JPH01219675A - Testing apparatus of dynamic current interruption characteristic of lightning insulator with serial gap - Google Patents

Abstract

PURPOSE:To make a testing apparatus small and simple by enabling the implementation of a dynamic current interruption test of a lightning insulator applied to high-voltage classes, only by means of a high-voltage generator, a switching mechanism and a fuse. CONSTITUTION:A fuse 11 connected to a serial gap G is melted within a prescribed time by making a sharp current I flow therethrough by an instantaneously chargeable switching mechanism 2. Thereafter a dynamic current arc generated in the serial gap G of a lightning insulator 23 is interrupted by a current- limiting element 24 and the serial gap G. By this constitution, the dynamic current interrupting current capacity of the current-limiting element 24 is made large, and even when the serial gap G is made long, an interruption characteristic test of the lightning insulator can be implemented by replacing the fuse 11 in accordance with the length of the gap and by adjusting an impression voltage E by an AC transformer 1. Accordingly, a testing apparatus can be made small and simple.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention quickly discharges high voltage caused by a lightning surge to the ground when it is applied to a power transmission line, and the following current that occurs thereafter is characterized by voltage-current characteristics. This invention relates to a follow-current interrupting characteristic test device for a lightning arrester device with a series gap, which interrupts the current by a current limiting element mainly made of non-linear zinc oxide, etc., and prevents the occurrence of ground faults.

(Prior Art) Generally, a power transmission line is supported on a support arm of a steel tower via a suspension insulator, and a power transmission line is also attached to the support arm via a mounting adapter to connect zinc oxide, which has non-linear voltage-current characteristics, to the support arm. A lightning arrester with a built-in current limiting element mainly made of is installed in parallel with the suspension insulator, a discharge electrode on the energized side provided on the side of the suspension insulator, and a discharge electrode on the ground side provided on the lightning arrester. A predetermined air discharge gap, that is, a series gap is provided between the two. An equivalent circuit of this lightning arrester device for power transmission lines is shown in FIG. 4, and the principle of operation up to lightning strike processing in actual use will be explained with reference to FIG. 5.

During normal operation, the power transmission line 20 and the ground (
As shown in Figure 5(a), a commercial frequency AC operating voltage is connected between the tower and the overhead ground wire 21) via a suspension insulator 22.
is applied, and the current limiting element 2 built into the lightning arrester 23
Voltage applied to 4■2. (See Figure 5(d)) is almost zero, so both discharge voltage &! 5. Also in the series gap G between 26 and 1
(see FIG. 5(c)) is applied, and the operating voltage (2) of the power transmission line 20 is applied through the series gap G, and the insulated state is maintained.

Now, when lightning enters the power transmission line 20, the lightning surge voltage increases
As shown in FIGS. (a) and (C), it is superimposed on the operating voltage (2) and the voltage (1) between the gears 710. A part of this steep lightning surge energy is absorbed by the current limiting element 24, suppressing a rise in the lightning surge voltage between the power transmission vA 20 and the steel tower. When this lightning surge voltage exceeds a predetermined value, the current limiting element 2
4, a flange over occurs in the series gap G, and a lightning impulse current I flows through the current limiting element 24 and the series gap G as shown in FIG. 5(b). This lightning impulse current I
After passing through, since the operating voltage ■ is applied, the follow-on current 1V flows to the tower via the series gap G and the current limiting element 24. When this follow-on current Iv is cut off by the series gap G and the current limiting element 24, the insulation of the series gap G is restored.

Note that the same principle applies when a lightning surge occurs in the overhead ground wire 21.

In the gap-combined lightning arrester device, in order to obtain desirable follow-on current breaking characteristics, the voltage-current characteristics of the current limiting element 24, the length and shape of the series gap G, and the relative relationship with the operating voltage (2) must be appropriately designed. Must be selected according to the conditions.

In order to obtain the above-mentioned appropriate design conditions, we conducted a test that simulated actual usage conditions and examined the design conditions by electrically superimposing a lightning impulse voltage generator on an AC high voltage generator (transformer). was going on. A device shown in FIG. 6 has been proposed as such a follow-on current interruption characteristic testing device. This test device includes a suitable phase closing device 28 connected in series to a back amplifier circuit breaker 27, and an AC transformer 2 connected in series to the closing device 28 for generating high voltage and high current.
9, a connection terminal 30.31 connected to the secondary side terminal of the AC transformer 29 and for connecting the lightning arrester 23, and a connection terminal 30.31 for forming the series gap G! @ko32.33
It further comprises a lightning impulse voltage generator 34 and a lightning impulse current generator 35 connected to the secondary side terminal of the AC transformer 29.

