JPH10201082A - Automatic section switch for distribution line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To disconnect the faulty section of a grounded loop system distribution line automatically by making a decision that its own section is faulty when the absolute value of phase difference of overcurrent generating phase between its own section and an adjacent section on the load side exceeds a specified value thereby opening a section switch before the distribution line is recovered. SOLUTION: When a distribution line 13 is interrupted through a control processing section 34, serial interface 40 and a communication modem 42, overcurrent information and phase difference information is received from a memory 35 in the following section on the load side through communication with a switch controller 22 in that section when the overcurrent information is present in its own section and occurrence of overcurrent is detected, the control processing section 34 determines the absolute value of difference between a phase difference of overcurrent generating phase of its own section and a phase difference of overcurrent generating phase of the following section on the load side stored in the memory 35 and makes a decision that its own section is faulty when the absolute value exceeds 90 deg.. Consequently, a section switch 20 is opened before the distribution line is recharged and recovered along with a control output circuit 38 and an open coil 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic distribution line switchgear suitable for dividing distribution lines of a normally closed loop direct grounding system or a low resistance grounding system supplied with power from upstream and downstream sides.

[0002]

2. Description of the Related Art Conventionally, a grounding system in which a neutral point is directly grounded or low-resistance grounded is formed in a non-loop (dendritic). In this case, as shown in FIG.
Is connected to a three-phase distribution line 4 via a circuit breaker 3.

The distribution line 4 is divided into a plurality of sections # 0, # 1, # 2, # 3,... From the upstream side (substation side) by a section switch 6 of a plurality of distribution line automatic section switchgears 5. It is divided into

Each automatic section switch 5 includes a section switch 6 and a switch controller 7 for controlling the opening and closing of the switch 6. Each section switch is controlled by the switch control of the switch controller 7. 6 own sections # 1 and # on the load side
2, # 3,... Are connected to the system so that they can be freely separated.

[0005] When an accident such as a ground fault or a short circuit occurs in any section of this system, the circuit breaker 3 of the substation 1 is opened, and the power distribution line 4 is cut off, the substation is conventionally transformed by test transmission described below. It is common practice to reclose the circuit breaker at the site and restore a healthy section upstream of the accident section.

[0006] For example, as shown in FIG. 22, when the land絡又an accident point P ₁ of the section # 2 accident short circuit occurs, on the basis of the overcurrent conduction, distribution lines 4 accident blackout breaker 3 is immediately released become. In addition, each of the segment switches 6 is opened based on the disappearance of the voltage on the upstream side.

[0007] When a certain period of time has passed since the occurrence of the accidental power failure, the circuit breaker 3 is reclosed. It is timed sequentially from the vessel 6.

When the section switch 6 of the section # 2 is reclosed by this timed closing, the circuit breaker 3 is opened again and the distribution line 4
Power outage.

At this time, the section switch 6 in the section # 2 is opened and locked in the open state within the time period for detecting an accident from the power recovery on the upstream side.

The circuit breaker 3 is reclosed after a certain period of time from the power failure, and based on the reclosed circuit, the circuit breaker 3 is operated in the same manner as when the circuit is closed again.
The section switch 6 in the section # 1 is first turned on for a time period, and the section # 1 on the load side is restored.

Further, even if the closing time elapses after the restoration of power in section # 1, since the sectional switch 6 in the accident section # 2 is locked in the open state at this time, the sectional switch 6 is closed. Accident section # 2 is disconnected from the system.

As a result of the separation of the accident section # 2, the sound sections # 0 and # 1 on the upstream side are restored, and the restoration of the sound section by test transmission is completed.

Conventionally, in order to identify an accident section and take measures against the accident by means of base station equipment for so-called distant monitoring and control such as a sales office of a power company or a distribution system control center, each switch control device 7 communicates. For example, the communication device 11 of the distribution system control center 10 is connected via the line 9 to the communication device 11.
Is connected to the monitoring control device 12 of the center 10.

The monitoring control device 12 and each switch control device 7 connect the monitoring control device 12 to a base station (master station),
Using each switch control device 7 as a slave station, information is exchanged by polling communication, and by exchanging this information, the monitoring control device 12 obtains the measurement results and the like by the sensors 8 such as the three-phase current transformer of each switch control device 7. The stored information is collected as accident information, the accident section is determined based on the result of the collection, and a monitor display of the determination result is performed.

By the way, the circuit breaker 3 is closed again by the test power transmission to separate the accident section # 2, and the sound sections # 0, # 1
To restore the normal sections # 0 and # 1 immediately after the power failure
Cannot be restored, and healthy sections # 0 and # 1
However, a power outage also occurs due to test transmission after an accidental power outage, and power outages occur repeatedly before recovery.

Particularly, in a direct grounding system or a low-resistance grounding system, a large fault current flows even in a single-line ground fault, which occurs much more frequently than a short circuit between lines. In the trial charging method in which the accident point is detected by being inserted, the load on the sectional switch becomes large.

Therefore, it is desired to have a system in which the number of times of opening and closing of the sectional switches is reduced, and the sectional switches in the accident section need not be turned on.

