KR20090022716A - Apparatus and method for fault detection and fault location decision on a distribution line using load current - Google Patents

Abstract

An apparatus for determining fault position of distribution line in consideration of influence of load device and a method thereof are provided to improve reliability of distribution line operation by determining half-open and half-input of a distribution line. A measuring part(530) measures one among a current or a voltage flowing in a predetermined position of a distribution line. A control part(520) determines malfunction of the distribution line according to a measured current amount and a current direction. A key pad changes phase information of the distribution line according to the detected phase information. A communication part(510) transmits one among direction information of a current flowing in the predetermined position of the distribution line, non-current/non-voltage information of the distribution line, malfunction information of the line, half-open information, and half-input information to a distribution control device on the distribution line.

Description

Apparatus and method for detecting a failure of a distribution line and determining the location considering the influence of load equipment {APPARATUS AND METHOD FOR FAULT DETECTION AND FAULT LOCATION DECISION ON A DISTRIBUTION LINE USING LOAD CURRENT}

The present invention relates to an apparatus and a method for detecting a fault and determining a fault location occurring on a power distribution line. More particularly, the present invention relates to an automatic fault switch installed on a power distribution line. An apparatus and method for determining a fault location.

In general, power generating power plants are spatially separated from homes, factories, and offices, which are the main sources of power, due to pollution and pollution during power generation. Therefore, there is a need for a distribution line that supplies power from a power plant or substation to a home, factory, office, or the like.

In recent years, the capacity of the load using the power is gradually increasing, the demand for high quality and high reliability power supply is increasing. In order to meet these demands, a distribution automation system has been introduced in Korea, and much progress has been made in reducing the reliability of power supply and reducing the power failure time.

The distribution automation system collects data from a terminal device connected to a switch and a recloser installed on a distribution line, and performs a failure detection function to determine whether a failure occurs at each measurement point when an abnormality is detected in the line. In addition, the distribution automation system collects and analyzes the fault information of the terminal devices for the distribution line of the corresponding distribution line based on the fault detection information, identifies the fault section, separates the fault section, and distributes the neighboring power to the power failure section that is not the fault section. By attempting to load balance over the line, a reliable high quality power supply is achieved.

The distribution automation system supplies the power of the substation to the load of the customer through the distribution line, and the terminal device for the distribution line (for example, the recloser control unit) connected to the recloser and the automation switch installed in the distribution line. ) And FRTU (Feeder Remote Terminal Unit) and configured to perform measurement data collection, fault detection, remote control, etc. on the distribution line. As such, the power distribution automation system of a power system utilizes a computer or a communication technology to operate a distribution line device such as a switchgear or a recloser through a distribution line terminal device scattered at a long distance without directly going to the field, or to a distribution line. It performs key functions in the power system, such as automatically detecting fault zones.

On the other hand, devices installed in substations and distribution lines can be divided into protection devices and switchgear. Protection devices include circuit breakers (C / B) installed on the substation side and reclosers installed on the distribution line side.

When the breaker detects a very large fault current from the distribution line, the breaker may open or close the line by the set information. In addition, if necessary, the line can be opened and closed even in the normal current flow.

The recloser is a special type of breaker that recloses itself based on the set information. If a fault current is detected from the power distribution line and continues for a certain range, the recloser opens the line and closes the line again after a predetermined time. If the fault current is still detected after the line is closed, the recloser repeats the above line reclose process by a preset number of times, and after that, if the fault current continues, the line is completely opened and no further reclose operation is performed. .

The switchgear is classified into the ground used for the underground line and the processing installed in the overhead line according to the installation position and the configuration of the device. The switch unit includes a main body connected to a distribution line, a control unit for linking the main unit and a terminal device for a distribution line, and a terminal device for a distribution line for communication, measurement, monitoring, and control with a remote site. In general, a terminal device for a distribution line detects whether a failure occurs by using a current change and a voltage change on a distribution line when a failure occurs, and the terminal device for a distribution line transmits a control signal to a switch controller according to a remote control command. Open and close the distribution line through the switch body.

