KR101253992B1 - Protecting apparatus of power distributer for preventing earthquake damage - Google Patents

Abstract

PURPOSE: A distributor protecting device for preventing earthquake damage is provided to enhance the reliability of a distributor by discharging charged power remaining inside the distributor, which is weakened due to an earthquake, with a ground. CONSTITUTION: A sequence managing part(120) successively operates or blocks a first breaker and a second breaker. An error detector(150) detects errors of a power entering wire and errors of wires at a second side and a load side of a transformer. A communication part(170) transmits the detection information of the error detector to a management center and receives a control signal. A connecting part(160) comprises a ground switch which connects a power managing part and the ground. A control part(110) discharges charged power remaining in the power managing part to the ground. [Reference numerals] (10) Power managing part; (11) Primary breaker; (110) Control part; (12) Transformer; (120) Sequence managing part; (13) Secondary breaker; (130) Earthquake detector; (150) Error detector; (160) Grounding part; (170) Communication part; (180) Sensing part; (200) Managing center; (AA) Power lead-in wire; (BB) Load;

Description

Protecting apparatus of power distributer for preventing earthquake damage}

The present invention relates to a distribution device protection device for preventing earthquake damage, and more particularly, earthquake damage that can prevent damage caused by earthquake by the stable block and recovery when the vibration caused by the earthquake in the switchgear, such as switchboard or distribution panel The present invention relates to a distributor protection device for prevention.

In general, a switchgear such as a switchboard or a switchboard receives high voltage power from a power plant and distributes the power to various electric equipment systems, so that there is always a high voltage residual power inside the switchgear. Such a distributor may generate a short circuit according to the dew even in a general natural situation in which dew is generated inside, and may cause a disaster such as a fire.In the case of a switchboard through which high-voltage power passes compared to other devices, the same short circuit may be large. May cause damage.

Therefore, the distributor is designed to prepare for various abnormal situations, and for this purpose, the distributor is basically provided with a circuit breaker such as VCB, ACB, MCCB, and the like. The circuit breaker is configured to automatically trip when an abnormality occurs in a track to protect the track and various electric equipments connected to the corresponding track, and operate to recover if there is no abnormality through a later track inspection.

However, in spite of such a breaker, when a large-scale natural disaster such as an earthquake occurs, the distributor itself is shocked by the vibration caused by the earthquake. Thus, even when the breaker is tripped, residual power inside the distributor is lost. If such damage occurs to the internal parts that are impacted, such residual power may leak and cause a great damage by a short circuit or a short circuit.

In addition, when the breaker is restored through a simple line check, the high-voltage power is instantaneously provided to increase the load on the parts that have become weak due to the earthquake, which may cause damage to the distributor or more seriously. There is a danger that it can not endure a sudden electric current and cause a fire.

Therefore, in order to prevent the damage caused by the earthquake, there is a need to develop a device that guarantees reliability of power operation by safely shutting off and recovering the distributor.

Korean Registered Patent No. 008097

In order to solve the above problems, the present invention is to perform the control of the circuit breaker installed in the distributor in the event of an earthquake having a predetermined size or more in order to achieve a stable power cut and at the same time after the earthquake is released The purpose is to recover the breaker air stream to provide a stable power supply.

In addition, an object of the present invention to stably process the power remaining in the distributor in the state in which the breaker flow is cut off during the earthquake to protect it from damage caused by the remaining power.

In addition, an object of the present invention is to provide a device that can stably protect the distributor from the aftershocks that occur continuously after the first earthquake due to the nature of the earthquake.

Distributor protection device for earthquake damage prevention according to an embodiment of the present invention for achieving the above object includes a variety of wiring and a transformer, the primary circuit breaker connected to the primary side of the transformer and the secondary side of the transformer A power management unit configured with a breaker including one or more secondary breakers, a UPS providing auxiliary power when the power is cut off, an earthquake detecting unit detecting an earthquake, and a primary breaker and a secondary breaker of the power management unit A sequence manager to block or start the controller, an abnormality detector for detecting an abnormality of the power lead line, a transformer secondary side, and a load side line, a communication unit for transmitting detection information of the abnormality detector to a management center and receiving a control signal; A grounding unit including a grounding switch for selectively connecting the power management unit and the ground, and receiving power through the UPS; It operates and converts the vibration detected by the earthquake detection unit to the magnitude of the magnitude, compare with the blocking criteria, determine whether to block accordingly, and then sequentially cut off the power through the sequence manager, according to the recovery control signal through the communication unit The power is sequentially restored through the power control unit, and the blocking state of each breaker airflow unit of the power management unit is determined so that the grounding switch is shorted through the grounding unit for a predetermined time in a state where all breaker airflows are blocked. And a control unit for discharging power to ground.