Therefore, as described below, the distribution system control center 10 is required until the circuit breaker 3 is closed again after the power failure.
It is also proposed to open the sectional switch 6 in the accident section # 2 by remote monitoring control such as the above and restore the healthy sections # 0 and # 1 without performing test power transmission.

That is, each switch control device 7 is provided with a backup power source such as a battery power source at the time of a system power failure.
When an accident occurs at the accident point P ₁ in FIG. 2, as shown in FIG. 2, during the accidental power failure of the distribution line 4, each switch controller 7 sends the stored information to the monitoring controller 12 via the communication line 9. # 1 information, # 2 information,...) Are transmitted.

Further, based on this transmission, the monitoring control device 1
2 to identify accident section # 2, as shown in FIG.
During the power failure of the accident, the supervisory control device 12 instructs the switch control device 7 in the accident section # 2 to perform opening control via the communication line 9, and based on this command, the section switch 6 in the accident section # 2 is opened. Lock.

When the circuit breaker 3 is closed again, FIG.
As shown in (1), the healthy sections # 0 and # 1 are restored.

In FIGS. 21 to 24, the distribution line 4
A bold line indicates that the battery is in a charged state.

[0023]

The distribution line of the grounding system such as the distribution line 4 cannot be formed in a loop system of the same bank or a different bank which simultaneously supplies power from the upstream side and the downstream side. In this case, it is formed in the so-called one-power-supply non-loop system described above.

This is because if the faulty section is formed in a loop system, the faulty section cannot be separated by the test power transmission, and an overcurrent also flows on the load side of the faulty section. It is also difficult to identify the accident section, and the accident section cannot be automatically separated.

By the way, even in the conventional direct grounding system or the non-loop system of the low resistance grounding system, when a healthy section is restored by remote monitoring control of base station equipment such as the distribution system control center 10 described above, There is an inconvenience that the recovery requires a base station facility including a large-scale monitoring and control device 12 having a computer configuration having an automatic determination function of an accident section and the like.

In addition, for example, in Japan, it is general that several base station facilities are installed in each prefecture. In this case, a distribution network such as the distribution line 4 is mainly located in suburban areas. 5-10km radius in the district, 50 radius in the county
Because it is formed on a scale of about Km, there are many cases where the distance between the base station equipment and the distribution network exceeds 50 km to 100 km, and a long communication path connecting the base station equipment and the distribution network is required.
The communication line 9 becomes extremely long, requiring a great deal of construction of communication equipment and the like, and also requires large power as communication power.

It should be noted that even if wireless communication is adopted in place of the wired communication by the communication line 9, the distribution system control center 10
Such base station equipment requires high power communication equipment for the base station.

Further, if communication is performed by a distribution line transport system using the distribution line 4 in order to omit the communication line 9, the communication power required for that will be as large as several megawatts.

According to the present invention, an accidental section of a distribution line of a direct grounding system or a loop system of a low-resistance grounding system can be automatically performed without providing the conventional base station equipment for remote monitoring and control or performing test power transmission. To provide an automatic distribution line switchgear capable of separating and quickly restoring a healthy section upstream of the accident section and realizing separation of the accident section by automatic classification of a direct grounding system or a loop system of a low resistance grounding system. Make it an issue.

[0030]

In order to solve the above-mentioned problems, in an automatic distribution line switchgear of the present invention, a switch control device includes a backup power supply for forming an operation power supply during a power failure of a distribution line. Means for measuring each phase current in its own section on the load side of the classifying switch, and the occurrence of overcurrent when the measurement result of each phase current exceeds the set value due to ground fault or short circuit accident Means for detecting and storing information of overcurrent of each phase, and the phase current of the overcurrent generation phase when the occurrence of overcurrent and the predetermined two-phase line voltage of the distribution line before the occurrence of the accident is detected. Means for storing information on the phase difference between the power supply and the switch control device in the section adjacent to the load side of the section during the power failure of the distribution line based on the detection of the occurrence of the overcurrent. Means for receiving information on the overcurrent of the section and information on the phase difference; Means for judging the own section fault when the absolute value of the difference between the stored value of the phase difference of the flow generation phase and the stored value of the phase difference of the phase in the adjacent section on the load side is greater than 90 °; Means for opening the sectional switch before the distribution line is restored by the judgment of the accident.

Therefore, if a ground fault or short circuit occurs in any section of the distribution line of the direct grounding system or the loop system of the low resistance grounding system and the fault phase of the distribution line becomes an overcurrent, the switch control is performed. The device detects the occurrence of overcurrent and stores the information of the overcurrent of each phase and the information of the phase difference between this voltage and the phase current of the overcurrent phase based on a predetermined two-phase line voltage. .

At this time, the overcurrent flows to the downstream side (load side) in the fault section and the section upstream thereof, flows to the upstream side in the section on the load side from the fault section, and the predetermined two-phase current of the distribution line immediately before the fault. The phase difference between this voltage and the phase of the overcurrent based on the line voltage is 180 ° because the directions are almost opposite between the fault section and the section upstream thereof and the section on the load side of the fault section. It will be different soon.

