JPH02126169A - Device for detecting current short-circuiting position - Google Patents

Abstract

PURPOSE:To accurately and quickly identify a short circuit and the occurring position of the short circuit with a small number of detection coils by using detection coils which simultaneously detect plural coordinate components and inputting the detected signal of each coil to a computer for prescribed arithmetic operations. CONSTITUTION:Bidirectional magnetic flux detection coils 8 are arranged in a line at regular intervals on the outer peripheral section of a container 3. Output cables 9 of the coils 8 are connected with a data input device 10. Magnetic flux signals from each detection coil 8 are sent to a post-stage computer 11 after the signals are sampled at regular time intervals. the computer 11 processes the inputted magnetic flux signals of each point in accordance with a prescribed procedure and calculates the spatial distribution of a current in an insulating gas 3. The result obtained from the calculation is sent to a post- stage output device 12 by which the result is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for detecting current short circuits and short circuit positions in gas used in gas insulated switches and the like.

[Conventional technology]

Conventional current short circuit detection devices are described in Japanese Patent Application Laid-open Nos. 59-37812 and 61-120067.

Figure 2 shows a gas insulated switchgear. A gas insulated switchgear is a device that interrupts or relays a current between conductors 1 kept at a high potential in a container 3 filled with an insulating gas 2. Two circuit breakers 4 and a disconnector 5 are used to turn on and off the current. Since the container 3 is normally grounded to the ground, the center conductor 1 and the container 3 are insulated by the gas 2 to prevent a ground fault.

FIG. 3 shows the configuration of a conventional ground fault detection device.

According to this example, a detection coil 6 capable of detecting a magnetic flux component in one direction is arranged at predetermined intervals on the outer periphery of the container 3, and detects a one-directional component of magnetic flux φ generated by an arc current 7 at the time of a ground fault. Arc current, therefore.

Can detect occurrence of ground fault.

[Problem to be solved by the invention]

However, although conventional detection devices can detect the presence or absence of a ground fault, it is difficult to accurately determine the location of the ground fault. This requires the arrangement of a huge number of detection coils, which increases the size of the device itself, and poses problems such as a long data processing time required for position identification.

An object of the present invention is to provide a detection device that can accurately and quickly identify a ground fault and its occurrence location using a small number of detection coils.

[Means to solve the problem]

In order to achieve the above object, the present invention uses a coil capable of simultaneously detecting a plurality of coordinate components as a coil for detecting magnetic flux.

In addition, we can immediately calculate the spatial distribution of current in the insulating gas from the spatial distribution of magnetic flux obtained by inputting the detection signals of each coil into a computer. When a current is generated, a current distribution occurs at the ground position.

[Effect]

By using the detection coils marked L, magnetic flux components in multiple directions can be measured simultaneously, so the number of detection coils can be reduced to the 1/2 power or less. (1/3 power in three-direction simultaneous measurement) Furthermore, since the direction of the magnetic flux can be determined at the detection position, the location of the ground fault can be accurately and easily identified.

Furthermore, since the detection position is identified based on the results of the spatial current distribution obtained using the signals from all the detection coils, the accuracy of identification is improved. Furthermore, in the present invention, since signal processing is performed by a computer, the time required for detection is not a problem.6 [Examples] The present invention will be explained in detail below using examples.

FIG. 1 shows the overall configuration of an embodiment of the present invention.

Two-way magnetic flux detection coils 8 are arranged in a line at regular intervals around the outer circumference of the container 3. The output cable 9 of the detection coil is connected to the data input device 10. Here, the magnetic flux signals from each detection coil are sampled at regular time intervals and sent to the computer 11 at the subsequent stage. calculator】
1, the input magnetic flux signals at each point are processed according to a predetermined procedure, and the current spatial distribution in the insulating gas 3 is calculated. The results obtained by the calculations are sent to the subsequent output device 12 and displayed. 15 in the figure is memory.

