SU1357888A1 - Method and device for diagnosis of electric insulation condition - Google Patents

Abstract

The invention relates to electrical measurements and makes it possible to improve the accuracy of diagnosing the state of electrical insulation of the test object. The device implementing the method comprises a constant voltage source 1, a ballast capacitance 2, a switch 4 and an integrator 8 of thermoelectric current. A thermoelectric converter 6 with a thermocouple 7 is inserted into the device, which allows testing the energy of the desorption charge when the test object is subjected to a test voltage, according to which, based on the dependences of the specific energy and the breakdown voltage on the operation time, isolation of the object of control. 2 sec. f-ly, 2 ill. 1C (L 00 O1 00 OO 00 Fig. 1

Description

The invention relates to electrical measurements and can be used to diagnose the state (electrical strength) of electrical insulation of electrical machines, apparatuses, cables during their manufacture and operation.

The purpose of the invention is to improve the accuracy of diagnosing the state of electrical insulation of an object of control by measuring the levels of absorption properties of the system.

This 3 (Cx) control (and) switch 4, heater 5 of thermoelectric converter 6, thermocouple 7 of this converter, integrator 8 of thermoelectric current (for example, a photocompensation device).

The device works as follows.

The charge or discharge current pulse, the passage through the heater 5 of the thermal converter 6, heats it. When translating

isolation during its operational Yu switch 4 to the position "Discharge

Capacity 3 (Cx) is disconnected from the power source and closed. The discharge current from C heats up element 5, as a result of which a pulse of thermoelectric current integrated by device 8 arises in the thermocouple circuit 7. In the thermocouple circuit, this current pulse in total gives a charge that is linearly related to energy A of the capacitance of the test object.

aging and calculation of the insulation strength for these levels.

FIG. 1 shows a diagram of an apparatus for carrying out the proposed method; in FIG. 2 - U.p and -i dependence on aging time.

The method is carried out as follows.

Previously known methods carry out artificial aging of identical objects of control, for which the dependence of the unp (t) breakdown voltage on operation time is constructed (removed). At the same time build dependency

B (t) AltI,

where A (t) is the desorption charge energy;

С - capacity of the tested system

isolation

The dependences Un (t) and (t) are well adjusted and their product is approximate.

1. A method for diagnosing the state of electrical insulation, consisting in acting on a test object by a test voltage, characterized in that, in order to increase the accuracy of diagnostics of the state of electrical insulation, the desorption charge energy is measured, on which, based on The dependences of the specific energy and voltage of the sample on the time of operation determine the state of isolation of the test object.

2. The device for diagnosing is perturbed is equal to the constant coefficient K of the SO of electrical isolation, consisting

(Fig. 2).

Proper

from a constant voltage source, a baldastic capacitance, a switch and a resistor, the first terminal of which is connected to the first terminal of the control object, the second terminal of which is connected to the first terminal

insulation strength test is as follows. Determine the capacity of the test object at an industrial frequency. Then the object

the control is charged to a potential difference of the switch, the second terminal of which is the Ui connection, and then the control object is discharged, the wire is at the same time measuring the energy A (t). According to the measured value of A (t) and pre-built dependencies

B (t) and Ur, (t) judge the state of isolation of the test object

TO

4o (t) -o1

B (t) is connected to the first output of a parallel-connected source of constant voltage and ballast capacitance, the second output of which is connected to the second output of the resistor and the third output of the switch, characterized in that, in order to improve the accuracy of the diagnosis of the insulation, A thermoelectric converter with a thermocouple connected to a thermoelectric current integrator is introduced, adjacent to the first output of a parallel connected DC voltage source and ballast capacitance, the second output of which is connected to the second The output of the resistor and the third output of the switch, characterized in that, in order to improve the accuracy of isolation diagnosis, a thermoelectric converter with a thermocouple connected to the thermoelectric current integrator is inserted into it, the device consists of a constant voltage source 1, ballast capacitance 2 (Co), which makes it possible to provide a constant to the resistor, is made in the form of a heated U voltage when charging the capacitance of the thermoelectric converter objects.

This 3 (Cx) control (and) switch 4, heater 5 of thermoelectric converter 6, thermocouple 7 of this converter, integrator 8 of thermoelectric current (for example, a photocompensation device).

The device works as follows.

The charge or discharge current pulse, the passage through the heater 5 of the thermal converter 6, heats it. When translating

 switch 4 to “Discharge” position

switch 4 to “Discharge” position

Capacity 3 (Cx) is disconnected from the power source and closed. The discharge current from C heats up element 5, as a result of which a pulse of thermoelectric current integrated by device 8 arises in the thermocouple circuit 7. In the thermocouple circuit, this current pulse in total gives a charge that is linearly related to energy A of the capacitance of the test object.

Claims (2)

1. A method for diagnosing the state of electrical insulation, consisting in acting on a test object by a test voltage, characterized in that, in order to increase the accuracy of diagnostics of the state of electrical insulation, the desorption charge energy is measured, on which, based on The dependences of the specific energy and voltage of the sample on the time of operation determine the state of isolation of the test object. 2. A device for diagnosing the state of electrical insulation, consisting from a constant voltage source, a baldastic capacitance, a switch and a resistor, the first terminal of which is connected to the first terminal of the control object, the second terminal of which is connected to the first terminal  switch, the second output of which is switch, the second output of which is A dinene with the first output of a parallel-connected constant voltage source and ballast capacitance, the second output of which is connected to the second output of the resistor and the third output of the switch, characterized in that, in order to improve the accuracy of diagnostics of the insulation, a thermoelectric converter with a thermocouple is inserted into it connected to the thermoelectric current integrator, the resistor is designed as a preheater of the thermoelectric converter. "Nj