Then, during an accidental power outage of the distribution line, the communication with the switch control device in the adjacent section on the load side provides information on overcurrent in the adjacent section on the load side and the phase difference between the information and the line voltage. When the information is received and the absolute value of the difference between the stored value of the phase difference of the own section of the same phase (overcurrent phase) and the stored value of the phase difference of the adjacent section on the load side is found, an accident occurs in the own section. Only when this occurs, the absolute value of the difference becomes larger than 90 °, and from this, it is accurately determined whether or not the own section accident has occurred.

Further, in the case of a local section accident, before the distribution line is restored, the sectional switchgear of the own section is opened, so that after a power failure, the circuit breaker of the substation is closed again and the distribution line is restored. By then, the section switch of the accident section is opened and the accident section is automatically disconnected from the upstream side,
A healthy section upstream of the accident section will be restored.

In this case, after an accidental power outage of the distribution line, the upstream healthy section is quickly restored without performing conventional test power transmission and the like, and only communicates with the switch control device in the adjacent section on the load side. Therefore, the conventional large-scale base station equipment for remote monitoring control and its communication equipment are unnecessary.

Therefore, without performing conventional test power transmission and the like, without providing a large-scale base station facility for remote monitoring control and its communication facility, etc., only communication with the switch control device in an adjacent section is performed. Automatic disconnection of the accident section of the distribution line of the grounded loop system, which could not be done conventionally,
By this separation, the upstream healthy section can be quickly restored.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. First, the grounded loop system of the present embodiment is configured as shown in FIG. 6, and the three-phase distribution line 13 has a circuit breaker 15 of the substation 14 at the upstream end.
The downstream end is connected to the circuit breaker 17 of the substation 16, and the secondary system power of the distribution transformer 18 of the substation 14 is supplied with power through the circuit breaker 15. System power supply on the secondary side of the power distribution transformer 19 is
7.

The substations 14 and 16 are substations of the same or different banks, and the power distribution transformers 18 and 19 are supplied with power from the same or different upstream systems.

The distribution line 13 is divided into, for example, five sections # 0, # 1, # 2, # 3, and # 4 by the division switch 21 of the automatic distribution line switchgear 20. The sections # 1 to # 4 on the load side of 21 are the own sections of each switching device 20.

Further, each section switch 21 is controlled to open and close by a switch controller 22 of each automatic section switch 20.
Each switch control device 22 communicates via the communication line 23 with the switch control devices 22 in the adjacent sections # 2 to # 4 on the load side.

Further, in the vicinity of the load side of each section switch 21,
A current sensor 24 having a three-phase current transformer configuration for measuring the system current of each of the load-side own sections # 1 to # 4 for each phase is provided.
The measurement signal of this sensor 24 is supplied to the switch control device 22 of each automatic section switchgear 20.

In the case of the grounding system according to the present embodiment, the distribution system control center 1 shown in FIG.
Since the base station equipment for remote monitoring control such as 0 is not used, the distribution system control center 10 in the figure is omitted, and a communication path corresponding to the communication path between the center 10 and the automatic section switchgear 5 is provided. Not.

Next, the segment switch 21, the switch controller 22 and the current sensor 24 of each automatic segment switch 20 are
The distribution line automatic section switchgear 20 in section # 2 is configured as shown in FIG.

The sectional switch 21 is connected to the main circuit contacts 25a, 25 that are linked to each other for each of the phases A, B, and C of the distribution line 13.
b, 25c, an auxiliary display contact 26 interlocked with these contacts 25a to 25c, and a closing coil 27 and an open coil 28 of each of the contacts 25a to 25c, 26.

The switch control device 22 is connected to the distribution line 13.
Are processed into a single-phase drive power supply (control power supply) by a control transformer 29 and supplied to a power supply input circuit 30.
Power is supplied to each part in the device from the device to operate.

Further, a power failure backup circuit 32 of a backup power supply 31 is connected to the power supply input circuit 30, and the control transformer 30
, The secondary battery 33 of the backup power supply 31 is charged via the power input circuit 30 and the power failure backup circuit 32,
When a power failure occurs in the distribution line 13 due to a ground fault or the like, power is supplied from the secondary battery 33 to each unit in the device via the power failure backup circuit 32 and the power supply input circuit 30. Also works during a power outage.

The switch control device 22 includes a memory 35, a current measurement circuit 36, a voltage measurement circuit 37, a control output circuit 38, a display input circuit 39, and a communication serial interface 4 in a control processing section 34 having a microcomputer configuration.
0 and the like are connected by a bus, and the control processing unit 34 executes the accident monitoring control processing shown in FIGS.

At this time, the current transformers 41a, 41b, 41c of the respective phases A, B, C of the current sensor 24 are connected to their own sections # 1 to # 4.
Current measurement circuit 36 measures the current of each current
The information of the instantaneous measurement result of each phase of to 41c is supplied to the control processing unit 34, and the control processing unit 34 monitors each phase current of the own section # 1 to # 4.

The voltage measuring circuit 37 is connected to the control transformer 2
9 and supplies the information to the control processing unit 34. The control processing unit 34 monitors the line voltages of the A and C phases.

