JPH01291630A - Control method for switchgear of distribution line section - Google Patents

Abstract

PURPOSE:To supply power with high quality by arranging a switchgear provided with a state detecting means such as ground/shortcircuit relay at a section separating point on a distribution line and separating a faulty section prior to function of a power interrupting/protecting means based on information fed from the state detecting means. CONSTITUTION:Automatic switchgears DM1, DM2,... arranged at each section of a transmission line 41 are provided with ground fault relays T1, T2,... and relay slave stations RL1, RL2,..., where the relay slave stations are entirely connected through a communication cable 42 with a master station 43 arranged in a substation. The master station 43 judges a ground fault section based on data fed from the relay slave stations RL1, RL2,... and provides a specific signal to a section switchgear to be opened. Since the series of operation is carried out prior to function of a circuitbreaker CB arranged in the substation and the like, faulty section and following sections can be separated with no power interruption in the preceding sections.

Description

[Detailed Description of the Invention] (Field of Application for Industry 1-7) The present invention is a distribution line segment switch control method that prevents a power outage caused by a ground fault on a power transmission distribution line from extending to other healthy sections. Regarding.

(Prior technology) Various measures have been tried to ensure a stable power supply by minimizing power outage times due to short circuits, ground faults, etc. in power transmission lines, and 11 of them have been put to practical use. There is.

Conventionally, as a method for this, for example, a distribution line is divided into several sections using section switches, and when a fault occurs, the section switches are controlled to separate the faulty section from the healthy section.

There are two methods of controlling sectional switches: the progressive method and the conveyance control method, but the commonly used method is to supply power sequentially from the power supply end to the terminal at a predetermined time interval. It is a timed sequential method.

FIG. 2 (at (b) is a configuration explanatory diagram showing an example of this timed sequential transmission system. It shows the operating state of the switch when a failure occurs in the section.

This method includes a circuit breaker 30 installed in a substation and switches 32, 34, 36, etc. installed at each separation point of each distribution section 3133, 35, . When the power is turned on after a predetermined time has elapsed after the trip function is activated and a ground fault current is detected within the predetermined time period, the device will be automatically locked open if t14 and ground fault current are detected within the predetermined time period.

In the distribution line having this configuration, as shown in FIG. 2(b), Y
(Let us now consider the case where a ground fault occurs in the fourth section 37.

In a ground fault state, an excessive current flows to the ground, and the ground fault relays of each switch are activated, and at the same time, the substation circuit breaker is opened and power transmission is stopped.

After 15 seconds, the substation circuit breaker is closed and power is supplied to the first section 31, and after 7 seconds, the switch 32 between the first section 31 and the first section 3:3 is closed. It is automatically closed and power is supplied to the next section.

While repeating this operation, power is supplied to each section in turn, but when power is supplied to the faulty section, the substation circuit breaker opens again, causing a power outage in all sections, but at this time,
The switch 36 in the μ failure section is locked open. After 60 seconds, the power is transmitted again, and the switches of each section are sequentially closed every 7 seconds, and after 14 seconds, the power is restored to the third section 35. However, since the switch 36 is locked in the open state as described above, the failure has occurred.
The section is not energized and the first section is healthy. Second. Power is restored to the third section, and the fourth and subsequent sections, where 11 faults exist, are disconnected.

However, in the conventional time-sequential distribution line segment switch control method, two power outages occur, albeit for a short time, between the occurrence of an S fault and the power supply to a healthy section. .

However, if equipment that uses a lot of computer systems such as OA and FA in recent years gets wet, if the power supply is cut off, even if it is instantaneous, it will not only cause destruction of the software information stored in the computer, but also cause problems. This is not desirable as there is a risk of damaging the IC and other hardware.

For this reason, there is a demand for a higher quality power supply, and as one of the countermeasures, attempts are being made to make the power distribution &Q1 uninterrupted in healthy sections at the time of failure.

In recent years, as a means of achieving uninterrupted power outages, communication lines, etc. have been added to the sectional switches installed in each section, and these are connected to the master station computer equipment installed at substations, etc., to instantly switch between faulty sections. A method has been proposed to detect this, control the power supply switch on a separate route, secure the power supply from the accident section to the terminal section, and then turn off the switch at the [m] + step section. ing. According to this method, it is possible to disconnect only the i<dead section without momentarily interrupting the supply to the healthy section, and research is underway to put it into practical use.

