JP3432236B2 - 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, power transmission can be performed again 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, as power demand has increased, 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 becomes 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. The current arc is extinguished, and 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 the high-speed reclosable grounding switch will be specifically described below with reference to the drawings.
FIG. 3 is an explanatory diagram showing the configuration of this system. In the figure, 11 is a bushing and 13 is a UHV-type steel tower. Reference numeral 12 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 11 and the tower 13 or between the towers 13. Each tower 13 has
An insulator series 13b having an arc horn 13a is provided,
The transmission line 12 is suspended from the tower 13 by the insulator string 13b. At both ends of a fixed section of the transmission line 12, a circuit breaker (GCB) and a high-speed reclosable grounding device (HSES) are provided. In addition, 14 is a thundercloud and 15 is lightning. In this system, when lightning 15 falls from a thundercloud 14 on one of the three transmission lines 12, a reverse flashover 13c occurs between the arc horns 13a of the insulator string 13b suspending the transmission line 12. Then, a ground fault current flows from the transmission line 12 to the steel tower 13 through the reverse flashover 13c, and a ground fault occurs. [0005] 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 13c 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 in the transmission line 12 occurs, after time T ₁ elapses is power transmission line protection relay time, first circuit breaker (GCB) performs opening operation. However, an induced current flows through the accident transmission line 12 due to electrostatic electromagnetic induction from another phase, whereby the reverse flashover 13c is still maintained between the arc horns 13a. Therefore, with the circuit breaker (GCB) opened, the closing operation of the high-speed reclosable grounding device (HSES) is forcibly performed at a high speed, and the induction current grounded at the arc horn 13a is reduced by the high-speed reclosable grounding device. By guiding to the (HSES) side, the reverse flashover of the arc horn 13a is extinguished. The high-speed reclosable grounding device (HSES) continues to be turned on for θ hours, extinguishes the reverse flashover, returns to the open state, cuts off the induced current, and finally turns off the circuit breaker (GCB).
Performs a power-on operation and restarts power transmission. By the way, as shown in FIG.
Has an upper phase, a middle phase, and a lower phase, and a predetermined load current flows in each phase. However, a ground fault occurs in the middle phase of the power transmission line 12 as shown in FIG. Assuming that the reclosing operation is performed in such an operation sequence, the transmission line 1
The current flowing in each phase of No. 2 is as shown in the current change diagram of FIG. That is, as shown in FIG. 5, in the middle phase of the transmission line 12, a ground fault occurrence time T _01, the circuit breaker (GC
Fault current flows only during the opening operation start T ₀₂ of B). However, the middle phase of the transmission line 12 receives electrostatic and electromagnetic induction from other sound phases, that is, the upper phase and the lower phase, and other lines that are bridged. Therefore, in a state where the circuit breaker (GCB) is opened, a reverse flashover caused by the induced current still occurs in the middle-phase arc horn of the transmission line 12, and the arc of the reverse flashover is extinguished. , to introduce high-speed reclosing ground device (HSES) (turned on at the time T _03). Then, the high-speed reclosing grounding device, as shown in FIG. 5, the - on T ₀₃ later, was initially displaced than the included ground fault current and the electromagnetic induction current and is superimposed current zero point of the direct current component As the current flows, as the ground fault current is grounded, the electromagnetic induction current component increases, and an alternating current passing through the current zero point flows. Therefore, when such an induced current is cut off by the high-speed reclosing grounding device (HSES), the opening operation is performed by capturing the timing at which the current becomes zero. However, as described above, in order to extinguish the reverse flashover, when the closing operation of the high-speed reclosable grounding device (HSES) is performed with the circuit breaker (GCB) opened, The electromagnetic induction current flowing through the reclosing grounding device (HSES) reaches 2000 A as shown in FIG. At the time of such a large current interruption, FIG.
As shown in (2), a transient recovery voltage is applied in which a transient phenomenon of the electric circuit and an electrostatic induction voltage received by the failed transmission line from another line are superimposed. Such a relatively large current, a relatively large rate of rise, and interruption of the transient recovery voltage condition with a high peak value can be achieved by a side-by-side grounding device that merely opens and closes a rod-shaped contact in SF ₆ gas. A high-speed reclosable grounding device (HSES), which cannot be interrupted and has a puffer-type arc-extinguishing chamber like a circuit breaker, is required. FIG. 8 shows an example of a high-speed reclosable grounding device (HSES) as described above. In this figure, a conductor 16 connected to a power transmission line is accommodated in a central portion in the grounding tank 23, and a fixed contact 17 is provided so as to branch off from a part thereof. Fixed contact 1 in ground tank 23
The movable contact 18 is fixed to the fixed contact 1
7 is provided so as to be able to come and go. This movable contact 18
Is connected at its base to an operating device (not shown). A nozzle 19 for guiding the arc-extinguishing gas is provided concentrically with the movable contact 18 on the outer periphery on the tip side of the movable contact 18.