Then, the control processing section 34 compares each phase current with the set value for overcurrent detection, and when a ground fault or short circuit occurs, the current (phase current) of one of the phases becomes larger than the set value. Then, the occurrence of the overcurrent is detected, and information of the overcurrent such as the overcurrent occurrence phase and the phase angle of the phase current is stored in the memory 35.

Further, information on the phase angles of the line voltages of the A and C phases is stored and stored in an internal register or the like over the latest several cycles, for example. The information of the line voltage several cycles before (immediately before the accident) held in a register or the like is read, and the vector angle based on the line voltage is used to calculate the phase angle of this voltage and the phase current in the overcurrent state of the overcurrent generation phase. Find the phase difference with the phase angle,
This phase difference information is also stored in the memory 35.

The phase angle information of the line voltage, the magnitude and the phase angle of each phase current are sampled by the well-known digital waveform processing, and the line voltage and each phase current are sampled and Fourier-integrated. , Can be obtained by Fourier analysis of the respective waveforms.

Next, the control output circuit 38 controls the control processing unit 3
Under the control of 4, the closing coil 27 and the opening coil 28 of the section switch 21 are driven to turn on and open the section switch 21.

Further, a contact signal of the auxiliary display contact 26 is supplied to the display input circuit 39, and the control processing section 34 grasps the open / close state of the sectional switch 21 based on the contact signal.

Further, the serial interface 40 is connected to the communication line 23 via the communication modem 42, and each section #
The switch control devices 22 of # 1 to # 4 communicate with the switch control devices 22 of adjacent sections (hereinafter referred to as load-side next sections) # 2, # 3, and # 4 via respective communication lines 23. .

Then, when the power distribution line 13 is cut off by the control processing unit 34, the serial interface 40, and the communication modem 42, the control unit 34 communicates with the switch control device 22 in the next section on the load side to store the overcurrent in the memory 35 in the next section on the load side. Means are provided for receiving the information and the phase difference information.

Further, the control processing section 34 stores the information of the overcurrent in the own section, and when the occurrence of the overcurrent is detected, the storage value of the phase difference of the generated phase of the own section in the memory 35 and the load Means for determining the absolute value of the difference between the phase difference of the relevant phase and the stored value of the phase in the secondary section and determining that the own section has an accident when the absolute value is greater than 90 ° is formed.
Together with the open coil 29, a means for opening the sectional switch 20 before the distribution line 4 is recharged and restored by the judgment of the own section accident is formed.

Next, the accident monitoring control processing of the control processing section 34 will be described. First, the memory 35 is reset or the like in the initial setting of Step S ₁ of FIG. 2, the self segment # 1 to # 4 of A by step, holding the line voltage of the C phase, the steps S ₃ ~ Step S ₉ Monitor the occurrence of overcurrent due to ground fault or short circuit accident.

[0059] Then, one of the section, the accident occurs for example in an accident point P ₂ of the section # 2, as shown in FIG. 7, A,
In any one of the phases B and C, if the phase current becomes overcurrent and becomes larger than the set value, steps S ₄ , S ₆ ,
Step S _10a detects the overcurrent by S _8, S
_{The process proceeds to steps 11a} and _S12a , and the information of the overcurrent such as the generated phase and its current vector is written in the memory 35.

[0060] Further and stores data erasure of the memory 28 by detecting the disappearance of overcurrent due to the power recovery system during such momentary accident, step S _10b, S _11b, the S _12b each phase reset count memory to extinction detection time N _a, N _b, N _c
Set the initial value (setting value) of.

[0061] When the disappearance of the overcurrent is detected in step S _4, S _6, S ₈ is detected that there is the system voltage by the step S _9, step S _10c, S _11c, each by S _12c, reset count each time each phase memory N _a, counts down N _b, the N _c by 1, the time N _a, N _b, the N _c is 0, clear the stored value of the corresponding phase of the memory 35.

Steps S _10c , S _11c and S _12c are as follows:
Specifically, it is configured as shown in FIGS. 3 (a), 3 (b) and 3 (c).

On the other hand, if the accidents continue and the circuit breakers 15 and 17 of the substations 14 and 16 are opened and the distribution line 13 is cut off,
Step S ₁₃ from step S ₉ that system voltage disappears
Move to

Then, immediately before the occurrence of the accident (before a certain cycle)
Phase angle of the line voltage when the system is normal and the memory 35
Obtains a phase difference between the phase angle of the phase current of the stored accident during overcurrent phase, after storing the information in memory 35, the process proceeds to step S ₁₄ in FIG.

[0065] Further, the step confirms the detection of overcurrent by S _14, the process proceeds to step S _15, the most load side of the section # each control processing unit 34 except for the control processing unit 34 of the 4
Starts the built-in timer, and each cargo side next section # 2
Call waiting time _{~ # 4 Ni (= N 1} , N 2, N 3)
(Seconds).

This standby time Ni is determined by each switch control device 22.
Is set in order to shift the time for calling the switch control device 22 in the load-side next section to receive the information and to prevent information collision due to sharing of the communication line 23, and in the present embodiment, the most upstream section N ₁ <N ₂ <N ₃ is set in order to call sequentially from the switch control device 22 of # 1.