(Objective of the Invention) The present invention has the same object as the above, but has been made in order to achieve uninterrupted power in a healthy section for t+7 using a simpler device.

In other words, as will be explained later, the already proposed method f-stage has the disadvantage that the equipment to be added to each section switch is extremely complicated, and it is difficult to fully implement it due to the need to make major changes and modifications to existing facilities. It will take many years to reach this point.

The present invention has been made in view of this situation, and by providing the main function to the master station device,
A 1-1 objective is to provide a distribution line section switch control method that can simplify the configuration of a large number of slave station devices (additional sections of section switches) and make maximum use of existing equipment. It is said that

(Summary of the Invention) [1-] In order to achieve the first objective, the distribution line segment switch control method of the present invention provides an automatic switch (
L S ), ground fault relay (1') and short circuit detection relay (
It is equipped with a slave station device including a slave station device W? , n are constantly monitored by a predetermined polling means to collect their status information.

゛11 In the event of an error, 1) depending on the type of fault (earth fault or short circuit); The type and occurrence interval can be detected.

Therefore, based on this information, the master station sends a signal to control the necessary switches in order to disconnect the area after the accident.

This sequence of operations is performed within a predetermined period of time 1, for example, before the circuit breaker in the substation is activated (for example, 800+ms).
However, at this time, it is determined whether it is a ground fault, a short circuit, a slight ground fault, or a temporary ground fault, and the optimal response is taken for each case. It is characterized by the control as follows.

(Example) A distribution line sectional switch control method according to the present invention will be described in detail below, but prior to that, the above-mentioned prior art that has already been proposed will be described in detail in order to help understand the present invention.

The final purpose of the research currently underway is "1! It includes so-called different-phase power supply, which prevents power outages not only in the front section but also in the terminal section from the dead section by using multiple power supply routes. However, to simplify the explanation,
On the river route, the old town flit +iii
In the case where only the stage section is made uninterrupted, only the response to a ground fault will be explained.

Figure 3 (a) shows the distribution line °111 that has already been proposed in recent years.
It is a system diagram for explaining the section detection method, and is an automatic switch DM provided for each section of the power transmission line 4I.

, DM, ..., history ground fault relay T,,T,.

・---Try relay j station R1, , Rt, , R1,2
..., and all of the relay slave stations are connected by communication cables 42 to a master station installed in a substation or the like.

To briefly explain the functions of each block in this configuration, the switch 1) M opens and closes according to the processing calculation results in the Shiroko station and the control signal from the master station, and is a ground fault relay attached to the switch. operates in response to a ground fault on the terminal (farther) side of the switch.

In addition, the relay slave station RL controls each section switch DM, monitors the status signal of the ground fault relay T, creates data corresponding to each status, and sends the data to the master station device 43 via the communication cable 42. I will send it to you.

In addition, the operation of the ground fault/short circuit relay of each switch is all connected by a direct connection cable separate from the above-mentioned 4's wire, and the DC current/voltage generated by the ground fault/short circuit detection is is transmitted to other relay slave stations.

The master station device 43 determines the ground fault section based on the data sent from each relay slave station, and at the same time sends a predetermined signal to the section switch to be opened.

These series of operations are performed by circuit breakers C at substations, etc.
n from the accident point because it is processed by 6iJ when I3 is activated.
The area beyond the accident area was disconnected without any power outage.

Although this explanation did not mention the relief measures for healthy sections beyond section 111, if the distribution line system is connected to each other by multiple routes, the switches connecting these routes should be selected as appropriate. It may be configured such that power is supplied from the separate route to the portion beyond the accident section.

The configuration of the relay slave station RL is as shown in FIG. 3(b), for example.
The following has been proposed.

This device is described in detail in the 19861 Electric Power Industry Research Presentation Contribution Collection of the Electric Power Division, so we will omit the explanation here, but as is clear from the figure, the relay slave station The zero-phase current transformer component (Z C1' output) flowing to the ground and the reactive current component (7, P I output) flowing to the ground are detected, and three current transformers ( CT) output, the value and direction of the current flowing through each switch section, as well as active/ineffective components in the history, are detected. This is to allow the relay slave stations attached to each switch to identify the type of 1S fault and the switch to be opened/closed by themselves.

