KR101208467B1 - Cabinet panel for prevention disaster of neutral line peculiar and control method thereof - Google Patents

Abstract

PURPOSE: A cabinet panel for preventing a disaster and a controlling method thereof are provided to prevent a rear device from being damaged due to an overvoltage by preventing voltage imbalance due to the disconnection of a neutral line at each phase. CONSTITUTION: A phase detector(210) detects the disconnection of a neutral line by sensing a phase of a power supply device(100). A controller(220) generates a control signal for recovering a neutral line in a disconnection state. A neutral line recovering unit(230) recovers a neutral line formed in a power supply device according to a control signal generated from the controller. An alarm generator(240) gives an alarm about the disconnection of a neutral line according to an alarm control signal outputted from the controller. An alarm release signal input unit(250) generates an alarm release signal and transmits the alarm release signal to the controller. [Reference numerals] (210) Phase detector; (220) Controller; (230) Neutral line recovering unit; (240) Alarm generator; (250) Alarm release signal input unit

Description

Cabinet panel for prevention disaster of neutral line peculiar and control method

The present invention relates to a disaster prevention distribution panel and its control method in the event of a neutral wire, and more particularly, a neutral wire fault to prevent the occurrence of overvoltage and maintain a steady voltage when a neutral line break occurs in the distribution board. The entire disaster prevention distribution and the control method thereof.

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.

In the three-phase four-wire distribution system, the neutral wire (N) and the power line (A phase, B phase, C phase) are combined to supply power by a Y connection, a delta connection, and a delta connection. In this case, when one power line and another power line are connected, 380V becomes, and when one power line (for example, A phase) and the neutral line (N) are connected, it becomes 220V and supplies power to the load.

In this case, the neutral line N means a line in which one line of each phase is common in a multiphase multi-line line. In principle, three wires require six strands. However, if the phases of a single-phase two-wire line are twisted by 120 ° and one line is made common, the potential is reduced to four strands. This zero potential (zero potential) immediately becomes the reference potential, and so-called N-phase, that is, the neutral line.

In this state, the neutral should in principle have a zero potential, which is an earth potential, but may actually have some voltage when the phase of each phase is not exactly 120 ° out of the field. In this case, to prevent the rise of the neutral potential, if the neutral line is commonly connected to the ground line which is the ground potential line, even if the phase of each phase slightly changes, the ground potential is maintained because it is in contact with the ground.

The characteristics of the distribution system of Korea which adopts 3 phase 4 wire system is that single phase load and 3 phase load are mixed and unbalanced current flows in the neutral line. Recently, computer, LED, lighting equipment, office equipment such as copying machine, uninterruptible power supply (UPS) due to the increase of nonlinear load devices, more neutral image lines were flowing more 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, especially high frequency orders such as 3, 6, 9, etc. The high frequency component corresponding to the multiple of 3 is called image harmonic.

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. If excessive image harmonics flow in the neutral line, the bushing portion is broken or the neutral line is broken due to overheating of the neutral conductor.

If the neutral wire is disconnected, damage of the load-side earth leakage breaker with a large impedance occurs, and an accident occurs that the load of the elevator weak circuit equipment connected to the neutral wire and the voltage side line burns out.

In other words, if the neutral wire is disconnected in the three-phase four-wire distribution system, the voltage of the lightly loaded terminal will increase, the heavy load will decrease, and the light load will cause an abnormality. As a result, the switch is turned off or the circuit is opened due to a failure, and the voltage unbalance is intensified, causing almost all light load electrical equipment to be damaged, exploded, or fired.

In addition, in the single-phase three-wire distribution system, if the neutral wire is disconnected, an overvoltage flows, thereby causing a problem that the load-side electric equipment is damaged.

In order to solve all the problems caused by the disconnection of the neutral wire, the conventionally proposed technology is registered in Korea Patent Office Registration No. 10-1052471 (registered on July 2, 2011) (Invention: Neutral wire replacement device and method in the power system) ) Is disclosed.

In the disclosed prior art, when a neutral line disconnection is detected, a three-phase (R, S, T) power source is connected to an internal neutral line protector to form a common line to replace the generated neutral line to prevent the generation of an abnormal voltage.