Is provided. The nozzle 19 is provided with a movable contact 18
Is fixed to the tip of a puffer cylinder 22 which is arranged concentrically with the movable contact 18 on the outer periphery of. The base of the puffer cylinder 22 is connected to the operating device of the movable contact 18 and is configured to reciprocate with the movable contact 18 toward the fixed contact. A puffer chamber 20 is formed between the movable contact 18 and the puffer cylinder 22, and the tip side thereof communicates with the nozzle 19. A fixed puffer piston 21 is provided on the base end side (the side opposite to the nozzle 19) of the puffer chamber 20. The puffer piston 21 is slidably assembled with the movable contact 18 and the puffer cylinder 22. The operation of the high-speed reclosable grounding apparatus having such a configuration is as follows. That is, at the time of the opening operation, an operating device (not shown) is driven to move the movable contact 18 and the puffer cylinder 22 toward the ground tank 23 (downward in the figure), and the fixed contact 17 and the movable contact 18 are opened. Let go. Then, the volume of the puffer chamber 20 between the moving puffer cylinder 22 and the fixed puffer piston 21 is reduced, and the insulating gas inside the puffer chamber 20 becomes the arc-extinguishing gas 24 and is blown out from the nozzle 19 to be fixed. The arc between the contact 17 and the movable contact 18 is extinguished. The relationship between the stroke of the movable contact 18 and the puffer pressure ΔP in the puffer chamber 20 in this case is as shown in FIG. That is, the opening stroke 2 of the movable contact 18
In almost half the stroke of 5, the puffer pressure reaches the maximum value, and the pressure decreases with the completion of the opening. As described above, when a ground fault occurs in one phase of a transmission line and current is interrupted by a high-speed reclosing grounding device, as described above, furthermore, the adjacent line of the transmission line When a follow-up failure having a large DC current component occurs in another phase, a problem arises in that a zero-miss current flows through the high-speed reclosable grounding device in the preceding ground fault accident occurrence phase. That is, for example, as shown in FIG. 5, a ground fault occurs in the middle phase of the transmission line, and the upper phase adjacent to the middle phase has a time difference of time T _04.
In this case, a ground fault (back-up fault) occurs at the same time, the timing of the back-up fault overlaps with the opening timing of the medium-phase high-speed reclosable grounding device (HSES), and the follow-up fault fault current has a large DC current component. In the medium-phase transmission line, an induced current having a large DC current component generated by electromagnetic induction due to the upper-phase fault current flows, and as shown in part A of FIG. In (HSES), a zero-miss current that does not form a current zero point flows for several cycles. 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 same timing as the opening timing of the middle-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 serious problem that high-voltage power transmission stops is generated. [0011] This point will be specifically described below according to the operation of the high-speed reclosable grounding device of FIG. First,
8, the insulating arc-extinguishing gas in the puffer cylinder 22 is generated between the fixed-side and movable-side contacts 17 and 18 until the movable contact 18 stops the opening operation. By spraying the arc, the arc is extinguished, the current is interrupted, and the inter-electrode voltage duty after the current is interrupted is processed. However, considering the transient recovery voltage performance at the time of opening required for the high-speed reclosable grounding device, as shown in the waveform of FIG. 7, the transient recovery voltage peaks at a half cycle of the commercial frequency. The pole speed requires a speed equivalent to that of a circuit breaker, and the time t from the start of opening to the end of stroke as shown in FIG. 9 is shortened. The limit is about two cycles. 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. After that, even if the arc current has returned to the current zero point, the arc-extinguishing time, which is about two cycles, has already passed since the gas flow from the puffer chamber has already passed, and the arc-extinguishing state remains. The present invention has been proposed to solve the above-mentioned problems of the prior art. It is an object of the present invention to provide a method in which after a single-line ground fault occurs, a trailing ground fault occurs in another phase. Even if it is during the opening of the grounding device of the preceding ground fault accident phase, the induced current in the preceding ground fault accident phase can be reliably shut off, and the high-speed reclosing of the circuit breaker after that can be performed. It is an object of the present invention to provide a high-speed reclosable grounding device. A high-speed reclosable grounding device according to the present invention is provided in each phase of a high-voltage transmission line connecting a circuit breaker, and has a main contact and a grounding circuit. In response to a single-line ground fault due to reverse flashover in an arc horn of an insulator series provided on an electric wire, a closing operation is performed at a high speed with circuit breakers at both ends of the transmission line being opened, and the reverse flashover is performed. In the high-speed reclosable grounding device that performs the opening operation after the arc is extinguished, a second opening contact is electrically connected in series to the main contact, and the second opening contact is directly connected to the grounding circuit. a second main contact is, the second opening