In addition, in history, these relay slave stations used a direct connection cable installed in addition to the communication line to transmit the DC voltage/current generated in response to the operation of the ground fault/short circuit relay by other people. Target 1 is achieved only by transmitting the information to all relay slave stations.

However, in the conventional method as described above, data processing and status monitoring of each section switch are performed by relay slave stations, so as is clear from Figure 3 (bl), a large number of As mentioned above, the structure of the relay slave station is complicated and expensive.

FIG. 1 is a schematic diagram for explaining the present invention in detail.

In the figure, reference numeral 1 denotes a circuit breaker inserted into the distribution line 2 at a substation or the like, and an automatic switch LS1. LS8,..., and each switch is equipped with a ground fault relay 1', , l'
, , ... and short-circuit relay X.

, X, , ---.
3. Add...

Historically, the control unit of this slave station device was configured to be connected via a communication cable 4 to a master station device MP installed at a control center of the distribution line such as a substation.

An overview of the operation in this configuration will be explained.

Normally, the master station device MPU polls the slave station device codes -1, 3-2, :S-:S, etc. in each section via the communication cable, and receives information from each r station. collect.

Each slave station device 6 encodes and transmits the state change of the current ground fault relay and short-circuit relay X according to the polling timing from the master station, but the ground fault relay and short-circuit relay are conventional ones. There is nothing particularly different.

In other words, a ground fault relay detects a current of several amperes (earth fault current rIL) flowing between a distribution line and the ground due to poor insulation, etc., whereas a short circuit relay detects a current of several amperes flowing between distribution lines or between distribution lines. It responds to the excessive current that flows as a result of connecting the ground and the ground with a low resistance value, and the operating current is set to be different for each person.

The thus collected data from each -r station is monitored in the master station device, and polling is continued sequentially as long as there is no abnormality frJ1.

Next, what to do when a ground fault occurs in the fourth section in FIG. 1(a), for example, will be explained with reference to the flowchart shown in FIG. 1(bl).

In response to a ground fault, the ground fault relay in the section before the fault point is activated, and the result is detected by the master station device in accordance with the polling timing of each r station.

When the 1S fault section is determined, the section is displayed on the 1 display device, and at the same time it is determined whether the fault is a short circuit or not.

This judgment is made based on the operation of the short-circuit relay attached to the switch, but if it is determined that the short-circuit has occurred, the substation's circuit breaker CB is immediately opened to cut off the power supply to this system. . The reason for this is that the section switch handles excessive current due to short circuits.

This is because there is a risk of burnout due to insufficient contact field 19.

Thereafter, the -μ breaker is turned on again to determine whether the short circuit is temporary. Note that the response to the short-circuit failure will be omitted.

Next, if it is determined that there is no short circuit, it is determined whether or not the ground fault detection relay is activated, and if it is a ground fault "μ", a predetermined period of time has elapsed to determine whether this is a temporary ground fault or a continuous one. Detect the presence or absence of a +tjU ground fault phenomenon.

・Temporal ground fault '7! An example of this is when a ground fault 1 in a power customer equipment containing an internal switch or local circuit breaker activates the protection device and spontaneously disconnects it from the power distribution system.

If the first fault is removed by this, control 1 returns to the initial state without operating the switch.

If the ground fault condition continues, it will be necessary to identify whether the short circuit relay is activated or not. The reason for this is short circuit -1 because the ground fault is! Therefore, the rate of progress is extremely large, so +11
For the reason stated above, it is only necessary to control the switch.
This is because there is a risk of damage to the 4 equipment, and it is generally said that the possibility of this happening is high for 500 to 600 ms after the ground fault occurs.

Therefore, after monitoring the occurrence of a short circuit fault within this time, a control signal is sent to the required switch to disconnect the relevant short circuit fault section.