In this case, the primary circuit breaker may be VCB or ACB, when the primary circuit breaker is VCB, the secondary circuit breaker is ACB or MCCB, and when the primary circuit breaker is ACB, the secondary circuit breaker is MCCB. can do.

In addition, the control unit may be characterized in that to continue or stop the recovery in accordance with the detection information of the abnormality detection unit in each recovery step.

In addition, the control unit may not recover during the preset aftershock period for each progress class when the progress class according to the detection of the earthquake detector is equal to or greater than a predetermined level.

The sensing unit may further include a sensing unit including a sensor or a camera for sensing a physical abnormality of the power management unit, and the control unit may be configured based on sensing information of the sensing unit when the progress level according to the detection of the earthquake sensing unit is lower than a blocking criterion. Depending on whether or not an abnormality can be characterized in that the power is sequentially blocked through the sequence management unit.

In this case, the control unit may increase the sensing sensitivity of the sensing unit when the progress level according to the detection of the earthquake sensing unit is lower than the blocking criterion.

In addition, the detection information of the earthquake detection unit and the abnormality detection unit and the information on the cutoff state of the breaker of the power management unit may be characterized in that it is transmitted to the management center for transmitting the recovery control signal through a communication unit.

On the other hand, the control unit may be characterized in that in the order of the second breaker from the primary breaker through the sequence management unit when the power is cut off.

In addition, the control unit in the recovery step to restore from the primary circuit breaker to the secondary circuit breaker in the order, if the secondary circuit breaker is configured in a plurality of secondary circuit breakers in order to prevent damage due to the inrush current Can be.

According to the present invention, in the event of an earthquake, the interruption of the breaker configured in the distributor is sequentially blocked so that stable power is cut off, and after the earthquake is released, the breaker flow is sequentially checked to prevent damage caused by the inrush current while checking the abnormality of the line of the distributor. Since the load on the distributor can be minimized by restoring it, the reliability of the distributor can be guaranteed by protecting the distributor not only in the interruption process during the earthquake but also in the recovery process after the earthquake.

In addition, the present invention has the effect of preventing the damage that may occur due to leakage or short circuit of the remaining charging power by discharging the charging power remaining in the internal components of the distributor having a weak durability during the earthquake.

In addition, the present invention has an effect of preventing the damage caused by the aftershock by controlling the breaker setting time of the breaker differently according to the progress class in preparation for aftershocks that occur continuously after the earthquake.

1 is a block diagram of a distributor protection device for preventing earthquake damage according to an embodiment of the present invention.
Figure 2 is a block diagram showing a process for the blocking and recovery of the breaker airflow of the distributor protection device for earthquake damage prevention according to an embodiment of the present invention.
3 is an operation configuration diagram according to the aftershocks of the distributor protection device for preventing earthquake damage according to an embodiment of the present invention.
Figure 4 is an operation configuration for blocking the breaker according to the sensor configuration of the distributor protection device for preventing earthquake damage in accordance with an embodiment of the present invention.
5 is a configuration diagram for discharging the charging power of the distributor protection device for preventing earthquake damage in accordance with an embodiment of the present invention.

Hereinafter, a distributor protection device for preventing earthquake damage according to an embodiment of the present invention with reference to the drawings.

1 is a detailed configuration diagram of a distributor protection device for preventing earthquake damage according to an embodiment of the present invention, as shown in the distributor protection device is a switchboard, distribution panel, motor control panel, automatic control panel, photovoltaic device control panel It is applied to a distributor including a circuit and the like to cut off the power provided to the distributor in the event of an earthquake and to discharge the remaining charge power according to the operation of the distributor is configured to protect the components of the distributor weakened due to the earthquake. .

In the following description, a distributor protection device for preventing earthquake damage according to the present invention may be applied to various distributors including one distribution panel so as to be described based on a distribution panel.

