CN104714158A - Alternating-current ultrahigh voltage main transformer and regulation transformer combined partial discharge testing system and method - Google Patents

Abstract

The invention provides an alternating-current ultrahigh voltage main transformer and regulation transformer combined partial discharge testing system which comprises a variable frequency power source, a testing transformer, a compensation reactor, a capacitive voltage divider, partial discharge detection systems, a regulation compensation transformer and an alternating-current ultrahigh voltage main transformer. The output end of the variable frequency power source is connected with the low voltage side of the testing transformer. The high voltage side of the testing transformer is connected with the low voltage side of the regulation compensation transformer. The high voltage side of the regulation compensation transformer is connected with the low voltage side of the alternating-current ultrahigh voltage main transformer. The compensation reactor and the capacitive voltage divider are connected between the testing transformer and the regulation compensation transformer in parallel. The alternating-current ultrahigh voltage main transformer and the regulation compensation transformer are each provided with one partial discharge detection system. Alternating-current ultrahigh voltage main transformer and regulation transformer on-site partial discharge testing can be completed at a time, so that the testing procedures are greatly simplified; during testing, electrical connecting wires of the alternating-current ultrahigh voltage main transformer and the regulation compensation transformer do not need to be disassembled, on-site workloads are lowered, and the working efficiency is improved.

Description

AC extra high voltage main transformer modulation associating partial discharge test system and method

Technical field

The present invention relates to Power Transformer in Field test method, specifically a kind of AC extra high voltage main transformer modulation associating partial discharge test system and method.

Background technology

1000kV AC extra high voltage power transmission engineering is the ac transmission engineering that electric pressure is the highest in the world at present, along with southeast Shanxi-Nanyang-Jingmen UHVAC demonstration project and extension project, Wan electricity Dong send in succession putting into operation of Huainan-Shanghai AC extra high voltage power transmission engineering, AC extra high voltage presents rapid growth momentum in China.

AC extra high voltage transformer is one of AC extra high voltage power transmission engineering the most expensive most important equipment.In order to ensure transformer production, installation quality, searching the hidden danger of Transformer, needing to carry out transformer handing-over and prerun test at the scene.For AC extra high voltage transformer, be that difficulty is maximum, examination is the strictest with induced over voltage withstand test (ACLD, usually referred to as partial discharge test) during measurement of partial discharge long, to one of the sensitiveest handing-over prerun test of inside transformer insulation defect reflection.

The body of extra-high voltage transformer and regulating compensation part branch mailbox, because electric pressure is high, size large, for the ease of transport, are arranged, are main body transformer and regulating compensation transformer by extra-high voltage transformer.

At present, the general AC extra high voltage partial discharge of transformer measuring method of China carries out measurement of partial discharge to main body transformer and regulating compensation transformer respectively, and this measuring method mainly exists following problem:

1) the transformer insulated examination of regulating compensation is inadequate.

2) need the connecting line of dismounting, reduction main transformer modulation, workload is large.

3) to twice local discharge test be carried out, need that testing equipment is many, efficiency is low.

Given this, set about have developed AC extra high voltage main transformer modulation associating partial discharge test method and test unit.

Summary of the invention

The object of the invention is the blank in order to overcome prior art existence and deficiency, providing a kind of AC extra high voltage main transformer modulation to combine partial discharge test system and method, test routine is greatly simplified, reducing work on the spot amount, increase work efficiency.

The present invention adopts following technical scheme:

A kind of AC extra high voltage main transformer modulation associating partial discharge test system, comprise variable-frequency power sources, testing transformer, compensation reactor, capacitive divider, partial discharge detecting system, and subjects regulating compensation transformer and AC extra high voltage main body transformer, the output terminal of variable-frequency power sources is connected with the low-pressure side of testing transformer, the high-pressure side of testing transformer is connected with the low-pressure side of regulating compensation transformer, the high-pressure side of regulating compensation transformer is connected with the low-pressure side of AC extra high voltage main body transformer, the compensation reactor for compensating perceptual capacity and the capacitive divider for measuring is parallel with between testing transformer and regulating compensation transformer, AC extra high voltage main body transformer and regulating compensation transformer are all equipped with partial discharge detecting system.