When the appropriate phase injector 28 is turned on, the lightning impulse voltage generator 3 is connected between the secondary terminals of the AC transformer 29.
4, as shown in FIG. 5(a), a lightning impulse voltage (2) for triggering the series gap G is generated, and the impulse voltage V is applied to the series gap G to cause a floodover in the series gap G. Characteristic tests were conducted on the following current cutoff time in the gap G, the residual voltage of the current limiting element 24, etc. Then, a current limiting element 2 with a predetermined capacity
By measuring the cut-off time of the following current in the lightning arrester 23 using the lightning arrester 4, the operation start voltage of the current limiting element 24 or the desired dimension of the series gap G can be set.

(Problems to be Solved by the Invention) In the conventional lightning arrester insulator follow current breaking characteristic test device, the higher the applied line voltage of the lightning arrester, the larger the length and diameter of the current limiting element 24, and the series gap G. It also gets bigger, so the lightning impulse! There was also a problem in that test equipment such as the pressure generator 34 and the lightning impulse current generator 35 became larger.

In addition to the appropriate phase injector 28 for weighting the lightning impulse in synchronization with the AC voltage phase, its sequencer 36, and the backup circuit breaker 27 in case of failure to cut off the follow-on current, there are also devices (not shown) for controlling lightning impulses entering the AC power source. As the test equipment becomes larger and the control technology becomes more sophisticated, and the line voltage becomes a voltage class of 275KV to 500KV,
The problem was that it would be difficult to implement.

The purpose of the present invention is to omit a necessary protection device by connecting a lightning impulse voltage generator and an impulse voltage generator, and to simplify the control technology for superimposing the lightning impulse voltage on the operating voltage. An object of the present invention is to provide a series-interruption characteristic testing device for a lightning arrester with a series gap.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a connection between an AC transformer and a lightning arrester with a gap, which is a specimen, and which is connected to the primary or secondary terminal of the AC transformer. an opening/closing mechanism that enables electrical connection in a time shorter than the current interruption time; a discharge terminal for forming a series gap between the opening/closing mechanism and the lightning arrester as a test object directly or via the transformer; a fuse connected to a part or the entire length of the series gap to the terminal and having a characteristic of blowing out in a time shorter than a follow-on cutoff time specific to the lightning arrester with a series gap that is the test object; and a fuse on the secondary side of the transformer. A connection terminal is connected to the lead wire in series with the fuse and electrically connected to the electrode of the lightning arrester.

(Function) When the switching mechanism that can be turned on instantly is turned on, a high voltage is applied from the secondary terminal of the AC transformer to the fuse connected to the series gap and the current-limiting element of the lightning arrester, and the fuse is instantly blown. Ru. Thereafter, a follow-on current flows between the series gaps, but this current is suppressed and interrupted by the current limiting element and the series gap.

In this way, in the present invention, by using a high voltage generation transformer, an instantaneous switching mechanism, and a fuse for the discharge terminal, a sudden alternating current voltage can be applied to the series gap of the discharge terminal without causing a floodover short circuit caused by a lightning impulse. A follow-on current can be easily generated by the mark, and the test equipment can be simplified and miniaturized.

(Example) An example embodying the present invention will be described below with reference to FIGS. 1 to 3.

Reference numeral 1 in FIG. 1 is an AC transformer connected to a high-voltage line, and its secondary terminal has a lead H1l.

An opening/closing mechanism 2 that can be turned on instantly is connected by 12. This opening/closing mechanism 2 includes, for example, a spherical fixed contact 4 supported by an SP support insulator 3, and an operation arm 6 that rotates around a support shaft 5 supported by the SP support insulator 3; A spherical movable contact 8 is fixed to the tip of the spherical movable contact 8, which corresponds to the fixed contact 4 so as to be able to come into contact with and separate from the fixed contact 4, and has a plate-shaped contact piece T fixed to the back surface, and the operating arm 6 is instantly moved. The drive mechanism 9 is mainly composed of a coil spring that rotates.

A lead wire β3 is connected to the fixed contact 4, a fuse 11 is connected to the lead wire 13 and the lead wire 12, and a discharge terminal 12 for forming a series gap G is connected.
Further, connection terminals 14 and 15 are provided in series with the discharge terminals 12 and 13, which are electrically connected to the electrodes at both ends of a lightning arrester 230 having a built-in current limiting element 24.

Next, the operation of the follow current interruption test device for the gap type lightning arrester device constructed as described above will be explained.

