JP3372054B2 - High-speed reclosable grounding device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-voltage power transmission line, in which a single line is formed by a reverse flashover generated between arc horns on a power transmission line. The present invention relates to a high-speed reclosable grounding device used to reclose a transmission line at a high speed when a ground fault occurs, particularly, in the other phase of the same line as the phase in which the ground fault occurred. Even if a trailing ground fault occurs with a time difference from the ground fault,
The present invention relates to a high-speed reclosable grounding device capable of retransmitting power by reclosing a circuit breaker. 2. Description of the Related Art When lightning strikes a transmission line, a reverse flashover occurs in an arc horn of a series of insulators suspended on the transmission line. Most of the accidents that occur in transmission lines are single-line ground faults caused by this reverse flashover. In order to eliminate the fault due to the ground fault, it is only necessary to set the fault section to no voltage and extinguish the reverse flashover which is the cause of the fault. Specifically, it is effective to cause the circuit breakers for the transmission line at both ends of the failed transmission line to perform the reclosing operation. The reclosing operation is to open the pole once, set the fault section to no voltage, extinguish the reverse flashover, and then turn it on again. By performing such a reclosing operation,
Retransmission can be performed without a power failure. As a typical method of reclosing, there is a single-phase reclosing method. This single-phase reclosing method is widely used because of its small power fluctuation and excellent transient stability. However, in recent years, with the increase in power demand, UHV transmission lines such as 1100 kV have been used as high-voltage transmission lines. When a single-phase reclosing is performed on this UHV transmission line, electrostatic electromagnetic induction received from another phase of the same line or another line that is paralleled is larger than in the case of the conventional 500 kV system. If such electromagnetic induction from other phases is large, the reverse flashover is extinguished when a reverse flashover of the arc horn occurs, even if the circuit breakers at both ends of the fault section are opened. It becomes difficult to do. Therefore, in a high-voltage transmission line such as a UHV system, a high-speed reclosing grounding device is installed in each phase of the high-voltage transmission line to extinguish the reverse flashover. In other words, after the location where the accident occurred is cut off from the transmission line by the circuit breakers at both ends, this high-speed reclosing grounding device is turned on at high speed in coordination with the opening and closing operation of the circuit breaker, so that the electromagnetic induction sustained by the insulator-connected arc horn can be maintained. Extinguishes the current arc,
In addition, the opening operation is immediately performed to cut off the induced current, thereby enabling the power transmission by re-closing the circuit breaker. [0004] A protection system employing this high-speed reclosing and grounding device will be specifically described with reference to the drawings. FIG. 3 is an explanatory diagram showing the configuration of this system. In the figure, 1 is a bushing and 3 is a UHV-type steel tower. Reference numeral 2 denotes a high-voltage transmission line, which has three lines of an upper phase, a middle phase, and a lower phase, and is stretched between the bushing 1 and the tower 3 or between the towers 3. Each tower 3 is provided with an insulator string 3b having an arc horn 3a.
Is suspended from the steel tower 3. A circuit breaker GCB and a high-speed reclosable grounding device HSES are provided at both ends of a certain section of the transmission line 2.
Is provided. In addition, 4 is a thundercloud and 5 is lightning. In this system, when a lightning strike 5 falls from a thundercloud 4 on a certain line of a three-line power transmission line 2, a reverse flashover 3 is applied to an arc horn 3a of an insulator string 3b suspending the transmission line 2.