A kind of AC extra high voltage main transformer modulation associating partial discharge test method, complete AC extra high voltage main transformer modulation scene associating partial discharge test by above-mentioned pilot system, concrete steps are:

Step one, connection variable-frequency power sources, testing transformer, compensation reactor, capacitive divider, partial discharge detecting system, and subjects AC extra high voltage main body transformer and regulating compensation transformer, form associating partial discharge test loop, AC extra high voltage main transformer modulation scene;

Step 2, put measuring junction in AC extra high voltage main body high voltage side of transformer, medium voltage side, low-pressure side and regulating compensation high voltage side of transformer 4 offices and carry out pulse matching, and record mutual office and put transmission and compare relation;

Step 3, associating partial discharge test loop, AC extra high voltage main transformer modulation scene is carried out to pressurization drawn game and put measurement, wherein regulating compensation transformer is both as subjects, serve as again the effect of testing transformer, AC extra high voltage main-transformer and regulating compensation transformer reach local discharge test voltage simultaneously, and partial discharge detecting system completes the measurement of partial discharge of AC extra high voltage main-transformer and regulating compensation transformer simultaneously;

Step 4, to put measurement result as office abnormal, carries out analyzing and judging according to shelf depreciation localization method.

Technical scheme of the present invention has following beneficial effect:

1, achieve AC extra high voltage main transformer modulation associating Partial Discharge Testing on Site at home and abroad first, be applicable to domestic all AC extra high voltage transformer field partial discharge tests;

2, AC extra high voltage main transformer and regulating compensation change Partial Discharge Testing on Site once complete, and test routine is greatly simplified, improves work efficiency;

3, during the independent local discharge test of AC extra high voltage main transformer, low-pressure side precharge is generally 173.2kV; Body becomes and modulation associating local discharge test, due to two-stage boosting, only need exchange and become tap-changing windings applying voltage 45.6kV (for station, Jingmen AC extra high voltage transformer), therefore testing equipment output voltage drops to 45.6kV from 173.2kV, thus trial voltage is more prone to, the testing equipment such as variable-frequency power sources, compensation reactor is greatly simplified, has saved experimentation cost;

4, match to examine with the insulation of AC extra high voltage main transformer, regulating compensation become apply voltage comparatively its routine tests time greatly increase, and increase the insulation examination dynamics of modulation, make the insulation of modulation examine science and comprehensively more;

5, the electrical cable that during test, AC extra high voltage main transformer and regulating compensation become need not be removed, and reduces work on the spot amount, improves work efficiency.

Accompanying drawing explanation

Fig. 1 is the structural principle block diagram of AC extra high voltage main transformer modulation of the present invention associating partial discharge test system;

Fig. 2 is partial discharge test pressurization protocols schematic diagram of the present invention.

Wherein: 1-variable-frequency power sources; 2-testing transformer; 3-compensation reactor; 4-capacitive divider; 5-partial discharge detecting system; 6-regulating compensation transformer; 7-AC extra high voltage main body transformer.

Embodiment

Below in conjunction with the accompanying drawing in the present invention, the technical scheme in the present invention is clearly and completely described.

Refer to Fig. 1, AC extra high voltage main transformer modulation associating partial discharge test system of the present invention comprises variable-frequency power sources 1, testing transformer 2, compensation reactor 3, capacitive divider 4, partial discharge detecting system 5, and subjects regulating compensation transformer 6 and AC extra high voltage main body transformer 7, wherein the output terminal of variable-frequency power sources 1 is connected with the low-pressure side of testing transformer 2, the high-pressure side of testing transformer 2 is connected with the low-pressure side of regulating compensation transformer 6, the high-pressure side of regulating compensation transformer 6 is connected with the low-pressure side of AC extra high voltage main body transformer 7, the compensation reactor 3 for compensating perceptual capacity and the capacitive divider 4 for measuring is parallel with between testing transformer 2 and regulating compensation transformer 6, AC extra high voltage main body transformer 7 and regulating compensation transformer 6 are all equipped with partial discharge detecting system 5, concrete, in AC extra high voltage main body transformer 7 high-pressure side, medium voltage side, partial discharge detecting system 5 is installed at low-pressure side and bottom shielding of bushing place, four, regulating compensation transformer 6 high-pressure side respectively.