The failure on the distribution line is a momentary failure caused by tree contact, a bird contact, a load device, etc., which means that the momentary failure is solved and restored by itself when the circuit breaker (C / B) or the recloser is reclosed. .

In addition, there are temporary failures (hereinafter, referred to as "permanent failures" to distinguish them from the above-mentioned failures of failures) in which failures are not resolved on their own due to abnormalities in facilities or distribution lines.

Failure on the distribution line causes a lot of inconvenience due to power outages on numerous loads installed on the distribution line, resulting in economic and human damage. Therefore, when a line failure occurs, it is necessary to minimize the power failure time through a quick and accurate failure section check.

FIG. 1 is a sequence diagram illustrating a recloser and a load side voltage change installed in a distribution line to cut off power supply when a current exceeding a set value flows.

First, a drawing 110 showing a change in current flowing through the recloser and a drawing 120 showing a state of the recloser will be described.

In the section 111 where normal current flows, the recloser does not take any action. However, if a section 112 through which an abnormal amount of current flows for a predetermined time continues due to a failure in the distribution line, the recloser sets a curve. The circuit is opened (122) so that no current flows through the distribution line (113). After a predetermined time again, the recloser operates the circuit 123 again, and thus excessive current flows through the distribution line that is not recovered (114). The recloser repeats this process a predetermined number of times (124, 125, 126, 127) (115, 116, 117, 118). If the distribution line does not recover from a failure after a predetermined number of times, the recloser finally opens the circuit 128 to prevent current from flowing in the distribution line (119). The recloser is generally open 122 for the first two abnormal currents 112, 114 and the closure 123 in a short time (current current curve) of fault current energization time (fast trip), and then The opening 126 and the closing 127 for abnormal currents 116 and 118 are distinguished by performing (delay tripping) at a long cycle of fault current energizing time.

In addition, in the drawing 130 showing the load-side voltage change, an oblique line means a state in which the three-phase voltage is less than or equal to a predetermined prescribed value, and a live line means a state in which one or more phases is equal to or greater than a predetermined prescribed value.

As described above, the recloser performs a predetermined number of opening operations by itself, and reclosing is possible. When the recloser detects a failure and repeats the operation of opening and closing the circuit, if the failure is resolved by itself and the amount of current flowing in the recloser remains below the minimum operating current, the failure occurs and the circuit is opened. And the case where the failure is not solved despite the repetition of the closing operation (119) corresponds to the permanent failure.

2 is a failure detection sequence diagram of a FRTU for detecting a failure of a distribution line.

A diagram 210 showing a current change sensed by the FRTU and a diagram 220 showing a voltage change will be described.

Referring to FIG. 2, the current flowing in the FRTU is similar to the drawing 110 showing the current flowing in the recloser. However, FRTU does not detect the failure by itself and cut off the power supply so that no more fault current flows, but detect the failure according to the operation of the recloser or breaker on the power supply side. When the FRTU detects a fault current (211), the wiring after a predetermined time (temporary FI Setting time) flows at a time point (212, 214, 216, 218) at which the current does not flow in accordance with the opening and closing operation of the recloser. It is determined that a permanent track failure has occurred. In the case of Figure 2, a permanent failure is detected in the section in which the reclosing operation of the recloser is completed (218).

If the failure is eliminated in the section where the reclosing operation is repeated and the normal state is determined, it is determined as the instantaneous failure. The instantaneous failure is detected as a momentary failure when the distribution line is in a steady state for a predetermined time period (instantaneous FI Setting time).

In addition, when the system recovers to the normal state without the voltageless / currentless state after the initial failure current detection section 211, it is assumed that a temporary inrush current has occurred on the wiring line and is not judged as a failure. In general, the FRTU has an inrush suppression function which does not detect a fault for a predetermined time in preparation for the inrush current in the non-current / voltage-free state when no fault occurs.