In addition, in order to confirm whether this command signal has been transmitted without error and whether one switch has operated, the operating status of the ground fault relays is detected again, and if none of the ground fault relays has operated, the control moves to the initial state assuming that it has been completed, but
If the ground fault relay is still operating, the command signal is sent again, or the relay returns to the initial state and the fault area is detected again.

Further, in order to ensure accuracy, the operation of the 11-degree short circuit relay may be checked and necessary processing performed.

The operation of this example is designed to be completed in, say, 800 m5, and the time it takes for a substation circuit breaker to trip after a fault occurs - typically about 1
This is to complete the necessary processing within seconds and separate the 1-1 section.

For example, if this time control is performed at a transmission speed of 1 Mbps, the polling time per slave station is about 10 m5, which is nl capability, and if current sequencer technology is used, it can be put to practical use even if multiple speed control devices are installed. be able to.

According to the above configuration, before the circuit breaker is activated, the faulty section is determined and the necessary switches are opened.
Since we will be separating the section after the previous section, 11?
There are no power outages in the healthy sections of the system.

In addition, in the following examples, the method for repairing the terminal part from the failed section is not described in 1, but as in the previous proposal, if an inter-grid switch is installed in advance to supply power from a different route. It is also possible to automatically control this switch to make all healthy sections, excluding only the failed sections, uninterrupted.

As is clear from the description in 1- below, in the present invention, information from each switch can be processed mainly in the master station device. The reason for this is that the data to be extracted for each switch is only the operating status of the ground fault relay or short circuit relay, and therefore the r/station equipment (
The configuration of the section switch (added to the section switch) can be significantly simplified compared to the conventional one shown in FIG. In addition, the amount of data is extremely small because the signal to be sent from the slave station need only represent the ON-Or:F of the ground fault/short circuit relay or the range of current flowing in the electrical path. Therefore,
It is easy to see that polling is possible at extremely high baud rates.

-r station devices are used in large numbers in addition to switches, and are installed on utility poles, etc., so it is extremely convenient to downsize the slave stations due to the simplification of the configuration.

In addition, in the method of the present invention, a ground fault relay and a short circuit relay are connected to the switch in order to isolate the faulty section, and the details of the fault are determined by the control station (master station) via the control line, and the fault is detected in the event of a ground fault or short circuit. The purpose is to carry out necessary controls. Therefore, a configuration in which the switch is controlled based on information manually inputted into operation [ij] after the circuit breaker of the substation is operated, that is, after the entire section is stopped 1-, is also included in the scope of the claims.

(Effects of the Invention) As described in 1 below, according to the distribution line segment switch control method of the present invention, the status of the switch provided at the segment separation point of the distribution line and the ground fault/short circuit relay attached thereto can be controlled. Based on the information from the detection means, a ground fault/short circuit or other 111 section is detected, and a power interruption protection stage such as a circuit breaker is activated to disconnect the faulty section. Therefore, if the accident spreads to the healthy section, it is possible to prevent it from spreading.
High quality power can be supplied.

Furthermore, in the method according to the present invention, the data to be collected for each switch is extremely simple;
The structure of the r station is simple, and it is effective in reducing its size.

[Brief explanation of the drawing]

Fig. 1 (al) is a block diagram schematically showing a configuration for disconnecting the faulty section and subsequent sections without causing a power outage in the healthy section according to an embodiment of the present invention, and Fig. 1 (b) shows the operation of the present invention. Flowchart, Fig. 2 (al is a block diagram showing the operation of each switch of a conventional power distribution line, Fig. 2 (bl is Fig. 2)
A configuration diagram showing the operation of each switch of the distribution line when a failure occurs in the fourth section of the distribution line of Al, 3rd
Figures (al and (b)) are a system diagram of a conventional uninterruptible system and a block diagram of its slave station equipment. average price line

Claims (1)

[Claims] (1) In a power distribution line arranged via a section switch including a ground fault relay and a short circuit relay, each switch is equipped with a slave station device that detects the operating state of the ground fault relay and the short circuit relay, Connecting the slave station device to a master station device installed in a substation or the like via a communication line, and detecting the section where the accident occurred based on information collected by polling each of the slave stations by the master station device, A distribution line segment switch control method characterized in that the section where the accident occurred is disconnected before a power cutoff means such as a substation is activated.