JP3086955B2 - Method and apparatus for minimizing electrode interruption in power system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a method and a device for minimizing a blackout electrode in a power system, and more particularly to a method for shortening a blackout time at the time of restoration when a resilient accident such as a ground fault occurs in a distribution line connecting a substation and a load. The present invention relates to a method and an apparatus for minimizing electrode interruption in a suitable power system.

[0002]

[Prior art]

Conventionally, when a ground fault or short circuit accident occurs on the distribution line connecting a substation and a load, a "segment switch for automatic detection of fault sections" (Showa 63 As described in “Electrical Engineering Handbook”, p. 1264, published by the Institute of Electrical Engineers of Japan in February, a time-sequential transmission power application method is adopted. According to this method, after all the segment switches have been opened due to the occurrence of an accident, each of the segment switches is automatically turned on again sequentially at preset time intervals,
At the time of re-input, if an accident is detected again by the protective relay installed at the distribution line outlet of the substation, the circuit breaker at the distribution line outlet shall be opened immediately and immediately before this circuit breaker is opened. It is possible to detect the section switch that has been turned on, and to determine in which section the accident has occurred from the detection result.

[0003]

[Problems to be solved by the invention]

However, in the above-mentioned prior art, sufficient consideration is not given to a recovery accident occurring in a distribution line, and there is a problem that it takes a long time to restore all sections of the distribution line. That is, according to the conventional timed sequential transmission charging method,
It takes (number of switches with timed forward function) x (forwarding time) time to complete the power distribution to the end of the distribution line, and the power outage time increases as the accident occurs at the end. become longer. For this reason, in order to shorten the power failure time, the number of switches provided with the timed sequential forwarding function must be limited, and even if the number of switches is restricted, the protection section (power failure section) becomes long.

[0004] An object of the present invention is to provide a method and apparatus for minimizing a blackout in a power system, which can shorten the recovery time of a recoverable accident.

[0005]

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides, as a first method, dividing a distribution line connecting a power supply and a load into a plurality of monitoring sections, and providing a section opening / closing means for opening and closing the distribution line in each monitoring section, In a power system in which main switching means is provided at the power supply side end of the distribution line, the occurrence and direction of an accident are monitored from the amount of electricity in the distribution line in each monitoring section, and the main switching means is opened due to the distribution line accident. Sometimes, only on the condition that the power supply is cut off with the opening of the main opening / closing means and an accident occurs on the load side from the self monitoring section, only the section opening / closing means of the monitoring section is opened, After that, when the main opening / closing means is turned on again, only the segmented opening / closing means in the open state is sequentially turned on again, and a method for reducing the number of electrode interruptions in the power system is adopted.

[0006] As a second method, a distribution line connecting a power supply and a load is divided into a plurality of monitoring sections, and divided monitoring means for opening and closing the distribution line in each monitoring section are provided. In the power system provided with the means, when the main switching means is opened due to an accident in the distribution line in each monitoring section, the supply of power is cut off with the opening of the main switching means and the monitoring section of the self Only on the condition that the occurrence of an accident is detected based on the amount of electricity, only the section opening / closing means of the monitoring section is opened, and then when the main opening / closing means is turned on again, only the section opening / closing means in the open state are sequentially restarted. The method employs a method for reducing the number of electrode stops in a power system, which is characterized by being turned on.

As a first device, a distribution line connecting a power supply and a load is divided into a plurality of monitoring sections, and a section opening / closing means for opening and closing the distribution line in each monitoring section is provided. In an electric power system provided with a means, an accident detecting means for detecting the occurrence of an accident from the amount of electricity in the distribution line, and detecting that the direction of occurrence of the accident is on the load side of its own monitoring section from the amount of electricity in the distribution line. Direction detection means, power interruption detection means for detecting that power supply has been interrupted, and opening for opening the sectional switching means on condition that each detection output of the accident detection means, the direction detection means, and the power interruption detection means is generated. And a re-opening means for re-opening in a specified order the divided opening-and-closing means which are in an open state when the main opening-and-closing means is turned on again in each monitoring section. This constitutes a minimizing device.

As a second device, a distribution line connecting a power supply and a load is divided into a plurality of monitoring sections, and a section opening / closing means for opening and closing the distribution line in each monitoring section is provided. In an electric power system provided with means, an accident detecting means for detecting occurrence of an accident from the amount of electricity in a distribution line, an electric power interruption detecting means for detecting an interruption of power supply, an accident detecting means, and an electric power interruption detection Open means for opening the section opening / closing means on condition that each detection output of the means is generated, and re-opening means for re-entering the section opening / closing means in the open state when the main opening / closing means is turned on again in a specified order. Each of the monitoring sections is provided with a device for minimizing a blackout electrode in a power system, which is provided in each monitoring section.