As described in the above fault detection process of the recloser and the FRTU, the fault position detection method of the wiring line according to the prior art detects the fault only by the occurrence of fault current, no voltage, and no current regardless of the fault current direction. Therefore, there is a problem that the accurate fault detection function cannot be performed on the fault current caused by the load device.

As described above, in detecting a fault on a distribution line, the basic precondition is that the side supplying the fault current exists only in the power system, and the state of the load becomes a no-voltage and no current when the line is interrupted.

However, in the case of performing a fault detection on a distribution line under such preconditions, when a fault occurs on the distribution line, since the fault current is supplied from the various facilities and the load side constituting the distribution line to the point of failure, the reliability of the fault detection is high. Deterioration, and thus, a large amount of time is required to identify the failure section, and there is a problem that the reliability of the power supply is deteriorated.

The present invention has been made to solve the problems of the prior art as described above, the object of the present invention is to detect the failure in consideration of the current direction, current strength or the type of voltage flowing in the automation switch installed on the distribution line The present invention provides an apparatus and a method for reliably detecting and determining a fault.

In addition, another object of the present invention is to provide an apparatus and method which can further increase the reliability in operating the distribution line by accurately determining the half-open state and the semi-input state of the equipment for the distribution line.

In order to achieve the above object and to solve the problems of the prior art, the present invention includes a measuring unit for measuring at least one of the current or voltage flowing in a predetermined position of the distribution line; And a control unit for determining whether the distribution line has a failure according to the measured current amount and the current direction.

According to one aspect of the invention, the control unit, after the fault current is detected on the distribution line, when the current direction of the current measured at the predetermined position is changed from the current direction before the fault current is detected of the load device Judging by the fault current supplied by the effect.

According to another aspect of the present invention, the control unit determines the half-open state according to the difference between the power supply voltage and the load side voltage measured by the measuring unit after performing the opening operation of the distribution line device, after performing the closing operation of the distribution line In accordance with the difference between the power supply side voltage and the load side voltage measured by the measurement unit, it is determined as a semi-input state.

Another aspect of the invention, the step of determining whether the amount of current flowing on the distribution line is more than a predetermined set value; And determining whether a failure occurs on the distribution line according to the direction of the measured current when a current flow of a predetermined value or more is detected on the distribution line. Is provided.

Another aspect of the invention, the fault current is sensed on the distribution line to cut off the power supply; Measuring a current and a voltage supplied to a power distribution line at a predetermined position of the power distribution line; And when the strength of the measured three-phase voltage at a predetermined position of the distribution line is continuously decreased for a predetermined time and is less than or equal to a predetermined voltage, the distribution line is determined as a no current / no voltage state, and the power distribution is performed at a predetermined position of the distribution line. When the frequency of one or more phase voltages supplied to the line is continuously slowed for a predetermined time to be below a certain frequency, determining the location and the failure detection on the distribution line comprising determining the distribution line as a non-current / no voltage state Provide a method.

According to the present invention, it is possible to reliably determine the location of the failure by performing the failure detection in consideration of the current flow direction, current strength or the type of voltage flowing through the automation switch installed on the distribution line.

In addition, the present invention has the advantage of accurately determining the half-open state and the semi-input state of the power distribution line to prevent degradation of the power supply quality caused by the device abnormality, and to improve the reliability of the operation of the power distribution line.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As described above, when a failure occurs on the power distribution line, various facilities and various load devices constituting the power distribution line supply a fault current to a failure point, which makes it difficult to accurately detect a fault.

Loads that can supply a fault current to a fault point when a fault occurs on a distribution line include a generator, a synchronous motor, an induction motor, a capacitor, and various distributed power supplies. The magnitude of the fault current supplied from the load device is determined by the impedance of each device and the line impedance to the point of failure, and the duration thereof also has various forms according to the characteristics of each device.

Hereinafter, an apparatus and method for detecting a failure of a distribution line and determining a generation position in consideration of the influence of a fault current generated by a load according to an embodiment of the present invention will be described in detail.

