KR100675739B1 - Method for separating and recovering fault section of ungrounded distribution system using feeder agent and system - Google Patents

Abstract

The present invention relates to a method for separating and recovering an ungrounded distribution system failure section, and more particularly, to a method for separating and recovering an ungrounded distribution system section using a feeder agent. The present invention provides a method for recovering and repairing a failure section of an ungrounded distribution line including first and second feeder agents each responsible for a predetermined associated line section, the method comprising: (a) a first feeder agent detecting a failure of a line; (B) the first feeder agent propagating failure experience communication to the second feeder agent, (c) the first feeder agent moving the normally open point on the line to the power side, (d) Detecting the failure of the line by the first and second agents according to the movement of the normally open point; (e) when the failure is detected by the second agent, the second agent switches the switch immediately before the normally open point. Opening and (f) repeating steps (c) and (e) if a failure is not detected at the second agent. It provides a separate section recovery.

Distribution Line, Forwarding Method, Failure Section, Feeder Agent, Always Open Point, Linked Line

Description

Method for separating and repairing fault section of ungrounded power distribution system using feeder agent and system therefor {METHOD FOR FAULT SECTION ISOLATION AND RESTORATION USING FEEDER AGENT AND SYSTEM THEREFOR}

1 is a diagram illustrating a failure processing process in a conventional forwarding method.

FIG. 2 is a diagram sequentially illustrating a power failure recovery algorithm when a failure occurs in a single linkage distribution line according to an embodiment of the present invention.

3A is a diagram illustrating an example of a multiple linkage distribution line to which the method of the present invention is applicable.

FIG. 3B is a diagram showing the change of the system after the multiple linkage lines of FIG. 3A are separated and restored.

4A is a schematic diagram of a multiple linkage distribution line according to an embodiment of the present invention.

FIG. 4B is a diagram showing a resultant system diagram after separately recovering the failure section of FIG. 4A.

The present invention relates to a method for separating and recovering an ungrounded distribution system fault section, and more particularly, to a method for separating and recovering a fault section of an ungrounded power distribution system using a feeder agent.

Increasing power demand due to industrial development and innovative development of the IT industry has increased the impact on social life in the event of a power failure caused by failure, and interest in the details of the failure is also increasing. In addition, the distribution system automation system was introduced to solve the problems occurring in the distribution system when the operating environment is rapidly changing and to increase the reliability of the power supply. In the case of power distribution system, it operates radially, so if power failure section occurs due to a failure, power supply can be continued by switching the power failure area to a nearby link line. In order to minimize the power outage of the customer in the event of a failure, fast power outage recovery has become an important function in the distribution automation system. If this function is not present in the distribution automation system, the grid operator must visually identify the wide range of transmission and distribution lines in order to find fault points, which requires much manpower and cost.

In the power distribution system, the ungrounded method is used for a system with short line voltage and low voltage. In these lines, the charge current is not large because the ground capacitance is small. If a one-wire ground fault occurs on a line of an ungrounded system, a fault current due to a healthy ground capacitance flows into the fault point, but its magnitude is so small that it can continue to supply power.

In addition, since the main transformer is connected by Δ-Δ, it is possible to continue transmission by switching to V-connection in case of transformer breakdown or maintenance work. However, when the ungrounded system is expanded, the capacitance increases, and when a one-wire ground fault occurs, an intermittent arc ground caused by the charging current causes an abnormal voltage. In addition, since the fault current is less than a few amps in case of 1-wire ground fault, it is difficult to detect faults, so it is difficult to expect a reliable operation of the ground fault protection relay. Moreover, in case of protection failure, there is a high possibility that it will develop into an extended fault range and short circuit failure. Therefore, in order to solve this problem, after determining the fault line using the selective ground overcurrent relay, the forwarding method for searching the fault section through the sequential injection of the automatic switch is used.

The forwarding method has a high reliability because of low dependence on the system and a communication network and a low possibility of failure, but has a disadvantage in that a switch has a large number of operations and a customer has a large number of power failure experiences.

Hereinafter, with reference to Figure 1 is a diagram illustrating a failure processing process in a conventional forwarding method.