[0067] Then, organic loss of the system voltage by the step S _16, to determine non confirms the continuation of the power failure, the elapsed call waiting time Ni by a loop back to step S ₁₆ through step S _17, S ₁₈ Until the call is monitored from the switch control device 22 in an adjacent section on the upstream side (hereinafter referred to as an upstream next section).

[0068] When invoked from the switch controller 22 of the upstream-side next interval during the monitoring, the memory 3 in step S ₁₉
5 is read, and a response signal (reply signal) based on the stored information is transmitted to the switch control device 22 in the next section on the upstream side.

[0069] In addition, call the waiting time Ni has elapsed, sends a call information of the information and the phase difference of the overcurrent from step S ₁₈ to step S ₂₀ switch controller 22 proceeds to load the next interval (the transmission ) and receives the response signal from the switch controller 22 on the load side following sections based on this call, the process proceeds to step S ₂₂ through step S _21.

Then, for the same overcurrent phase, the memory 3
The absolute value of the difference between the stored value of the phase difference of the own section # 1 to # 3 and the stored value of the received phase difference of the next load side sections # 2 to # 4 is determined.

At this time, as is clear from the arrow line indicating the direction of the overcurrent passage in FIG. 7, the overcurrent in the fault section # 2 and the sections # 0 and # 1 upstream thereof flows to the load side, and The overcurrent in the sections # 3 and # 4 on the load side from # 2 flows upstream, and the overcurrent in the accident section # 2 and the overcurrent in the next section # 3 on the load side have a phase difference as shown in FIG. And the overcurrents in the other sections # 1 and # 3 and the overcurrents in the load-side next sections # 2 and # 4 have substantially the same phase difference as shown in FIGS. Become.

It should be noted that θ (# 1) in FIGS. 8, 9, and 10
θ (# 2), θ (# 3), θ (# 4) are the phase differences of the overcurrent phases in sections # 1, # 2, # 3, and # 4 based on the line voltages of the A and C phases. Is shown.

Therefore, it is determined whether or not the absolute value of the difference between the phase differences is greater than 90 ° by using 90 ° as a threshold value, and it is determined from the result whether or not the own section accident has occurred.

By this determination, the fault section of the distribution line 13 of the normally closed loop grounding system, which was impossible in the past, can be specified, and the fault occurs in the own section, and the absolute value of the phase difference difference becomes larger than 90 °. When it gets bigger, based on the judgment of the own section accident,
The process proceeds from step S ₂₂ of FIG. 4 in step S _23, the opening coil 28 energized driven to lock the section switch 21 of its own section in the open state.

[0075] Further, when it is determined that the own section accident in step S _22, the process proceeds from step S ₂₃ to step S _24,
When it is determined that the other section accident in step S _22, the program proceeds from step S ₂₂ to step S _24.

[0076] When confirming the power failure continues with step S _24, in re-closing of the circuit breaker 18, 19 of the substation 14, 16 etc. until the system power supply distribution lines 13 is restored, the loop of steps S ₂₅ to S ₂₇ the to send a response signal by detecting a call from the switch controller 22 of the upstream-side next interval, the system voltage returns from step S ₂₇ if the recovery step S ₁ of FIG.

Note that the distribution line 1 is determined in steps S ₁₆ and S _24.
Also when the restoration of the system power supply of _No. 3 is detected, the process returns to step S1 in FIG.

Therefore, if the distribution line 13 fails due to an accident, the section switch 21 of the accident section # 2 is locked in the open state during the interruption, and when the power of the distribution line 13 is restored, the accident section # 2 moves to the upstream side. Is automatically disconnected from the accident section # 2
The sound sections # 0 and # 1 located further upstream are restored.

Next, the operation of the entire power distribution system of FIG. 6 when a ground fault occurs in section # 2 of FIG. 7 will be described with reference to the timing chart of FIG.

First, at t ₁ , a ground fault or a short circuit occurs at the fault point P ₂ in the section # 2, and the breakers 1 of the substations 14 and 16 are turned off.
5 and 17 are opened at t ₂ by an appropriate timed operation, and as shown in FIG. 5A, the system voltage (distribution line voltage) of the distribution line 13 disappears, and the state where there is no voltage changes to the state where there is no voltage. , that is, becomes a power failure, overcurrent energization of t _1, switch controller 22 of each section # 1 to # 4 of FIG. 5 (b),
As shown in (f), (j) and (n), the overcurrent is detected and the information of the overcurrent is stored in the memory 35, and the information of the phase difference from the voltage is also stored in the memory 35 at the same time.

[0081] Furthermore, the timer is actuated accident outage at the same time the switch controller 22 of t _2, after a lapse of the call waiting time N ₁ from t _2, in section as shown in (c) of FIG. 5 #
The switch control device 22 transmits a call signal to the switch control device 22 in the load-side next section # 2, and based on the reception of the call signal shown in FIG. The device 22 reads the information stored in the memory 35 (the information of # 2) and converts the response signal into the upstream next section #, as shown in FIG.
1 to the switch control device 22.