3 is a diagram illustrating an example of supplying a fault current to a fault point not only by a power distribution system but also by a load device when a fault occurs in a distribution line.

The direction of the normal load current where no failure occurs flows from the substation side to the load side.

As shown in FIG. 3, when a failure occurs at the failure point 301, the system fault current 301 supplied from the system becomes in the same direction as that of the normal load current, and is determined by the load device 330. The fault current 302 supplied to the advantage 301 is in the opposite direction to the usual load current.

Since the fault detection according to the prior art does not consider the direction of the fault current, the FRTU 320 detects a fault, and the distribution automation system and the operator determine that a fault has occurred in the section after the FRTU 320. .

According to the related art, when a failure occurs and the recloser 310 is locked out, the FRTU 320 is opened in the open state, and when the recloser 310 is closed again, the failure occurs again. Is generated.

As described above, when a fault current 302 (hereinafter referred to as a "load fault current") supplied by the load device 330 to the fault point 301 occurs, confusion arises in finding the fault point, It takes a lot of time and human resources to solve and repair the breakdown, and a lot of damages occur in the homes, factories, offices, etc., which are supplied with power through distribution lines.

4 is a diagram illustrating an example in which a fault current caused by a power distribution system and a load device is partially overlapped to supply current to a failure point when a failure occurs in a distribution line.

The load current direction before the failure occurs at the failure point 403 flows from the substation side to the load side at all positions, and when the failure occurs at the failure point 403, the second FRTU 430 system fault current 401 and the load The load fault currents 402 generated by the device are overlapped to flow.

In the case of FIG. 4, when the fault current by the load device and the residual voltage flowing in the distribution line persist even after a predetermined time interval (instantaneous FI Setting Time) has elapsed, the first FRTU 420 and the second The FRTU 430 may not detect a failure even if a current higher than an operating current for detecting the failure flows.

The distribution automation system and the operator determine the failure section in FIG. 4 as between the first FRTU 420 and the second FRTU 430.

In this case, if another distribution line is connected to the fault point 403, an attempt is made to separate the fault section and link the system, and an additional fault occurs due to the fault point detection.

The present invention proposes an apparatus and method for detecting an accurate failure point even in the case of FIGS. 3 and 4 by detecting a failure point in consideration of the direction of the current flowing through the distribution line, the strength of the current, or the shape of the voltage.

5 is a block diagram showing the configuration of an apparatus for determining a fault occurrence position of a distribution line in consideration of a load current according to the present invention.

Referring to FIG. 5, the failure occurrence position determining apparatus 500 of the power distribution line includes a measurement unit 530 for measuring at least one of a current or a voltage flowing at a predetermined position of the power distribution line, and the measured current amount and current direction. Therefore, the control unit 520 is configured to determine whether the distribution line has a failure.

Preferably, the current and voltage signals are obtained by CT and PT installed in the switch body installed in the distribution line, and the obtained current and voltage signals may be provided to the FRTU through the signal interface of the switch controller.

The failure location determining apparatus 500 may be a FRTU that detects the failure information of the distribution line and controls the opening and closing of the line based on the voltage and current signals supplied from the switchgear or the power distribution equipment, and in some cases is installed separately Can be.

According to another aspect of the present invention, the failure location determining apparatus 500 according to the determination of the control unit 520, the direction information of the current flowing in a predetermined position of the distribution line, the non-current / voltage-free information of the distribution line, The communication unit 510 may further include a communication unit 510 which transmits at least one of line fault information, semi-open state information, and semi-open state information to an upper apparatus (main unit or server) of the distribution automation system on the distribution line.

According to another aspect of the present invention, the failure location determining apparatus 500 according to the determination of the control unit 520, the direction information of the current flowing in a predetermined position of the distribution line, the non-current / no voltage information of the distribution line The display unit 540 may further include a display unit 540 for displaying at least one of line fault information, semi-open state information, and semi-open state information.

After the fault current is detected on the power distribution line, the controller 520 determines that the current measured at the predetermined position is a fault current caused by the load when the direction of the current is changed from the current direction before the fault current is detected.