1.Registered Patent No. 10-1052471 (registered on 22/22/2001) (Name of invention: Neutral wire replacement device and method in power system)

However, the prior art as described above can solve to some extent the problem that the light load side electric equipment is burned out when the neutral wire is disconnected in the three-phase four-wire distribution panel, on the other hand, a switch for connecting the neutral wire is provided at each phase input part. In addition, the large size of the inductance has a disadvantage that a relatively large capacity switch must be used. In other words, if the inductance is small, the capacity of the switch can be reduced, and if the inductance is large, the switch must be relatively large. A switch must be used.

Therefore, the implementation cost of the apparatus is increased due to the use of a large-capacity high-capacity switch, resulting in poor economical efficiency. Since the inductance is large, a high current flows to the switch relatively.

Accordingly, the present invention has been proposed to solve various problems occurring in the conventional neutral conductor replacement device as described above.

The problem to be solved by the present invention is a disaster prevention distribution board and its control method in the event of a neutral wire abnormality to prevent the occurrence of overvoltage and to maintain a normal voltage when a neutral line disconnection occurs in the three-phase four-wire distribution panel To provide.

Another problem to be solved by the present invention is to provide a disaster prevention distribution board and its control method in the event of a neutral wire abnormality to reduce the implementation cost of the device by using a small capacity switch by providing a switch in the neutral current flowing less current have.

Another problem to be solved by the present invention is to provide a small-capacity switch in the neutral current flowing less current, the disaster prevention distribution board in the event of a neutral wire abnormality to minimize the failure by minimizing the current flowing through the switch by restoring the neutral wire To provide a way.

Another problem to be solved by the present invention is to provide a general distribution of disaster prevention and disaster control in the event of a neutral wire abnormality to warn when a neutral wire break is detected, so that subsequent actions can be taken.

Another problem to be solved by the present invention is a disaster in case of a neutral wire abnormality to prevent the load device from being burned by an overvoltage by automatically operating the main circuit breaker when voltage unbalance is detected even when the neutral wire breaker is operated by the neutral wire break. It is to provide a general disaster prevention distribution and a control method thereof.

According to an aspect of the present invention, there is provided a disaster prevention device for a neutral line in a power system,

A power supply having a main breaker and a distribution breaker;

Detects the phase loss of the power supply device, and if the phase is detected, it is judged to be a neutral wire disconnection and connects each phase inductance, and connects the connected inductance to the recovery neutral wire to prevent the occurrence of overvoltage and maintain the normal voltage by recovering the neutral wire. It is characterized by including a neutral wire recovery device.

The neutral ray restoration apparatus includes:

An imaging detector for detecting an open circuit of the power supply device and detecting whether a neutral wire is disconnected;

A controller for judging disconnection based on the disconnection detection value output by the imaging detector, and generating a control signal for neutral line recovery when disconnection;

And a neutral wire recoverer for recovering a neutral wire provided in the power supply device according to a control signal generated by the controller to maintain the balance of single-phase voltage.

The imaging detector,

A phase detector for sensing phase signals of R, S, and T phases of the power supply line;

If the phase level of any one of the detected R, S, T phase is maintained at a high level for a predetermined time or more, it is determined that the phase of any one phase is missing and outputs an open circuit detection value to the controller. It is characterized by including.

The neutral-

A first switch for connecting an inductance of R phase and an inductance of S phase;

A second switch for connecting the inductance of the S phase and the inductance of the T phase and then connecting the recovery neutral wire;

A third switch for connecting the R phase inductance and the T phase inductance and then connecting to a recovery neutral line (N) to maintain a single phase voltage balance;

The first to third switches are characterized in that for using a small capacity switch corresponding to the small current applied to the neutral wire.

According to the present invention for solving the above problems, "disaster prevention distribution distribution control method in the event of a neutral wire",

In the method of recovering the neutral wire in the case of disconnection of the neutral wire in the controller provided in the neutral wire recovery device,

(a) detecting the disconnection of the power supply line and detecting whether the neutral line is disconnected;

(b) if it is determined that the neutral wire is disconnected, operating the neutral wire restorer to recover the disconnected neutral wire;

(c) checking whether the neutral line is normally restored and generating an alarm for the neutral line disconnection when the neutral line is restored normally;

(d) generating an alarm for the disconnection of the neutral wire after generating a breaker operation signal when the neutral wire is not normally restored;

(e) if an alarm release request is generated after the alarm is generated, releasing the generated alarm.

According to the present invention, when a neutral line disconnection occurs in a three-phase four-wire distribution panel, the neutral line is quickly restored, thereby preventing the occurrence of overvoltage and continuously introducing a steady voltage to the load side. have.