FIG. 4 explains the principle of detection in the above embodiment. (b) shows a longitudinal section of the container, and (c) shows a view of the container from above the ground fault arc current. Generally, when a ground fault occurs, an arc current 7 runs from the center conductor 1 toward the outer container 3, as shown in (a) and (b). This arc current extends radially in the radial direction from the center, and as a result, a concentric magnetic flux φ centered on the arc current is generated on a plane 13 perpendicular to the arc current 7. The magnetic flux density at this time is inversely proportional to the distance X from the arc current.

Since the outer container 3 is usually made of stainless steel I (non-magnetic material), the magnetic flux φ penetrates the wall of the container 3 and spreads concentrically into the space outside the container.

Therefore, considering a certain horizontal plane 13, coil A and coil B as shown in (c) are placed on the line where this horizontal plane intersects the container 3.
(The number of turns is the same value, the axis of the coil is parallel to the axis of container 3,
Alternatively, if the coils (vertically) are arranged at regular intervals, a current lp + lv is induced in each coil. Since the number of turns of all coils is the same, the il flow ip H
The magnitude of lv corresponds to the magnitude of the horizontal component φP and the vertical component φ of the magnetic flux φ at the coil attachment point C. That is, as shown in (d), the detected current value 1p 11v
The direction of the magnetic flux φ at position C can be found from .

To identify the ground fault position, detection currents 1'p and 1i+' from coils installed at other positions are also used. Current value ip
, lv and l'P11v', the directions of the magnetic fluxes φ and φ' at the attachment points C and D are determined, as shown in (d). Previous page 11 for magnetic flux φ and φ'.

If U' is set and the intersection point S of these vertical lines is found, the intersection point S becomes the point where the ground fault occurs.

FIG. 5 shows a more general method for identifying the point of ground fault occurrence. This example deals with a case where the direction of the ground fault arc 7 is inclined by an angle θ from the vertical direction. In Figure 5 (a)
shows a vertical cross section of the container, and (b) is a view of the container viewed from directly above the ground fault arc.

As in the embodiment described above, from the center conductor 1 to the outer container 3
When the ground fault arc 7 runs toward the arc flow 7, a concentric magnetic flux φ is generated around the arc flow 7. Therefore, if we consider a plane 14 that is perpendicular to the A current 7 and includes the arrangement points C and D of the detection coils A and B, on the plane 14, the magnetic flux φ as shown by the broken line in (b) Spread concentrically.

In particular, the magnetic fluxes φ and φ' at the detection coil attachment points C and D
The size of is given by the following formula.

φ1=1φ' 1=φ. / x (1) Here φ. is a constant, and X is the distance from the arc current 7 to the detection coil attachment point.

Also, components φP, φ' parallel to the axial direction of the container 3, and components φ9 perpendicular to the axial direction of the container 3. φ'9 is expressed as in the following equation.

φP = φ′P= φl ・cos a (2) φ
, =lφl ”sin a (3)φ
'9=-φν (4) Furthermore, since the plane 14 is inclined at an angle θ with respect to the horizontal plane ]-3, the axis of the detection coil 13 and the plane 1-4 intersect at an angle of 0. For this reason, coil A.

current detected by B], pH1v has a slope angle of 0,
Using distance X, formulas (1), (2), (3), (
4), it can be expressed as follows.

(1) At attachment point C, ip:k φp”k φtv=φ9−k 1 φI ・sin a 1
cos θφo Q = k I-Q-6cos θ x x = to φoQ/x”cos O(6) (2) At the attachment point.

xp=1p (7)1,=
-1v (8) where k is a constant related to the conversion of magnetic flux density and current.

p is the length of a perpendicular line extending from the arc current 7 toward the container 3 on the plane 14, and is expressed by the following equation.

p”rosin(θ+β) (9) Also, Q is the distance from the foot H of the perpendicular line to the detection coil.

Figure 3 shows the detected current calculated using equations (5) to (9), p+lv, with respect to the axial pressure sQ of the container 3.The detected current ip is determined by the change in distance Q. It increases with time, reaches a maximum value at a certain position, and then decreases again.

This maximum point is the point closest to Ata' Ichiryu,
That is, it corresponds to the foot I-■ of the perpendicular line in FIG.

On the other hand, the detection current 1v increases by -degrees, reaches a maximum, then decreases, changes direction, and then shows a minimum value.