c occurs, and this reverse flashover 3c
, A ground fault current flows to the tower 3 to cause a ground fault. The operation sequence of the circuit breaker GCB and the high-speed reclosing grounding device HSES when a one-line ground fault occurs due to the reverse flashover 3c will be described with reference to the operation sequence diagram of FIG. That is, before the occurrence of the ground fault, the circuit breaker GCB is in the closed state, and the high-speed reclosable grounding device HSES is in the open state. When a ground fault occurs in the transmission line 2, after the transmission line protection relay time T1 has elapsed, first, the circuit breaker GC
B performs the opening operation. However, an induced current flows through the accident transmission line 2 due to electrostatic electromagnetic induction from another phase, whereby the reverse flashover 3c is still maintained between the arc horns 3a. Therefore, with the circuit breaker GCB opened, the high-speed reclosable grounding device HSES is forcibly turned on at a high speed, and the induced current grounded at the arc horn 3a is guided to the high-speed reclosable grounding device HSES. This extinguishes the reverse flashover of the arc horn 3a. The high-speed reclosable grounding device continues the closed state for θ hours, extinguishes the reverse flashover, returns to the open state, cuts off the induced current, and finally the breaker performs the closing operation to restart power transmission. Next, a ground fault current and a current flowing through the high-speed reclosable grounding device HSES will be described with reference to FIG. As described above, the transmission line 2 has an upper phase, a middle phase, and a lower phase, and a predetermined load current flows in each phase. Assume that it has occurred. In the middle phase of the transmission line 2, T01 in the figure indicates the occurrence of a ground fault, T02 indicates the start of the opening operation of the circuit breaker GCB, and an accident current flows through the middle phase of the transmission line 2 only between T01 and T02. However, since the middle phase of the transmission line 2 receives electrostatic and electromagnetic induction from the upper and lower phases, which are other sound phases, and other parallel lines, the arc horn is opened when the circuit breaker is opened. In this case, the reverse flashover caused by the induced current is still occurring, and the high-speed reclosing grounding device is turned on to extinguish the reverse flashover. Then, as shown in FIG.
Thereafter, at first, the ground fault current containing the DC component and the electromagnetic induction current are superimposed, and a current shifted from the current zero point flows.After that, as the ground fault current is grounded, the electromagnetic induction current component increases, An alternating current passing through the current zero point flows. Therefore, when the induced current is cut off by the high-speed reclosing grounding device, the opening operation is performed by capturing the timing at which the current becomes zero. However, such an electromagnetically induced current is
As shown in FIG. 7, when the current is interrupted, as shown in FIG. 7, a transient recovery voltage in which the transient phenomenon of the electric circuit and the electrostatic induction voltage received from the other line by the faulty transmission line are superimposed as shown in FIG. Is applied. Such a relatively large current and the interruption of the transient recovery voltage condition of a relatively large rising rate and a high peak value are interrupted by a parallel-type grounding switch which merely opens and closes a rod-shaped contact in SF6 gas. A high-speed reclosable grounding device having a puffer-type arc-extinguishing chamber like a circuit breaker is required. FIG. 8 shows a specific configuration of a device conventionally known as a high-speed reclosing ground device as described above. This high-speed reclosable grounding device is housed in a grounding tank 19 filled with an insulating gas, and a conductor 11 connected to the transmission line side is provided at the center of the tank 19, and a fixed electrode 12 is partially provided on the conductor 11. Is provided. A movable electrode 13 is provided on a portion of the tank 19 facing the fixed electrode 12.
Are supported so as to be able to approach and separate from the fixed electrode 12.
The fixed electrode 12 is connected at its base to an operating device (not shown). A nozzle 14 for guiding an arc-extinguishing gas is provided concentrically with the movable electrode 13 on the tip side of the movable electrode 13. The nozzle 14 is fixed to a tip of a puffer cylinder 18 which is arranged concentrically on the outer periphery of the movable electrode 13. The base of the puffer cylinder 18 is connected to the operation device of the movable electrode 13 and reciprocates with the movable electrode 13 toward the fixed electrode. A space between the movable electrode 13 and the puffer cylinder 18 is a puffer chamber 16, and the tip side thereof communicates with the nozzle 14. A fixed puffer piston 17 is provided on the base end side of the puffer chamber 16 (the side opposite to the nozzle 14). The puffer piston 17 is slidably incorporated into the movable electrode 13 and the puffer cylinder 18. When the conventional high-speed reclosable grounding apparatus having such a configuration is brought into the open state as shown in FIG. 8, an operating device (not shown) is driven to move the movable electrode 13 and the puffer cylinder 18 to the tank. The movable electrode 13 is separated from the fixed electrode 12 by moving the fixed electrode 12 to the 19 side (downward in the figure). Then, the volume of the puffer chamber 16 between the moving puffer cylinder 18 and the fixed puffer piston 17 is reduced, and the insulating gas inside the puffer chamber 16 becomes the arc-extinguishing gas 21 and is blown out from the nozzle 14 to be fixed. The arc between the electrode 12 and the movable electrode 13 is extinguished. FIG. 9 shows the relationship between the stroke 20 of the movable electrode 13 and the puffer pressure ΔP in the puffer chamber 16 in this case. That is, the puffer pressure reaches the maximum value in a stroke approximately half of the opening stroke of the movable electrode 13, and the pressure decreases with the completion of the opening. [0010] By the way, at the time of current interruption by the above-mentioned high-speed reclosing grounding device, at the time T04 in another phase adjacent to the transmission line, for example, the upper phase in FIG. If a follow-up failure occurs with a large current component,
