CN217561636U

CN217561636U - Low-voltage partial discharge test system for iron core and clamping piece of oil-immersed transformer

Info

Publication number: CN217561636U
Application number: CN202123018260.6U
Authority: CN
Inventors: 甘强; 崔光鲁; 张正东; 张鹏飞; 谭婷月; 蒋阳; 孔岩; 杨斌
Original assignee: Maintenance Branch of State Grid Jiangsu Electric Power Co Ltd
Current assignee: Maintenance Branch of State Grid Jiangsu Electric Power Co Ltd
Priority date: 2021-12-03
Filing date: 2021-12-03
Publication date: 2022-10-11
Anticipated expiration: 2031-12-03

Abstract

The utility model discloses a low-voltage partial discharge test system for an iron core and a clamping piece of an oil-immersed transformer, which comprises a non-partial discharge power supply system and a partial discharge test system; the non-partial discharge power supply system is configured to convert input commercial power into non-partial discharge voltage output; the partial discharge test system is configured to collect partial discharge signals at one end and collect high-frequency partial signals at the other end; one of the iron core and the clamping piece of the oil-immersed transformer is configured to input a non-partial discharge voltage and output a partial discharge signal, and the other one of the iron core and the clamping piece of the oil-immersed transformer is grounded and outputs a high-frequency partial signal. The utility model discloses can realize the effective diagnosis to iron core and folder insulation defect.

Description

Low-voltage partial discharge test system for iron core and clamping piece of oil-immersed transformer

Technical Field

The utility model relates to an electric power detects technical field, concretely relates to low-voltage partial discharge test system of oily formula transformer's iron core and folder.

Background

The high-voltage partial discharge test is carried out on the transformer, the iron core and the clamping piece are synchronously detected, and the effect of finding the insulation defects of the iron core and the clamping piece is obvious. However, for a large oil-immersed transformer with a higher voltage level, a conventional partial discharge test is carried out, and the required voltage boosting equipment, field requirements and cost are huge. On the other hand, even if hundreds of kilovolts are applied to the end of the bushing, the induction field intensity of the iron core and the clamping piece at the ground potential is not high, and the voltage difference between the iron core and the clamping piece is only dozens to hundreds of volts.

Disclosure of Invention

The invention aims at providing a low-voltage partial discharge test system for an iron core and a clamping piece of an oil-immersed transformer, which can effectively diagnose the insulation defects of the iron core and the clamping piece.

In order to achieve the purpose of the invention, the technical scheme adopted by the utility model is as follows: a low-voltage partial discharge test system for an iron core and a clamping piece of an oil-immersed transformer comprises a non-partial discharge power supply system and a partial discharge test system;

the non-partial discharge power supply system is configured to convert input commercial power into non-partial discharge voltage output;

the partial discharge test system is configured to collect partial discharge signals at one end and collect high-frequency partial signals at the other end;

one of the iron core and the clamping piece of the oil-immersed transformer is configured to input a non-partial discharge voltage and output a partial discharge signal, and the other one of the iron core and the clamping piece of the oil-immersed transformer is grounded and outputs a high-frequency partial signal.

Among the above-mentioned technical scheme, no partial discharge electrical power generating system is including electric connection's voltage regulator, isolation filter transformer and no partial discharge test transformer in order, an output electric connection of no partial discharge test transformer has the one end of current-limiting resistor, the other end output of current-limiting resistor does not have partial discharge voltage and electric connection to the one end of a coupling capacitor, the other end output partial discharge signal of coupling capacitor, another output ground connection of no partial discharge test transformer.

In the above technical solution, the voltage regulator is configured to output a voltage of 0-250V.

In the above technical solution, the partial discharge free test transformer is configured to output a voltage of 0 to 100 kV.

In the above technical solution, the coupling capacitor is a capacitor without partial discharge.

In the above technical scheme, the partial discharge test system includes an input unit, a high-frequency current sensor and a partial discharge tester host;

the input end of the input unit is configured to collect a partial discharge signal, and the output end of the input unit is electrically connected to one input end of the partial discharge tester host;

the input end of the high-frequency current sensor is configured to collect a high-frequency local signal, and the output end of the high-frequency current sensor is electrically connected to the other input end of the partial discharge tester host.

In the above technical scheme, the partial discharge tester host is an electric pulse method multi-channel partial discharge measuring instrument.

Because of the application of the technical scheme, compared with the prior art, the utility model has the following advantages:

the utility model discloses having opened up new detection thinking to the insulation state aassessment of oily formula transformer's iron core and folder, the whole set of test system convenient to detach equipment is developed the implementation at the production site easily, adopts no office to put electrical power generating system and can effectively restrain external disturbance, can effectively improve the maintenance quality and the fault diagnosis ability of transformer.

Drawings

Fig. 1 is a schematic circuit diagram of a test system according to an embodiment of the present invention.