Then, the switch control device 22 of the section # 1
The absolute value of the difference between the phase difference of the overcurrent phase in the own section # 1 of the memory 35 and the received phase difference of the same overcurrent phase in the load-side next section # 2 shown in FIG. Identify if greater than °.

At this time, as shown in FIG.
2, the phase differences θ (# 1) and θ (# 2) are both about 45 ° before,
Later, since the absolute value of the difference is smaller than 90 °, the switch control device 22 of the section # 1 identifies that the section # 1 is not an accident section, and determines that the other section is an accident.

When the other section accident is determined,
Since the switch control device 22 does not lock the sectional switch 21 in the open state, the sectional switch 21 in the section # 1 is kept in the closed state as shown in FIG.

Next, when the call waiting time N ₂ has elapsed from t ₂ , as shown in FIG. 5 (g), the switch control device 22 in the section # 2 is switched to the switch control device 22 in the load-side next section # 3. 2
2, and based on the reception of the calling signal shown in (l) of the figure, the switch control device 22 in the section # 3 stores the information stored in the memory 35 as shown in (k) of FIG. # 3) and sends a response signal to the switch control device 22 in the upstream next section # 2.

Then, the switch control device 22 of the section # 2
FIG. 5 shows the phase difference between the overcurrent phases of the section # 2 of the memory 35 and
(H), it is determined whether the absolute value of the difference between the received load-side next section # 3 and the phase difference of the same overcurrent phase is greater than 90 °. At this time, as shown in FIG. The phase differences θ (# 2) and θ (# 3) of # 2 and # 3 are about 45 ° and about 225 °
(−135 °), and the absolute value of the difference is larger than 90 °.

Therefore, the switch control device 22 in the section # 2
Identifies that the own section # 2 is an accident section and determines that the own section is an accident.

Then, based on the judgment of the own section accident, the switch control device 22 of the section # 2 locks the sectional switch 21 of the own section # 2 in an open state as shown in FIG. Automatically disconnect # 2 from the upstream side of the system.

Next, when the call waiting time N ₃ elapses from t ₂ , as shown in FIG. 5 (k), the switch control device 22 in the section # 3 is switched to the switch control device 22 in the load-side next section # 4.
And operates in the same manner as the switch control device 22 in the sections # 1 and # 2.

At this time, as shown in FIG.
The phase difference θ (# 3) and θ (# 4) of # 4 are both about 225 °
(-135 °) before and after, the absolute value of the difference is 90 °
Since it becomes smaller, the switch control device 22 of the section # 3
Determines that this is an accident in another section, as in the case of the switch control device 22 in the section # 1, and keeps the sectional switch 21 in the ON state as shown in FIG. 5 (m).

Further, as shown in FIG. 5 (o), the switch control device 22 in the section # 4 on the most load side transmits a response signal in the section # 3, and thereafter, as shown in FIG. 5 (p). As a result, no response signal was received,
No judgment is made, and therefore, as shown in (q) of FIG.

As a result, during the accidental power failure of the distribution line 13, the section switch 21 of the accident section # 2 is locked open as shown in FIG. 11, and the accident section # 2 is automatically disconnected from the upstream system. When the circuit breaker 15 of the substation 14 is reclosed and the distribution line 13 is recharged and the power is restored, a power outage does not occur as in the case of the conventional test power transmission, and as shown in FIG. Healthy sections # 0 and # 1 upstream of section # 2 are immediately restored.

Next, communication signals between the switch control devices 22 will be described. Communication between the switch control devices 22 is performed, for example, by setting an address for each switch control device 22 and using a signal format described below.

Then, the calling signal and the answer signal are
As in the case of general digital transmission, FIG.
The call signal is formed in the frame configuration shown in FIG. 3B, and the call signal is a synchronization signal SYNC, a destination address AD ₁ , a transmission source address AD ₂ , an information type ID, and information, as shown in FIG. (Data) DAT ₁ , end flag END
As shown in FIG. 3B, the response signal includes a synchronization signal SYNC, a destination address AD ₁ , a transmission source address AD ₂ , an information type ID, and information (data) DAT _{2, which are in order from the beginning.} .. DAT ₅ , an area of an end flag END.

Further, as shown in FIG. 14, each area is composed of a start bit st, data data, a stop bit sp, and a parity bit pt. The start bit st is logic 0 and the stop bit sp is logic 1.

The data data is DAT ₃ to DAT.
The area of ₅ has 16 bits, and the other areas have 8 bits.

The eight bits of the data data in the ID area are as shown in FIG. 15 according to the calling (calling signal) and the response (response signal).

The eight bits of the data data in the area of DAT ₁ of the call signal are as shown in FIG. 16 according to the contents.

Further, each bit a ₀ , a ₁ ,... _{, A 7} of the data DAT ₂ area of the response signal is shown in FIG.
As shown in (1), ON / OFF of the sectional switch 21 in the own section (switch state), presence / absence of system voltage (with voltage), presence / absence of overcurrent information (with overcurrent), ..., response state (good response) Bit a ₀ corresponds to logic 1, 0 on / off, bit a ₁ corresponds to logic 1, 0 for presence or absence of voltage,
Bit a ₂ is chromatic logical 1,0 overcurrent information, corresponding to the no.