As shown, the power distribution unit protection device for earthquake damage prevention according to an embodiment of the present invention is applied to the switchboard (1) receives the power transmitted through the power inlet line, transform the power management unit 10 to be sent to the load And, sequence management unit 120 for controlling the interruption and recovery of the power of the power management unit 10, the abnormality detection unit 150 for detecting a line abnormality of the power management unit 10, and detecting the earthquake The earthquake detection unit 130, the UPS (Uninterruptible Power Supply) 140 to provide an auxiliary power when the power is cut off, the communication unit 170 to support the communication with the external management center 200, and determine whether the earthquake And a control unit 110 that manages the power management unit 10.

The power management unit 10 includes various wirings and a transformer 12 to convert power provided through a power lead wire through the transformer 12 to be transmitted to the load side. At this time, in order to cut off and restore the power provided to the power management unit 10, the primary circuit breaker 11 connected to the primary side of the transformer and at least one secondary circuit breaker 13 configured on the secondary side of the transformer Breakers can be configured.

In this case, the primary breaker 11 may be configured as a VCB (Vacuum Circuit Breaker), the secondary breaker 13 may be configured as an ACB (Air Circuit Breaker), the MCCB (Molded Case Circuit Breaker) is The ACB may be replaced or further added. In addition, the primary circuit breaker 11 may be configured as an ACB and the secondary circuit breaker 13 may be configured as an MCCB. In addition, the secondary circuit breaker 13 may be configured in plural.

Therefore, the controller 110 controls the breaker airflow when the earthquake occurs through the sequence manager 120 to cut off the power provided to the power management unit 10, and restores the breaker airflow when the earthquake is released again. Ensure power is supplied.

However, unlike the general abnormal situation, the earthquake can directly reduce the durability of the power management unit 10 by directly applying a vibration to the power management unit 10, and accordingly, the power management unit ( Damage may occur due to the charging power remaining in the inside of 10). In addition, in the case of simply restoring the blocked air flow due to the characteristics of the switchboard 1 that receives and transmits high voltage power, the power provided to the power management unit 10 increases rapidly, resulting in breakage of the power management unit 10 or the like. It may cause damage.

Accordingly, the control unit 110 according to the present invention performs more precise control in preparation for the earthquake, which is an embodiment of the control unit 110 is supplied with power through the UPS 140 and continuously operated and the earthquake After converting the vibration sensed by the sensing unit 130 to the magnitude of the comparison and compare with the blocking criteria and determine whether to block accordingly, and then sequentially block the blocking air through the sequence management unit 120, recovery through the communication unit 170 The breakers included in the breakers 11 and 13 are sequentially restored through the sequence manager 120 according to a control signal.

At this time, the control unit 110 may transmit the detection information of the abnormality detection unit 150 to the management center through the communication unit 170, the management center 200 is transmitted from the control unit 110 after the earthquake is released. The recovery control signal may be transmitted by determining whether to recover the breaker streams 11 and 13 based on the received information.

In addition, the control unit 110 provides information on the progress level according to the detection of the earthquake detecting unit 130 and information on the blocking state of the breakers included in the breakers 11 and 13. It can also be transmitted to the management center 200 through.

Accordingly, the control unit 110 may receive the recovery control signal of the management center 200 through the communication unit 170 to perform the recovery of the blockers 11 and 13. That is, by the management center 200 to determine whether to recover by combining the information on the state caused by the earthquake of the switchboard 1, it is possible to ensure a stable recovery under the control of the management center (200).

Meanwhile, the control unit 110 sequentially restores each breaker included in the breakers 11 and 13 during recovery according to the recovery control signal received through the communication unit 170, and detects the abnormality at each break of the breakers. If there is no abnormality in the line based on the detected information on whether the abnormality of the line of the unit 150, the recovery can be stopped if there is an error in the line.

For example, the control unit 110 determines whether or not a line abnormality is based on the detection information received from the abnormality sensing unit 150 after the restoration of the primary circuit breaker 11, and if there is no abnormality, the secondary circuit breaker 13 ) Can be restored. However, if an error occurs in the line based on the detection information received from the abnormality detector 150 after the recovery of the primary circuit breaker 11, the controller 110 may stop the recovery of the secondary circuit breaker 13. have.

In addition, the controller 110, when the primary circuit breaker 11 and the secondary circuit breaker 13 are all restored in sequence, based on the detection information of the abnormality detection unit 150, the primary and Secondary breakers 11 and 13 may be sequentially blocked again through the sequence manager 120.