Wherein: 1. an oil-immersed transformer; 2. an iron core; 3. a clamp; 4. a voltage regulator; 5. an isolation filter transformer; 6. no partial discharge test transformer; 7. a current limiting resistor; 8. a coupling capacitor; 9. an input unit; 10. a high-frequency current sensor; 11. a partial discharge tester host; 12. and (4) a transformer bushing.

Detailed Description

The invention will be further described with reference to the following drawings and examples:

example (b):

referring to fig. 1, the present invention provides a low voltage partial discharge test system for an iron core and a clamp of an oil-immersed transformer, which includes a non-partial discharge power supply system and a partial discharge test system;

one of the iron core 2 and the clamping piece 3 of the oil-immersed transformer 1 is configured to input a non-partial discharge voltage and output a partial discharge signal, and the other one is grounded and outputs a high-frequency partial signal.

The oil-immersed transformer is a large oil-immersed transformer, which generally refers to an oil-immersed transformer with a voltage of more than 110 (66) kV level, and an iron core and a clamping piece are separately led out and grounded.

The no partial discharge electrical power generating system is including electric connection's voltage regulator 4, isolation filter transformer 5 and no partial discharge test transformer 6 in order, an output electric connection of no partial discharge test transformer has the one end of current-limiting resistor 7, no partial discharge voltage and electric connection to the one end of a coupling capacitor 8 are put to current-limiting resistor's other end output, the other end output partial discharge signal of coupling capacitor, no another output ground connection of partial discharge test transformer.

The voltage regulator realizes voltage regulation control of the partial discharge-free test transformer and outputs voltage of 0-250V.

The isolation filter transformer realizes the isolation filtering function on the input power supply;

the non-partial discharge test transformer outputs high voltage, the output voltage is 0-100kV, and the system partial discharge is less than or equal to 5pC;

the current-limiting resistor realizes the protection effect on the power supply loop;

the coupling capacitor is a capacitor without partial discharge, forms a pulse current circulation loop and isolates power frequency high voltage.

The partial discharge test system comprises an input unit 9, a high-frequency current sensor 10 and a partial discharge tester host 11;

Wherein the input unit converts an electric pulse generated by the partial discharge into a pulse voltage.

The high-frequency current sensor is used for collecting high-frequency induced current flowing through a directly grounded iron core or a clamping piece.

The main machine of the partial discharge tester is an electric pulse method multi-channel partial discharge tester.

As shown in fig. 1, the testing system can pressurize the iron core of the large oil-immersed transformer, and also can pressurize the clamping member, for example, the iron core is pressurized, the originally grounded iron core is grounded and disconnected, the output voltage of the partial discharge free power supply system is directly applied to the iron core, the clamping member is kept grounded, and all the outgoing lines of the transformer bushing 12 are grounded.

The non-partial discharge power supply system is connected with commercial power through a voltage regulator, filtering is carried out sequentially through an isolation filter transformer to ensure that an input power supply has no clutter, boosting is carried out through a non-partial discharge test transformer, voltage is directly output through a current-limiting resistor, and a coupling capacitor is connected in parallel at an output end;

the partial discharge test system is connected with the coupling capacitor through the input unit and used for collecting iron core partial discharge signals to the partial discharge tester; sleeving a high-frequency current sensor on the clamping piece, and measuring a high-frequency local signal of the clamping piece to a partial discharge tester;

during testing, the output high voltage without partial discharge can be obtained at the iron core end by adjusting the output voltage of the voltage regulator, and partial discharge test signals on the iron core and the clamping piece can be observed simultaneously on a partial discharge tester host.

Various modifications to the above-described embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The utility model provides a low-voltage partial discharge test system of oily formula transformer's iron core and folder which characterized in that: the system comprises a power supply system without partial discharge and a partial discharge test system;

2. The system for testing low voltage partial discharge of the core and the clip of the oil filled transformer according to claim 1, wherein: the no partial discharge electrical power generating system includes electric connection's voltage regulator, isolation filter transformer and no partial discharge test transformer in order, an output electric connection of no partial discharge test transformer has current-limiting resistor's one end, current-limiting resistor's other end output does not have partial discharge voltage and electric connection to a coupling capacitor's one end, coupling capacitor's other end output partial discharge signal, no partial discharge test transformer's another output ground connection.

3. The system for testing low voltage partial discharge of the core and the clip of the oil filled transformer according to claim 2, wherein: the voltage regulator is configured to output a voltage of 0-250V.

4. The system for testing low voltage partial discharge of an oil filled transformer core and clip of claim 2, wherein: the no partial discharge test transformer is configured to output a voltage of 0-100 kV.

5. The system for testing low voltage partial discharge of an oil filled transformer core and clip of claim 2, wherein: the coupling capacitor is a non-partial discharge capacitor.

6. The system for testing low voltage partial discharge of an oil filled transformer core and clip of claim 1, wherein: the partial discharge test system comprises an input unit, a high-frequency current sensor and a partial discharge tester host;

7. The system for testing low voltage partial discharge of the core and the clip of the oil filled transformer according to claim 6, wherein: the partial discharge tester host is an electric pulse method multi-channel partial discharge measuring instrument.