Next, the response signal D shown in FIG.
AT ₃ , DAT ₄ , and DAT ₅ are assigned to the transmission of the overcurrent information and the phase difference information of the A, B, and C phases, and each of the 16-bit b _{0 to} b ₁₅ data data is the first two bits b. _0, b ₁ is used to display the phase shown in FIG. (b), used in the presence of 1 bit following the overcurrent, used information of the phase difference of each bit 0 ° to 360 ° after .

Therefore, a call signal from the switch control device 22 in the section # 1 to the switch control device 22 in the load-side next section # 2 and a response signal to the call signal are shown in FIGS. ), From the switch control device 22 in the section # 2 to the switch control device 22 in the load-side next section # 3.
FIG. 20 shows a calling signal to the telephone and a response signal to the calling signal.
(A) and (b) are obtained.

As described above, the communication between the switch control devices 22 in the sections # 1 to # 3 and the switch control devices 22 in the load-side next sections # 2 to # 4 via the communication line 23, as described above. As a result, during the accidental power failure of the distribution line 13, the section switch 21 of the accident section # 2 is locked in the open state, and the accident section # 2 is automatically disconnected from the system upstream, as in the case of performing the conventional test power transmission. Since the healthy sections # 0 and # 1 are restored immediately upon the restoration of the distribution line 13 without repeated power failures, the grounded loop-type distribution line 13 supplied with power from the upstream side and the load side.
The accident section can be quickly separated by automatic classification without power failure.

The base stations such as the conventional power distribution system control center 10 shown in FIG. 21 are not required, and the communication lines from the distribution line 4 to the base station shown in FIG.
Can be quickly restored, and in this case, communication with the switch control device 22 in the adjacent section can be performed over a relatively short distance, so that communication power is significantly less than when communicating with the base station equipment. There is also an advantage that can be done.

The switch 23 is provided with a radio transmission / reception function by omitting the communication line 23.
The communication between the terminals may be wireless communication. In this case, the power of the wireless communication may be a small power of several kilowatts. For example, the wireless communication may be made extremely inexpensive and small by using a small transceiver modem of a specific low power wireless. Can be.

The communication line 23 may be omitted and communication may be performed by a distribution line transport system. In this case, the required communication power is significantly reduced as compared with the related art.

The present invention can be applied not only to a domestic distribution system but also to an overseas distribution system.

Note that the internal configuration and communication format of the switch control device 22 are not limited to those of the present embodiment.

The predetermined two phases may be other than the A and C phases, and it goes without saying that the present invention can be applied to a multi-phase system other than the three phases.

[0109] Incidentally, fault section # 2 from the load side of the sound interval # 3, the case of simultaneously recovering # 4, for example, DAT ₃ to DA shown in FIG. 18 (a) the calling signal on the load side following sections
By adding an area T ₅ performs a call switch controller 2
The information of the overcurrent in the section 2 and the information of the phase difference with the voltage are transmitted to the switch control device 22 in the load-side next section, and the control processing unit 34 of the switch control device 22 in the load-side next section,
It is determined whether or not the absolute value of the difference between the stored value of the phase difference of the own section of the memory 35 and the received stored value of the phase difference of the next upstream section is greater than 90 °. The section is determined to be an accident section, and the section switch 21 of the own section is determined.
Can be locked in the open state.

In this case, for example, steps S ₁₉ and S _{19 in} FIG.
Subsequent to ₂₆ , a step of the above-described discrimination and the opening control of the sectional switch 21 may be added.

Then, the sectional switches 21 of the accident section # 2 and the load-side next section # 3 are opened and locked, and the accident section #
2 When the upper and lower segmented switches 21 are open,
The sections # 0 and # 1 are restored by the power recovery from the upstream side of the distribution line 13, and the sections # 4 and # 3 are restored by the power recovery from the downstream side of the distribution line 13. The section recovers quickly with automatic classification.

Instead of adding the overcurrent information and the phase difference information to the call signal and transmitting it to the switch control device 22 in the next section on the load side, instead of determining the accident in the own section, While opening the sectional switch 21, the communication line 23 is opened.
An open command may be transmitted to the switch control device 22 in the load-side next section via the control unit, and based on this command, the sectional switch 21 in the load-side next section in the accident section may be locked in the open state.

[0113] In this case, for example, figure next fourth step S ₂₃ is provided the steps of transmitting an open command to the switch controller 22 on the load side next section, step S ₁₇ of FIG, S ₂₅ and step S _19, respectively between the S _26, the step of receiving is determined whether the opening command from the device on the upstream side next section,
It is sufficient to provide a step of executing the opening control of the sectional switch when this determination is the reception of the opening command.

[0114]

The present invention has the following effects. If a ground fault or short circuit occurs in any section of the distribution line 13 and the fault phase becomes an overcurrent, the switch control device 22 detects the occurrence of the overcurrent and outputs the information of the overcurrent of each phase and a predetermined 2
Information on the phase difference between the phase current of the overcurrent phase and a predetermined line voltage based on the line voltage of the phase is stored.