The direction of the current can be determined by the phase information, and when the fault current is generated by the load according to the setting, the control unit 520 suppresses the fault detection or distributes the fault by the communication unit 510 that a reverse fault has occurred. It can be notified to an upper part of the automation system.

In this case, when the failure as shown in FIG. 3 occurs, the distribution automation system and the operator can recognize that the current flowing in the FRTU 320 is a failure current by the load device, It can be determined that the advantage 303 is located.

The control unit 520 is a predetermined amount when the voltage level of the three-phase measured at the predetermined position is continuously reduced for a predetermined time and less than a predetermined voltage after a fault current is sensed on the distribution line and the power supply is cut off. Even if a current exists, the distribution line is judged as a non-current / voltage-free state, or when the frequency of one or more voltages supplied to the distribution line at the predetermined position is continuously lowered for a predetermined time, regardless of the strength of the current. Determine the furnace as no current / no voltage.

In the case of FIG. 4, when the power supply is cut off on the power distribution line, the load failure current 402 and the residual voltage supplied by the load device 440 are reduced over time. In addition, according to the type of load, the voltage applied to the second FRTU 430 has a characteristic that the frequency is continuously lowered compared to the fundamental wave (60 Hz).

Therefore, after a fault current equal to or greater than a set value measured on the distribution line is sensed and the power supply is cut off by the protection device on the power supply side, after the current becomes less than or equal to the minimum operating current, the control unit 520 maintains a voltage for a predetermined time. If the intensity of the three-phase voltage continuously decreases for a predetermined time (within the instantaneous FI Setting Time) by analyzing the change of current, and becomes below a certain voltage, a certain amount of current exists or the frequency of one or more phase voltages is predetermined. If it is continuously slowed down for a certain time and falls below a certain frequency, it is determined that the power supplied to the distribution line is influenced by the load device regardless of the magnitude of the current.

In this case, when the failure as shown in FIG. 4 occurs, the distribution automation system and the operator overlap the failure current due to the influence of the failure current supplied from the system and the load device. Since it can be seen that it can be determined that the failure point 403 is located in the section after the second FRTU (430).

In addition, when a failure as shown in FIG. 4 occurs, since the current flowing through the first FRTU 420 is a failure current caused by the influence of the load device, the failure point is located in a section before the second FRTU 430. It can be judged.

Therefore, the present invention provides a method for identifying a failure section as a failure point 403 when a failure as shown in FIG. 4 occurs.

Since the FRTU and the recloser installed on the power distribution line have been installed and operated for a long time, the mechanical structural device may not operate in a normal state because its characteristics change according to the operating environment and the number of years of operation.

The recloser or FRTU is a structure in which three phases are open / closed collectively, and some devices may malfunction.

This abnormal operation corresponds to a case in which the devices installed on the distribution line are in a semi-open state or a semi-open state, rather than a completely open or closed state, and when such an abnormal operation occurs, not only does it cause a casualty and damage to the load device, but also the corresponding device. It is also likely to break.

The half-open state is a case in which part of the power is undesirably supplied to the load side due to the device abnormality after the device is opened.

The semi-loaded state refers to a case in which power is not completely supplied to the load side due to a device failure after the device is closed.

The control unit 520 of the failure location determining apparatus 500 according to the present invention can detect the above abnormal operation by detecting the semi-open state and the semi-input state.

That is, the controller 520 determines the half-open state according to the presence or absence of a voltage difference and current between the power supply side and the load side measured by the measurement unit after performing the opening operation of the distribution line, or after performing the closing operation of the distribution line, It determines with the semi-input state according to the power supply side voltage and load side voltage difference measured by the said measurement part.

The controller 520 is half-opened when the voltage measured at the power supply side and the load side is in the same phase, the voltage at any one of the power supply side and the load side is in a normal range, and the voltage and current are partially measured at the other side. Judging by the state.

In addition, after the closing operation, the controller 520 determines that the voltage measured at the power supply side and the load side is in the same phase, and the voltage difference between the power supply side and the load side is greater than or equal to a predetermined set value.