AC extra high voltage main transformer modulation associating local discharge test adopts variable-frequency power sources 1 to supply testing transformer 2 low-pressure side, testing transformer 2 high-pressure side applies trial voltage to modulation (regulating compensation transformer 6) low-pressure side, and the effect of testing transformer 2 is that the voltage exported is elevated to modulation low-pressure side trial voltage 45.6kV.Modulation high-pressure side is that body becomes (AC extra high voltage main body transformer 7) low-pressure side voltage supply, and the excitation voltage of AC extra high voltage main body transformer 7 local discharge test is reached $U1=1.5\mathrm{Um}/\sqrt{3}=1.5\×1100/\sqrt{3}=952.7\mathrm{kV},$ The measuring voltage of local discharge test reaches $U2=1.3\mathrm{Um}/\sqrt{3}=1.3\×1100/\sqrt{3}=825.6\mathrm{kV}.$ The parameter of the testing equipment such as variable-frequency power sources 1, testing transformer 2 is determined according to above-mentioned voltage.

Each parameters of operating part:

1, variable-frequency power sources 1

Power supply inputs: 380 (1 ± 10%) V, three-phase, 50Hz;

Output voltage: 0 ~ 350V, single-phase, continuously adjustabe;

Output power: 2 × 400kW

Operating frequency range: 30Hz ~ 300Hz;

Frequency adjustment resolution: 0.1Hz;

Output waveform aberration rate :≤1.0%;

Output voltage instability :≤1.0%;

Partial discharge quantity :≤50pC.

2, testing transformer 2

Rated capacity: >=600kVA;

Rated voltage: 60/0.4kV or 55/0.35kV;

Rated frequency: 100Hz;

The number of phases: single-phase;

Polarity: I, I0;

Partial discharge quantity: under rated voltage, the partial discharge quantity≤50pC of HV Terminal.

3, compensation reactor 3

Rated voltage: 50kV;

Rated current: >=60A;

Rated frequency: 100Hz;

Saturation characteristic: when 0% ~ 100% rated voltage, its volt-ampere characteristic is linear;

Partial discharge quantity: under rated voltage, partial discharge quantity≤50pC.

4, other parts are function instrument.

The present invention also provides a kind of AC extra high voltage main transformer modulation to combine partial discharge test method, and it adopts above-mentioned pilot system to complete AC extra high voltage main transformer modulation scene associating partial discharge test, and concrete steps are:

Step one, connection variable-frequency power sources 1, testing transformer 2, compensation reactor 3, capacitive divider 4, partial discharge detecting system 5, and subjects AC extra high voltage main body transformer 7 and regulating compensation transformer 6, form associating partial discharge test loop, AC extra high voltage main transformer modulation scene;

Step 2, in AC extra high voltage main body transformer 7 high-pressure side, medium voltage side, low-pressure side and 4, regulating compensation transformer 6 high-pressure side office put measuring junction and carry out pulse matching, and record mutual office and put transmission and compare relation;

Step 3, associating partial discharge test loop, AC extra high voltage main transformer modulation scene is carried out to pressurization drawn game and is put measurement, pressurization protocols as shown in Figure 2:

AC extra high voltage main body transformer 7 high-pressure side pre-add (excitatory) voltage U 1=952.7kV, regulating compensation transformer 6 high-pressure side pre-add (excitatory) voltage U 1=173.2kV, during test frequency >=100Hz, pressing time T=100 × 60/fs; During test frequency <100Hz, T=60s.Measuring voltage U2=825.6kV is put in AC extra high voltage main body transformer 7 high-pressure side office, and measuring voltage U2=150.1kV is put in regulating compensation transformer 6 high-pressure side office, pressing time 60min; AC extra high voltage main transformer voltage U 3=698.6kV, regulating compensation transformer voltage U3=127.0kV.

The present invention matches to examine with the insulation of AC extra high voltage main transformer, the applying voltage of regulating compensation transformer 6 increases greatly compared with during its routine tests, office puts measuring voltage and is increased to 150.1kV by 109.1kV, and increase the insulation examination dynamics of modulation, make the insulation of modulation examine science and comprehensively more.

During the independent local discharge test of AC extra high voltage main transformer, low-pressure side precharge and testing equipment output voltage are generally 173.2kV, the present invention adopts body to become and modulation associating local discharge test, due to two-stage boosting, only need exchange modified tone pressure compensator transformer 6 and apply voltage 45.6kV (for station, Jingmen AC extra high voltage transformer), therefore the output voltage of testing transformer 2 drops to 45.6kV from 173.2kV, thus trial voltage is more prone to, the testing equipment such as variable-frequency power sources, compensation reactor is greatly simplified, has saved experimentation cost.