Then, during an accidental power outage of the distribution line 13, communication with the switch control device 22 in the adjacent section on the load side allows
Receives the information of the overcurrent in the adjacent section on the load side and the information of the phase difference, and stores the stored value of the phase difference in the own section of the same phase (overcurrent phase) and the stored value of the phase difference in the adjacent section on the load side The absolute value of the difference is calculated as follows. At this time, if an accident occurs in the own section, the absolute value of the difference becomes larger than 90 °.
It is possible to accurately determine whether or not the accident is in the own section.

Furthermore, in the case of a local section accident, before the distribution line 13 is restored, the section switch 21 of the own section is opened. By opening the switch 21, the faulty section can be automatically separated from the upstream side, and a healthy section upstream from the faulty section can be restored simultaneously with the restoration of the distribution line.

In this case, after an accidental power outage of the distribution line 13, the upstream healthy section can be quickly restored without performing test power transmission or the like performed in the conventional non-loop system, and the adjacent section on the load side can be restored. Since it only communicates with the switch control device 22, large-scale base station equipment for remote monitoring and control and its communication equipment are unnecessary.

[0118] Therefore, the conventional power transmission system does not perform a test power transmission or the like, does not include a large-scale base station facility for remote monitoring and control, and does not include a communication facility therefor. The automatic disconnection of the fault section of the distribution line 13 of the loop system in which the neutral point is grounded, which could not be performed, is realized, and this disconnection can quickly restore the upstream healthy section.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of one embodiment of the present invention.

FIG. 2 is a first flowchart for explaining the operation of FIG. 1;

3 (a), (b), and (c) are each a detailed flowchart of a part of FIG.

FIG. 4 is a second flowchart for explaining the operation of FIG. 1;

5 (a) to (q) are timing charts for explaining the operation when a ground fault occurs in a distribution line provided with the switch control device of FIG.

FIG. 6 is a system diagram showing a state in which a distribution line of a grounded loop system provided with the switch control device of FIG. 1 is energized.

FIG. 7 is a system diagram of the system of FIG. 6 at the time of an accident power failure.

FIG. 8 is an explanatory diagram of an accident section determination of the switch control device in the section # 1 of FIG. 7;

FIG. 9 is an explanatory diagram of an accident section determination of the switch control device in the section # 2 of FIG. 7;

10 is an explanatory diagram of an accident section determination of the switch control device in the section # 3 of FIG. 7;

11 is a system diagram for explaining separation of an accident section in FIG. 7;

FIG. 12 is a system diagram at the time of power restoration of FIG. 7;

13 (a) and (b) are explanatory diagrams of communication formats of a call signal and a response signal of the switch control device of FIG.

14 is an explanatory diagram of a configuration of each area of the communication format of FIG. 13;

15 is an explanatory diagram of a part of information content of both signals in FIG. 13;

16 is an explanatory diagram of another part of the information content of the call signal of FIG. 13;

17 is an explanatory diagram of another part of the information content of the response signal of FIG. 13;

18 (a) and (b) are explanatory diagrams of still another part of the configuration and information content of the response signal of FIG. 13.

19 (a) and (b) are explanatory diagrams of a call signal and a response signal of the switch control device in a section # 1 in FIG.

20 (a) and (b) are explanatory diagrams of a call signal and a response signal of the switch control device in a section # 2 of FIG.

FIG. 21 is a system diagram of a conventional non-loop system distribution line having base station equipment during energization.

22 is a system diagram of the conventional system of FIG. 21 at the time of an accident power failure.

FIG. 23 is a system diagram for explaining separation of an accident section of the conventional system of FIG. 21;

24 is a system diagram of the conventional system of FIG. 21 at the time of power restoration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 13 Distribution line 21 Division switch 22 Switch control device 31 Backup power supply 35 Memory 36 Current measurement circuit 37 Voltage measurement circuit 42 Communication modem

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // H02H 11/00 H02H 11/00 K

Claims (1)

[Claims] 1. A segment switch for dividing a distribution line of a loop system in which a neutral point is directly grounded or low-resistance ground, which is supplied with power from an upstream side and a load side, and a switch for controlling opening and closing of the segment switch. An automatic distribution line switchgear comprising a switchgear control device, wherein the switchgear control device includes: a backup power supply for forming an operation power supply during a power failure of the distribution line; Means for measuring current, and detecting the occurrence of overcurrent when any of the measurement results of the respective phase currents becomes larger than a set value due to a ground fault or short circuit accident, and storing information of overcurrent of each phase. Means for storing phase difference information between a predetermined two-phase line voltage of the distribution line before the occurrence of the accident and a phase current of an overcurrent generation phase when the occurrence of the overcurrent is detected. Based on the detection of the occurrence of the overcurrent, During the power outage of the distribution line, it communicates with the switch control device in the section adjacent to the load on the own section to receive the overcurrent information and the phase difference information in the section adjacent to the load. Means, when the absolute value of the difference between the stored value of the phase difference of the overcurrent generation phase in the own section and the stored value of the phase difference of the phase in the adjacent section on the load side is greater than 90 °. An automatic distribution line switchgear comprising: means for judging an own section accident; and means for opening the section switch before the distribution line is restored by the judgment of the own section accident.