DEVICE FOR DIAGNOSING THE STATE OF INSULATION OF HIGH-VOLTAGE ELECTRICAL EQUIPMENT

Abstract

This utility model relates to the field of electrical measurements of insulation parameters and can be used to diagnose the condition of paper-oil insulation in power transformer equipment. The technical result of the utility model consists of expanding the functionality of insulating gap testing, increasing the information content and reliability of the obtained test results. A measuring module 3 and a programmable module 4 for processing measurement results are housed in a polymer housing 1, equipped with an operator panel 2. Measuring module 3 is located in compartment 5 of the polymer housing 1, shielded from electromagnetic interference. Modules 3 and 4 are connected via low-speed interfaces with optical isolation. Module 3 contains a test DC voltage generator U and a digital current meter I for the insulating gap.Module 4 is a computer with a pre-installed Linux operating system, equipped with panel 2, which provides the operator with control tools and test results. It is programmed to obtain the time dependence of the digital values ​​of the insulating gap current received from module 3. By analyzing this time dependence, module 4 calculates the parameters characterizing the current state of the insulating gap being tested and displays their values ​​on panel 2. Module 4 is additionally programmed to obtain, based on the calculated parameters, the values ​​of the insulating gap capacitance, the degree of wetting of the solid insulation, the degree of its polymerization and to use the obtained values ​​to determine and indicate on panel 2 the remaining service life of the insulating gap being tested. 2 fig.

Description

[0001] Technical field

[0002] The utility model relates to the field of electrical measurements of insulation parameters and can be used to diagnose the condition of paper-oil insulation of power transformer equipment.

[0003] Technology Level

[0004] A device for diagnosing the insulation condition of high-voltage electrical equipment, the "Megohmmeter S.A. 6547," is known to be selected as a prototype. It comprises an operator panel and a measuring module and a programmable measurement results processing module, both housed in a polymer housing, with informationally linked measurements. The measuring module comprises a test voltage generator and a digital insulating gap current meter, while the measurement results processing module is programmed to obtain the time dependence of digital insulating gap current values ​​and calculate polarization current parameters characterizing the current state of the tested insulating gap. A description of the prototype is available at [https: / / nnn.ktopoverit.ru / prof / opisanie / 61209-15.pdf].

[0005] The disadvantage of the prototype is that it does not provide the necessary information content for non-destructive testing of the condition of the paper-oil insulation system of power transformer equipment. This is due to the lack of an assessment of the degree of moisture and the degree of polymerization of the solid (paper, cellulose) portion of the insulation system. Consequently, the reliability (approximateness) of the residual life estimate of the tested insulation gap is low, without taking into account the aging of the solid portion of the insulation gap. The reduced reliability of the prototype's test results is exacerbated by the influence of external and internal electromagnetic interference on the results of low-level current measurements flowing through the tested insulation gap.

[0006] Disclosure of the essence of the utility model

[0007] The technical result of the utility model consists in expanding the functionality for testing the insulating gap, in increasing the information content and reliability of the obtained test results.

[0008] The subject of the utility model is a device for diagnosing the state of insulation of high-voltage electrical equipment, containing an operator panel and a measuring module and a programmable module for processing measurement results, which are located in a polymer housing and are informationally connected, wherein the measuring module contains a test voltage generator and a digital meter of the insulating gap current, and the module for processing measurement results is programmed with the ability to obtain a time dependence of the digital values ​​of the insulating gap current and calculate the polarization current parameters characterizing the current state of the insulating gap being tested, characterized in that the measuring module is located in a shielded compartment of the polymer housing, the information communication of the modules is carried out by low-speed interfaces with optical isolation,and the measurement results processing module is additionally programmed with the ability to obtain, based on the calculated parameters of the polarization current, the values ​​of the insulating gap capacitance, the degree of wetting of the solid insulation, the degree of its polarization and to use the obtained values ​​to determine and indicate on the operator panel the remaining service life of the tested insulating gap.

[0009] Implementation of a utility model

[0010] Fig. 1 shows a drawing of the assembled device, Fig. 2 shows its polymer housing.

[0011] Figure 1 shows a polymer housing 1, an operator panel 2, a measuring module 3, and a programmable measurement results processing module 4. Measuring module 3 is housed in compartment 5 (Fig. 2) of the polymer housing 1, shielded from electromagnetic interference. Modules 3 and 4 are connected via low-speed optically isolated interfaces.

[0012] Module 3 contains a test DC voltage generator U and a digital insulating gap current meter I. Module 4 is a computer with a pre-installed Linux operating system, equipped with panel 2, which provides the operator with control tools and test results. It is programmed to obtain a time dependence of the digital insulating gap current values ​​received from Module 3. By analyzing this time dependence, Module 4 calculates parameters characterizing the current state of the insulating gap being tested and displays their values ​​on panel 2.

[0013] Panel 2 features a touchscreen display, a mechanical mode switch, and a test start button (for diagnosing the device's condition). The device is powered by a battery located in compartment 5 and equipped with a charging unit.

[0014] Module 4 for processing measurement results is additionally programmed to obtain, based on calculated polarization current parameters, values ​​for the insulating gap capacitance, the degree of moisture content of the solid insulation, and its degree of polymerization. These values ​​are then used to determine and display on panel 2 the remaining service life of the insulating gap being tested. The device operates as follows.

[0015] According to the current values ​​I measured in module 3 T , where T is the time in seconds from the moment of applying the constant test voltage U, module 4 calculates the following parameters characterizing the current state of the tested insulating gap:

[0016] insulation resistance R изол =U / I 600 ;

[0017] Dielectric absorption coefficient (DAR=I 30 / I 60 );

[0018] polarization index (PI=I 60 / I 600 );

[0019] electric capacitance of insulating gap C х ;

[0020] Dielectric discharge coefficient (DD=I 60 / UC x );

[0021] generalized polarization index (TPI=[t⋅(I(t) / I yт -1)] max ).

[0022] Three parameters (DD, TPI, R изол ) of the above, module 4 uses as coordinates for accessing the data of the triangle of possible states of the insulation system, previously loaded into its memory, divided into numbered zones characterizing typical states of the insulation gap.

[0023] The zone number obtained from this call is, in turn, used to extract from the database (created based on previous experience for diagnosing the condition of the corresponding electrical equipment, such as power transformers) regression relationships refined for the given insulation condition zone number. The extracted regression relationships are used to determine additional parameters characterizing the insulation aging processes in the tested insulation gap. These parameters include:

[0024] degree of moisture content of solid (paper) insulation;

[0025] its degree of polymerization;

[0026] Remaining working life.

[0027] The above-described measurement process and processing of its results is controlled by the built-in computer of module 4. Display of test results, as well as work with saved data, is carried out using panel 2, equipped with a ten-inch touch screen.

[0028] Placing the measuring module 3 in the shielded compartment 5 of the polymer housing 1, using low-speed interfaces with optical isolation for information communication between modules 3 and 4, which is not affected by electromagnetic interference, as well as additional processing of the pre-calculated polarization current parameters in the computer of module 4 to determine the degree of moistening and the degree of polymerization of paper (cellulose) insulation, and assess the remaining resource τ ост , characterizing the degree of wear of the materials of the tested insulating gap, made it possible to increase the reliability of the assessment of the general condition of high-voltage power electrical equipment obtained within the framework of comprehensive diagnostic surveys and, thereby, to obtain the above-mentioned technical result of the utility model.

Claims

A device for diagnosing the state of insulation of high-voltage electrical equipment, comprising an operator panel and a measuring module and a programmable measurement results processing module, which are located in a polymer housing and are informationally linked, wherein the measuring module contains a test voltage generator and a digital insulating gap current meter, and the measurement results processing module is programmed with the ability to obtain a time dependence of digital values ​​of the insulating gap current and to calculate polarization current parameters characterizing the current state of the insulating gap being tested, characterized in that the measuring module is located in a shielded compartment of the polymer housing, the information communication between the modules is carried out by low-speed interfaces with optical isolation, and the measurement results processing module is additionally programmed with the ability to obtain, based on the calculated polarization current parameters,values ​​of the capacity of the insulating gap, the degree of wetting of the solid insulation, the degree of its polymerization and the use of the obtained values ​​to determine and indicate on the operator panel the remaining service life of the tested insulating gap,

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