An induction current having a large DC current component generated by electromagnetic induction due to an upper-phase fault current flows through the medium-phase transmission line, and as shown in part A of FIG. A zero miss current that does not form a zero will flow. It is much more difficult to cut off this zero-miss current than to cut off the zero point of ordinary alternating current, and it exceeds the capability of the conventional high-speed reclosable grounding device. As a result, when the follow-up failure occurs exactly at the opening timing of the medium-phase high-speed reclosing grounding device, and when the follow-up failure current includes a large amount of DC current, reclosing is realized. Therefore, a severe problem occurs in the transmission of high-voltage power. [0011] This point will be specifically described below according to the operation of the high-speed reclosable grounding apparatus of FIG. First,
8, the insulating arc-extinguishing gas in the puffer cylinder 18 is generated between the fixed-side and movable-side contacts 12 and 13 until the movable-side contact 13 stops the opening operation. By spraying the arc, the arc is extinguished, the current is interrupted, and the voltage tolerance between poles after the current is processed. However, considering the transient recovery voltage performance at the time of opening required for the high-speed reclosing grounding device, the transient recovery voltage peak is obtained in a half cycle of the commercial frequency as shown in the waveform of FIG. The speed is equivalent to the speed of a circuit breaker, the time t from the start of opening of the electrode to the end of the stroke in FIG. 9 is short, and the actual gas flow blowing time when ΔP is a certain value or more is limited to about two cycles. is there. On the other hand, if a follow-up failure occurs in the adjacent phase as described above immediately after the opening operation of the high-speed reclosable grounding device and before the high-speed reclosable grounding device completes the current interruption, as shown in part A of FIG. A condition occurs in which an induced current (about several thousand A) that does not form a current zero point flows for about four cycles. In this case, the arc extinguishing mechanism of the alternating current makes it difficult to extinguish an arc that does not form a current zero point.Therefore, the high-speed reclosable grounding device that has received the follow-up failure induced current at this timing ends the opening operation until the end of the stroke. Even so, an arc is continuously formed between the poles. Then, even after the current zero returns to the restored arc current, the arc extinguishing state remains in the arc extinguishing state because the gas flow blowing time from the puffer chamber, which is about two cycles, has already elapsed. The present invention has been proposed in order to solve the above-mentioned problems of the prior art. The purpose of the present invention is to generate a back-to-back ground fault in another phase after a single-line ground fault occurs. However, even during the opening of the grounding device in the accident occurrence phase, the induction current in the accident occurrence phase can be reliably shut off, and the high-speed re-closing of the circuit breaker can be performed thereafter. An object of the present invention is to provide a closed-circuit grounding device. [0014] In order to achieve the above object, the present invention is provided in each phase of a high voltage transmission line connecting a circuit breaker, and an insulator link provided on the transmission line is provided. In response to a single-line ground fault caused by reverse flashover in the arc horn, the closing operation at the both ends of the transmission line is opened at a high speed, and the opening operation is performed after the reverse flashover is extinguished. A high-speed reclosable grounding device, a transmission line protection relay that detects that a back-to-back ground fault has occurred with a time difference from the ground fault in the other phase of the same circuit as the phase in which the ground fault has occurred, and The high-speed reclosable grounding device
During the opening operation after the opening command is output , when the transmission line protection relay detects the trailing ground fault, the closing operation is performed immediately after the opening operation is completed. And a control unit that issues an opening command immediately so that the grounding fault in the other phase is removed by the opening of the circuit breaker of the other phase and then the opening operation is performed. It is characterized by. In the present invention having the above configuration,
If a back-to-ground fault occurs in another phase of the same line where the influence of electrostatic electromagnetic induction is large within a certain time difference from the time when the opening command is issued to the high-speed
Thereafter, the ground fault detection protection relay of the phase in which the follow-up fault occurs generates a ground fault detection signal. On the basis of this detection signal, a closing command is issued to the high-speed reclosable grounding device in the ground fault occurrence phase during the opening operation, and the opening command is output to the high-speed reclosable grounding device.
During the opening / closing operation, the transmission line protection relay
Detects the back-to-ground fault, after the opening operation is completed.
Immediately issue a throw command so that the throw operation is performed continuously.