Further, according to the present invention, since a switch is provided in a neutral line through which a small current flows, it is possible to use a small-capacity switch to reduce the cost, and the current flowing through the switch is small, so that failure of the switch due to overheating can be minimized .

1 is a circuit diagram of the disaster prevention apparatus at the time of the neutral line abnormality in the power system according to an embodiment of the present invention,
FIG. 2 is a circuit diagram of an embodiment of the neutral line recoverer of FIG. 1.
3 is a flowchart illustrating a disaster prevention method when a neutral line fault occurs in a power system according to an exemplary embodiment of 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 the entire disaster prevention distribution in the event of a neutral wire fault according to a preferred embodiment of the present invention, and includes a neutral wire recovery device 200 associated with the power supply device 100.

When the neutrone recovery device 200 is implemented as a single module and commercialized, it can be easily applied to existing installed electric devices.

The power supply device 100 refers to a general power supply device that supplies power provided by KEPCO in a three-phase four-wire type (R, S, T, N).

Neutral wire recovery device 200 is connected to the power supply device 100 for supplying power through three-phase four-wire (R, S, T, N), the neutral wire (N) provided in the power supply device 100 Detects phase loss and detects phase loss as neutral wire and connects inductance for each phase, and connects connected inductance to recovery neutral to prevent overvoltage and maintain normal voltage through neutral wire recovery. do.

The neutral line recovery device 200 includes: an phase detector 210 that detects an open phase of the power supply device 100 and detects whether the neutral line N is disconnected; A controller (220) for determining whether the disconnection is detected by the disconnection detection value output by the imaging detector (210), and generating a control signal for recovering the neutral line in the event of disconnection; And a neutral wire recoverer 230 for recovering the neutral wire provided in the power supply device 100 according to the control signal generated by the controller 220 and maintaining the balance of the voltage of each phase.

Although not shown in the figure, the imaging detector 210 includes a phase detector configured to detect phase signals of R, S, and T phases of a supply power line therein; When the phase level of any one of the detected R, S, T phase is maintained at a high level for a predetermined time or more, it is determined that the phase of any of the phases, and an image detection detector for outputting the disconnection detection value to the controller It is desirable to.

In addition, the controller 220 may be implemented as a microcomputer, a microprocessor, a central processing unit, a microcontroller, and the like, which store a controllable program and control the overall operation of the neutral line recovery device according to the stored program.

As shown in FIG. 2, the neutral recovery device 230 includes a first switch M1 for connecting an inductance L1 of R phase and an inductance L2 of S phase; A second switch M2 for connecting the inductance L2 of the S phase to the inductance L3 of the T phase and then connecting the inductance L2 to the recovery neutral line N; And a third switch M3 for connecting the inductance L1 of the R phase to the T phase inductance L3 and then connecting the inductance L1 to the restoration neutral line N to maintain the balance of the single phase voltage.

The neutral line recovery apparatus 200 may further include an alarm generator 240 for alarming the neutral line disconnection according to an alarm generation control signal output by the controller 220.

In addition, when the alarm release switch for alarm release is operated by the manager after the alarm is generated by the alarm generator 240, the neutral line recovery device 200 generates an alarm release signal and transmits the alarm release signal to the controller 220 And an alarm release signal input unit 250. The signal input unit 250 includes an alarm release switch as is well known in the art.

Disaster prevention distribution panel at the time of neutral wire fault according to the present invention configured as described above, after receiving the power supplied from the Korea Electric Power through the primary transformer, the power supply device 100 is supplied to the distribution panel and switchboard through the Y connection method. .

At this time, when the neutral line is disconnected, the voltage supplied to each phase differs according to the capacity of the load, and thus, a fire or a load device is burned due to an abnormal voltage (overvoltage) at the light load side.

In order to prevent such an accident in advance, in the present invention, the neutral ray restoring device 200 senses the state of the neutral line at all times, performs an alarm immediately upon detection of disconnection of the neutral line and restores to the neutral line for recovery, At the same time, it works to prevent the overvoltage from flowing under the light load.

In more detail, when power is supplied by the power supply device 100, the imaging detector 210 detects phase signals of R, S, and T phases of the power supply line through an internal phase detector, and forms an image. If the phase level of any one of the R, S, and T phases detected by the detector is maintained at a high level for a predetermined time or more, it is determined that the phase is any one phase and outputs a disconnection detection value to the controller 220. To pass. That is, the imaging detector checks whether the high level lasts for a predetermined time or more when the level of any one of the R, S, and T phases becomes a high level, and determines that the high level lasts for a predetermined time or more. Done.