Referring to FIG. 1, when a failure occurs in a distribution line, a circuit breaker CB is operated after determining a failure line by the direction ground relay SGR, thereby causing a failure of the broken line. Most forwarding methods do not use reclosers, so a power outage between line bulbs is essential. When the CB operates and becomes a no-voltage, all forward type automatic switchgear of the corresponding distribution line is automatically opened (FIG. 1 b)). After a certain time, the CB is reclosed to pressurize the power distribution line, and as shown in c) and d) of FIG. This check is made to see if the fault current is experienced. When the automatic switch immediately before the failure section as shown in Figure 1 e) the permanent failure state is maintained, as shown in Figure 1 f) CB of the substation is operated again, at this time was finally put just before the failure point The switch is locked as shown in g) of FIG. 1 by determining that a permanent failure has occurred in a section protected by the switch because the switch is again outage before a predetermined time after the input. The switch immediately after the failure section is locked because the power is lost and the power supply is not maintained for a predetermined time after the power is turned on. Afterwards, as the first time, the breaker is re-inserted after a certain time, and the first and second automation switches are re-inserted at regular time intervals, so that electricity is supplied to the power section of the power supply side. After that, electricity is supplied to the healthy section at the end of the fault section through a connecting line.

Table 1 below shows a time chart of a failure handling process of the forwarding method when a failure occurs as shown in FIG. 1.

As shown in Table 1, in the case of consumers immediately before a failure such as SW2 and SW3, the power failure can be experienced during the A section.

This forwarding method has the advantage of high reliability due to low dependence on system and communication network and low possibility of failure, and it can accept the existing protection cooperative principle. However, the troubleshooting speed is slow and depends on the function of the switch itself, and the overall operation frequency of the switch is high, so it is likely to fail. It also has the disadvantage of having a high number of blackout experiences. Moreover, since the forwarding method can be used only in a single linkage method, the facility utilization rate does not exceed 50%.

SUMMARY OF THE INVENTION In order to solve the problems of the prior art, an object of the present invention is to provide a method for rapidly recovering and recovering a fault section by minimizing a power failure of a consumer in an ungrounded power distribution system and reducing the number of operation of a switch. It is done.

It is also an object of the present invention to provide a method for separating and recovering fault sections suitable for multiple linkage distribution lines.

In order to achieve the above technical problem, the present invention provides a method for recovering and repairing fault sections of an ungrounded power distribution line including first and second feeder agents each responsible for a predetermined associated line section, the method comprising: (a) a first feeder agent; (B) propagating a failure experience communication to the second feeder agent by the first feeder agent; and (c) the first feeder agent moves the normally open point on the line to the power side. (D) detecting the failure of the line by the first and second agents according to the movement of the normally open point; (e) when the failure is detected by the second agent, the second agent Opening the switch immediately before the normally open point; and (f) repeating steps (c) and (e) if a failure is not detected at the second agent. It provides a fault section separation recovery method of ungrounded power distribution track to the gong.

The method may further comprise (g) if the failure is detected in the second agent in step (e), the second agent may issue a failure experience communication to the first agent.

The present invention also provides a method for restoring fault section separation of a multiple linkage distribution line connected to a plurality of linkage lines by a branch point, the method comprising: (a) a first feeder agent detecting a failure of the distribution line; 1, the feeder agent issues a failure experience communication to a plurality of feeder agents of the associated line, (c) the first feeder agent moves a regular open point on the power distribution line a predetermined section to the power side, (d) the always Detecting a failure of the plurality of feeder agents of the linkage line according to the movement of the open point; (e) when a failure is detected at any one of the plurality of feeder agents of the linkage line, the failure detection feeder agent Opening the switchgear immediately before the opening point; and (f) a failure is detected in any one of the plurality of feeder agents of the linkage line. If it does, there is provided a fault section separation recovery method of the distribution line, characterized in that it comprises the step of repeating said steps (c) and step (e).

According to a preferred embodiment of the present invention, in the method (b), when the normally open point meets the branch point in the movement of the predetermined section, the linkage having a large allowable transfer capacity of the line among the plurality of connecting lines connected by the branch point is connected. It is preferable to restore the predetermined section by a track.

