SU1233651A1 - Apraratus for checking voltage drop rate - Google Patents

Description

2. According to Rogowski according to claim 1, characterized in that it is additionally equipped with matching resistors located at the junction points of the coil layers, each connected between the junction point of the coil layers and the metal and the metal

The invention relates to electrical measurements and can be used for contactless measurement of pulsed current parameters.

The purpose of the invention is to improve the accuracy of measuring pulsed current with a nanosecond front by increasing the inductance and the electrical length of the coil according to Rogowski,

FIG. 1 is shown in two projections of Rogowski with matching / equal / wave impedance coil layers, two layers being presented to simplify the drawing; in fig. 2 is a sectional view of FIG. one; in fig. Figure 3 shows a device with ca. matching the values of wave resistances of layers due to the connection between the junction point of adjacent layers and the screen of an additional resistor at the point of transition of one layer to another / shows the form of a cut of ca /; in fig. Figure 4 shows an electrical circuit with a three-layer coil and with an additional: and terminating resistors at the points of transition of the layers.

The device contains a toroidal dielectric, e.g. made of polystyrene, a frame 1 (see Fig. 1), on which a mechanical screen 2, for example, of stainless foil, has an azimuthal annular gap 3 to exclude a short-circuited coil (screen 2 may not be used however, it simplifies the matching of the wave resistances by the coil layer). On the screen 2, the first layer 4 of the rolls is wound, filled with insulated wire, for example with polyethylene insulation, with a pitch between turns (winding can be made with non-insulated

cheskom screen and the gap connection of adjacent layers,

3. According to Rogowsky according to claim 2, characterized in that the azimuthal slits in the adjacent screens are mutually offset.

S

wire, but then you need to wrap the screen 2 with an insulating film, for example, from (fluoroplastic, and a similar insulation should be put on layer 4). The initial end 5 of the wire of this extreme, in this case the lower layer 4 of the coil, is attached, for example, soldered to screen 2, on layer 4 there is a screen 6 made, for example, of stainless steel, with an annular azimuthal slit 7 and a layer with thickness walls greater than, for example, 5 times the depth of the skin layer at the minimum frequency of the range of the measured pulse current, determined by the expression

S 50.3: 10 -, mm,

where p is the resistivity of the screen material. Om-cm; —frequency equivalent to the pulse duration of the measured current, Hz;

p is the relative magnetic penetrability of the material.

{This condition is not necessary for screen 2, since under screen 2 there is no coil layer).

B. the junction of the layers, i.e. at the transition point of the conductor 8 from the last turn of layer 4 to the second layer 9, located on screen 6 and wound similarly to layer 4 in increments, an opening is made in screen 6 (see FIG. 2), and screens 2 and 6 are electrically connected between a conductor 10. A screen 1 is placed on top of layer 9, similar to screen 6, with a slot 12 offset from slot 7. At the end 13 of the wire of the last turn of layer 9 located in the second outermost (upper) layer of the coil, there is a hole in screen 11, and screens 6 and

0

0

3 -12

1 I are electrically interconnected by conductor 14. End 13 is connected through this hole, for example, attached to terminal 15 of a load resistor 16 (the resistive layer of the resistor is located on its cylindrical surface and is shown by thick lines), and through its resistive layer and tubular conductor 17 is connected to eq anom 1 1. The signal from resistor 16 is transmitted, for example, by cable, to a recorder (not shown). The wave resistances of coil layer 4 relative to the surface of screens 2 and 6 and layer 9 relative to screens 6 and 11 are matched in magnitude, which is achieved by winding additional insulation on screens 2 and 6 or by different winding steps of layers 4 and 9, since their wave resistance Z is related to the number of turns uJ per unit length and the diameter d of a turn by the ratio

Z ft du)

where B is a numerical factor that depends on the coil geometry in ca.

Depicted in FIG. 3, the device according to Rogowski is similar to that shown in FIG. 1 except that at the point where the layer 4 transitions to layer 9 and their connections, conductor 8 is bare and an additional resistor 18 is connected to it, for example, which is connected to shield 1I by a second terminal. Thus, the resistance of the resistor 18 is connected parallel to the wave resistance of layer 4, since the wave resistance of this layer is greater than the wave resistance of layer 9. The resistance of this resistor 18 is chosen such that the total resistance of the resistor 18 and the wave resistance of layer 4 are equal to the wave resistance of layer 9 .

Fig. 4 additionally shows the series connection of a resistor 19 between the second 9 and the third layers of the coil, and shows a cable 20 through which the signal from the load resistor 16 is transmitted to the recorder. Total resistance value of the series-connected resistances of the resistor 19 and the wave resistance

5 0 15 0

five

thirty

35

0

five

0

five

I4

No layer 9 is equal to the wave resistance of the third layer of the coil.