Accordingly, it is possible to determine whether or not the leakage of power generated according to the abnormality of the power management unit 10 after the earthquake to ensure a stable recovery.

On the other hand, the abnormality detection unit 150 is connected to the power lead line and the transformer secondary side and the load side line to determine the abnormality by measuring the power difference on the line each time each breaker of the breakers (11, 13) is restored. This may be provided to the controller 110 as sensing information.

In addition, the controller 110 determines a blocking state for each breaker included in the breakers 11 and 13 of the power management unit 10 to ground through the ground unit 160 in a state where all breakers are blocked. By shorting the switch, the power remaining in the power management unit 10 may be discharged to ground, thereby protecting the switchboard from damage caused by the charging power remaining in the power management unit 10.

Various embodiments of the distributor protection device for preventing earthquake damage with reference to the configuration of FIG. 1 will be described in detail with reference to FIGS.

First, FIG. 2 is a block diagram of a block airflow control process when an earthquake occurs in a distributor protection device for preventing earthquake damage according to an embodiment of the present invention. As shown, the control unit 110 is the earthquake detection unit 130. ), The detected vibration can be converted to a Richter scale magnitude class and compared with a preset cutoff criterion.

Accordingly, the control unit 110 is a breaker 11, 13 configured in the power management unit 10 through the sequence management unit 120, as shown in Figure 2 (a) when the magnitude of the magnitude is greater than the blocking criteria. ) Can be blocked. In this case, the control unit 110 may operate to block the primary circuit breaker 11 first through the sequence manager 120 and to block the secondary circuit breaker 13 after a predetermined time elapses.

As a result, the electric power may be consumed in the power management unit 10 by preventing power from being charged to the line or the transformer 12 configured in the power management unit 10 and at the same time as the power is consumed to the load side.

On the other hand, when the earthquake situation is over, the control unit 110 may receive the recovery control signal from the management center 200, the control unit 110 receiving the recovery control signal to the sequence management unit 120 By restarting the breaker (11, 13) configured in the power management unit 10 can be restored.

In this case, as shown in FIG. 2 (b), the controller 110 first starts and restores the primary circuit breaker 11 through the sequence manager 120, and then starts the secondary circuit breaker 13. Can be controlled to recover. As such, the sequence manager 120 sequentially recovers the primary circuit breaker 11 from the primary circuit breaker 11 to the secondary circuit breaker 13, so as to start the secondary circuit breaker 13 first or the primary circuit breaker 11 and the secondary circuit breaker. Simultaneously recover (13) to prevent instantaneous inrush current from occurring to the primary breaker (11), through which the primary breaker (11) is damaged due to the inrush current or the line and the primary circuit breaker (11) Sparks can be prevented from occurring at the contacts.

In addition, when the secondary circuit breaker 13 is configured in plural, the controller 110 controls the sequence manager 120 to control each of the secondary circuit breakers 13 after the start of the primary circuit breaker 11. It can be started at timed intervals to recover.

As a result, the inrush current rapidly increases when the secondary circuit breakers 13 connected to the load side are simultaneously started, whereas the inrush currents generated by the primary circuit breakers 11 when the plurality of secondary circuit breakers 13 are individually operated. It can greatly reduce the primary circuit breaker (11) also can prevent the spark generated at the contact point of the line and the breaker stream.

On the other hand, as described above, the control unit 110 restores when there is no abnormality in the line on the basis of the detection information on whether the abnormality of the abnormality detection unit 150 at the time of recovery of each breaker, and recovers when there is an error in the line. Can be stopped.

That is, the control unit 110 determines whether or not the line abnormality based on the detection information received from the abnormality detection unit 150 after the recovery of the primary circuit breaker 11, and if there is no abnormality, the secondary circuit breaker 13 Can be restored. However, when an error occurs in the line based on the detection information received from the abnormality detecting unit 150 after the restoration of the primary circuit breaker 11, the controller 110 controls the sequence manager 120 to control the secondary circuit breaker. Recovery of (13) can be stopped.

In addition, the controller 110, when the primary circuit breaker 11 and the secondary circuit breaker 13 are all restored in sequence, based on the detection information of the abnormality detection unit 150, the primary and Secondary breakers 11 and 13 may be sequentially blocked again through the sequence manager 120.