In addition, the present invention in the failure section separation recovery system of the distribution line including the first line and the second line associated with each other, the first feeder agent and the second line and the first feeder agent and each other capable of transmitting and receiving each other And a second feeder agent, wherein the first and second feeder agents provide a failure experience communication to the other party when a failure occurs in their own line and move the regular open point of their own line. Provide a system.

Movement of the open point in the system can be achieved by controlling the switchgear of the first and second lines. The first and second feeder agents open the switch immediately before the normally open point when a failure is experienced by the movement of the normally open point after receiving the failure experience communication from the counterpart.

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

In the present invention, a feeder agent is an agent in charge of a predetermined portion of a line, and has a communication device, which enables communication between adjacent agents, and has a function corresponding to a software for performing a predetermined function as described below. A device having logic logic implemented in hardware to perform the operation.

In the present invention, the feeder agent is responsible for its own line, and maintains a cooperative relationship with other feeders such as other feeder agents (linked line feeder agents) or a central agent (Central Agent). The central agent is an agent that manages the entire distribution system.

In the present invention, the feeder agent has the following characteristics. First, individual feeder agents distributed in the distribution system control their Agent's Staff. Here, the agent staff refers to a device that provides information to the feeder agent or is driven by the control of the feeder agent, such as an automated switch existing on the track. Second, feeder agents maintain mutual cooperation through communication. Third, the feeder agent may actively respond to communication with other agents or agent staff.

The feeder agent of the present invention has the following advantages. First, the device failure distribution and fault tolerance are improved by the effect of distributing information, and even when the system is large, individual targets of the system are small, so that the system can flexibly cope with changes in the system. In addition, feeder agents are only responsible for their own tracks, allowing them to actively maintain their optimum conditions. In addition, because the control functions are distributed locally, high robustness can be obtained locally, and the computer load is distributed.

Hereinafter, the failure handling process performed by the feeder agent of the present invention will be described in detail.

When a feeder agent has a failure in a line in charge thereof (referred to as a 'fault tracker feeder agent'), it sends 'failure experience communication' indicating that a failure has occurred in its own line to the associated line feeder agent. Subsequently, the fault line feeder agent controls the agent staff such as the switchgear to sequentially move the normally open point to the power supply side.

As the normal open point moves, the fault line feeder agent checks the fault state of the line. At this time, if the user continues to experience the failure, check if the failure experience communication is performed, and if the communication is performed, always move the open point to the power side again. If you continue to move open at this point and do not experience a failure, the track feeder agent will perform his job.

If the link line feeder agent experiences a failure as the line feeder agent moves the open point at all times, check whether there is a failure experience communication from another feeder agent, and then communicate with the feeder agent that he / she has experienced a failure. Open the switch just before its end. This series of steps completes the fault segmentation and power failure recovery.

Hereinafter, the failure recovery algorithm in the link line will be described in more detail.

A. Blackout Recovery Algorithm of Feeder Agent in Single Linkage

Single linkage is a track with one linkage line. 2 is a diagram illustrating a single linkage feeder agent power failure recovery algorithm in sequence when a failure occurs.

Referring to FIG. 2, when a failure occurs in a line that is in charge thereof, the failure line feeder agent communicates that a failure has occurred to the associated line feeder agent as shown in b) of FIG. 2. The faulty line feeder agent moves the normally open point on the line from the end to the power side. At this time, if the failure is not found and the faulty line feeder agent is experiencing a permanent failure, it constantly moves to the open point (FIG. 2C)). Since the associated line feeder agent experiences a failure at the normally open point position as shown in FIG. Opens the switch just before its end to separate the failure section (FIG. 2 f)). Each feeder agent then redefines and optimizes its own tracks.

In the conventional forwarding method described above, the customer is forced to experience a power outage since all of the forwarding type automatic switchgear of the faulty line is opened and then inputted in order to find the faulty section. However, in the case of the feeder agent power failure recovery according to the present invention, the customer does not experience the power failure and has the advantage of increasing the reliability since the number of operation of the relay is smaller than the forward type.

