JPH071980B2 - Distribution line accident section detection and separation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention detects, in a high voltage distribution line, whether or not a ground fault accident is an accident in a protection section and causes a power failure in a sound section. The present invention relates to a device for separating an accident section from another sound section.

[Conventional technology]

In order to improve the reliability of power supply, conventionally, when an accident occurs in the distribution line, the division switches are sequentially turned on to automatically detect the faulty section, disconnect the faulty section, and then the sections after the faulty section. Employs a so-called DM method in which power is reversely transmitted to other healthy sections.

FIG. 5 is a block diagram of the power distribution system based on the DM method. The DM type distribution system is the breaker 1-1 to 1 of the substation SS.
-5, normally closed switch 2-1 to 2-8,3-1,4-1,5-1,5
-2, normally open section switch for reverse transportation 2-9,2-10,2-1
1, distribution line that is transmitted by the circuit breaker 1-1
It is composed of a, b, c, d, e, f, g, h, i, an accident detection device 9 and control devices 7-1 to 7-15 for detecting an accident section of each of the above-mentioned section switches.

Conventionally, for example, in the control method described in Japanese Patent Publication No. 57-43021, when an accident occurs in the distribution line d, the circuit breaker 1-1 of the substation SS is tripped by the accident detection signal and the circuit breaker 1-1. Wait for the reclosing of the switch, turn on the section switches 2-1 and 2-2 from the power supply side, and then the section switch 2-3.
Therefore, when the accident section is thrown in, the circuit breaker 1-1 trips again to determine the accident section d.

As a result, power supply reliability such as the range of accidental blackouts, reduction of time, and shortening of power supply can be achieved.

[Problems to be solved by the invention]

However, in the case of this conventional method, the circuit breaker 1-1
After the trip, the circuit breaker 1-1 was closed again to detect the faulty section, and the circuit was reclosed to transmit power only to the healthy section.
Power is transmitted from the distribution line 1-1 to the sections a, b, c, i on the power supply side of the accident section, and then the distribution lines 1-4, 1 on the sections e, f, g, h on the load side.
It was necessary to carry out reverse transfer accommodation from -5. In the above method, the stable supply of electric power is hindered also in the sections a, b, c, d, e, f, g, h, i other than the accident section d due to long-term blackouts.

In recent years, due to the progress of OA and FA, and the transition to an advanced information society, even a short power outage will have a great impact on society, and demand for higher quality and reliable power supply. Came to be. This request is not satisfied with the function and performance of the conventional DM system, which involves a short power outage of once or twice from the occurrence of an accident to the distribution of electricity in a healthy section, and the development of a new accident processing system is required. There is.

The present invention has been made in view of such social requirements, without causing a power failure in a sound section at the time of a ground fault,
The purpose is to quickly disconnect the accident area and eliminate the circuit breaker.

[Means for solving problems]

In order to achieve this object, the distribution line accident section detection and disconnection device of the present invention includes a distribution substation busbar, a distribution circuit breaker, an accident detection device, a classification switch, and a normally open classification for performing reverse transmission and transmission. In a power distribution system consisting of switches and electric wires connecting them, the ground fault direction detector provided at each of the division switch installation locations causes the ground fault occurrence location from the power supply side to the ground fault direction detector installation location. Detects whether it is the load side, detects the ground fault section by the logical operation of the ground fault occurrence direction signal detected by the local fault direction detector, and turns on the normally open section switch at a preset location, then, A slave station for issuing a command to open the section switch connected to the ground fault section is provided before the distribution breaker is cut off.

〔Example〕

Hereinafter, the present invention will be specifically described based on the embodiments shown in the drawings.

FIG. 4 is a block diagram showing a part of the configuration of a distribution line ground fault accident section detection system to which the present invention is applied. In the figure, 10A and 10B are substations of different systems, 20-1, ...
, 20-3 is a normally-closed switch that is normally turned on for power transmission from the substation 10A, and 20-4 is normally open, but power is transmitted from another substation 10B, that is, reverse transmission. It is a normally open switch that is switched on when flexible power transmission is required. Controllers 30-1 to 30-4, which have the function of controlling the opening and closing of the respective switches to each of the section switches 20-1 to 20-4 and automatically detecting and disconnecting the faulty section at the time of closing, overcurrent It is equipped with a detector, a ground fault direction relay, and a communication circuit with the master station 50.By monitoring the zero-phase current and zero-phase voltage of the distribution line at the installation point of the division switch, the location of the ground fault accident can be identified. The relay slave stations 40-1 to 40-4 having a function of detecting whether the power switch side or the load side is seen from the installation point of the division switch are provided, and the controllers 30-1 to 30-4 and the relay slave station 40 are provided. Each division switch 20-1 to 20-4 is turned on and off according to commands from -1 to 40-4. Communication between the master station 50 and each relay slave station 40-1 to 40-4,
They are connected by a transfer input cable 60, and the relay slave stations at adjacent division switch installation locations are connected by a ground fault section detection cable 70.