Regarding the distance Q to the position showing the maximum and minimum values, see 26.
It is found by differentiating the relationship by the distance mQ. That is, Q umbrella = P = ra sin ((1+β) (
10) Since ro and β are known in the L equation, the distance Q11
If it is known, the inclination angle θ of the arc current can be found. That is, 0 = sin-1(Q*/ro)-β
(11) In the embodiment shown in FIG.
Detect the point of closest approach F (. Then, using the signal 1v from the detection coil B, find out the inclination angle θ of the arc current 7 from the vertical direction.Finally, the above two pieces of information (H and O)
Determine the point of occurrence of ground fault arc current using Note that, in order to more accurately identify the position of the point of occurrence of a wire, it is sufficient to perform three-dimensional interpolation between adjacent coils.

FIG. 7 is a flow diagram showing the procedure for data processing by a computer in the embodiment of FIG. 1. The procedure will be explained below.

7-1. First, input the position coordinates of the detection coil and the detection currents IP, iv from the data input device 10, and input the detection current IP11v into the memory 15 in correspondence with the position coordinates.

7-2 Detection current] Find the position of the detection coil where p is maximum. Perform interpolation as necessary to accurately calculate the position of the maximum point.

7-3. Based on the above results, identify the position coordinates of the point 11 closest to the ground fault arc current.

7-4. Find the position of the detection coil showing the maximum and minimum in the detection current iv. If necessary, interpolation is performed to calculate the positions Q* of the maximum and minimum points with high precision.

7-5. Based on the results in section 2, identify the inclination angle O of the ground fault arc current. Equation (11) is used for this.

7-3. The position coordinates of the closest point H that have already been found and the ground fault a~
The ground fault occurrence point is identified from the slope angle θ of the current and sent to the subsequent output device.

FIG. 8 shows an embodiment regarding the detection coil. Coil A and coil B are incorporated as a pair in a non-magnetic box 16. The axial direction Za to the coil and the axial direction zb of the coil B are set so as to be orthogonal to each other. In order to fix the gap between the coil windings, the inside of the box 16 is filled with a non-magnetic material 17 and solidified in a molded manner. Coil A
, B is made of copper, which is highly malleable. Also, in order to improve detection sensitivity, the wire should be thin and the number of turns should be large. Furthermore, in order to eliminate variations in sensitivity between detection coils, the number of turns of the coils should be equal.

In addition to this embodiment, an embodiment may also be considered in which a magnetic flux detection end using a Hall element instead of a coil is used.

〔Effect of the invention〕

According to the present invention, the signal processing time required for detection is reduced;
The frequency of coil failure also decreases.

[Brief explanation of drawings]

Fig. 1 is a system diagram of one embodiment of the current short circuit detection device of the present invention, Fig. 2 is a sectional view of a conventional gas insulated switchgear, and Fig. 3 is a conventional current short circuit installed in a gas insulated switchgear. An explanatory diagram of the detection device; FIGS. 4, 5, and 6 are explanatory diagrams of the principle of the short-circuit current detection device used in the present invention; FIG. 7 is an explanatory diagram of the processing procedure of the computer according to the embodiment of FIG. , FIG. 8 is a structural explanatory diagram of a two-way detection coil. 1... Conductor, 2... Insulating gas, 3... Container, 7.
・Ground fault arc current, 8. A, B...detection coil, 10
...Data input device, ``-1...Calculator, 12...
・Output device. 16...Box (non-magnetic material). −
1 Agent Patent Attorney Small Jl+! □・Male 1. ", Pa dream 1 Seki's 3rd figure 0su (me) 5th figure 5 (nose) Yong W shi single white o bow 1;

Claims (1)

[Scope of Claims] 1. means for detecting magnetic flux in a space arranged around the outer periphery of a container through which a conductor is inserted; means for inputting the coordinate position and detection signal of the detection means into a computer; A current short circuit position detection device comprising a computer that processes a detection signal according to a predetermined procedure and calculates a current short circuit position, and means that outputs and displays the calculated result. 2. The current short circuit position detecting device according to claim 1, wherein the detecting means comprises means capable of simultaneously measuring components in a plurality of directions.