B. Blackout Recovery Algorithm of Feeder Agent in Multiple Linkages

Multiple linkages can increase line utilization more than single linkages, but the existing fault-segment separation algorithm, forwarding, cannot be used for multiple linkages. However, the feeder agent power failure recovery algorithm of the present invention is particularly advantageous when applied to multiple linkages because it has an advantage in cooperative operation through communication between feeder agents.

The cooperative relationship between feeder agents is very important in multiple linkages. 3A is a diagram illustrating an example of a multiple linkage distribution line to which the method of the present invention is applicable. In these lines, the loads for each section and the allowable transfer capacity of the connecting lines are shown in Tables 2 and 3.

SECTION FROM TO LOAD (kVA) S01 SW1 SW2 100 S02 SW2 SW3 / SW11 600 S03 SW3 SW4 400 S04 SW4 SW5 500 S05 SW5 SW6 / SW8 1000 S06 SW6 SW7 1000 S07 SW8 SW9 1000 S08 SW9 SW10 500 S09 SW11 SW12 500 S10 SW12 SW13 500 S11 SW13 SW14 1000

Linked Line Name Always open point Transfer allowable capacity (kVA) F2 SW10 4000 F3 SW7 3000 F4 SW14 5000

Referring to Figs. 3A, 2 and 3, the line F1 is composed of 14 switches and one CB. There are three connecting lines, F2, F3, and F4. When a fault occurs, it can be repaired by dividing the fault into up to three lines.

In a single linkage, fault experience communication is propagated to one link line feeder agent, but here it needs to be propagated to all link line feeder agents attached to the failing line. In addition, since there is a branching point in multiple linkages, consideration should be given to how to move the open point at the branching point and to recover using the transfer allowance of the linking line.

If a failure occurs between SW1 and SW2, the F1 feeder agent detects the failure and propagates the failure experience communication to the link line feeder agents F2, F3 and F4. The link line feeder agent returns its transfer allowance to the F1 feeder agent, which is the faulty line feeder agent. The F1 feeder agent moves normally open and recovers sequentially from the end. However, when the branch line on the F2 side is restored to SW8 and the branch line on the F3 side is restored to SW6, the branch point is met. At this time, the allowable transfer capacity of the F2 line is 2500 kVA minus the restored load of 1500 kVA from the original allowance of 4000 kVA. In addition, the transfer allowance for the F3 line is 2000 kVA minus the recovered load 1000 kVA from 3000 kVA, the original F3 transfer allowance. Therefore, it is desirable to proceed with the recovery by the F2 line with large transfer capacity.

In the same way, when comparing the transfer allowances of F2 and F4 in section S02, the transfer allowance of F2 is 600kVA and the transfer allowance of F4 is 3000kVA, so it is restored to the F4 line. If you move the open point to the power supply of F1 and then move to the switch of SW1, the feeder agent of F4 experiences a failure and received the failure experience communication from the feeder agent of F1. do. As a result, all power failure sections are restored. FIG. 3B shows the change of the system after the multiple linkage lines of FIG. 3A have been blackout.

In Japan, since a single link is used, the line utilization cannot exceed 50%. However, when the power distribution system is configured by multiple linkages according to the method of the present invention, the line utilization can be increased as shown in Equation (1) below.

Where F _u is the line utilization rate and n is the number of link lines.

4A is a schematic diagram of a multiple linkage line. The simulation system is composed of 71 nodes and 6 tracks in a network, radially for each feeder, and has 14 normally open points.

When a failure occurs between N17 and N25 of the F4 line, the feeder agent of F4 detects the failure and communicates with the feeder agent of the F2, F3, and F6 line feeder agents.