As described above, the controller 110 sequentially blocks and restores the breakers 11 and 13 through the sequence manager 120, thereby remaining components of the power manager 10 that have become weak due to the earthquake. Can easily be protected from charging power and inrush current.

On the other hand, the earthquake is characterized by the fact that a number of additional aftershocks occur. Thus, additional protection processes are required for such aftershocks.

3 is an embodiment of an operation configuration of a control unit in preparation for an aftershock, and as shown, the control unit 110 converts the vibration received through the earthquake detection unit 130 into the magnitude of the magnitude of the magnitude of magnitude. When the value is equal to or greater than a predetermined reference value, it may be configured to cut off the power provided to the power management unit 10 even after the excitation generated afterwards.

For example, as illustrated, the control unit 110 may preset an aftershock setting time for each magnitude of the magnitude of the earthquake, which is measured by the earthquake detection unit 130 or more.

Accordingly, when the earthquake detected by the earthquake detector 130 is a magnitude of magnitude 4, the control unit 110 cuts off when the main station occurs through the sequence manager 120 for t time, which is an aftershock setting time corresponding thereto. It can be controlled to keep the airflow blocked.

In addition, the controller 110 maintains the blocking state of the breakers 11 and 13 through the sequence manager 120 for a longer time since the corresponding preset aftershock time increases as the progress level of the main train increases. Can be controlled.

On the other hand, even when the progress level measured according to the earthquake is lower than the predetermined cutoff criteria, the line or transformer 12 included in the power management unit 10 may be caused by vibration, so that the power management unit to prevent this It may further include a sensing unit 180 for detecting a physical abnormality of (10).

As shown in FIG. 4, the control unit 110 may determine a physical abnormality based on the sensing information of the sensing unit 180 when the magnitude of progress according to the detection of the earthquake sensing unit 130 is lower than a blocking criterion. Depending on whether or not the blocker (11, 13) can be blocked through the sequence manager 120.

In this case, even when the control unit 110 blocks based on the sensing information, the first circuit breaker 11 to the second circuit breaker 13 may be ordered in the same manner as the blocking according to the vibration detection of the earthquake detection unit 130 described above. You can block.

In addition, the control unit 110 increases the sensing sensitivity of the sensing unit 180 when the progress level measured by the earthquake detecting unit 130 is less than or equal to a predetermined blocking criterion to more accurately detect the occurrence of a physical abnormality. You can also carry out.

That is, even if an earthquake with a lower magnitude than that for the power cutoff of the switchboard is generated, an impact may be applied to the switchboard. Thus, damage to the switchboard according to the low magnitude can be easily prevented through the above-described configuration.

In addition, when the control unit 110 cuts off power through the sequence manager 120 based on the sensing information, the sensing center and the detection information of the abnormal information detection unit through the communication unit 170. 200, and when receiving a recovery control signal from the management center 200, as described above, it is possible to restore power by sequentially starting the breakers 11 and 13 blocked through the sequence manager 120. FIG. .

Meanwhile, the sensing unit 180 may include a sensor or a camera for detecting a flame, and preferably, an infrared camera having a flame sensor or an image analysis function may be applied.

In the case of cutting off the power provided to the power management unit 10 through the breakers 11 and 13 in preparation for the earthquake as described above, the charging circuit of the line or transformer 12 configured in the power management unit 10 is blocked. Charged charging power remains during operation.

Accordingly, the power management unit 10 may be short-circuited charging power remaining due to the impact of the earthquake, which may cause an electric shock, and may cause damage to the switchboard itself when a short circuit occurs.

Therefore, it is required to discharge the charging power remaining in the power management unit in the event of an earthquake.

To this end, as shown in Figure 5 may further include a ground unit 160 for selectively discharging the remaining charge power to the external ground when interrupted by the interruption air flow of the power management unit.

In this case, as shown in FIG. 5, the ground unit 160 connecting the power management unit 10 and the ground may include a contact point formed on at least one of the primary line and the secondary line of the transformer 12, and the transformer. 12 may be configured to selectively interconnect at least one of the charging circuit and the PCB substrate constituting the power management unit 10 and the ground. In addition, the ground unit 160 may be configured to include a ground switch therein to selectively control the short-circuit and opening of the connection between the power management unit 10 and the ground.