On the other hand, if the phase detection is detected in the imaging detector 210, the determination is made to the neutral line abnormality (neutral wire disconnection), and the neutral wire disconnection detection value is included in the neutral wire disconnection information is provided to the controller 220. 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 220 analyzes the disconnection detection value provided from the imaging detector 210 by using a built-in control program, and when it is determined that the disconnection is not the neutral line, the neutral line restorer 230 does not operate. If it is determined that the neutral restorer 230 is operated. That is, if the disconnection detection value is a high signal, it is determined to be a neutral line disconnection. If the disconnection detection value is a low signal, it is determined that the disconnection line is not a neutral line disconnection.

As shown in FIG. 2, the neutral line recoverer 230 includes a neutral line for recovery internally, and when the operation control signal is transmitted by the controller 220, the first switch M1 is turned on. Operation to connect the R phase inductance (L1) and the S phase inductance (L2), the second switch (M2) is turned on to operate the S phase inductance (L2) and T phase inductance (L3) After that, it is connected to the recovery neutral (N). In addition, the third switch M3 operates in a turn-on state to connect the inductance L1 of the R and the inductance L3 of the T, and then connects with the recovery neutral line N. That is, in the state where the recovery neutral line (N) is always present, the three phases connected when the neutral line is disconnected is connected to the recovery neutral line to recover the disconnected neutral line. Here, it is preferable that the first to third switches use a small capacity switch, such as a magnet switch.

When the neutral line recoverer 230 operates to recover the disconnected neutral line, the unbalance of the single-phase voltage of each phase, which may occur due to the neutral line disconnection, can be maintained in the equilibrium state as before, Even if the neutral wire is disconnected, the overvoltage is prevented from flowing under the light load as in the conventional case, and the normal voltage is maintained. Thus, the overvoltage flows to prevent the electric appliance from burning down.

Also, by connecting the first to third switches M1 to M3 to the neutral line with less current, it is possible to use a small-capacity switch without using a large-capacity switch as in the prior art. Therefore, the size of the apparatus can be reduced, The cost of device implementation can be reduced. Particularly, since the small-capacity switch is provided in the neutral line flowing less current, the current flowing in the small-capacity switch is relatively small and the phenomenon of overheating due to the high current is remarkably reduced as in the conventional case. There are advantages.

On the other hand, the controller 220 drives the alarm generator 240 as soon as it is determined that the neutral line is broken. The alarm generator 240 drives and warns the neutral line disconnection. In the present invention, the alarm is generated using a visual alarm and / or audible alarm.

If the administrator recognizes this in the presence of a visual and / or audible alarm, then it will take immediate follow-up action, thereby preventing various accidents that may occur due to 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 250 is operated, the alarm release signal input unit 250 generates an alarm release signal and transmits the alarm release signal to the controller 220.

When the alarm release signal is transmitted, the controller 220 stops the operation of the alarm generator 240 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.

Also, as is well known in the present invention, the neutral wire breaker 230 is continuously operated by the neutral wire breaker, and the neutral wire breaker is continuously detected through the breaker detector 210. At this time, (LBS, AISS, ASS, VCB, ACB, MCCB, ELB, etc.) by using the control signal in the controller 220 when the voltage imbalance is detected It is possible to prevent the load device from being burned out by interrupting the single phase load electric power (using M2) or by simultaneously interrupting the main breaker and the single phase load electric power.

Figure 3 is a flow chart showing a "disaster prevention and distribution distribution control method in the event of a neutral wire fault" according to a preferred embodiment of the present invention, (a) detecting the disconnection of the power supply line to detect the disconnection of the neutral wire (S101 ~ S103) Wow; (b) if it is determined that the disconnection of the neutral is detected, operating the neutral recovery device to recover the disconnected neutral (S105 to S107); (c) checking whether the neutral line is normally recovered and generating an alarm for neutral line disconnection if it is normally recovered (S109 to S111); (d) generating an alarm for the neutral line disconnection after the breaker operation signal is generated when the neutral line is not normally restored (S112, S111); (e) a step (S113-S115) of releasing an alarm when an alarm release request is generated after the alarm occurrence.

As shown therein, first, when power is supplied by the power supply device in step S101, the imaging detector 210 detects whether the neutral line is disconnected in step S103. Here, the method of detecting whether or not the neutral wire is disconnected will be described in order to avoid disconnection of the neutral wire in the same manner as the operation of the disaster neutralizer in the case of the neutral wire abnormality described above.