Emit. Subsequently, the high-speed reclosing grounding device performs the opening operation again, taking into account the timing at which the trailing fault of the other phase has been eliminated and the zero-point miss current has disappeared. To shut off. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the high-speed reclosing and grounding apparatus according to the present invention will be specifically described below with reference to FIGS. The same parts as those of the prior art shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. (1) Configuration of Embodiment FIG. 1A is a configuration diagram of a system including this embodiment.
As shown in FIG. 1A, the circuit breaker GCB is provided at both ends of the transmission line 2 of each phase constituting the same line as in the prior art.
And a high-speed reclosable grounding device HSES. The high-speed reclosable grounding device HSES of each phase is connected to its operation control unit 10, and this unit 10
It opens and closes on the basis of a closing command and an opening command from the controller, and extinguishes the arc of the reverse flashover 3c generated in the arc horn 3a and cuts off the induced current. The operation control unit 10 of the high-speed reclosable grounding device is connected to a transmission line protection relay Ry for detecting a ground fault in each phase. This protection relay Ry
Is to detect a ground fault in the phase in which it is provided, and send a detection signal to the operation control unit 10. Conventionally known detecting means can be appropriately used as the ground fault detecting means. In the present embodiment, a current transformer CT is provided in the vicinity of the circuit breaker GCB of each phase, and the current is transmitted by the current transformer CT. The ground fault is detected by monitoring the current of the electric wire 2. The structure of the operation control unit 10 is shown in FIG.
(B) is an enlarged view. The operation control unit 10 includes a high-speed reclosing grounding device HSE in the ground fault occurrence phase.
An input unit 10a for an S opening command and a detection unit 10b for detecting a trailing ground fault detection signal input from a protection relay Ry of another phase of the same line. After this, the detection unit 10b of the trailing ground fault detection signal sets the operation holding time to 1 as an example.
Timed timer that can be changed between 5 and 5 cycles
The timer 6 and the input unit 10 a for the opening command are connected to an AND circuit 7. The AND circuit 7 has two output units 8, a closing command and an opening command,
9 of which the output unit 9 of the opening command is an example.
The operation time after the time limit is between 1 cycle and 1 second
Via the post-timer operation timer 10c that can change the setting,
The operation control unit 10 is connected to a high speed reclosable grounding device outside the operation control unit 10. The opening command input unit 10a is directly connected to the opening command output unit 9 without going through the AND circuit 7 or the timed operation timer 10c. Here, the two output units 8 and 9 for the closing and opening of the operation control unit 10 are set to have a closing free function in which the closing command has priority. That is, during and immediately after the opening operation of the high-speed reclosable grounding device,
If a closing command is received before the previously issued opening command is restored (before the opening completion signal is returned to the operation control unit), the high-speed reclosable grounding device is turned on by the closing command. However, if it is left as it is, the high-speed reclosable grounding device once input is brought into a pumping state in which the opening is started again by the previously unopened opening command. In the present embodiment, in order to prevent this, priority is given to the closing command, so that the unreturned opening command is not accepted unless it is restored once,
The operation control unit 10 is configured. (2) Operation of the embodiment In this embodiment having the above-mentioned configuration, as shown in FIG. 2, when a single-line ground fault occurs in a certain phase, the transmission line 2 in that phase is cut off. The device GCB opens and cuts off the current.
Then, at a certain timing, the high-speed reclosable grounding device HSE
S is input to extinguish the reverse flashover 3c of the arc horn 3a. The high-speed reclosable grounding device
An opening command is issued after a lapse of a predetermined time θ ′. This opening command is input to the operation control unit 10 from the input unit 10a, and is output from the output unit 9 to the high-speed reclosing grounding device to start the opening operation, and at the same time, the operation of the time limit holding timer 6 is performed. A command to start holding time counting is given. In this state, especially if a trailing ground fault does not occur in another phase, the opening of the high-speed reclosable grounding device is successful, the induced current is cut off, and the circuit breaker GCB is subsequently turned on to re-establish the transmission line. A cycle is made. However, if a back-to-ground fault occurs in a phase other than the operating phase of the high-speed reclosable grounding device during opening, a zero-point miss current is generated due to the influence, and in the opening operation as described above, an induced current of the induced current is reduced. Blocking may not be possible.
