormality of the power supply device, if a neutral line abnormality is detected, attempts to recover the neutral line first, and if the overcurrent flows in the neutral line even after the neutral line recovery, attempts to recover the neutral line as the secondary, and recovers the neutral line to the secondary. Disaster disaster prevention apparatus for the entire distribution, characterized in that it comprises a neutral wire recovery device that automatically operates the breaker when an overcurrent flows in the neutral wire even after the attempt.
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;
And a neutral recovery device for maintaining the balance of single-phase voltages by reducing the image harmonics flowing to the neutral wire or restoring the disconnected neutral wire according to the control signal generated by the controller.
The method according to claim 2, wherein the disconnection detector,
And measuring the neutral voltage and the ground voltage, and outputting the disconnection detection value through the neutral disconnection when the neutral voltage and the ground voltage are detected, and transmitting the detected disconnection value to the controller.
The method of claim 2, wherein the neutral wire recovery device,
An alarm generator for generating an alarm for an increase in image harmonics or a disconnection of a neutral wire according to an alarm control signal generated by the controller;
A memory for storing abnormal state information output from the controller;
Disaster prevention throughout the distribution, characterized in that it further comprises an alarm release signal input unit for generating an alarm release signal to deliver to the controller when the alarm release switch for the alarm release by the manager after the alarm is generated by the alarm generator; Device.
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 second switch connecting the respective phases to the restoring neutral wire (N) to maintain the balance of the single phase voltage through a first neutral recovery operation;
And a third switch performing secondary neutral recovery by connecting each phase to the neutral neutral for recovery N through inductance when the neutral wire recovery is not performed even after the second switch operation. Disaster prevention equipment.

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