The associated line feeder agent returns its allowable transfer capacity to the F4 feeder agent, which is the faulty line feeder agent. The transferred allowable capacity data is 6000 (kVA) for the F1 line, 4000 (kVA) for the F2 line, and 5000 (kVA) for the F6 line. The F4 feeder agent recovers the track sequentially from the end. When the normally open point moves from N06 to N25, the F2 feeder agent detects a failure and communicates with the F4 feeder agent with a failure experience. The F2 feeder agent opens the N17 switch to separate the failure section. Figure 4b shows the resulting schematic diagram after the recovery of the failure interval, and Table 4 below shows the changes in the line utilization capacity and utilization rate before and after the recovery. The failure rate of the failed track F4 decreased from 72.73% to 18.35%, but the utilization rates of the associated tracks F2, F3, and F5 increased up to 82.36% and do not exceed 100%.

Track name Before recovery After recovery Track capacity / total capacity Utilization (%) Track usage capacity / total capacity (kVA) Utilization (%) F1 8000/14000 57.14 8000/14000 57.14 F2 8000/12000 66.67 9202/12000 76.68 F3 9000/14000 64.29 11531/14000 82.36 F4 8000/11000 72.73 2018/11000 18.35 F5 10000/14000 71.43 10000/14000 71.43 F6 9000/14000 64.29 10337/14000 73.84

According to the method of the present invention, it is possible to minimize and recover the failure section quickly by minimizing the power failure of the customer in the non-grounded power distribution system and reducing the operation frequency of the switch.

In addition, the method of the present invention can be easily applied to not only a single link line but also multiple link lines. In the case of a multi-link line, the feeder agent of the link line returns to its fault transfer capacity to the faulty line feeder agent through communication with the faulty line feeder agent to facilitate the power failure recovery.

The method of the present invention is particularly suitable for replacing the forwarding method of a single linked power distribution system such as Japan, and also has an advantage of improving the line utilization rate when the existing single linked power distribution system is configured as a multiple linked power distribution system. .

Claims (7)

In the failure section separation recovery method of a non-grounded distribution line comprising a first and a second feeder agent each responsible for the line section associated with each other (a) the first feeder agent detecting a failure of the line; (b) the first feeder agent propagating failure experience communication to the second feeder agent; (c) the first feeder agent moving the normally open point on the line to the power side; (d) detecting failure of the line by the first and second agents according to the movement of the normally open point; (e) when the second agent detects a failure, opening the switch immediately before the normally open point by the second agent; And and (f) repeating the steps (c) and (e) if a failure is not detected in the second agent. The method of claim 1, (g) when the second agent detects a failure in the step (e), the second agent further comprises a failure experience communication with the first agent. Bind recovery recovery method. In the failure section separation recovery method of the multiple linkage distribution line connected to the plurality of linking line by the branch point, (a) a first feeder agent detecting a failure of the distribution line; (b) the first feeder agent propagating failure experience communication to a plurality of feeder agents of the link line; (c) moving, by the first feeder agent, a regular opening point on the distribution line to a power supply section; (d) detecting a failure of the plurality of feeder agents of the link line according to the movement of the normally open point; (e) when a failure is detected in any one of the plurality of feeder agents of the link line, the failure detection feeder agent opening the switch immediately before the normally open point; And (f) if a failure is not detected in any of the plurality of feeder agents of the link line, repeating steps (c) and (e), wherein the failure section of the distribution line is separated. Recovery method. The method of claim 3, In the step (b), when the normally open point meets the branch point in the movement of the predetermined section, the predetermined section is restored by the linking line having a large transfer capacity of the line among the plurality of linking lines connected by the branching point. Breakdown section recovery method of the distribution line. In the failure section separation recovery system of the distribution line including a first line and a second line connected to each other, Each of the first line and the second line includes a first feeder agent and a second feeder agent capable of transmitting and receiving to each other, and the first and second feeder agents issue a failure experience communication to the other party when a failure occurs in their own line. Breakdown section separation recovery system of the distribution line, characterized in that to move the always open point of its own line. The method of claim 5, The break point separation recovery system of the distribution line, characterized in that the movement of the opening point is made by controlling the switchgear of the first and second lines. The method of claim 6, The first and second feeder agents, after receiving a failure experience communication from the other party, when the failure occurs according to the movement of the normally open point, the breakdown of the distribution line, characterized in that for opening the switch immediately before the always open point. Segmental Recovery System.

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