According to the above-described means, the occurrence and direction of an accident are monitored from the amount of electricity in the distribution line in each monitoring section, and a recovery accident occurs in the distribution line, the main opening means is opened, and power is supplied. Is shut off, the section opening / closing means of only the monitoring section that has detected that an accident has occurred on the load side of its own monitoring section is opened, and the section opening / closing means of the other monitoring sections are maintained in a closed state. After that, when the main opening means is turned on again, only the section opening / closing means in the open state are turned on again sequentially. That is, the power distribution state of the entire distribution line can be set by simply re-entering only the section switching means in the monitoring section where the occurrence of the accident is detected, and the restoration time can be reduced.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, a power distribution transformer installed in a substation
A 6.6KV high-voltage distribution line BUS is connected to the output side of the TR, and distribution lines L1, L2, ... Ln for guiding power from the substation to the load are drawn out from the distribution line BUS. It is connected via a mouth switch (main switch) CB. The switching state of each switch CB is controlled by a current transformer CT and a ground fault protection relay RY, and the distribution lines L1 to Ln between the switch CB outlet side and the load are each monitored by a plurality of switches. It is divided into sections. For example, distribution line L1 has seven monitoring sections
It is divided into S1 to S7. In each of the monitoring sections S1 to S7, sorting devices D1 to D6 are provided. Each of the sorting devices D1 to D6 has a sorting switch (segment switching means) for opening and closing the distribution line L1.
A DM, a current transformer FCT for detecting the amount of electricity in the distribution line L1, and a voltage transformer PT are provided, and the open / close state of the segment switch DM is controlled from the outputs of the current transformer FCT and the voltage transformer PT. A controller CONT is provided.

As shown in FIG. 2, the dividing devices D1 to D6 include a voltage transformer PD, a zero-phase current transformer ZCT, a segment switch DM, a control power transformer Tr, a rectifier REC, It comprises a controller CONT, an auxiliary relay CX, a relay contact CX-a, and the like.

[0013] The segmented switch DM includes distribution lines A1, A2,
It is inserted in the line of A3 and distribution lines B1, B2, B3, and the main contact
11a, 11b, 11c, a closing coil CC, and an auxiliary contact 12. The closing coil CC is connected to the relay contact CX-a, and the auxiliary contact 12 is connected to the controller CONT.
When the relay contact CX-a is closed and the exciting coil C is excited, the main contacts 11a, 11b and 11c are connected to the distribution lines A1 and A1, respectively.
A2, A3 are connected to distribution lines B1, B2, B3.
That is, the section switch DM is turned on by the excitation of the closing coil CC, and when the section switch DM is turned on, the auxiliary contact 12 is closed, and information on the turned-on state is sent to the controller CONT. It has become. on the other hand,
When the relay contact CX-a is opened, the closing coil CC
Are de-energized, the main contacts 11a, 11b, 11c are opened, and the sectional switch DM is opened.

The distribution lines A1, A2, A3 are provided with a voltage transformer PD constituted by capacitors C1, C2, C3, C4 and a zero-phase current transformer ZCT. Voltage transformer PD is distribution line L
The zero-phase voltage is detected as the quantity of electricity in 1 and this zero-phase voltage Vo is output to the controller CONT.
The zero-phase current transformer ZCT is the zero-phase current Io as the quantity of electricity in the distribution line L1.
Is detected, and the detected zero-phase current Io is output to the controller CONT. Further, a control power transformer Tr is connected to the distribution lines A1 and A3.
Converts the voltage of 6.6kv to 100v and converts the converted voltage to rectifier R
Supply to EC. The output of the rectifier REC is supplied to the controller CONT and the relay contact CX-a.

The controller CONT receives supply of power from the rectifier REC, inputs a signal regarding the open / closed state of the segmented switch DM from the auxiliary contact 12, and inputs a zero-phase current Io and a zero-phase voltage Vo as the quantity of electricity of the distribution line L1. Auxiliary relay based on these input signals
It controls the operation of CX. When controlling the operation of the auxiliary relay CX, the controller CO
NT is a fault detection circuit that detects that a ground fault has occurred in the distribution line L1 when the zero-phase current Io is equal to or greater than the set value, and a ground fault is detected based on the phase of the zero-phase current Io and the zero-phase voltage Vo. A direction detection circuit that detects that the direction of occurrence of the accident is on the load side from the self-monitoring section, a power cutoff detection circuit that detects that no voltage is supplied from the rectifier REC, and that there is no voltage,
A memory that stores the output of the accident detection circuit as nonvolatile accident history data, an open command circuit that generates an open command signal on condition that each detection output of the accident detection circuit, the direction detection circuit, and the power cutoff detection circuit is generated; When the switch CB is turned on again after the occurrence of the recovery accident, the switch CB is provided with a restart command circuit that outputs a restart command in accordance with the timed sequential transmission power application method. That is, the controller CONT is a zero-phase current transformer ZCT
And the voltage transformer PD together with the fault detection means and the direction detection means, together with the control power transformer Tr and the rectifier REC to form the power cut-off detection means. The opening means and the recharging means are constituted together with the CC.