Pole commutation contact unit for commutation poles between arc generated between the contacts upon opening operation of the contacts, and the resistor connected to the commutation contact terminal part is disposed, said second opening The contact is configured to be opened in accordance with the opening of the main contact. The operation of the present invention configured as described above is as follows. In other words, a ground fault occurs and the high-speed reclosing grounding device of the ground fault phase is turned on at high speed with the circuit breaker of the ground fault phase open to extinguish the reverse flashover in the arc horn. From the point when the opening command was issued to the high-speed reclosable grounding device in the phase where the ground fault occurred Occurs, and a current having a large DC current component that does not form a current zero point flows in the preceding ground fault occurrence phase, in accordance with the opening of the main contact of the high-speed reclosable grounding device of the preceding ground fault occurrence phase. By opening the second opening contact, the arc between the contacts generated between the contacts is moved to the commutation contact portion, and a current having a large DC current component that does not form the current zero point is flowed by resistance, so that the DC current is reduced. Attenuate the current component to return the current zero point It is possible. As a result, it is possible to easily cut off the induced current in the ground fault occurrence phase at the main contact. 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. FIG. 1 is a block diagram showing an embodiment of a high-speed reclosing grounding device according to the present invention. That is, FIG.
As shown in the figure, below the conductor 16 housed in the grounding tank 23 and connected to the transmission line, the main contact 1 and the second opening contact 2 of the high-speed reclosable grounding device are vertically arranged, Are connected in series. In this case, the second opening contact 2 is
A second main contact 3 disposed on the ground side and directly connected to a ground circuit, and a commutation contact 4 for commutating an arc between the poles generated between the contacts during the opening operation. Further, the commutation contact part 4 is provided around the tip of the second main contact
The commutation contact 5 is disposed so as to cover the surface of the tip of the main contact 3 at a certain interval, and is disposed around the second main contact 3 and connected to the commutation contact 5. The resistor 6 is provided. In the figure, reference numeral 7 denotes an operating mechanism for driving the movable portions of the main contact 1 and the second opening contact 2, and 8 denotes an electric / mechanical operation of the movable side of the main contact 1 and the second opening contact 2. A centerpiece connected to More specifically, the second movable contact 9 is attached to the second opening contact 2 so as to face the second main contact 3.
Are driven by the operating mechanism 7 and the second
The main contact 3 and the commutation contact 5 are configured to be in contact with and separated from each other. Further, the whole of the second opening contact 2 as described above is covered with an insulating cylinder 10.
Reference numeral 0 also serves as a support member for the center piece 8. Note that the detailed configuration of the main contact 1 is basically the same as the conventional example shown in FIG. The operation of this embodiment having the above configuration is as follows. That is, as shown in FIG. 3, when a one-line ground fault occurs in a certain phase, the circuit breaker (GCB) is opened in the transmission line 12 in that phase to cut off the current. Thereafter, at a certain timing, the high-speed reclosing grounding device (HSES) of this embodiment is turned on to extinguish the reverse flashover 13c between the arc horns 13a. An opening command is sent to the input high-speed reclosing grounding device (HSES) after a lapse of a predetermined time θ. By this opening command, the operating mechanism 7
Is activated to open the main contact 1. At the same time,
The second movable contact 9 of the second opening contact 2 is operated by the operating mechanism 7.
Is operated to open the second opening contact 2. With the opening operation of the second opening contact 2, the arc generated between the contacts moves to the commutation contact 5, and a current having a large DC current component that does not form a current zero point flows through the resistor 6. Then, the DC current component is immediately attenuated. As a result, the current zero is restored, and the current at the main contact 1 can be interrupted. Also, in this state, if a back-to-back ground fault does not occur, especially in another phase, the opening of the high-speed reclosing grounding device is successful, the induction current is cut off, and the circuit breaker (GCB) is subsequently turned on. The transmission line is reclosed. Generally, in order to extinguish the reverse flashover 13c between the arc horns 13a, the arc cannot be extinguished unless a voltage equivalent to the voltage between the arc horns is obtained. In this case, the voltage between the arc horns
Although it depends on the installation conditions and the like, in the case of a 1000 kV transmission line, the arc cannot be extinguished unless it is approximately 4 to 8 kV or less. For example, when the high-speed reclosable grounding device (HSES) is turned on when the high-speed reclosable grounding device (HSES) is turned on, the current is 2
000 A, the resistance value of the resistor 6 is 2
If it is not more than 4Ω, the reverse flashover 13c cannot be extinguished. However, as shown in the characteristic diagram of FIG. 2, with a resistance value of 2 to 4Ω, it is impossible to return the current zero point within サ イ ク ル cycle.