If it is determined that the neutral wire is disconnected (S105), the neutral wire recoverer 230 is driven to recover the disconnected neutral wire (S107). For example, if the neutral line is separately provided and the neutral line N of the power supply device 100 is disconnected, the phase voltage is inputted to the neutral line recoverer 230 to recover the neutral line of the power supply device by the neutral line separately, To prevent the burden of load equipment connected to single phase power due to overvoltage that may occur from neutral line break due to voltage balance, maintain normal voltage.

Then, in step S109, it is confirmed whether the neutral line is normally restored (through the disconnection detection value of the disconnection detector). If the neutral line is normally restored, the alarm generator 240 is driven to generate an alarm for the neutral line disconnection If the alarm is to be released by the administrator, the alarm generator 240 is stopped and the generated alarm is released (S111 to S115).

If the neutral line has not been normally recovered after attempting to recover the neutral line, the process proceeds to step S112 to generate a breaker operation control signal. Thereafter, the alarm generator 240 is activated to generate an alarm for the neutral line disconnection When the alarm generated by the manager is requested to be released, the operation of the alarm generator 240 is stopped and the generated alarm is released (S111 to S115).

For example, according to the present invention, when the neutral line of the power supply device is disconnected, the automatic restoration is automatically performed to the restoration neutral line, thereby preventing the abnormal voltage imbalance caused by the disconnection of the neutral line, do. If the neutral line is disconnected, the alarm is generated and the administrator can recognize it. Then, the manager can take the follow-up action promptly, so that the system failure due to the overheat which may occur due to the neutral line disconnection. It is possible to prevent the accident of

In addition, when the neutral line recovery fails, the circuit breaker operation control signal is generated to operate the circuit breaker, thereby preventing damage to the rear stage device due to overvoltage or the like.

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... Imaging detector
220 ... Controller
230... Neutral Line Restore
240... Alarm generator
250... Alarm release signal input section

Claims (5)

A power supply having a main breaker and a distribution breaker;
Detects the phase loss of the power supply device, and if the phase is detected, it is judged to be a neutral wire disconnection and connects each phase inductance, and connects the connected inductance to the recovery neutral wire to prevent the occurrence of overvoltage and maintain the normal voltage by recovering the neutral wire. Disaster prevention distribution in the event of a neutral wire, characterized in that the neutral wire recovery device.
The apparatus according to claim 1,
An imaging detector for detecting an open circuit of the power supply device and detecting whether a neutral wire is disconnected;
A controller for judging disconnection based on the disconnection detection value output by the imaging detector, and generating a control signal for neutral line recovery when disconnection;
Disaster prevention distribution board in the event of neutral line abnormality, characterized in that it comprises a neutral line recovery device for maintaining the balance of the single-phase voltage by recovering the neutral line provided in the power supply in accordance with the control signal generated by the controller.
The method of claim 2, wherein the imaging detector,
A phase detector for sensing phase signals of R, S, and T phases of the power supply line;
If the phase level of any one of the detected R, S, T phase is maintained at a high level for a predetermined time or more, it is determined that the phase of any one phase is missing and outputs an open circuit detection value to the controller. Disaster prevention distribution overall in the case of neutral wire, characterized in that it comprises.
The method according to claim 2, The neutral line recovering device,
A first switch for connecting an inductance of R phase and an inductance of S phase;
A second switch for connecting the inductance of the S phase and the inductance of the T phase and then connecting the recovery neutral wire;
A third switch for connecting the R phase inductance and the T phase inductance and then connecting to a recovery neutral line (N) to maintain a single phase voltage balance;
Disaster prevention distribution board in the event of neutral line abnormality, characterized in that the first to the third switch uses a small capacity switch corresponding to the small current applied to the neutral wire.
In the method of recovering the neutral wire in the case of disconnection of the neutral wire in the controller provided in the neutral wire recovery device,
(a) detecting the disconnection of the power supply line and detecting whether the neutral line is disconnected;
(b) if it is determined that the neutral wire is disconnected, operating the neutral wire restorer to recover the disconnected neutral wire;
(c) checking whether the neutral line is normally restored and generating an alarm for the neutral line disconnection when the neutral line is restored normally;
(d) generating an alarm for the disconnection of the neutral wire after generating a breaker operation signal when the neutral wire is not normally restored;
(e) when the alarm release request occurs after the alarm occurs, comprising the step of releasing the generated alarm disaster control panel distribution control method for the neutral line fault.

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