Therefore, the control unit 110 determines the blocking state of all the breakers 11 and 13 configured in the power management unit 10 through the sequence manager 120 according to the earthquake, the breaker streams 11 and 13. If all are blocked, the ground switch of the ground unit 160 may be shorted for a predetermined time to connect the power management unit 10 and the ground.

Accordingly, the ground potential is applied to the power management unit 10 so that the charging power remaining in the line, the case and the charging circuit of the transformer can be easily discharged to the ground.

Meanwhile, the controller 110 opens the ground switch of the ground unit 160 after a predetermined time elapses, so that the power provided to the power management unit 10 according to the restoration of the breakers 11 and 13 after the earthquake is released. It can be transformed and sent to the load.

1: switchboard 10: power management
11: primary circuit breaker 12: transformer
13: secondary breaker 110: control unit
120: sequence management unit 130: earthquake detection unit
140: UPS 150: abnormal detection unit
160: grounding unit 170: communication unit
180: sensing unit 200: management center

Claims (10)

A power management unit including various wirings and a transformer, the breaker including a primary circuit breaker connected to the primary side of the transformer and at least one secondary circuit breaker configured on the secondary side of the transformer;
A UPS providing auxiliary power at power down;
An earthquake detection unit for detecting an earthquake;
A sequence manager for sequentially blocking or starting the primary circuit breaker and the secondary circuit breaker of the power manager;
An abnormality detecting unit detecting an abnormality of the power lead line and the transformer secondary side and load side lines;
A communication unit which transmits detection information of the abnormality detection unit to a management center and receives a control signal;
A grounding unit including a grounding switch for selectively connecting the power management unit and the ground; And
The power is supplied through the UPS and continuously operated, and the vibration detected by the earthquake detection unit is converted into a progress class to compare with a blocking criterion and determine whether to cut off accordingly, and then sequentially cut off power through the sequence management unit. Restore power sequentially through the sequence management unit according to the recovery control signal through the control unit, and determine the blocking state for each breaker current of the power management unit, and set the ground switch through the ground unit for a predetermined time in a state where all breakers are blocked. A control unit that discharges the charging power remaining in the power management unit to the ground by a short circuit
Distributor protection device for earthquake damage prevention comprising a.
The method according to claim 1,
The primary circuit breaker protection device for earthquake damage, characterized in that the VCB or ACB.
The method according to claim 2,
When the primary circuit breaker is VCB, the secondary circuit breaker is ACB or MCCB, when the primary circuit breaker is ACB, the secondary circuit breaker protection device for earthquake damage prevention, characterized in that the MCCB.
The method according to claim 1,
The control unit is a distributor protection device for earthquake damage prevention, characterized in that for continuing the recovery or stop in accordance with the detection information of the abnormality detection unit in each recovery step.
The method according to claim 1,
The control unit distributor protection device for earthquake damage prevention, characterized in that when the progress class according to the detection of the earthquake detection unit is more than a predetermined level does not recover for a predetermined aftershock period for each progress class.
The method according to claim 1,
Further comprising a sensing unit including a sensor or a camera for detecting a physical abnormality of the power management unit,
The control unit blocks power sequentially through the sequence manager according to whether or not an abnormality occurs based on the sensing information of the sensing unit when the progress level according to the detection of the earthquake detection unit is lower than the blocking criterion. Distributor Protection.
The method of claim 6,
The control unit distributor protection device for earthquake damage prevention, characterized in that to increase the sensing sensitivity of the sensing unit when the progress level according to the detection of the earthquake detection unit is lower than the cutoff criteria.
The method according to claim 1,
Distributor protection for earthquake damage prevention, characterized in that the detection information of the earthquake detection unit and the abnormality detection unit and the information on the blocking state of the breaker air flow of the power management unit to the management center for transmitting the recovery control signal through a communication unit Device.
The method according to claim 1,
The control unit is a distributor protection device for earthquake damage prevention, characterized in that when the power cut off the first breaker in order to the second breaker through the sequence management unit.
The method according to claim 1,
The control unit recovers from the primary circuit breaker to the secondary circuit breaker in the recovery step in the order of the secondary circuit breaker, and when the secondary circuit breakers are configured in plural, the secondary circuit breakers are sequentially restored to prevent damage due to the inrush current. Distributor protection device for earthquake damage prevention.

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