A resistance of about 10 to 10Ω is required. On the other hand, in the present embodiment, the resistor 6 is energized only during the opening operation of the main contact 1 and can be directly grounded via the second main contact 3 at the time of closing. Flashover 13c
Can be extinguished. The resistance is constantly applied to the resistor for about 800 ms, which is the closing time of the high speed reclosable grounding device (HSES).
When a current of 0 A flows, the energy consumption of a 10Ω resistor is about 10 MJ, but in this embodiment, the energizing time to the resistor is about 10 ms during the opening operation.
And the energy consumption of a 10Ω resistor is 100
This is about kJ, and there is also an advantage that the design of the resistor is advantageous. The present invention is not limited to the above-described embodiment. For example, specific configurations such as a main contact, a second opening contact, and an operation mechanism can be appropriately selected.
The detailed configuration of the opening contact can also be appropriately selected. As described above, in the present invention,
A second open contact is electrically connected in series to the main contact, and a second main contact, a commutation contact portion, and a resistor are arranged on the second open contact, thereby forming a one-line ground fault. After the accident, a back-to-back ground fault occurs in another phase, and even if it is in the process of opening the grounding device in the preceding ground fault accident phase, the second opening contact is opened in accordance with the opening of the main contact. By setting the pole, a current with a large DC current component that does not form a current zero point can be conducted by resistance, and the DC current component can be attenuated to restore the current zero point. Can be performed reliably, and a high-speed reclosable grounding device that enables high-speed reclosing of the circuit breaker thereafter can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing one embodiment of a high-speed reclosable grounding device according to the present invention. FIG. 2 is a characteristic diagram showing a relationship between a resistance value of the resistor in FIG. 1 and a time point at which a current zero point returns. FIG. 3 is a system configuration diagram showing an example of a high-speed reclosing ground device. FIG. 4 is an operation sequence diagram of the high speed reclosable grounding 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 sectional view showing an open state of an electrode portion in the conventional high-speed reclosable grounding device. FIG. 9 is a characteristic diagram showing a relationship between a puffer chamber pressure and an operation stroke in the high-speed reclosing-grounding device of FIG. 8; [Description of Signs] 1 ... Main contact 2 ... Second opening contact 3 ... Second main contact 4 ... Commuting contact part 5 ... Commuting contact 6 ... Resistor 7 ... Operation mechanism 8 ... Center piece 9 ... 2nd movable contact 10 ... insulating cylinder 11 ... bushing 12 ... transmission line 13 ... steel tower 13a ... arc horn 13b ... insulator string 13c ... reverse flashover 16 ... conductor 17 ... fixed contact 18 ... movable contact 19 ... nozzle 20 ... Puffer chamber 21 Puffer piston 22 Puffer cylinder 23 Ground tank 24 Arc extinguishing gas

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hideki Noda 1-1-1, Shibaura, Minato-ku, Tokyo Inside the head office of Toshiba Corporation (56) References JP-A-5-199653 (JP, A) Showa 55-92530 (JP, A) Actually open Showa 60-183517 (JP, U) Actually open Showa 56-110707 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 33 / 70-33/99 H02B 13 / 02,13 / 075 H02H 1/00-3/07

Claims (1)

(57) [Claims 1] A high voltage power transmission line connected to a circuit breaker is provided in each phase and includes a main contact and a grounding circuit. In response to a one-line ground fault due to reverse flashover in the arc horn, perform closing operation at high speed with the circuit breakers at both ends of the transmission line open,
In a high-speed reclosable grounding device that performs an opening operation after the reverse flashover is extinguished, a second opening contact is electrically connected to the main contact in series, and the grounding is connected to the second opening contact. the second and main contact, the commutation contact unit for commutation poles between arc generated between the contacts upon opening operation of the second opening contact that is connected directly to the circuit, and the commutation contact A high-speed reclosable grounding device, wherein a resistor connected to the slave portion is arranged, and the second opening contact is configured to open in accordance with the opening of the main contact.