Work on sa is as follows.

With the passage of an impulse of current along the axis (through a conductor or a beam of charged particles), a magnetic flux is created, which, when reaching the core, passes through slots 12 and 7 in screens

II and 6 and, crossing the cross sections of the coil windings in layers 4 and 9, induce between the ends 5 and 13 of both layers of the pulsed EMF coil applied to the resistor 16 and transmitted from it to the recorder. At the same time through screens 2 and 6 of layer 4 and screens

6 and 11 of layer 9, a reverse current flows, which is equal in magnitude to the current in the coil, which creates a pulsed voltage drop across the active resistance of the screens. But since the thick walls of the screens exceed the depth of the skin layer, the voltage drop on the resistance of the screen 6 on the side of layer 4 does not have time to transfer to the other side of the screen 6 surface and impart a parasitic signal of interference in the turns of the layer 9. Similarly, From the reverse current, the resistance of the screen 6 on the side of layer 9 does not affect the turns in layer 4, which in total reduces the interference distortion of the useful signal at the output. Since the screens 6 and 11 are interconnected by a short conductor. 10, located near the junction of the layers - the transition of the end 8 of the underlying layer 4 to the beginning of the viewing layer 9, a low-inductive continuous circuit is created for the flow of reverse current between the screens 2 and 6, which is almost not distorting useful waveform. The possible distortion here is due to the change in magnitude. impedance over conductor length 10; however, if the distance between the conductors 10 and 4 is equal to the distance between the screens 2 and 6 and the width of the conductors 10 and 14 is several times larger than the wire diameter, this distortion does not exceed 0.1%, and its duration is close to the electrical length of the considered section of the line, which in practical designs is no more than 0.02 10 s. Since the places of transition 4 and 9 are matched in magnitude of their wave impedances

512

and the coils in the layers are wound according to, then this excludes the excitation of any parasitic oscillations in all that change the shape of the useful signal. Connecting the first end 5 of the coil in the extreme - lower layer 4 to the screen 2 of this layer and simultaneously through the conductor 10 - to the screen 6 forms a low-inductance contact with minimal idle inductance and capacitance and the minimum electrical length of the connection section. Such an interconnection does not interfere with the wanted signal from CA. Attaching the second end 13 of the coil in the extreme top layer 9 to the terminal 15 of the load resistor 6, and through the resistor 16 and the tubular conductor 17 to the screen 11 connected by the conductor 14 s: screen 6, also forms a connection with small parasitic parameters, which reduces the distortion of the useful signal by ca.

Performance on sa multilayer coil increases inductance

Aa

and electrical length by ca, which together increases the measurement accuracy of the parameters of the pulsed current — its shape, current pulse duration, its front, decay, and amplitude. At the same time, the offset of the mutual position of the azimuthal annular slots 7 and 12 in the screens 6 and 11 reduces the electrical capacitive coupling between the layers and relative to the elements of the system with the measured current, which reduces the likelihood of high-frequency resonance oscillations in plasma and additionally reduces the distortion of the useful signal output sa and increases measurement accuracy.

Work on the ca shown in FIG. 3 and 4, similar to that described for the image depicted in FIG. I.

The test results showed that the measurement accuracy (reproduction) was suggested by the som pulse. current compared with the prototype is no less than 5 times.

sh

FIG. 2

l

15

Fig.Z

17

Editor L. Lashkova

Compiled by S. Veysky Tehred I.Popovich

Order 6642/4 Circulation 728

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, 4/5 Raushskaya Embankment.

Production and printing company, Uzhgorod, st. Project, 4

Proofreader V. Booth ha

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Claims (3)

1. ROGOVSKY’S BELT containing a belt coil located in a metal screen with an azimuthal end directly, and the second through a load resistor, characterized in that, in order to improve measurement accuracy, the belt coil is multilayer, each layer of which, except the first, is placed between metal screens and wound on the screen of the previous layer, at the places where the layers transition, adjacent screens are electrically connected to each other, the winding layers are connected in accordance and agreed on the magnitude of the wave impedance, and first and second belt ends multilayer coil connected in this manner to the screens outer layers and the wall thickness of each screen is selected greater skin depth at the lowest Figure 1 2. Rogowski belt in π. I, characterized in that it is additionally equipped with terminating resistors located at the transition points of the layers of the coil of the belt, each connected between the connection point of the layers of the coil of the belt and the metal screen and in the gap of the connection of adjacent layers. · 3. Rogowski belt according to claim 2, characterized in that the azimuthal slots in adjacent screens are mutually offset.