In the above configuration, in the monitoring section S3, when a ground fault, which is a recoverable accident (accident that the accident is restored to a normal state in a short time) due to contact with a tree or the like, occurs, the sorting device D1,
D2 detects the zero-sequence current Io and zero-sequence voltage Vo.
CB is tripped by relay RY. At this time, only in the sorting devices D1 and D2, it is detected that the ground fault is on the load side of its own monitoring section. Then, when the power supply is cut off due to the trip of the switch CB and the output of the rectifier REC decreases, the section switch DM of the sorting devices D1 and D2 is opened. At this time, in the sorting devices D3 to D6, the zero-phase current Io
And the zero-phase voltage Vo cannot be detected, and the segmented switch DM of these devices is kept closed.

After that, when the switch CB is turned on again after a predetermined time, the power is sequentially supplied to the sorting devices D1 and D2. At this time, since the data indicating the occurrence of the accident is stored as the accident history data in the memories of the sorting devices D1 and D2, the sorting devices D1 and D2
Are switched on again in the specified order according to the time-sequential power transmission system. At this time, the sorting switches of sorting devices D3 to D6
Since the DM is maintained in the closed state, the entire distribution line L1 can be restored to the charged state only by re-entering the sectional switches DM of the sorting devices D1 and D2, and the restoration time can be greatly reduced. Can be.

Further, the controller CONT is provided with an open command circuit for outputting an open command to the sectional switch DM based on a detection output of the power cutoff detection circuit, and when the switch CB is turned on again,
Prior to this re-switching, the segmented switch DM is re-switched in the time-sequential transmission application method on condition that a detection output is generated from the accident detection circuit and the direction detection circuit.
It is also possible to provide a re-entry command circuit for instantly re-entering the sectional switch DM in accordance with the re-entry of CB.

In this case, if a ground fault occurs in the monitoring section S3, when the switch CB is turned on again, the segment switches DM of the segmenting devices D1 and D2 are sequentially restarted by the time-sequential transmission power application method. Is turned on, and the sorting switches DM of the sorting devices D3 to D6 are instantly turned on again. Therefore, even in the case of this method, the entire distribution line L1 can be restored to the charged state only by the time required for re-entering the segment switch DM of the segmenting devices D1 and D2, and the restoration time is shortened. be able to.

In the above-described embodiment, the case where the direction of occurrence of an accident is detected from the zero-phase current Io and the zero-phase voltage Vo has been described. However, a line current detector that detects a line current and a line voltage are detected in each distribution line. Provide a line voltage detector or phase voltage detector to detect that an accident has occurred when the line current exceeds the set value, and when the line voltage or phase voltage falls below the set value, Even when the occurrence of an accident is detected, the same effect as in the above embodiment can be obtained.

In this case, as a first method, the controller CONT
An open command circuit that outputs an open command to the segment switch DM is provided on condition that each detection output of the accident detection circuit and the power cutoff detection circuit is generated, and a segment switch that is open when the switch CB is turned on again A re-instruction circuit is provided for instructing the re-application of the device DM in accordance with the time-sequential transmission power application method.

As a second method, when an open command circuit for instructing the controller CONT to open the segmented switch DM by the detection output of the power cutoff detection circuit, and when the switch CB is turned on again,
Prior to this re-input, a command is issued to the segmented switch DM in accordance with the time-sequential power transmission method on condition that a detection output is generated from the accident detection circuit.
A method is conceivable in which a re-entry command circuit for outputting a re-entry command for instantly re-entering the sectional switch DM in accordance with the re-entry of the CB is considered.

In the above-described embodiment, only the ground fault accident has been described as a recoverable accident. However, even in the case of a short circuit accident, the above embodiment can be applied to a recoverable accident. That is, in the case of a short-circuit fault, the short-circuit current flowing at the fault point is determined by the distribution line impedance. Therefore, it is possible to cope by setting the magnitude of the short-circuit current detected by each of the sorting devices D1 to D6 in each of the sorting devices D1 to D6.