As described above, when the control unit 520 detects a half-open or semi-open state, the control unit 520 shows it on the display unit 540, and transmits it to the host device of the distribution automation system through the communication unit 510.

Meanwhile, the failure location determining apparatus 500 may further include a user interface such as a display unit and a keypad (not shown), and the distribution line manager operates by changing phase information of the distribution line through the keypad. can do.

The distribution automation system performs consistent phase information management from the withdrawal end of the substation to the end of the load. Phase detection of a distribution line is possible by the "Automated system and method for automatically detecting the phase of a distribution line" filed October 18, 2006 (application number: 10-2006-0101345).

If the phase information of the distribution line that is fixedly used is changed according to the detected phase information, the voltage (power supply side, load side) and current can be logically changed and operated in accordance with the set phase.

6 is a flowchart illustrating a method of determining a failure occurrence position of a distribution line according to the present invention.

Referring to FIG. 6, the method of determining a location of a failure may include determining whether an amount of current flowing on a distribution line is greater than or equal to a predetermined set value, and when a current flow of a predetermined value or more is detected on the distribution line, the direction of the measured current. And determining whether a failure occurs on the distribution line.

More specifically, the measuring unit 530 measures the amount of current between the power supply side and the load side on the line (S610).

The controller 520 determines whether the amount of current measured by the measurement unit 530 is equal to or greater than a predetermined set value for fault detection (S620).

If the current flow above the predetermined setting value is detected, the direction of the current before the current flow above the predetermined setting value is detected (in a steady state without failure) is compared with the direction of the current flowing on the current distribution line ( As a result of the comparison, when the current direction is changed, it is determined that the current flowing on the current distribution line is a fault current caused by the load (S640, S650).

The distribution automation system and the operator, when the current flowing on the distribution line is determined to be a fault current by the load, it is determined that the fault point is located in the position transfer section (that is, the power supply side) where the fault current by the load is detected. Done.

As described above, the method for determining a failure location on the distribution line according to another aspect of the present invention, the step of detecting a fault current on the distribution line to cut off the power supply, and the power distribution at a predetermined position of the distribution line Measuring the current and voltage supplied to the line, and if the voltage intensity of the three phases measured at a predetermined position of the distribution line is continuously decreased for a predetermined time, and the voltage is below a certain value, If it is determined that there is no current / voltage-free state and the frequency of one or more voltages supplied to the power distribution line at a predetermined position of the power distribution line is continuously slowed for a predetermined time and becomes less than a predetermined frequency, the power distribution line is irrespective of the current strength. Determining a non-current / voltage-free state.

When the distribution automation system and the operator measure a fault current (a forward fault current in which the current does not change direction) at a predetermined position of the distribution line and detect a non-current / no voltage state, a subsequent section (ie, the load side) of the predetermined position is detected. It is determined that the failure point is located at.

Therefore, a distribution automation system and an operator may have an unbalance between a point having forward fault information of more than one phase and a point having no fault information or a point having reverse fault information, or a point having unbalance of forward fault information of more than one phase. (Ground) A fault location is determined between a point having only fault information and a point having at least one phase of forward fault information and a point not having fault information.

Here, the forward fault information is a case where the phase of the fault current and the current before the fault is not changed, and the reverse fault information means a case where the current direction is changed.

In addition to the failures shown in FIGS. 3 and 4, the failure situation that may occur on the distribution line may include a failure that may occur during the closing operation at an open point at all times, no experience of failure, and a failure that occurs when power is supplied to the non-powered line. There is a malfunction in a small place. The failure detection method in consideration of the current direction on the distribution line according to the present invention is preferably set so that no malfunction occurs in this case.

The normally open point means the open / closed switch, and in the present invention, it is assumed that the switch is provided with an automated switch, that is, a FRTU.

The normally open point is normally kept open and supplies the power of other D / L to the power distribution line according to a specific purpose.