As shown in Figure 2, when applying trial voltage, switch on power under the voltage being not more than U2/3; Rise to U3, keep 5 minutes, record electric discharge value; Then raised voltage without exception, to U2, keeps 5 minutes, record electric discharge value; Raised voltage more without exception, to U1, keeps T second; Then, reduce voltage immediately incessantly to U2, keep 60min, carry out measurement of partial discharge, during this period, every 5 minutes record single step of releasing charge values; Reduce voltage again to U3, keep 5 minutes, record electric discharge value; Finally reduce voltage to cut off the electricity supply to during below U2/3, off-test.

Step 4, to put measurement result as office abnormal, carries out analyzing and judging according to multiple methods such as " calibration of four-terminal measurement-four end " shelf depreciation localization methods.

Advantage of the present invention and good effect: in the present invention, regulating compensation transformer depressor is subjects, serves as again the effect of testing transformer; AC extra high voltage main-transformer and regulating compensation transformer depressor reach local discharge test voltage simultaneously, partial discharge detecting system completes the measurement of partial discharge of AC extra high voltage main transformer and regulating compensation transformer simultaneously, AC extra high voltage main transformer and modulation Partial Discharge Testing on Site once complete, test routine is greatly simplified, improves work efficiency; The required voltage that applies of testing equipment reduces greatly, obtains trial voltage and is more prone to, the testing equipment such as variable-frequency power sources, compensation reactor is greatly simplified, has saved experimentation cost; Increase the insulation examination dynamics of modulation, make the insulation of modulation examine science and comprehensively more; The electrical cable that during test, AC extra high voltage main transformer and regulating compensation become need not be removed, and reduces work on the spot amount, improves work efficiency.

The above; be only the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, anyly belongs to those skilled in the art in the technical scope that the present invention discloses; the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claim.

Claims (2)

1. an AC extra high voltage main transformer modulation associating partial discharge test system, comprise variable-frequency power sources (1), testing transformer (2), compensation reactor (3), capacitive divider (4), partial discharge detecting system (5), and subjects regulating compensation transformer (6) and AC extra high voltage main body transformer (7), it is characterized in that: the output terminal of variable-frequency power sources (1) is connected with the low-pressure side of testing transformer (2), the high-pressure side of testing transformer (2) is connected with the low-pressure side of regulating compensation transformer (6), the high-pressure side of regulating compensation transformer (6) is connected with the low-pressure side of AC extra high voltage main body transformer (7), the compensation reactor (3) for compensating perceptual capacity and the capacitive divider (4) for measuring is parallel with between testing transformer (2) and regulating compensation transformer (6), AC extra high voltage main body transformer (7) and regulating compensation transformer (6) are all equipped with partial discharge detecting system (5).

2. an AC extra high voltage main transformer modulation associating partial discharge test method, is characterized in that: complete AC extra high voltage main transformer modulation scene associating partial discharge test by pilot system described in claim 1, concrete steps are:

Step one, connection variable-frequency power sources (1), testing transformer (2), compensation reactor (3), capacitive divider (4), partial discharge detecting system (5), and subjects AC extra high voltage main body transformer (7) and regulating compensation transformer (6), form associating partial discharge test loop, AC extra high voltage main transformer modulation scene;

Step 2, in AC extra high voltage main body transformer (7) high-pressure side, medium voltage side, low-pressure side and 4, regulating compensation transformer (6) high-pressure side office put measuring junction and carry out pulse matching, and record mutual office and put transmission and compare relation;

Step 3, associating partial discharge test loop, AC extra high voltage main transformer modulation scene is carried out to pressurization drawn game and put measurement, wherein regulating compensation transformer (6) is both as subjects, serve as again the effect of testing transformer, AC extra high voltage main-transformer (7) and regulating compensation transformer (6) reach local discharge test voltage simultaneously, and partial discharge detecting system (5) completes the measurement of partial discharge of AC extra high voltage main-transformer (7) and regulating compensation transformer (6) simultaneously;

Step 4, to put measurement result as office abnormal, carries out analyzing and judging according to shelf depreciation localization method.