CN106291296A - A kind of partial discharge of transformer defects simulation device and method - Google Patents

Abstract

The invention discloses a transformer partial discharge defect simulation device and method. The device includes a power transformer, a voltage regulator and an implantable discharge source; wherein, the voltage regulator and the implantable discharge source are connected with the power transformer connected; the head and tail ends of the low-voltage winding coil of the power transformer are disconnected, and the tail ends are respectively connected to the x-end, y-end and z-end provided outside the housing through 10kV bushings; the high-voltage voltage regulating coil of the power transformer is The first, fourth, and seventh voltage regulation gear ends are respectively connected to the outside of the power transformer through 35kV bushings, and connected to the implantable discharge source; the simulation device is low in cost by reconnecting the internal winding connection of the transformer. It is easy to use; it can simulate various types of partial discharge in different positions inside the transformer, and can truly reflect the partial discharge inside the transformer, which is conducive to timely detection and repair of partial discharge faults in the transformer and prolongs the operating life of the transformer.

Description

A transformer partial discharge defect simulation device and method

technical field

The invention belongs to the technical field of electric power engineering, and in particular relates to a transformer partial discharge defect simulation device and method.

Background technique

The transformer is the core equipment of the power grid system, and it is also one of the most expensive equipment. Its operation status directly affects the safety and stability of the entire power grid system. Due to the reasons of design and manufacture, process materials, operation and maintenance, and operating environment, internal insulation faults of transformers occur from time to time. Partial discharges are generally generated in the initial stage of transformer internal insulation faults, so it is very necessary to ensure the sensitivity and accuracy of partial discharge signal monitoring. At present, the partial discharge detection methods of transformers mainly include pulse current method, ultrasonic method and ultra-high frequency method. However, due to the complex internal structure of transformers, the accuracy and effectiveness of these detection methods have certain deficiencies.

Contents of the invention

The invention aims at the deficiencies in the prior art, and builds a simulation device by improving the connection mode of the transformer coil winding to accurately simulate and measure various partial discharge defects.

A transformer partial discharge defect simulation device, including a power transformer 1, a voltage regulator 2 and an implantable discharge source 3;

Wherein, both the voltage regulator 2 and the implantable discharge source 3 are connected to the power transformer 1;

The head and tail ends of the middle and low voltage winding coils of the power transformer are disconnected, and the tail ends are respectively connected to the x end, y end and z end provided outside the housing through a 10kV bushing;

The first, fourth, and seventh voltage regulation gear ends of the high-voltage voltage regulation coil in the power transformer are respectively connected to the outside of the power transformer through 35kV bushings, and connected to the implantable discharge source;

The three-phase A, B, C high-voltage coils of the power transformer are provided with capacitive bushings.

The wall of the oil tank of the power transformer is provided with a UHF flange interface, and an observation window is arranged on the UHF flange interface.

The end of the capacitive bushing outside the three-phase A, B, C high-voltage coils of the power transformer is provided with an end-screen measurement terminal.

A method for simulating partial discharge defects of a transformer, using the above-mentioned transformer partial discharge defect simulating device, between any two of the first, fourth, and seventh voltage regulation gear ends of the A-phase voltage regulation coil of a power transformer The implantable discharge source is indirectly connected, and the excitation power is connected between the first end a and the tail end x of the low-voltage coil winding of the A phase, and then the first end A and the B end of the A-phase and B-phase high-voltage coil windings of the power transformer are connected respectively. Terminal and O terminal are grounded, and the amplitude, phase and frequency spectrum of the partial discharge signal on the other terminals are measured.

The output end of the voltage regulation is connected with the low voltage end of the transformer through a non-discharge cable. By changing the output voltage of the voltage regulator to adjust the voltage of the low-voltage winding of the transformer, that is, the excitation voltage, under the action of the electromagnetic induction of the transformer itself, the required voltage is obtained on the high and low voltage sides of the transformer respectively to meet the needs of simulating various discharges.

When the B terminal is grounded, measure the signal amplitude, phase and frequency spectrum on the A terminal, C terminal, O terminal, between by, between cz and the core terminal respectively.

When the A terminal is grounded, measure the signal amplitude, phase and frequency spectrum on the B terminal, C terminal, O terminal, between by, between cz and the core terminal respectively.