FIG. 3 shows a configuration example of the relay slave station 40 installed in each of the switch sections 20-1 to 20-4. A zero-phase current transformer ZCT, a zero-phase voltage detector ZPD, and an overcurrent detection current transformer CT for overcurrent lock are installed on the distribution line. It is input to the waveform shaping circuit 81, the zero-phase voltage detection / waveform shaping circuit 82, and the overcurrent detection / waveform shaping circuit 83. The output signals of these circuits 81, 82, 83 are output as digital signals for digital processing by the microcomputer. Each signal is input to the CPU 85 through the input / output interface 84. In CPU85,
Detects the level of zero-phase current and zero-phase voltage, and determines from the phase of the zero-phase current and the phase of zero-phase voltage whether the ground fault is on the power supply side or the load side for each section switch installation location. Then, this is output as a ground fault occurrence direction signal. Less than,
The power supply side and the load side of a certain section switch are called A and B, respectively.

In the present embodiment, as the place絡発raw direction signal, direction signal I _A that it is the A-side, the direction signal I _B that is a B-side, the direction signal that it is not A side O _A, direction signal O _B that is not a B-side 4 signals are output as energizing signals for each relay. Here, I _A , O _B , and I _B O _A are signals output under the same conditions, but the latter is set so that the operating level is lower than the former, and it is faster. The sensitivity is set to operate. In FIG. 3, reference numeral 86 is a ROM for storing the operation program of the CPU 85, 87 is an input / output interface, 88 and 89 are switch opening circuits and switch closing circuits incorporated in the controller 30, respectively. A switch opening signal and a switch closing signal are given via the interface 87. 90 is a ground fault section detection logic circuit, 91 is a rewritable ROM,
Non-volatile external memory that stores set values for operating levels such as zero-phase current and zero-phase voltage. 92 is communication with the master station via a pair of communication lines and normally open / closed category switching at ground fault. It is a communication circuit that outputs a device closing command signal. The ground fault section detection logic circuit 90 transmits and receives the ground fault direction signal of itself and the ground fault direction signal of the adjacent switch to detect the ground fault section, and outputs the ground fault section detection signal.

FIG. 1 shows a method of connecting a relay slave station having such a ground fault generation signal output function. Here, three section switches 20- connected to the second section of the distribution line
The connection of the relay circuit in 1-20-3 is shown. The relay slave stations are connected to each other by a pair of signal cables 70. Focusing on the connection of the second section, the section switch 20-1
B side signal, the A side signal of the division switch 20-2 and the A side signal of the division switch 20-3 are connected by a relay sequence circuit. In this circuit, P _Ai , P _Bi (i = 1,2,
3) shows DC constant current power supplies. The use of a DC constant current power source means that when installed on an actual distribution line,
The distance between the division switches ranges from 1 to 2 km. The signal transmission / reception over such a long distance is greatly affected by the resistance of the signal line, and a general constant-voltage power supply has a problem due to a voltage drop or the like. Therefore, in this embodiment, a constant current power supply is used so that a constant current is supplied even if the resistance of the signal line increases, so that signals can be reliably transmitted and received.

Now, when a ground fault occurs in the second section of the distribution line, as described in the block diagram of FIG. 3, in the relay slave station 40-1 of the division switch 20-1, the accident in the B direction occurs. As such, relay contacts I _B1 and O _A1 close. At the same time, with respect to the sectional switch 20-2, since it is an accident in the A direction, I _A2 and O _B2 are closed. Further, for the relay slave station of section switch 20-3, similarly I _A3 and O _B3 are closed. When the contacts I _B1 , I _A2 and I _A3 are closed, the trip relays T _B1 , T _A2 and T _A3 of each section switch are excited by the power sources of the constant current power supplies P _B1 , P _A2 and P _A3 , and the section switch 20
-1, 20-2 and 20-3 are opened. In this case, contact I
If any one of _B1 , I _A2 and I _A3 is closed, all of the trip relays T _B1 , T _A2 and T _A3 are excited, and the power supplies P _B1 , P _A2 and P _A3 are respectively the exciting currents of all the trip relays. Is set up to supply.

Generally, the power supplies P _Bi and P _Ai are set so that the exciting currents of the trip relays in the relay circuit in which the power supplies are inserted can be supplied all at once.

