RU90217U1 - DEVICE FOR MONITORING THE CONDITION OF THE GROUNDING EARTH DEVICES OF ELECTRIC INSTALLATIONS - Google Patents

Abstract

A device for monitoring the state of grounding devices of electrical installations, containing a master oscillator, a recorder, a magnetic field sensor, potential and current electrodes, a magnetic field strength meter, a voltage meter, characterized in that a non-volatile memory, a frequency meter, a calibration signal generator, analog switch, calculator and transceiver.

Description

The utility model relates to electromagnetic testing and control equipment and can be used, first of all, to control the quality of grounding devices (memory) of various power facilities, for example, high-voltage substations without opening the ground according to RD 153-34.0-20.525-00, which provides the following diagnostic tasks :

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

- the presence and condition of communications equipment with memory;

- the presence or absence of communication at the intersection of longitudinal and transverse horizontal ground electrodes;

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

- resistance of the electrical installation memory;

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

- soil resistivity

However, none of the currently known devices allows you to control all these parameters with the necessary accuracy and performance.

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.

A device is known 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, PO 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 the touch voltage in potentially dangerous places (on equipment), the ability to measure the resistance of the charger, the ability to measure the resistance of the soil, the ability to identify the paths of current spreading from equipment during lightning strikes, or short circuit, etc. e. currents in the event of an accident. All of the above, as mentioned above, is included in the list of regulatory requirements for the diagnosis of memory.

Closest to the utility model in technical essence is a device for diagnosing underground conductive objects (see certificate for utility model No. 50316 by Borisov R.K. and Koliushko G.M.).

This device for the diagnosis of underground conductive objects, namely for grounding devices (GD), contains a master oscillator, recorder, sensor, current and potential electrodes. The generator provides the ability to tune to several different fixed frequencies. The sensor 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 recorder includes a magnetic field strength meter and a voltage meter. In working condition, the device is connected to the surveyed memory and units of equipment located in the territory occupied by the memory. The specified combination of functional elements of the device allows you to implement:

- 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.

The proposed utility model is based on the task of creating an improved device in order to provide higher metrological characteristics and higher measurement performance.

The problem is solved in that in the registrar of the device for monitoring the state of the grounding devices of electrical installations, containing a master oscillator, a recorder, a magnetic field sensor, potential and current electrodes, a magnetic field strength meter, a voltage meter, non-volatile memory, a frequency meter, a calibration signal shaper are additionally introduced , analog switch, calculator and transceiver.

The introduction of a frequency meter, a shaper of a calibration signal, an analog switch into a device for monitoring the state of the grounding devices of electrical installations allows eliminating the component of the measurement error caused by the mismatch of the frequency setting of the narrow-band filter of the voltage meter and the frequency of the master oscillator due to the temperature effects of operating conditions of use. This is achieved due to the fact that before measurements under conditions of ambient temperature, the frequency of the master oscillator is measured, a test signal of the measured frequency is generated, and the actual transmission coefficient of the voltage meter is determined. The measured calibration factors are stored in non-volatile memory. The frequency of calibration is determined by practical expediency.

In addition, the introduction of a calculator, non-volatile memory and a transceiver eliminates a number of “manual” operations during measurements, such as fixing on a hard copy of the measurement results, calculating the indicator from the measured voltage and current values and preparing test reports.

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

A device for monitoring the state of grounding devices of electrical installations contains a master generator 1, a recorder 2, a magnetic field sensor 3, a magnetic field strength meter 4, current 5 and potential 6 electrodes, a shunt 7, an analog switch 8, a frequency meter 9, a calibration signal shaper 10, a meter 11 voltages, a computer 12, a non-volatile memory 13, and a transceiver 14.

A device for monitoring the state of the grounding devices of electrical installations works as follows.

At the beginning, the actual location of the storage device 15 is determined (laying paths of the grounding devices of the storage device 15). For this, the master oscillator 1 is connected to two different remote points of the memory 15 (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 15 generate an alternating current of a given voltage and frequency. The current spreads along the memory 8, while inducing a magnetic field, the presence of which is determined to identify the 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 reading of the meter 4 of the magnetic field. Gradually passing from one node of the charger 15 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. If necessary, determine the laying path of an earthing switch connected only on one side, as follows. One terminal of the generator 1 is connected to the memory 15, and the second to the current electrode 5. At the same time, the current electrode 5 is driven into the proposed busbar location and moving it along the path determines the location of the latter using the maximum magnetic field.

Next, calibrate the voltage meter. To do this, the output of the master oscillator 1 is connected to the input of the frequency meter 9 and the frequency value of the generator 1 is determined under operating conditions. After that, the calibration signal generator 10 is connected via an analog switch 8 to the input of the voltage meter AND, while the frequency of the calibration signal is set equal to the measured value. The effective signal value is measured and the transmission coefficient of the measuring channel of the voltage meter 11 is determined. The resulting value is stored in non-volatile memory 13.

Measurement of the parameters of the memory is carried out by constructing measuring circuits by analogy with the prototype. The measured values of voltage and current are supplied to a calculator 12, where the values of the memory parameters are calculated, which are stored in non-volatile memory 13. After the entire complex of measurements, the output of the transceiver 14 of the device is connected to the serial port of a personal computer, which receives data and generates test reports of the memory.

Thus, the proposed device is universal in functions and provides higher metrological characteristics and high monitoring performance in comparison with known devices.

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 (1)

A device for monitoring the state of the grounding devices of electrical installations, containing a master oscillator, a recorder, a magnetic field sensor, potential and current electrodes, a magnetic field strength meter, a voltage meter, characterized in that the non-volatile memory, a frequency meter, a calibration signal generator, and an analog are added switchboard, calculator and transceiver.