When the O terminal is grounded, measure the signal amplitude, phase and frequency spectrum on the A terminal, B terminal, C terminal, between by, between cz and the core terminal respectively.

Connect y-terminal and/or c-terminal to ground. Shielding treatment is performed to facilitate the location of discharge defects.

Beneficial effect

The invention provides a transformer partial discharge defect simulation device and method, the device includes a power transformer, a voltage regulator and an implantable discharge source; wherein, both the voltage regulator and the implantable discharge source are connected to the power transformer connected; the head and tail ends of the low-voltage winding coil of the power transformer are disconnected, and the tail ends are respectively connected to the x-end, y-end and z-end provided outside the housing through 10kV bushings; the high-voltage voltage regulating coil of the power transformer is The first, fourth, and seventh voltage regulation gear ends are respectively connected to the outside of the power transformer through 35kV bushings, and are connected to the implantable discharge source; the three-phase A, B, and C high-voltage coils of the power transformer are equipped with Capacitive bushing. The simulation device is low in cost and easy to use by reconnecting the winding wires inside the transformer; it can simulate various types of partial discharge in different positions inside the transformer, and can truly reflect the partial discharge inside the transformer. It is of great significance to test the accuracy of the transformer partial discharge detection equipment and to study the transmission characteristics of the transformer partial discharge signal inside the transformer. It is conducive to timely detection and repair of transformer partial discharge faults, and prolongs the operating life of transformers.

Description of drawings

Fig. 1 is the overall structural representation of device of the present invention;

Fig. 2 is a schematic diagram of the wiring connection of the inner winding of the transformer in the prior art;

Fig. 3 is a schematic diagram of the internal winding connection of the transformer in the simulation device of the present invention;

Explanation of symbols: 1-power transformer, 2-voltage regulator, 3-implantable discharge source.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Referring to Fig. 1, a transformer partial discharge defect simulation device includes a power transformer 1, a voltage regulator 2 and an implantable discharge source 3;

Wherein, both the voltage regulator 2 and the implantable discharge source 3 are connected to the power transformer 1;

The head and tail ends of the middle and low voltage winding coils of the power transformer are disconnected, and the tail ends are respectively connected to the x end, y end and z end provided outside the housing through a 10kV bushing;

The first, fourth, and seventh voltage regulation gear ends of the high-voltage voltage regulation coil in the power transformer are respectively connected to the outside of the power transformer through 35kV bushings, and connected to the implantable discharge source;

The three-phase A, B, C high-voltage coils of the power transformer are provided with capacitive bushings.

Power transformer 1 is transformed with a 35kV transformer, its main parameters are as follows: model SZ10-5000/35, rated capacity 5000kVA, rated voltage and tap range: (35±3*2.5%)/10.5kV, connection method: YD11.

The internal wiring before transformation is shown in Figure 2, and the internal wiring after transformation is shown in Figure 3.

The content of the transformation is as follows: (1) Transformation of the low-voltage winding, open the head and tail connection of the transformer △ connection winding, and lead the x, y, and z terminals to the outside of the housing by adding three 10 kV bushings; (2) Transformation of the high-voltage winding , select the 1st, 4th, and 7th tap lead wires, and lead them to the outside through 35kV bushings, which are used to connect the inter-turn short-circuit discharge source model; (3) redesign the fuel tank, increase the UHF flange interface and observation window; ( 4) Replace the three high-voltage bushings with capacitive bushings with end-screen measurement terminals.

The voltage regulator 2 is a three-phase voltage regulator, the input voltage is three-phase AC 380V, the output three-phase AC is adjustable from 0-15.75kV, and the capacity is 10kVA. It has step-up/down control, voltage and current display, over-current protection, etc.

The output end of the voltage regulation is connected with the low voltage end of the transformer through a non-discharge cable. By changing the output voltage of the voltage regulator to adjust the voltage of the low-voltage winding of the transformer, that is, the excitation voltage, under the action of the electromagnetic induction of the transformer itself, the required voltage is obtained on the high and low voltage sides of the transformer respectively to meet the needs of simulating various discharges.

