RU2797293C1 - Device for measuring current, voltage in the transmission line - Google Patents

Abstract

FIELD: electrical engineering; accelerator technology; electronics; plasma physics; radio engineering.

SUBSTANCE: invention is intended for measuring pulsed currents, voltages in forming and transmitting lines, and can be mainly used to measure their amplitudes. In addition, the invention can be used to measure frequency, determine the presence of electromagnetic energy in transmission lines and to create sensors for currents, voltages of harmonic signals or pulse trains without breaking the line or where a beam of charged particles propagates or a plasma column is located. This technical result is achieved by the fact that in the device for measuring current, voltage in the transmission line, which is a closed toroidal coil, the leads of which are connected to the load, from which useful information is taken, and the current-carrying wire of the transmission line passes through the toroidal coil, where it is necessary to measure the current, consisting of at least one current-carrying conductor and one return current conductor. According to the invention, the toroidal coil covers the entire transmission line, including both the current-carrying wire and the return current conductor, the conclusions of the toroidal coil and the load are connected to the resonant system, the location and parameters of the resonant system ensure that its resonant frequency is equal to the frequency of the measured current or voltage.

EFFECT: implementation of the claimed invention is the ability to measure the amplitude and frequency of the current, the voltage of harmonic signals or a sequence of pulses, to determine the presence of electromagnetic energy in the forming and transmitting lines without breaking the forming or transmitting line.

5 cl, 3 dwg

Description

The present invention relates to electrical engineering, accelerator technology, electronics, plasma physics, radio engineering and is intended for measuring pulsed currents, voltages in forming and transmitting lines, and can be mainly used to measure their amplitudes. In addition, the invention can be used to measure frequency, determine the presence of electromagnetic energy in transmission lines and to create sensors for currents, voltages of harmonic signals or pulse trains without breaking the line or where a beam of charged particles propagates or a plasma column is located. The claimed device makes it possible to measure currents outside the housings of transmission lines.

A device is known - a Rogowski belt, designed to measure pulsed currents, voltages in forming and transmitting lines. The main feature of the Rogowski coil is its coverage of the wire of the main circuit, where it is necessary to measure the flowing current. This wire (bus, conductor) can be called differently: signal, potential, current-carrying, current-carrying, conductive, phase, just a current conductor, etc. In addition, it can be both single-core and multi-core.

A device for measuring the current flowing along the line is known, called the Rogowski belt [Rogowski W., Steinhaus W. Die messung dor magnetisehen spannung // Archiv fur Elektrotechnik, 1912, 1, p.141-150]. The device is a measuring coil wound with a wire on some core and closed in a toroidal shape. A load is connected to the ends of the wire, from which useful information is taken. Inside the coil there is one current-carrying wire. The measurement method is as follows: the current flowing through one current-carrying wire, when it changes, creates by its magnetic field in the coil put on this current-carrying wire, the electromotive force (EMF) of self-induction, which is subsequently recorded and carries information about the current flowing through the current-carrying wire.

The disadvantage of this device is the need to break the cable line in order to use only a current-carrying wire. If a return conductor and a current conductor pass through the coil at the same time, where it is necessary to measure the current, then noise will be recorded at the output of the coil, due to the fact that both currents flowing in different directions along the current conductor and the return current conductor will induce an EMF of opposite polarities in the coil that destroy each other.

It is also known a device for measuring the current flowing through the line, called the Rogowski coil [Kazakov M.K. The use of an air transformer as part of measuring current transducers in the electric power industry // Informatics, Computer Science and Management, 2019, No. 6-2, p. 74-80]. The Rogowski coil is a typical winding wound on a non-ferromagnetic frame (a flexible frame is possible). The winding covers the conductor with the measured alternating current, at the output of the winding there is a voltage associated with the measured current by a constant coefficient of proportionality.

The disadvantage of the known device is that it is necessary to break the cable line to use only the conductor passing through the belt. The known device does not allow measuring the current if you pass a whole cable or line with a direct (current-carrying) and reverse conductor through the belt without breaking them. This drawback is due to the fact that both currents flowing in different directions along the current conductor and the return current conductor will induce an EMF of opposite polarities in the belt, destroying each other.

The set of features closest to the set of essential features of the invention is inherent in the known device for measuring current, voltage in the transmission line [High voltage technique: a textbook for universities / I.M. Bogatenkov. Yu.N. Bocharov. N.I. Gumerov. G.M. Imanov and others. Edited by G.S. Kuchinsky. - St. Petersburg: Energoatomizdat. 2003. - 608 p. (S. 560-563)]. The Rogowski coil is a toroidal coil that encloses the main circuit wire. To measure the current, its outputs are closed to a resistor with low resistance, then connected to an oscilloscope.

A disadvantage of the known device, taken as a prototype, is that it is necessary to break the cable, the line, in order to use only the wire of the main circuit passing through the coil. It is impossible to pass a whole cable or line with a wire of the main circuit and a return conductor through a known device and take measurements. This disadvantage is due to the fact that both currents flowing in different directions through the wire of the main circuit and the return current conductor will induce an EMF of opposite polarities in the coil, destroying each other.

The task to be solved by the claimed invention is the creation of a new device for measuring current, voltage, determining the presence of electromagnetic energy in the forming and transmitting lines without breaking them.

The technical result of the claimed invention is the ability to measure the amplitude and frequency of the current, the voltage of harmonic signals or a sequence of pulses, to determine the presence of electromagnetic energy in the forming and transmitting lines without breaking the forming or transmitting line.

An additional technical result provided by the invention is the determination of the presence of electromagnetic energy in the transmission line without breaking the line with a single excitation of the transmission line by a current or voltage pulse.

This technical result is achieved by the fact that in the device for measuring current, voltage in the transmission line, which is a closed toroidal coil, the leads of which are connected to the load, from which useful information is taken, and the current-carrying wire of the transmission line passes through the toroidal coil, where it is necessary to measure the current, consisting of at least one current-carrying conductor and one return current conductor. According to the invention, the toroidal coil covers the entire transmission line, including both the current-carrying wire and the return current conductor, the conclusions of the toroidal coil and the load are connected to the resonant system, the location and parameters of the resonant system ensure that its resonant frequency is equal to the frequency of the measured current or voltage.

The conclusions of the toroidal coil are connected to the resonant system through the excitation device, the load is connected to the resonant system through the pickup device.

The toroidal coil has an open shape; it and the resonant system each consist of at least two detachable parts.

A magnetic layer, or a dielectric layer, or a plasma layer, or metamaterials, or combinations thereof, is installed in the toroidal coil, the resonant system, as well as between the excitation device, the pickup device and the resonant system.

The transmission line is enclosed in at least one conductive screen.

The coverage of the entire transmission line (forming line) with a toroidal coil, which simultaneously includes both a current-carrying wire and a return current conductor, allows not to break the transmission line, not to single out the current-carrying wire and the return current conductor separately, and additionally not to take measures for their separate isolation. Thus, there are no costs for preparing the transmission line for measurements.

The use of a resonant system, the resonant frequency of which is close to the frequency of the measured current or voltage, makes it possible to separate signals with the frequency of the measured current or voltage from the noise-like signal received by the toroidal coil and transmitted to the resonant system and amplify them. The location of the resonant system relative to the toroidal coil and the transmission line, as well as the parameters of the resonant system, ensure that the resonant frequency of the resonant system is tuned to the frequency of the measured current or voltage.

It is known that non-magnetic sheaths of coaxial cables poorly shield alternating magnetic fields of low frequency, so in a loop formed by the cores of a power coaxial cable and its lead rims, a magnetic field is determined [High voltage technique: a textbook for universities / I.M. Bogatenkov, Yu.N. Bocharov, N.I. Gumerova, G.M. Imanov and others. Edited by G.S. Cuban. - St. Petersburg: Energoatomizdat. 2003. 608 p. (S. 556, pp. 489-490)]. Thus, a non-zero value of the magnetic flux near the coaxial cable, but to which any signal is received, is intercepted by the toroidal coil and allows the resonant system to select the frequency of this signal, excite an oscillatory process in itself at a given frequency and amplify it.

Connecting the terminals of the toroidal coil to the resonant system through the excitation device, and the load to it through the pickup device ensures the convenience of using the resonant system in the form of resonators. When tuning the resonant frequency of the resonator to the frequency of the measured current or voltage, one should take into account the influence of the excitation and pickup devices on the resonant frequency of the resonator.

The implementation of a toroidal coil of an open shape, and a resonant system of at least two detachable parts increases the convenience in preparing for measurements on the transmission line.

The introduction of a magnetic layer, or a dielectric layer, or a plasma layer, or metamaterials, or combinations of them into the toroidal coil, resonant system, as well as between the excitation device and the resonant system and between the pickup device and the resonant system, provides additional control of the resonant frequency of the resonant system, as well as amplifying or attenuating the output signal from a resonant system.

The use of a resonant system for measuring the amplitude and frequency of current or voltage is possible when the transmission line is enclosed in at least one conductive screen. The conductive screen further attenuates the signal outside the transmission line, which is intercepted by the toroidal coil, and increases the demands on the parameters of the resonant system, such as its quality factor.

Brief description of the drawings

The essence of the invention is illustrated by drawings.

On FIG. 1 schematically shows a device for measuring current, voltage in the transmission line, where:

1 - a transmission line with a measured current or voltage, consisting of a current-carrying wire and a return conductor;

2 - toroidal coil (measurement coil);

3 - excitation device (excitation coil);

4 - resonant system (single-layer coil - sacral resonator);

5 - pickup device (pickup coil);

6 - generator;

7 - oscilloscope (load for the resonant system);

8 - load resistance for the transmission line.

On FIG. 2 shows oscillograms characterizing the operation of the device for measuring current, voltage in the transmission line when a periodic signal is applied, where:

9 - signal from the generator (6) entering the transmission line (1);

10 - signal from the removal device (5);

11 - signal triggering the oscilloscope (7).

On FIG. 3 shows an oscillogram characterizing the operation of a device for measuring current, voltage in a transmission line when a single pulse is applied, where:

12 - signal from the removal device (5);

13 - pulse signal from the generator (6) entering the transmission line (1).

Implementation of the invention

The claimed device includes a toroidal coil (2), an excitation device (3), a resonant system (4), a pickup device (5). The toroidal coil (2) covers the entire transmission line (1). The periodic signal generator (6) is connected to the transmission line (1), which is connected at the other end to the load resistance (8), which can be grounded. The transmission line (1) passes through the toroidal coil (2). The conclusions of the toroidal coil (2) are connected to the conclusions of the excitation device (3), which is put on the resonant system (4). The pickup device (5) is also put on the resonant system (4). The output of the pickup device (5) is connected to the load in the form of an oscilloscope (7).

A spiral resonator based on a single-layer multi-turn coil is used as a resonant system (4). Spiral coil - line with distributed parameters [Bessonov L.A. Theoretical foundations of electrical engineering. In three parts. - Moscow: Higher School. 1961. - 792 p. (S. 465)]. Like many resonators, the spiral resonator works on the wave effects of the spatial localization of an electromagnetic wave in it [Hanzel G. Handbook for filter calculation // Hansell G.E. Filter design and evaluation, 1969. Translation from English by Starostin V.A. Under the editorship of Znamensky A.E. Moscow: Soviet Radio, 1974. 287 p. (S. 257)].

Useful information can be taken with an oscilloscope (7) between the output of the pickup device (5) and ground.

The exciter (3), the resonant system (4) and the pickup device (5) can be enclosed in a conductive shield, which must not be earthed. When tuning the resonant system (4) to the frequency of the measured current or voltage, the influence of the conductive screen on the resonant frequency should be taken into account.

The resonant system (4), made on the basis of a resonator, can be open, closed, grounded, open on one side only. On FIG. 1 the resonant system (4) is shown as a helical resonator open on one side and grounded on the other side. The dimensions, parameters of the resonant system (4) and the location of the excitation device (3) and pickup device (5) on the resonant system (4) ensure that the natural frequency of the resonant system (4) is equal to the frequency of the measured current or voltage.

The device works as follows. A sequence of rectangular pulses (9) is fed from the generator (6) to the transmission line (1), which is loaded on the load resistance (8). The transmission line (1) passes through the toroidal coil (2). Or in other words, the toroidal coil (2) covers the entire transmission line (1). The outputs of the excitation device (3) are connected to the outputs of the toroidal coil (2), which is put on the resonant system (4), in the form of a spiral resonator, on which the pickup device (5) is also put on, the output of the pickup device (5) is connected to the oscilloscope (7 ). The currents I(t) flowing along the transmission line (1) in different directions excite with their magnetic fields an EMF in a toroidal coil (2), from which a noise-like signal is applied to the terminals of the excitation device (3), which inductively excites the EMF and electrical sinusoidal oscillations in the spiral resonator, which, in turn, inductively excites the EMF in the pickup device (5), the useful signal from which in the form of a harmonic sinusoidal oscillation (10) enters the oscilloscope (7). When the natural frequency of the resonant system (4) coincides with the frequency of the measured current, the voltage in the transmission line (1), the oscillation resonance appears in the resonant system (4) and, accordingly, in the pickup device (5), which selects and amplifies the frequency component of the measured signal in EMF of the toroidal coil (2). Selected and amplified harmonic sinusoidal oscillations (10) are recorded by an oscilloscope (7). The amplitude of the harmonic sinusoidal signal recorded by the oscilloscope (7). proportional to the current or voltage in the transmission line (1). The choice of measured current or voltage is determined by pre-calibrating the device at a known current or voltage in advance.

When a signal is supplied from the generator (6) in the form of a single pulse (13) to the transmission line (1), the device works in the same way. An EMF is induced in the toroidal coil (2) and a noise-like signal is applied to the outputs of the excitation device (3), which inductively excites the EMF and shock excites electrical sinusoidal oscillations in the spiral resonator, which in turn inductively excites the EMF in the pickup device (5), a useful signal from which, in the form of a damped sinusoidal oscillation (12), it enters the oscilloscope (7). Thus, the device detects the presence of electromagnetic energy in the transmission line (1).

The inventive device for measuring current, voltage in the transmission line is implemented as follows. The toroidal coil (2) consists of 64 turns wound with copper wire 1 mm in diameter on a dielectric tube 25 mm in diameter and forms a torus with an average diameter of 60 mm. The excitation device (3) is a flat coil of 2 turns wound with copper wire 2 mm in diameter. The resonant system (4) is a single-layer coil, which consists of 600 turns, made by winding copper wire with a diameter of 0.32 mm to each other on a dielectric tube with a diameter of 60 mm. The pickup device (5) is a flat coil of 2 turns wound with copper wire 2 mm in diameter. The transmission line (1) is a RK 50-4-11 coaxial cable and is loaded with a matched load resistance (8) equal to 50 Ohm, the generator (6) is of the TOP110 10 MHz Pulse Generator type, the oscilloscope (7) is of the TDS 3054 C type.

Thus, thanks to the claimed invention, it is possible to measure the amplitude and frequency of current, voltage, determine the presence of electromagnetic energy of a harmonic signal or a sequence of pulses in the forming and transmitting lines without breaking them or outside the line, and not inside. In addition, it is possible to determine the presence of electromagnetic energy in the transmission line without breaking the line with a single excitation of the transmission line by a current or voltage pulse.

The device has further development in the field of electrical engineering and power engineering, accelerator technology, electronics, plasma physics, radio engineering and radio communications, industry as a signal meter or detector, a breakdown or unauthorized connection detector in a cable, line or channel housing.

Claims (5)

1. A device for measuring current, voltage in the transmission line, which is a closed toroidal coil, the terminals of which are connected to the load, from which useful information is taken, and the current-carrying wire of the transmission line passes through the toroidal coil, where it is necessary to measure the current, consisting of at least , one current-carrying wire and one return current conductor, characterized in that the toroidal coil covers the entire transmission line, including both the current-carrying wire and the return current conductor, the conclusions of the toroidal coil and the load are connected to the resonant system, the location and parameters of the resonant system ensure the equality of its resonant frequency the frequency of the measured current or voltage. 2. A device for measuring current, voltage in the transmission line according to claim 1, characterized in that the conclusions of the toroidal coil are connected to the resonant system through the excitation device, the load is connected to the resonant system through the pickup device. 3. A device for measuring current, voltage in the transmission line according to claim 1, characterized in that the toroidal coil has an open shape, it and the resonant system each consist of at least two detachable parts. 4. A device for measuring current, voltage in the transmission line according to claim 1, characterized in that the transmission line is enclosed in at least one conductive screen. 5. A device for measuring current, voltage in the transmission line according to claim 2, characterized in that a magnetic layer, or a dielectric layer, or a plasma layer, or metamaterials, or their combinations.

Images