Therefore, in the present embodiment, when a trailing ground fault accident of another phase is detected by the transmission line protection relay Ry , the ground fault detection command of the other phase is used to control the operation of the high-speed reclosable grounding device of the already operating phase. It is led to the unit 10. When the other-phase ground fault detection command is entered immediately after the opening of the high-speed reclosing grounding device, that is, within the operation holding time of the time limit holding timer 6,
The other-phase ground fault detection command is input to the AND circuit 7 via the time limit timer 6. Only when the AND condition between the other-phase ground fault detection command and the opening command already input to the operation control unit 10 is satisfied, the immediate closing command is output from the output section 8 of the high-speed reclosing circuit. It is sent to a grounding device. as a result,
As shown in FIG. 2, the high-speed reclosable grounding device that has been opened according to the opening command is immediately turned on again. The return of the closing command becomes a count start command for the time period θ in FIG. 2 to the post-time operation timer 10c, and after the elapse of the time period θ, the opening command is again issued to the high-speed reclose circuit grounding device. At this point, the back-to-ground fault accident of the other phase has already been eliminated by the action of the circuit breaker and the high-speed reclosing grounding device of the other phase, and for example, the zero-point miss current that continues for about four cycles has been eliminated. The induced current in the accident phase can be cut off by utilizing the current zero point by the arc-extinguishing gas flow from the puffer chamber for performing the following. As described above, according to the present invention, when a back-to-back ground fault occurs in another phase, a high-speed reclosing grounding device that has been opened once is immediately turned on to be fixed. After the time elapses, it is possible to reliably cut off the induced current that does not form a current zero point induced in the operating phase by electrostatic or electromagnetic induction due to a trailing ground fault accident of another phase. A high-speed reclosable grounding device capable of high-speed reclosing even in an accident can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram showing one embodiment of a high-speed reclosable grounding device according to the present invention, wherein (A) shows the entirety thereof, and (B) shows operation control of the high-speed reclosable grounding device. 3 shows a unit section. FIG. 2 is an operation sequence diagram in the embodiment of FIG. FIG. 3 is a system configuration diagram showing an example of a conventional high-speed reclosing ground device. FIG. 4 is an operation sequence diagram of a conventional high-speed reclosing ground device. FIG. 5 is a characteristic diagram showing a change in a current flowing in each phase of the high-speed reclosable grounding device. FIG. 6 is a waveform diagram showing characteristics of an electrostatic induction current and an electromagnetic induction current from another phase to an operation phase of the high-speed reclosable grounding device. FIG. 7 is a transient recovery voltage waveform diagram when the high-speed reclosable grounding device is opened. FIG. 8 is a cross-sectional view showing an open state of an electrode portion in a conventional puffer-type high-speed reclosable grounding device. FIG. 9 is a graph showing a relationship between a puffer chamber pressure and an operation stroke in the high-speed reclosing and closing circuit shown in FIG. 8; [Description of Signs] GCB: Circuit breaker HSES: High-speed reclosable grounding device CT: Current transformer Ry: Transmission line protection relay 1: Bushing 2: Transmission line 3: Steel tower 6: Time limit holding timer 7: AND circuit 8: Input command Output unit 9 Opening command output unit 10 Operation control unit 10a for high-speed reclosable grounding device Opening command input unit 10b Other phase trailing ground fault detection command input unit 10c Timed after hold timer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-199653 (JP, A) JP-A-55-92530 (JP, A) JP-A-61-139206 (JP, A) 51632 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01H 33/70-33/99 H02B 13 / 20,13 / 075 H02H 1/00-3/07 H02H 7/22 -7/30

Claims (1)

(57) [Claim 1] A single line is installed in each phase of a high-voltage transmission line connecting a circuit breaker, and a reverse flashover is performed on an arc horn of a series of insulators provided on the transmission line. For a ground fault, a high-speed reclosable grounding device that performs a closing operation at a high speed in a state in which circuit breakers at both ends of the transmission line are opened, and performs an opening operation after extinguishing the reverse flashover, A transmission line protection relay that detects that a back-to-back ground fault has occurred with a time difference from the ground fault in another phase of the same circuit as the phase in which the ground fault occurred, and an opening in the high-speed reclosable grounding device. Open after command is output
While the pole operation is being performed, when the power line protection relay detects the trailing ground fault, it immediately issues a closing command to immediately perform the closing operation immediately after the completion of the opening operation. ground fault in the other phase Te of the circuit breaker of the other phases
And a control unit for issuing an opening command so as to perform an opening operation after being removed by opening .