Now, with the fuse 11 connected between the discharge fittings 12 and 13 and the current limiting element 24 of the lightning arrester 23 in contact between the connection terminals 14 and 15, the power supply device (the path shown in the figure)
When a predetermined voltage (for example, 3.3 KV) is applied to an AC transformer 1 with a winding ratio of 1:33, AC is applied to the secondary terminal of the transformer 1 as shown in FIG. 2(a). A voltage E (for example 300 KV) is generated. In this state, the drive mechanism 9 of the opening/closing mechanism 2 is operated to instantly rotate the operating arm 6 and the movable contact 8 toward the fixed contact 4. Before the movable contact 8 completely contacts the fixed contact 4, flange over occurs between the re-contactors 4 and 8, and the opening/closing mechanism 2 becomes substantially in the closing state.

Since the recontactor 4.8 has a spherical shape and maintains a uniform electric field, this floodover voltage is near the peak value of the applied voltage E, as shown in FIG. 2(b). In this embodiment, voltage (2) having a peak value is instantaneously applied, but this is to shorten the fuse 11 blowing time. Note that when the movable contact 8 completely contacts the fixed contact 4, complete electrical continuity is achieved.

The faster the moving speed of the movable contactor 8, the better;
In a range that does not significantly affect the follow-on breaking characteristics of the lightning arrester 23, that is, when the follow-on breaking time of the lightning arrester 23 is 1/f (1/f), where f is the frequency of the applied voltage E, , 1/10 f or less is preferable, 1/2 f is also acceptable, but (1/f - 1/2 f)
This will include errors.

When a voltage of the peak value of the voltage E is applied between both ends of the support insulator 3, that is, between the lead wires 13 and 14, as shown in FIG.
．． The fuse 11 and the current limiting element 24 connected to the
As shown in Figure (e), a steep current I flows. Then, until the fuse 11 is blown by this steep current I, the electrical resistance of the fuse 11 is almost zero, so the current limiting element 24 has the above-mentioned floodover voltage ■ as shown in FIG. 2(d). The same voltage ■2 is generated. When the fuse 11 blows, arc discharge occurs between the series gears 710 of the discharge terminals 12 and 13, and due to the arc resistance,
A small voltage 1 is generated in the series gap G as shown in FIG. 2(c).

Further, after the fuse 11 is blown, the current limiting element 24
Based on the voltage-current characteristics (follow-on current interruption characteristics), the arc current between the series gears 710 is limited and interrupted, and the voltage (2) and current I are as shown in FIG. 2(d).

As shown in FIG. 2(e), the voltage rapidly decreases to zero, and the insulation of the voltage 1 across the gap 0 is restored as shown in FIG. 2(c).

As described above, the fuse 11 is instantly blown by the steep current I. The fusing characteristics of the fuse 11, that is, the current i and the time t, need to be set smaller than the steep current I and the follow-on cutoff time 1/f of the current limiting element 24, respectively. That is, it is desirable to set 1<ISt<<1/f.

Specifically, similar to the input speed of the opening/closing mechanism 2 described above, 1
/10 f or less is desirable, and 1/2 f is also acceptable, but an error will occur.

Thereafter, when the opening/closing mechanism 2 is opened, the operating voltage (2) and the voltage (1) of the gap G disappear as shown in FIGS. 2(b) and (c).

Now, in the embodiment of the present invention, a steep current I is applied to the fuse 11 connected to the series gap G by the instantaneous opening/closing mechanism 2 to cause it to melt within a predetermined time, and then between the series gear 710 of the lightning arrester 23. Since the current limiting element 24 and the series gap G are configured to interrupt the following current arc generated in the current limiting element 24, even if the following current breaking current capacity of the current limiting element 24 becomes large and the series gap G becomes long, the fuse 11 By replacing them accordingly and adjusting the voltage E applied by the AC transformer 1, it is possible to perform a follow current breaking characteristic test of the lightning arrester. It is possible to perform a follow-current breaking characteristic test of a series gap lightning arrester insulator device used in high voltage class.

Note that the present invention can also be embodied as follows.

(1) In the above embodiment, the spherical fixed contact 4 and the movable contact 8 were used as the opening/closing mechanism 2, but instead of this, an equal electric field can be generated in the same way as the spherical contact 4.8. Use Rogowski electrodes (path shown).

(2) Instead of the opening/closing mechanism 2 shown in FIG. 1, which can only select the closing phase of π/2 or 3π/2, it is possible to freely select the closing phase from 0 to π or from π to 2π. Use the appropriate phase input device (shown in the diagram) as the opening/closing mechanism.

(3) In the above embodiment, the closing operation of the opening/closing mechanism 2 is performed by the drive mechanism 9 mainly made of a coil spring, but instead of this, means such as fluid pressure, a motor, or a magnetic force may be used. The input must operate.