Implantable discharge source 3, the discharge types include: surface discharge, suspension discharge, suspension discharge, turn-to-turn discharge, oil bubble discharge, tip discharge, oil gap discharge, magnetic shield discharge, electric shield discharge.

(1) ax is connected to the excitation power supply, and an external inter-turn short-circuit discharge source is connected between the two leads of the high-voltage A-phase voltage regulating winding to simulate various types of inter-turn discharge faults. By changing the grounding mode of the A, B, and O terminals , to realize the transmission and signal identification of discharge signals in different paths under each discharge defect;

(2) B grounding, ax excitation, simulate the discharge in the middle of the high-voltage coil, measure at A, C, O, by, cz, core terminals, and analyze the amplitude, phase and frequency spectrum of partial discharge signals;

(3) A grounding, ax excitation, simulate the discharge in the middle of the high-voltage coil, measure at B, C, O, by, cz, core terminals, and analyze the partial discharge signal amplitude, phase and frequency spectrum;

(4) O grounding, ax excitation, simulate high voltage coil tail discharge, measure at A, B, C, by, cz, iron core terminals, analyze partial discharge signal amplitude, phase and frequency spectrum;

(5) When it is necessary to accurately locate the partial discharge defect position, ground the y-terminal and/or c-terminal to realize shielding.

The above uses specific examples to illustrate the present invention, just to help those of ordinary skill in the art understand well. Without departing from the spirit and scope of the present invention, various inferences, modifications and substitutions can also be made to the specific embodiments of the present invention. These changes and substitutions will all fall within the scope defined by the claims of the present invention.

Claims (9)

1. a partial discharge of transformer defects simulation device, it is characterised in that include power transformer (1), pressure regulator (2) with And implantable discharge source (3)；

Wherein, pressure regulator (2) is all connected with described power transformer (1) with implantable discharge source (3)；

The two ends of described power transformer mesolow winding coil disconnect, and tail end is respectively by 10kV sleeve pipe and hull outside X end, y end and the z end arranged is connected；

First, the four, the 7th pressure regulation gear ends of described power transformer mesohigh voltage regulation coil are respectively by 35kV sleeve pipe even It is connected to outside power transformer, is connected with implantable discharge source (3)；

Three-phase A, B, C high-tension coil of described power transformer is outside equipped with condenser-type terminal.

Device the most according to claim 1, it is characterised in that be provided with hyperfrequency on the oil tank wall of described power transformer It is provided with watch window on flange-interface, and hyperfrequency flange-interface.

Device the most according to claim 2, it is characterised in that outside three-phase A, B, C high-tension coil of described power transformer Condenser-type terminal end be provided with end shield measurement terminal.

4. a partial discharge of transformer defects simulation method, it is characterised in that use the change described in any one of claim 1-3 Depressor shelf depreciation defects simulation device, at first, the four, the 7th pressure regulation gear ends of the A phase voltage regulation coil of power transformer Accessing implantable discharge source between middle any two gear end, the low-voltage coil winding head end a and tail end x in A phase is indirectly Enter excitation power supply, more respectively by the A phase of power transformer, the head end A end of B phase high-tension coil winding, B end and O end ground connection, survey Measure Partial discharge signal amplitude, phase place and the frequency spectrum on remaining terminal.

Method the most according to claim 4, it is characterised in that when B end ground connection, measures A end, C end, O end, by respectively Between, signal amplitude, phase place and frequency spectrum between cz and on terminal unshakable in one's determination.

Method the most according to claim 4, it is characterised in that when A end ground connection, measures B end, C end, O end, by respectively Between, signal amplitude, phase place and frequency spectrum between cz and on terminal unshakable in one's determination.

Method the most according to claim 4, it is characterised in that when O end ground connection, measures A end, B end, C end, by respectively Between, signal amplitude, phase place and frequency spectrum between cz and on terminal unshakable in one's determination.

8. according to the method described in any one of claim 4-7, it is characterised in that by y end and/or c end ground connection.

Method the most according to claim 8, it is characterised in that described implantable discharge source includes following several types:

Creeping discharge, suspended discharge, suspended discharge, turn-to-turn electric discharge, bubble in oil electric discharge, point discharge, oil clearance electric discharge, magnetic shield Electric discharge and electric screen electric discharge.