Next, assuming that a ground fault has occurred in the first section of the distribution line, in this case, it is the A side accident in the sectional switch 20-1, and the sectional switches 20-2 and 20-
Also in No. 3, it is an accident on the A side. Therefore, in the relay slave station of the division switch 20-1, the relay contacts I _A1 and O
_B1 is closed, I _A2 and O _B2 are closed for the division switch 20-2, and I _A3 and O _B3 are closed for the relay slave station of the division switch 20-3. At this time, as described above, the O contact has higher sensitivity than the I contact and is set to operate faster, so that the contact O _B1 is closed before the contacts I _A2 and I _A3 are closed. It will be. Therefore, even if the contacts I _A2 and I _A3 are subsequently closed, the power supply circuit of the relay circuit is short-circuited, and therefore the trip relays T _B1 , T _A2 and T _A3 are not excited. Therefore, the section switches 20-2 and 20-
3 will not be released. On the other hand, the division switch 20-1
With respect to, the contact I _A1 is opened by closing. In this way, only the division switch connected to the section where the ground fault occurred is opened, and the other sections,
That is, it does not affect the sound section.

The above operation is expressed as a logical expression as follows.

Becomes

Another feature of the present invention is to achieve uninterruption in a healthy section by reverse transmission power transmission prior to disconnection of an accident section. In the explanation of FIG. 1, when a ground fault occurs in the second section, the section switches 20-1, 20-2 and 20-3 are opened, and power transmission from the power supply side is stopped in the third section. However, in the third section and the fourth section on the B side of the section switch 20-3, flexible power transmission from another distribution system is performed prior to disconnection of the faulty section.

As shown in FIG. 2, the relay slave station of the section switch 20-1 has a relay slave station of the normally open section switches 21-1 and 21-2 when a ground fault occurs in the second section. , Communication line 60
It is set so as to transmit a closing command signal through (see FIG. 4). As a result, the normally open section switch 21-1 and
21-2 turns on and performs reverse interchange power transmission to the third and fourth sections. Then, as described above, the section switch 20-1,
Open 20-2 and 20-3 and disconnect the second section. Generally, when a ground fault occurs, the circuit breaker of that system will shut off. However, by turning on the normally open segment switch and disconnecting the fault zone within the circuit breaker shutoff time, for example, within 1 second. , It is possible to disconnect the accident section without breaking the circuit breaker.

Therefore, even if a ground fault occurs, continuous power distribution can be performed without causing a power failure in a healthy section.

According to statistics, 80 to 90% of power outages are ground faults,
Since there are few ground fault accidents, by taking uninterruptible measures against ground fault accidents as in the present invention, it is possible to eliminate power outages in most healthy sections for accidents.

〔The invention's effect〕

As described above, in the present invention, the ground fault occurrence direction is detected by the local fault direction detector provided at each section switch installation location, and the ground fault section is calculated by the logical operation of the detected ground fault occurrence direction signal. Is detected and the normally open section switch at a preset location is turned on, and then the section switch connected to the ground fault section is opened before the distribution breaker reaches the interruption. It has a slave station that issues commands. Therefore, when a ground fault occurs, it is possible to immediately detect the accident section, perform reverse transmission and transmission to a healthy section other than the accident section, and then separate the accident section. Since this processing is performed before the circuit breaker of the substation is shut off, there is no power failure in the healthy section. Therefore, as in the conventional method,
The quality of the power supply can be improved without two blackouts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing a configuration example of a relay device of the present invention, and FIG.
The figure is a block diagram of a power distribution system incorporating the relay device of the present invention,
FIG. 3 is a block diagram of a configuration example of a slave station, FIG. 4 is a block diagram showing a part of the configuration of a distribution line accident section detection system to which the present invention is applied, and FIG. 5 is a conventional DM type distribution system. It is a block diagram of. 10A, 10B: Substation 20-1 to 20-3: Division switch 20-4: Normally open division switch 30-1 to 30-4: Ground fault direction relay 40-1 to 40-4: Relay slave station 50 : Master station 60: Ground fault section detection cable 81: Zero-phase current detection / waveform shaping circuit 82: Zero-phase voltage detection / waveform shaping circuit 83: Overcurrent detection / waveform shaping circuit 84,87: Input / output interface 85: CPU 86: ROM 88: Switch open circuit 89: Switch closing circuit 90: Ground fault detection logic circuit 91: ROM

Front page continuation (72) Hideto Kawazoe, No. 1 Oitakitamachi, Saga City, Saga Prefecture, Toga Denki Seisakusho Co., Ltd. (72) No. 1 Oitakitamachi, Saga City, Saga City, Raga Togami Denki Seisakusho

Claims (1)

[Claims] 1. A distribution system comprising a distribution substation busbar, a distribution circuit breaker, an accident detection device, a section switch, a normally open section switch for performing reverse transmission and transmission, and an electric wire connecting them to each other, The ground fault direction detector provided at each section switch installation location detects whether the ground fault occurrence location is the power supply side or the load side with respect to the ground fault direction detector installation location, and is detected by the local fault direction detector. The ground fault section is detected by a logical operation of the ground fault occurrence direction signal and the normally open section switch at a preset location is closed, and thereafter, before the distribution breaker reaches the break, the ground fault is detected. A distribution line fault section detecting and disconnecting device, which is provided with a slave station that issues a command to open a section switch connected to a fault section.