That is, the normally open point is used for minimizing the blackout period by supplying power in connection with other D / L when a line breaks down or power cannot be supplied to some lines during a planned power outage construction. .

7 is a diagram illustrating an example in which two distribution lines are connected through a normally open point (Tie point).

Referring to FIG. 7, when a line failure occurs at the failure point 703 at the first D / L, first, the recloser 720 repeats the opening / closing operation as described above, and then all sections of the distribution line. It becomes a no-power state in which no power is supplied to the power supply.

Next, the second switch 730, the third switch 750, and the fourth switch 740 are opened to supply power to a healthy section that is not a failure on the distribution line.

The recloser 720 performs the closing operation again to supply power to the distribution line.

Then, the fifth switch 760 positioned at the normally open point is closed to supply power to the third switch 750 through the second distribution line D / L.

In addition, by performing the same operation for the section after the fourth switch 740 and supplying power through other linkable distribution lines, it is possible to supply power normally except for the fault section 701.

The failure detection method in the fifth switch 760 is the same as the operation of the failure detection device 500 described above, but since it is a non-powered state without a load failure current due to the load, power is reset through the second D / L. The direction of the current for failures occurring during closure should take this into account. That is, the failure direction can be determined as the forward direction (section after the switchgear).

On the other hand, in the case of a failure caused by the failure of the power supply to the no-power line and no power is supplied to the load, even if there is a failure in the line, the influence of the load hardly occurs. Section after the switch).

Here, the section before the switch means the substation side on the basis of the current switch installation point, and the section after the opening means the load side at the current switch installation point.

In addition, in the case of the switchgear installed at a position where the influence of the load is so small that phase detection with respect to the current is not possible, the failure direction can be ignored and the failure direction can be determined as the forward direction (after the switch). That is, since the magnitude and duration of the load failure current (voltage) due to the load flowing to the failure point at the moment of occurrence of the failure are proportional to the load capacity, the influence of the load can be neglected at or below a certain load current. The setting of the constant load current may be set to a ratio (%) or a current magnitude to a minimum operating current for detecting a failure.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

FIG. 1 is a sequence diagram illustrating a recloser and a load side voltage change installed in a distribution line to cut off power supply when a current exceeding a set value flows.

2 is a failure detection sequence diagram of a FRTU for detecting a failure of a distribution line.

3 is a diagram illustrating an example of supplying a fault current to a fault point not only by a power distribution system but also by a load device when a fault occurs in a distribution line.

4 is a diagram illustrating an example in which a fault current caused by a power distribution system and a load device is partially overlapped to supply current to a failure point when a failure occurs in a distribution line.

5 is a block diagram showing the configuration of an apparatus for determining a fault occurrence position of a distribution line in consideration of a load current according to the present invention.

6 is a flowchart illustrating a method of determining a failure occurrence position of a distribution line according to the present invention.

7 is a diagram illustrating an example in which two distribution lines are connected through a normally open point (Tie point).

Claims (18)