(4) The fuse 11 may be a metal fuse or a non-metallic material that is easily oxidized, such as carbon fiber. However, the latter is preferable. Metals are not completely oxidized during arc fusing and float as electrically charged metal particles.
This is because it interferes with proper breaking characteristic testing.

Incidentally, in the embodiment described above, the fuse 11 is attached to the entire length of the series gap G as shown in FIG. It can also be attached partially, provided it is set to a sufficiently short length. The differences between the two are as follows.

FIG. 3(a) shows the operation of a conventional test device with only a series gap G in actual use. In this state, if a follow-on arc occurs between the series gap G, the discharge terminals 32.
33 is melted away by the arc, and the resulting metal vapor is supplied. Further, FIG. 3(b) shows the case of the above-described embodiment of the present invention in which the fuse 11 is connected to the entire series gear G. In this case, not only the discharge terminals 12 and 13 are eroded by the arc, but also the fuse 11 is eroded and becomes metal vapor, so that the eroded vapor of the fuse 11 becomes redundant. Therefore, as shown in FIG. 3(c), it is desirable to suppress the amount of melting steam by using a partial fuse 11.

Although not shown, as a technique similar to the present invention, the series gap G between the discharge terminals 12 and 13 is made variable without using the fuse 11, and this gap length is adjusted to the length of the discharge terminal 1.
2.13 is instantaneously varied, that is, the gap length is initially set short to cause flange over by the applied alternating fLit pressure, and the flange is caused to flange over at the short gap length at the same time as the opening/closing mechanism 2 is turned on. Thereafter, it is conceivable to expand the interval of the series gap G to a target gap length that is desired to be instantaneously evaluated, almost in synchronization with the closing operation. In this case, since no melted metal vapor is emitted from the fuse, the follow-on current interruption test can be performed more accurately.

(Effects of the Invention) As described in detail above, the follow-current interruption testing device for the gap combination type lightning arrester device of the present invention can be used to test lightning arresters applicable to high voltage class using only the high voltage generator, switching mechanism, and fuse. Follow-current interruption tests can be easily performed, and by omitting lightning impulse voltage generators, lightning impulse current generators, or special protection devices and control devices, the test equipment can be made smaller and simpler, reducing costs. It has the effect of being able to measure

[Brief explanation of the drawing]

Fig. 1 is a road body circuit diagram showing an entire follow-on current interruption test device for a lightning arrester device with a series gap, which is an embodiment of the present invention, and Fig. 2 (a) to (e) respectively show follow-on current interruption test operations. Graphs for explanation, Figures 3(a) to (c) are front views of partial road bodies for explaining the melting state due to follow-on arc of series gaps, respectively, and Figure 4 is a conventional gap combination type lightning arrester. The equivalent circuit diagram of the device, FIGS. 5(a) to (d) are graphs for explaining the operation of the lightning arrester device shown in FIG. It is a road body circuit diagram showing the entire test device. DESCRIPTION OF SYMBOLS 1... AC transformer, 2... Opening/closing mechanism, 3... Support insulator, 4... Fixed contact, 5... Support shaft, 6...
- Operation arm, 7... Contact piece, 8... Movable contact, 9... Drive mechanism, 11... Fuse, 12.13
...Discharge terminal, 14.15...Connection terminal, 23...
・Lightning insulator, 24...Current limiting element, G...Series gap, E...Applied voltage, ■...Operating voltage, ■1...
Voltage between series gears 710, (2) Voltage between current limiting elements, (2) Current flowing through the gap and current limiting element.

Claims (1)

[Claims] 1. An AC transformer (1), and a time shorter than the follow-up interruption time of the lightning arrester with a gap, which is the test piece and is connected to the primary side or secondary side terminal of the AC transformer (1). an opening/closing mechanism (2) that can be electrically connected to the opening/closing mechanism (2), and a discharge terminal (G) for forming a series gap (G) between the opening/closing mechanism (2) and the lightning arrester that is the specimen, either directly or via the transformer. 12, 13) and its series gap (
a fuse (11) connected to a part or the entire length of the lightning arrester (11) that is connected to a part or the entire length of the lightning arrester (11) and has a characteristic of blowing out in a time shorter than the follow-on cutoff time specific to the lightning arrester (23) with a gap, which is the test object; and the transformer (1). Connection terminals (14, 1) connected in series with the fuse (11) and electrically connected to the electrodes of the lightning arrester (23) with respect to the secondary lead wires (l1, l2) of the
5) A follow-up current breaking characteristic testing device for a lightning arrester device with a series gap, characterized by comprising: