RU50316U1 - DEVICE FOR DIAGNOSTIC OF UNDERGROUND CONDUCTIVE OBJECTS - Google Patents

Abstract

The utility model relates to electromagnetic testing and control equipment and can be used, first of all, for diagnosing the quality of grounding devices (memory) of various power facilities, for example, high-voltage substations without opening the ground. An improved device with advanced functionality is proposed, which allows to determine the touch voltage, the resistance of the charger. soil resistance, to identify the paths of current spreading from equipment during lightning strikes or short-circuit, as well as on the basis of the obtained experimental data to calculate the potential distribution scheme on the territory of the power facility. In the device for diagnosing underground conductive objects containing a master oscillator, a recorder, a sensor in the form of an induction converter and a current electrode, potential electrodes and a voltage meter are additionally introduced in accordance with the utility model, and the voltage meter is introduced into the registrar. The induction converter can be made in the form of an air transformer and placed in an additionally introduced non-magnetic screen.

Description

The utility model relates to electromagnetic testing and control equipment and can be used, first of all, for diagnosing the quality of grounding devices (memory) of various power facilities, for example, high-voltage substations without opening the ground.

In accordance with modern regulatory safety requirements, the tasks of diagnostics of memory include the identification of:

- the presence in the ground and the actual location of the memory (laying paths), including the depth of grounding conductors;

- the presence and status of communications equipment with memory;

- the presence or absence of communication at the intersection of longitudinal and transverse horizontal grounding conductors;

- ways of spreading emergency currents from equipment during lightning strikes or short circuit (short circuit);

- resistance of the memory of electrical installations;

- contact voltage on the territory of the electrical installation in potentially dangerous places;

- soil resistivity

(see MLA 34.20.303. - 2003 “Vigilance monitoring of the grounding and electrical installations. Typical instructions.” - Galusev core document Min. heat and energy of Ukraine. - K. - 2003. - S.9-10, as well "Testing and monitoring the status of the grounding devices of electrical installations. Typical instructions." - Industry guidance document. Authentic translation. - K. - 2003). However, none of the currently known devices allows you to control all of these parameters.

A device for diagnosing underground conductive objects EASYLOC (see A.Yu. Saulov Metal detectors. St. Petersburg. - Science and technology. - 2004. - P.190). It contains a master oscillator and a recorder (receiver).

The specified device allows you to determine the path of grounding devices by magnetic fields induced by alternating current generated by the generator, or by currents from external sources. The disadvantages of the device are the inability to determine the touch voltage and the resistance of the charger, the resistivity of the soil, as well as to identify ways of spreading currents from the equipment during lightning strikes or short circuit.

There is also known a device for diagnosing underground conductive objects (ground resistance meter) Ф 4103, containing a master oscillator, as well as a recorder - a selective voltmeter with clamps for connecting current and potential electrodes. The latter are also part of the device. (see. Grounding resistance meter F 4103-M1. - Umanskoye PO MEGOMMETR. - Passport. - Monastery, regional printing house. - 1991)

This device allows you to measure the resistance of the memory and the resistivity of the soil. Using a generator create a current loop through the memory. To do this, a current auxiliary electrode and a potential auxiliary electrode for measuring the voltage drop on the resistance of the investigated memory (when current passes through it) are placed (hammered) at a distance. A selective voltmeter emits a useful signal in the background of interference, proportional to the measured resistance of the memory. The disadvantage of the device, as well as the previous one, is the functional narrowness.

The closest to the utility model in technical essence and the achieved result is a device for diagnosing underground conductive objects KAI-80, GK-80 (see Technical Description and Operating Instructions 92.2.899.001 TO. - Ministry of Energy and Electrification of the USSR, Production Association Soyuzenergoavtomatika ", Lviv specialized production enterprise" Spetsenergoavtomatika "). It contains a master oscillator, a recorder (receiver), as well as a sensor in the form of an induction converter and a current electrode.

The specified device allows you to detect the route of laying and to identify the depth of the underground conductive objects, namely, cables. However, its drawback, as with the solutions described above, is functional narrowness. The device, although it can, if necessary, carry out diagnostics of the memory, but only in the volume indicated above, since it only registers the presence of a magnetic field around the tires.

In addition, it should also be noted that it lacks:

- the ability to determine contact voltage in potentially dangerous places (on equipment),

- the ability to measure the resistance of the memory,

- the ability to measure soil resistance,

- the ability to identify the spreading paths of currents from equipment during lightning strikes or short circuit, i.e. currents in the event of an accident,

- the ability to carry out subsequently on the basis of these data the calculation of the potential distribution scheme.

All of the above, as mentioned above, is included in the list of regulatory requirements for the diagnosis of memory.

The utility model is based on the task of creating an improved device with enhanced functionality that allows you to determine the touch voltage, memory resistance, ground resistance, to identify the paths of current spreading from equipment during lightning or short-circuit, and also based on the obtained experimental data to calculate the potential distribution scheme for territory of the power facility.

The problem is solved by the fact that in the device for diagnosing underground conductive objects, containing a master oscillator, a recorder, a sensor in the form of an induction converter and a current electrode, potential electrodes and a voltage meter are additionally introduced in accordance with the utility model, while the voltage meter is introduced into the recorder.

The problem is also solved by the fact that the induction converter is made in the form of an air transformer and placed in an additionally introduced non-magnetic screen.

The introduction of potential electrodes into the device for diagnosing underground conductive objects, as well as a voltage meter in the recorder, expands the functionality of the device by introducing four additional functions, namely:

- the ability to measure touch voltage on the equipment,

- the ability to measure the resistance of the memory,

- the ability to measure soil resistance,

- the ability to identify paths spreading currents from equipment during lightning strikes or short circuit, i.e. currents in the event of an accident.

With the advent of these additional functions, it is also possible to calculate the distribution of potentials over the territory of the investigated object.

The implementation of the induction converter in the form of an air transformer and placing it in an additionally introduced non-magnetic screen eliminates the influence of the electrostatic field, as well as suppress extraneous signals and, ultimately, makes it possible to work in conditions of electromagnetic interference (within substations).

The applicant knows, as already mentioned, the use of an induction converter and a voltage meter as a part of the recorder in devices F 4103, EASYLOC, etc. However, in these solutions these blocks are used separately to perform private tasks and do not allow complex diagnostics of the power facility.

An example implementation of the utility model is illustrated in the drawing, which shows a functional diagram of the device.

In the following, the utility model is described in detail given for this particular example shown in the drawing. The number of examples is not limited to this drawing.

A device for diagnosing underground conductive objects, namely, grounding devices (GD), contains a master oscillator 1, a recorder 2, a sensor 3, current and potential electrodes 4, 5, respectively. The generator 1 provides the ability to tune to several different fixed frequencies. The sensor 3 is made in the form of an induction converter and is structurally an air transformer placed in a non-magnetic screen (not shown in the diagram). The registrar 2 includes a meter 6 of the magnetic field and a meter 7 voltages. In working condition, the device is connected to the examined memory 8 and units of equipment 9 located in the territory occupied by memory 8.

The device operates as follows.

With its help, an alternating voltage and current of a given frequency are generated in the memory 8, their effective values are measured and the presence and magnitude of the magnetic field created by the indicated current are determined at the test object.

When determining the actual location of the charger (search for laying paths of grounding devices of the charger 8), the master oscillator 1 is connected to two different remote points of the charger 8 (for example, on open switchgear, one of the points is the transformer housing, and the second is the grounding descent of the equipment). In the elements of the memory 8 generate an alternating current of a given voltage and frequency. The current flows through the memory 8,

while inducing a magnetic field, the presence of which is determined to identify an object in the ground. Starting from one of the points of attachment, using the sensor 3 find the direction on the earth's surface, corresponding to the maximum readings of the recorder 2 (its meter 6 of the magnetic field). Gradually passing from one node of the charger 8 to another, the location of the grounding buses (the route of their laying) is established. According to the measurement results, the tire is applied to the site plan. A decrease in the maximum reading of the meter 6 of the magnetic field may indicate, for example, the branching of the ground electrode (charger 8), or an increase in the depth of its occurrence.

If necessary, determine the laying path of an earthing switch connected only on one side, as follows. To the memory 8, one terminal of the generator 1 is connected, and the second to the current electrode 4. At the same time, the current electrode 4 is driven into the proposed location of the tires and, moving it along the path, determine the location of the latter by the maximum magnetic field.

When measuring the resistance of the memory 8, a current circuit is created through the tested memory. To do this, at a certain distance from it, a current electrode 4 and a potential electrode 5 are driven into the ground to measure the voltage drop in the resistance of the test memory 8 (when current passes through it).

The generator 1 is connected at one end to a piece of equipment 9, and at the other to a current electrode 4. A voltage meter 7 is connected at one end to the selected grounded equipment 9, and at the other to a potential electrode 5 and its readings are recorded, after which the voltage drop is measured with it the resistance of the shunt (not shown) of the generator 1. The potential electrode 5 is moved, measuring the voltage drop, until then, until you get a stationary value. Then this value is divided by the current flowing through the memory 8, and get the resistance of the memory 8.

Ways of current spreading during lightning and short-circuit are determined as follows. The generator 1 is connected to the equipment case 9. The magnetic field strength is measured at the connection point and the resulting value is taken as 100%. The recorder 2 is brought to each branch from the object (for example, grounding conductors, cable, pipelines, metal structures) and using a meter 6, the fraction of the magnetic field induced by the currents flowing in the branch is determined. According to the data revealed, where the main part of the current goes. In this case, if less than 50% of the current flows into the ground electrodes, they conclude that there is a fault in the memory 8 and the need to eliminate it.

Measurement of touch voltage on the territory of electrical installations is carried out as follows. Simulate the flow of the fault current through the equipment under test 9. For this, the generator 1 is connected at one end to the equipment 9, and the other to the current electrode 4. After that, a voltage of 1 kΩ, simulating the resistance of the human body and connected between the auxiliary potential electrode 5, is measured with a meter 7 (the location of the human legs) and the point of possible contact with the equipment 9. Then, with its help, the voltage drop is measured on the resistance of the shunt (not shown) of the generator 1. Voltage s touch is determined by calculation.

The determination of soil resistivity is carried out according to the Wenner method.

Thus, the proposed device is universal in functions and provides in full the necessary measurements in accordance with regulatory requirements. The device makes it possible to determine the route of laying the bus connected only on one side, which does not allow you to do any of the known devices for a similar purpose.

In addition, it should be noted a significant improvement in operational parameters: small weight and dimensions, the possibility of simultaneous operation of several teams with devices at the studied area due to the use of selective filters and several fixed frequencies of the master oscillator.

Claims (2)

1. A device for diagnosing underground conductive objects, containing a master oscillator, a recorder, a sensor in the form of an induction converter and a current electrode, characterized in that the potential electrodes and a voltage meter are additionally introduced, while the voltage meter is introduced into the recorder. 2. The device according to claim 1, characterized in that the induction converter is made in the form of an air transformer and placed in an additionally introduced non-magnetic screen.