In the apparatus for determining the distribution line failure position provided at a predetermined position on the distribution line, A measuring unit for measuring at least one of a current or a voltage flowing at a predetermined position of the distribution line; And A control unit for determining whether the distribution line is a failure according to the measured current amount and the current direction Apparatus for detecting the occurrence of a failure on the power distribution line comprising a. The method of claim 1, wherein the control unit, After the fault current is detected on the power distribution line, when the direction of the current measured at the predetermined position is changed from the current direction before the fault current is detected, it is determined that the fault current is generated by the load. For detecting faults on the bed. The method of claim 1, wherein the control unit, After the fault current is sensed on the distribution line and the power supply is cut off, when the intensity of the three-phase voltage measured at the predetermined position is continuously decreased for a predetermined time and becomes less than a predetermined value, the distribution line is turned off / no current. A device for detecting a failure on a distribution line, characterized in that it is judged to be a voltage state. The method of claim 1, wherein the control unit, After the fault current is sensed on the distribution line and the power supply is cut off, if the frequency of one or more voltages supplied to the distribution line at the predetermined position is continuously slowed for a predetermined time and becomes lower than or equal to the predetermined frequency, the distribution line is absent. A device for detecting a failure on a distribution line, characterized in that it is judged as a current / no voltage state. The method of claim 1, wherein the control unit, And a half-open state is determined according to the difference between the power supply side voltage and the load side voltage measured by the measuring unit after performing the opening operation of the power distribution line. The method of claim 1, wherein the control unit, And performing a closing operation of a distribution line, and determining a half-loading state according to a difference between a power supply side voltage and a load side voltage measured by the measurement unit. The method according to any one of claims 1 to 6, And a keypad for changing phase information of the distribution line according to the detected phase information. The method according to any one of claims 1 to 6, According to the determination of the controller, at least one of the direction information of the current flowing at a predetermined position of the distribution line, the non-current / voltage-free information of the distribution line, the failure information of the line, the half-open state information, and the semi-input state information An apparatus for detecting a failure on a distribution line, further comprising a communication unit for transmitting to the distribution control apparatus on the line. The method according to any one of claims 1 to 6, Displaying at least one of the direction information of the current flowing to a predetermined position of the distribution line, the non-current / voltage-free information of the distribution line, the failure information of the line, the half-open state information and the semi-input state information in accordance with the determination of the controller Apparatus for detecting a failure on the distribution line further comprises a display unit for. In the method of detecting and determining the fault on the distribution line, Determining whether the amount of current flowing on the distribution line is greater than or equal to a predetermined set value; And Determining whether a failure occurs on the distribution line according to the direction of the measured current when a current flow of a predetermined value or more is detected on the distribution line. The method of claim 10, wherein determining whether a failure occurs on the power distribution line comprises: Comparing the direction of the current flowing on the current distribution line with the direction of current before the current flow above the predetermined set value is detected; And And comparing the current flowing on the current distribution line with a fault current caused by a load when the current direction is changed as a result of the comparison. The method of claim 11, wherein If it is determined that the failure caused by the load flowing on the current distribution line is a reverse failure, the failure point and the location on the distribution line are determined to be located at a location transfer section where the failure current caused by the load is detected. How to judge. In the method of detecting and determining the fault on the distribution line, Blocking a power supply by detecting a fault current on the distribution line; Measuring a current and a voltage supplied to a power distribution line at a predetermined position of the power distribution line; And When the voltage intensity of the three-phase voltage measured at a predetermined position of the distribution line is continuously decreased for a predetermined time and is less than a predetermined value, the distribution line is determined as a no current / no voltage state, and the distribution line is located at a predetermined position of the distribution line. If the frequency of one or more voltages supplied to the power is continuously slowed for a predetermined time to become below a predetermined frequency, the method of determining and detecting a fault on the power distribution line comprising the step of determining the power distribution line as a non-current / no voltage state . The method of claim 13, When a fault current in the forward direction is detected at a predetermined position of the power distribution line and then in a non-current / no voltage state, it is determined that the fault point is located in a subsequent section of the predetermined position. How to judge. In the distribution automation system, in the method of determining the fault location on the distribution line, Receiving information on whether a failure is detected and current direction from each location on a distribution line; And Based on the failure detection and current direction information, it is determined as the fault location between a point having one or more forward fault information and a point having no fault information or a point having reverse fault information, Determining as a fault location between a point having and a point having only unbalanced fault information How to determine the fault location on the distribution line in the distribution automation system comprising a. The method of claim 15, In the case of supplying power by supplying switchgear at a location corresponding to the opening point, the failure direction at the location corresponding to the opening point is determined in the forward direction. How to. The method of claim 15, A method for determining a failure location on a distribution line in a distribution automation system, characterized in that the direction of failure in a place where power is supplied to a non-powered line with no experience of failure is determined in the forward direction. The method of claim 15, A method for determining a failure location on a distribution line in a distribution automation system, characterized in that the direction of the failure is determined in the forward direction at a location where the influence of the load is below a certain level.

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