Further, if the method according to the embodiment is adopted, not only the recovery fault in the distribution line, but also the primary side of the distribution transformer TR and the transmission system, the distribution lines L1 to Ln will be out of power, and after this power outage, Even when each of the distribution lines L1 to Ln is in the restoration state, each of the distribution lines L1 to Ln can be restored in a short time, which can contribute to shortening the restoration time.

As described above, according to the present embodiment, only the segment switches DM of the segmenting devices D1 and D2 need to be turned on again by the time-sequential transmission application method, and the other segment switches DM are kept in the closed state. In this case, or the power is turned on instantaneously, as shown in FIG. 3, the recovery time can be greatly reduced as compared with the conventional system employing only the time-sequential transmission power application system.

[0026]

【The invention's effect】

As described above, according to the present invention, when a recoverable accident occurs in a distribution line, only the sectional opening / closing means located on the load side from the accident point or the sectional opening / closing means in the monitoring section where the accident is detected are set to the open state. Since the other section opening / closing means are kept in a closed state, and only the section opening / closing means in the open state are sequentially re-opened when the main opening / closing means is re-input, the recovery time can be reduced.

[0027]

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention.

FIG. 2 is a specific configuration diagram of a sorting device.

FIG. 3 is a diagram for explaining a difference in restoration time between the present invention and a conventional example.

[Explanation of symbols]

 TR …… Distribution transformer, CB …… Switch for distribution line outlet, L1, L2 ‥ Ln …… Distribution line, S1, S2 ‥ S7 …… Monitoring section, D1, D2 ‥ D6 …… Segmentation device, DM… … Segment switch, ZCT… Zero phase current transformer, PD… Voltage transformer, CONT… Controller, CX …… Auxiliary relay.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02H 7/26 H02H 3/06

Claims (4)

(57) [Claims] 1. A distribution line connecting a power supply and a load is divided into a plurality of monitoring sections, a section switching means for opening and closing the distribution line is provided in each monitoring section, and a main switching means is provided at a power supply side end of the distribution line. In an electric power system, the occurrence and direction of an accident is monitored from the amount of electricity in the distribution line in each monitoring section, and when the main switching device is opened due to the distribution line accident, the power Only on the condition that the supply of power has been cut off and an accident has occurred on the load side of the self-monitoring section. A method for minimizing electrode interruption in a power system, characterized in that only the divided switching means in the state are sequentially turned on again. 2. A distribution line connecting a power source and a load is divided into a plurality of monitoring sections, a section switching means for opening and closing the distribution line is provided in each monitoring section, and a main switching means is provided at a power supply side end of the distribution line. In a power system, when the main switching means is opened due to an accident in the distribution line in each monitoring section, power supply is cut off with the opening of the main switching means and the amount of electricity in its own monitoring section Under the condition that the occurrence of an accident is detected, only the section opening / closing means of the monitoring section is opened, and then, when the main opening / closing means is turned on again, only the section opening / closing means in the open state is sequentially turned on again. Characteristic method for minimizing electrode interruption in power system. 3. A distribution line connecting a power supply and a load is divided into a plurality of monitoring sections, a section switching means for opening and closing the distribution line is provided in each monitoring section, and a main switching means is provided at a power supply side end of the distribution line. In an electric power system, accident detection means for detecting the occurrence of an accident from the amount of electricity in the distribution line, and direction detection means for detecting that the direction of occurrence of the accident from the amount of electricity in the distribution line is closer to the load than its own monitoring section Power cutoff detecting means for detecting that power supply has been cut off, opening means for opening the divisional opening / closing means on condition that each detection output of the accident detection means, direction detection means and power cutoff detection means is generated; An apparatus for minimizing electrode interruption in an electric power system, comprising: a re-input means for re-inputting, in a designated order, a divided open / close means which is in an open state when the open / close means is input again. 4. A distribution line connecting a power supply and a load is divided into a plurality of monitoring sections, a section switching means for opening and closing the distribution line is provided in each monitoring section, and a main switching means is provided at a power supply side end of the distribution line. In an electric power system, accident detection means for detecting the occurrence of an accident from the amount of electricity in a distribution line, power interruption detection means for detecting that power supply has been interrupted, and detection of each of the accident detection means and the power interruption detection means Opening means for opening the section opening / closing means on condition that an output is generated, and re-opening means for re-entering the section opening / closing means in the open state when the main opening / closing means is re-input in a specified order, respectively, in each monitoring section. An apparatus for minimizing electrode interruption in a power system, the apparatus comprising: