JPH07302674A - Arrester provided with switch - Google Patents

Abstract

PURPOSE:To provide an arrester provided with a switch of high reliability in which the damage to the arrester can be prevented. CONSTITUTION:In an arrester provided with a switch, the arrester 31 to restrict an overvoltage is connected and disposed between a conductive way 1 as a high voltage part and a grounding surface 2. A switch 4 is serially connected and disposed to the arrester 31. In this constitution, because the arrester 31 is actuated only when the overvoltage is generated, damage is not given to the arrester 31 by a current normally, thereby high reliability can be secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning arrester, and more particularly to a lightning arrester having a switch.

[0002]

2. Description of the Related Art In recent years, wide-area operation of electric power systems tends to expand, and along with this, improvement of system stability is required. Therefore, it is becoming more and more important to prevent accidents in equipment. For example, if an overvoltage surge enters a power plant or a substation due to lightning or the like, it may threaten the insulation of the device. Therefore, lightning arresters are installed at power plants and substations for the purpose of suppressing overvoltage such as lightning impulses.

FIG. 8 is a block diagram of a conventional lightning arrester. As shown in the figure, a lightning arrester 3 for suppressing an overvoltage is connected and arranged between a conductive path 1 which is a high voltage portion and a ground plane 2. The protection level of the lightning arrester 3 is 1 p. u. And then about 1.
5p. u. Degree is general. This value is mainly determined based on the following two factors.

[1] Impulsive overvoltage caused by lightning or the like has a very short duration of about 1 second or less. [2] Since a current always flows through the arrester 3, the protection level of the arrester 3 cannot be set too low.

[0005]

By the way, in addition to the impulsive overvoltage, there is an alternating overvoltage. Although this AC overvoltage has a lower voltage level than the impulse overvoltage, it has a property of long duration. Therefore, even when the peak value of the overvoltage is lower than the impulse overvoltage, the level is 1.1.
~ 1.3 p. u. If it is longer than this, the duration may be long and the device may be damaged.

Until now, AC overvoltage levels have been sufficiently low, typically about 1.1 p.s. u. It was the following level.
Therefore, it did not threaten the insulation of the equipment.
However, as the system configuration is diversifying at present, an AC / DC converter may be connected, and sometimes the AC overvoltage level is 1.1 to 1.3 p. u. Or there is a possibility that it will reach a higher level. Therefore, it may happen that the current protection level of the arrester is not always sufficient.

For example, the lightning arrester 3 shown in FIG. 8 has a protection level of 1.5 p. u. It is about 1.1 to 1.3
p. u. It will not operate for overvoltages below a certain level. Therefore, 1.1-1.3p.
u. An overvoltage of a certain level will always be applied. As described above, since the AC overvoltage has a long duration, 1.1 to 1.3 p. u. Even at such a level, the lightning arrester 3 may be damaged.

As described above, in the conventional lightning arrester, the protection level is set high in order to cope with the overvoltage having a high impulse property due to lightning or the like, so that an AC overvoltage with a low level and a long duration is generated. When the level reached a predetermined level or more, it was difficult to reliably protect the lightning arrester. Therefore, there has been a long-awaited demand for a lightning arrester with high reliability that can reliably prevent overvoltage from a high level to a low level and prevent damage to the lightning arrester.

The present invention has been proposed in order to solve the above problems, and its main purpose is to provide a lightning arrester with a switch which has high reliability and can prevent damage to the lightning arrester. is there. Another object of the present invention is to
It is an object of the present invention to provide a lightning arrester with a switch that can protect an arrester not only from an overvoltage having a high impulse property but also from an overvoltage having a low AC property.

[0010]

In order to achieve the above object, the invention of claim 1 connects a lightning arrester for suppressing overvoltage between a conductive path which is a high voltage portion and a ground plane. It is characterized in that the switch is connected in series to the lightning arrester.

According to a second aspect of the present invention, a gap is connected in series to the lightning arrester, and the gap is configured to start discharge by a trigger signal from the outside. In the invention of claim 3, first and second lightning arresters are connected in series between the conductive path and the ground plane, and are connected in parallel to the first or second lightning arrester. A switch for parallel connection is provided.

The invention of claim 4 is characterized in that the gap is connected and arranged in series with respect to the switch for parallel connection. The invention of claim 5 is characterized in that a first switch is connected and arranged in series to the first and second lightning arresters, and a second switch is connected and arranged in parallel.
The invention of claim 6 is characterized in that the gap is connected and arranged in series to at least one of the first and second switches.

[0013]

In the first aspect of the invention having the above-mentioned structure, the switch is kept open in a normal operation state, and the current does not always flow through the lightning arrester. On the other hand, when an overvoltage occurs, the lightning arrester is operated by turning on the switch, and thus the overvoltage can be suppressed. As described above, in the invention of claim 1, since the lightning arrester operates only when the overvoltage occurs, there is no fear that the lightning arrester will be damaged by the constant current.

According to the second aspect of the present invention, the switch is normally closed, and the gap is kept in a state where discharge is stopped. In this state, no current is flowing through the arrester.
Then, when an overvoltage occurs, a gap is started by inputting a trigger signal from the outside. Therefore, the arrester is turned on and the overvoltage can be removed. Since the starting speed of the gap is much faster than the closing speed of the switch, even if a sudden overvoltage occurs, it can be dealt with at an appropriate timing.

In the invention of claim 3, the switch for parallel connection is normally open, and the two lightning arresters connected in series are
It operates at a high protection level, which is the sum of both protection levels. Therefore, when a high level overvoltage such as an impulse overvoltage occurs, this overvoltage can be reliably suppressed. On the other hand, when a low level overvoltage such as an AC overvoltage occurs, the switch for parallel connection turns on. As a result, the lightning arrester on the side connected in parallel with the switch is short-circuited, the lightning arrester in the turned-on state becomes one, the protection level is lowered, and the low level overvoltage can be removed at an appropriate protection level. .

According to the invention of claim 4, the switch for parallel connection is normally closed, and the gap is in a state where discharge is stopped. At this time, the two lightning arresters connected in series operate at a high protection level which is the sum of both protection levels. Therefore, when a high level overvoltage such as an impulsive overvoltage occurs, this overvoltage can be reliably suppressed. On the other hand, when a low level overvoltage such as alternating current is generated, the trigger signal is input to start discharging the gap. As a result, the lightning arrester on the side connected to the parallel-connected switch in the closed state is short-circuited, and only one of the lightning arresters is turned on, and the protection level of the lightning arrester is lowered. Therefore, the low level overvoltage can be removed with an appropriate protection level. In the invention of claim 4 as described above,
Since the protection level of the lightning arrester can be lowered by the start operation of the gap faster than the closing operation of the switch, even if a low level overvoltage is suddenly generated, it can be reliably removed.

According to the fifth aspect of the present invention, the first and second switches are normally opened, and when an overvoltage having a high impulse characteristic is generated, only the first switch is turned on. The first and second lightning arresters connected in series are operated at a sufficiently high protection level that is the sum of the protection levels of both. On the other hand, when an overvoltage having a low AC characteristic is generated, both the first and second switches are closed.
At this time, since the second switch is connected in parallel to the lightning arrester, one of the first and second lightning arresters is short-circuited,
The protection level by the lightning arrester becomes low, and the protection level can cope with a low level overvoltage. That is, the low level overvoltage can be removed with an appropriate protection level.

In the sixth aspect of the present invention, since the gap starting operation can be used for at least one of the closing operations of the first and second arresters, the arrester can be operated at an excellent reaction speed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first to sixth embodiments of the present invention will be specifically described below with reference to the drawings. The same members as those in the conventional example are designated by the same reference numerals, and the description thereof will be omitted. Also the first
-In 6th Example, the same code | symbol is attached | subjected about the same member.

First embodiment: Corresponding to the invention of claim 1 / see FIG. 1 As shown in the drawing, a lightning arrester 3 is provided between the conductive path 1 and the ground plane 2.
1 is connected and arranged. The switch 4 is connected to the lightning arrester 31 in series. The protection level of the lightning arrester 31 is 1 p. u. 1.1-1.2 p. u.
It is set to a degree.

The operation of the first embodiment having the above construction is as follows. That is, the switch 4 is in an open state in a normal operating state. Therefore, no current flows through the arrester 3. On the other hand, when an overvoltage occurs, the lightning arrester 3 operates by turning on the switch 4. Therefore, the overvoltage is 1.1 to 1.2 p. u. The following can be suppressed. The switch 4 is opened again after the overvoltage is suppressed.

According to the first embodiment, since the lightning arrester 31 operates only when the overvoltage is generated, there is no fear of damage to the lightning arrester 31 due to the constant current, and the overvoltage is 1.1 to 1. 2p. u. Since it is suppressed below, the safety of the device can be ensured. Further, in the first embodiment, since the leakage current does not normally flow in the arrester 31, the life of the arrester 31 can be extended. Moreover, since the switch 4 is turned on only when necessary to remove the overvoltage, high reliability can be exhibited.

Second embodiment: Corresponding to the invention of claim 2 / see FIG. 2. The second embodiment is characterized in that the gap 5 is connected in series to the lightning arrester 31. This gap 5
Is configured to start discharge by an external trigger signal. The second embodiment, like the first embodiment, includes a switch 4 connected in series to the lightning arrester 31.

In the second embodiment as described above, the switch 4 is normally closed and the gap 5 is kept discharged. In this state, no current flows through the arrester 31. Then, when an overvoltage occurs, a trigger signal is input to start the gap 5 to start discharge, and the surge arrester 31 is turned on to remove the overvoltage. afterwards,
The circuit is opened by the switch 4.

According to the second embodiment as described above, in addition to the effects of the first embodiment, there are the following effects. That is, compared with the closing speed of the switch 4, the gap 5
Since the starting speed of is extremely fast, even if a sudden overvoltage occurs, it is possible to deal with this overvoltage without delay.

Third embodiment: Corresponding to the invention of claim 3 / see FIG. 3 The configuration of the third embodiment is shown in FIG. First and second lightning arresters 32, 33 are connected in series between the conductive path 1 and the ground plane 2. The protection level of the first lightning arrester 32 is 0.
4-0.5 p. u. , The protection level of the second lightning arrester 33 is 1.1 to 1.2 p. u. Is set to. A switch 41 is connected and arranged in parallel to the first lightning arrester 32. The switch 41 is a switch for parallel connection as defined in claim 3.

In the third embodiment having the above construction, the switch 41 is normally opened, and the two lightning arresters 32 and 33 are the sum of the protection levels of both.
5 to 1.6 p. u. It is designed to work at a degree.
Therefore, when a high level overvoltage occurs, the arrester 3
2, 33 can suppress this.

On the other hand, when a low level overvoltage such as an AC overvoltage occurs, the switch 41 is closed. Therefore, the first lightning arrester 32 is short-circuited at both ends,
Only the second lightning arrester 33 is turned on. Therefore,
The protection level of the third embodiment is 1.5 to 1.
6p. u. Therefore, the second lightning arrester 33 has about 1.1-
1.2 p. u. To an appropriate level for protection against AC overvoltage. Therefore, a low level overvoltage can be removed with an appropriate protection level. After removing the overvoltage, the circuit is opened by the switch 41.

As described above, according to the third embodiment, by turning on the switch 41 only when a low level overvoltage is generated, this overvoltage can be reliably removed.
As a result, high reliability can be maintained without damaging the first and second lightning arresters 32 and 33.

Fourth Embodiment: Corresponding to the invention of claim 4 / see FIG. 4 In the fourth embodiment, the gap 5 is provided with respect to the switch 41.
Is characterized in that they are connected and arranged in series. The fourth embodiment has first and second lightning arresters 32 and 33, as in the third embodiment.

In the fourth embodiment as described above, the switch 41 is normally closed and the gap 5 is in a state where discharge is stopped. At this time, the two lightning arresters 32 and 33 connected in series have a sum of the protection levels of both of 1.5 to
1.6 p. u. It is designed to work at a degree. Therefore, when a high level overvoltage occurs, the arrester 32,
33 can suppress this.

On the other hand, when a low level overvoltage such as an AC overvoltage occurs, the gap 5 is started by inputting a trigger signal from the outside. Therefore, as in the third embodiment, both ends of the first lightning arrester 32 are short-circuited, and only the second lightning arrester 33 is turned on. Therefore, the protection level of the fourth embodiment is 1.5 to 1.6.
p. u. From 1.1 to 1.2 p., Which is a sufficient protection level against AC overvoltage. u. To the value. This allows low level overvoltages to be removed with appropriate protection levels.

According to the fourth embodiment as described above, the protection level can be lowered by the starting operation of the gap 5 which is faster than the closing operation of the switch 41, so that a low level overvoltage is suddenly generated. However, there is an effect that this can be surely removed.

Fifth Embodiment: Corresponding to the invention of claim 5 / see FIG. 5 In the fifth embodiment, as in the third embodiment, first and second lightning arresters 32 and 33 are provided. A first switch 42 is connected in series to the first and second lightning arresters 32 and 33. Further, a second switch 43 is connected and arranged in parallel to the first lightning arrester 32.

The operation of the fifth embodiment having the above construction is as follows. That is, usually the first and second
The switches 42 and 43 of the
No current flows through the lightning arresters 32 and 33.

When a high overvoltage such as a lightning impulse is generated from the above state, only the first switch 42 is turned on. At this time, in the fifth embodiment, the first and second lightning arrester 3
The sum of the protection levels of 2,33 is 1.5 to 1.6 p.
u. It operates at a high level. Therefore, high overvoltage can be sufficiently suppressed. The circuit is opened by the first switch 42 after the overvoltage is removed.

On the other hand, when an overvoltage having a low AC characteristic is generated, both the first and second switches 42 and 43 are closed. In this case, since the second switch 43 is connected in parallel to the first lightning arrester 32, both ends of the first lightning arrester 32 are short-circuited. Therefore, the protection level of the fifth embodiment is 1.1 to 1.2 p.
u. This is a sufficient level for AC overvoltage. That is, it becomes possible to remove the low level overvoltage with an appropriate protection level. After removing the overvoltage, the circuit is opened by the first and second switches 42 and 43.

As described above, according to the fifth embodiment,
To suppress an overvoltage having a high impulse property by turning on only the first switch 42, and to remove an overvoltage having a low AC property by turning on both of the first and second switches 42 and 43. You can Moreover, as long as no overvoltage occurs, the lightning arresters 32 and 33 do not operate and no leakage current flows, so the life of the lightning arrester 31 can be extended.

Sixth Embodiment: Corresponding to the invention of claim 6 / see FIG. 6. The sixth embodiment is basically the same as the fifth embodiment, but the first and second switches 42 are provided. , 43, the gaps 51, 52 are connected and arranged in series. Like the gap 5, the gaps 51 and 52 are configured to start discharge by a trigger signal from the outside.

In the sixth embodiment, the first and second switches 42 and 43 are normally closed, and the gaps 51 and 52 are stopped from discharging. In this state, no current flows through the first and second lightning arresters 32, 33.

When a high overvoltage such as a lightning impulse occurs, a trigger signal is externally applied only to the gap 51 to start only the gap 51. Accordingly, the lightning arresters 32 and 33 perform the closing operation to remove the overvoltage.
At this time, in the sixth embodiment, the first and second lightning arresters 32,
33, which is the sum of protection levels of 1.5 to 1.6 p. u. It operates at a high level and can sufficiently suppress high overvoltage.

On the other hand, when a low overvoltage such as alternating current occurs, a trigger signal is externally input to both the gaps 51 and 52. At this time, since the second switch 43 is connected in parallel to the first lightning arrester 32, the first lightning arrester 32
Is in a state where both ends are short-circuited, and the protection level of the sixth embodiment is 1.1 to 1.2 p. u.
To a sufficient level against AC overvoltage. That is, the low level overvoltage can be removed with an appropriate protection level.

According to the sixth embodiment described above, the closing operation of both the first and second lightning arresters 32, 33 can be performed by utilizing the starting operation of the gaps 51, 52. Therefore, the first and second lightning arresters 32, 33 can be operated at an excellent reaction speed.

Other Embodiments The present invention is not limited to the above-mentioned embodiments, and the constituent members can be changed in shape, size, number of installations and the like as appropriate. For example, a plurality of lightning arresters 31, 32, 33 are connected in parallel, but the number can be freely selected according to the required energy processing amount. Further, as a trigger signal for starting the gaps 5, 51, 52, a pulse signal 6 as shown in FIG. 7 (A), a DC signal 7 as shown in FIG. 7 (B), and FIG. 7 (C) are shown. Any of such AC signals 8 may be used, and can be appropriately selected depending on the starting speed of the gaps 5, 51, 52.

[0045]

As described above, according to the arrester with a switch of the present invention, an overvoltage from a high level to a low level can be suppressed at an appropriate timing and with an appropriate protection level. The damage can be prevented and the reliability is improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram of a sixth embodiment of the present invention.

FIG. 7 is a waveform diagram of a trigger signal for starting a gap used in the present invention, (A) is a pulse signal, and (B) is a waveform diagram.
Indicates a DC signal, and (C) indicates an AC signal.

FIG. 8 is a configuration diagram of a conventional lightning arrester.

[Explanation of symbols]

 1 Conductive Path 2 Ground Plane 3 Lightning Arrester 4 Switch 5 Gap 6 Pulse Signal 7 DC Signal 8 AC Signal 31 First Lightning Arrester 32 Second Lightning Arrester 41 First Switch 42 Second Switch 51, 52 Gap

Claims (6)

[Claims] 1. A lightning arrester for suppressing overvoltage is connected and arranged between a conductive path, which is a high-voltage portion, and a ground plane, and a switch is connected and arranged in series to the lightning arrester. Lightning arrester with switch. 2. The lightning arrester with a switch according to claim 1, wherein a gap is connected in series to the lightning arrester, and the gap is configured to start discharge by a trigger signal from the outside. 3. A first lightning arrester and a second lightning arrester are connected in series between the conductive path and the ground plane, and the first and second lightning arresters are connected in series.
3. A lightning arrester with a switch according to claim 1 or 2, further comprising a switch for parallel connection, which is connected and arranged in parallel with the second lightning arrester. 4. The gap is connected and arranged in series with respect to the switch for parallel connection.
The lightning arrester with a switch according to any one of 3 to 3. 5. The first and second lightning arresters,
5. The lightning arrester with a switch according to claim 1, wherein the first switch is connected and arranged in series, and the second switch is connected and arranged in parallel. 6. The lightning arrester with a switch according to claim 5, wherein the gap is connected and arranged in series to at least one of the first and second switches.