CN101813731A - Method for judging running state of external arrester of transformer balancing winding - Google Patents

Abstract

The invention discloses a method for judging the running state of an external arrester of a transformer balancing winding, in the technical scheme, a voltage transducer is in bridge connection with the two ends of an arbitrary phase of a three-phase arrester, and the running state of the three-phase arrester is judged by monitoring the voltage of the two ends of the voltage transducer. The invention has the characteristics of stable and accurate output signal, strong antijamming capability, low loss, no influence of environmental factors and the like, 4-20mA standard current output provides convenience for an industrial personal computer to acquire signals on site, and thereby the possibility of remotely monitoring the running state of the arrester can be realized, and the antijamming capability of the system and the data accuracy are improved.

Description

A kind of determination methods of running state of external arrester of transformer balancing winding

Technical field

The present invention relates to the voltage transmission technical field, specifically a kind of determination methods of running state of external arrester of transformer balancing winding.

Background technology

Moving a large amount of high voltage electric equipments in electric system, the security of its power transformer is directly connected to the safe operation of electrical network.Power transformer balance winding is also referred to as stablizes the winding or the tertiary winding, is that a kind of auxiliary triangle connects winding.In the full Y-connection transformer of isolated neutral, the balance winding is used for providing the loop for the third-harmonic component in zero-sequence current and the exciting current.During power transformer balance winding external arrester operate as normal, can effectively reduce the balance winding the various superpotential that may meet with, for the transformer safe operation provides safeguard.Yet, the oxide lightning arrester is owing to reasons such as valve block is aging, electric property degenerates usually cause various faults, and explosion accident also happens occasionally, in case lightning arrester breaks down, just may cause the major accident of transformer short-circuit operation, threaten the safe operation of electric system.

At present, many lightning arrester monitors manufacturer has released relevant monitoring product one after another, but the principle of work of its product all is to realize by the leakage current of monitoring lightning arrester.Lightning arrester leakage current during operate as normal under good running environment is about 0.1～0.25mA.Except can causing owing to inner reason itself leakage current of an arrester increases, when overcast and rainy or external insulation pollution degree was higher, leakage current of an arrester also can increase by tens times, and temperature also produces certain influence to the size of leakage current of an arrester.To a this fruit many because of phenomenon, be difficult to whether to exist internal fault to make accurate judgement to lightning arrester according to the variation of leakage current.Though some producer has adopted the technology of the inside and outside leakage current of lightning arrester being carried out analyzing and processing, in the hope of avoiding the influence of atmospheric conditions, but because residing running environment of transformer and weather conditions change greatly, the state determine effect is not satisfactory, utilizes the mode of monitoring leakage electric current to analyze the lightning arrester running status and still has certain uncertainty.

Summary of the invention

For solving the technical matters of above-mentioned existence, the invention provides a kind of determination methods of running state of external arrester of transformer balancing winding, abandoned by the monitoring leakage current of an arrester and carried out the classic method that state is judged, integrated use technology such as transformation technology, electromagnetic isolation, judged result is not subjected to the influence of running environment state and voltage fluctuation.

For achieving the above object, the technical solution used in the present invention is as follows:

Voltage transmitter is connected across the two ends of any phase of three-phase lightning protector, judges the running status of three-phase lightning protector by the voltage at monitoring voltage transmitter two ends, concrete state is judged as follows:

(1) when the voltage transmitter both end voltage be transformer balance winding wire voltage

Times the time, the three-phase lightning protector operational excellence;

(2) when the voltage transmitter both end voltage is 0, a connected phase lightning arrester damages;

(3) when the voltage transmitter both end voltage is the line voltage of transformer balance winding, one in the two-phase lightning arrester damages mutually in addition.

Monitoring result of the present invention is not subjected to the influence of running environment pollution level and voltage fluctuation, thereby guarantees accurately, in time pinpoints the problems, and gets rid of the lightning arrester fault in the very first time, for the safe operation of power transformer provides reliable guarantee; The voltage transmitter compact conformation, the volume that are adopted are little, in light weight, utilize the voltage transmission technology to realize the isolation and the conversion of electric weight, have stable output signal, accurately, antijamming capability is strong, loss is low, be not subjected to characteristics such as such environmental effects, the normalized current of 4～20mA is output as industrial computer collection in worksite signal and provides convenient, and then make and the lightning arrester running status is carried out remote monitoring become possibility, and improved the degree of accuracy of system's antijamming capability and data.

Description of drawings

Accompanying drawing is a principle schematic of the present invention.

Embodiment:

Describe the present invention below in conjunction with the drawings and specific embodiments:

It is the voltage transmitter of RMPT-20/10.5 that voltage transmitter in the present embodiment adopts the model of being developed for the inventive method specially by Shandong Taikai Transformer Co., Ltd..

The action principle of voltage transmitter is the alternating voltage step-down once more with a transformation, the current signal of output 4～20mA after electromagnetic isolation, rectification, signal amplify, low voltage voltage and data acquisition system (DAS) through conversion are isolated fully, avoid system to be subjected to the interference of strong signal, thereby improve the reliability of system.

By the on-line monitoring of voltage transmitter realization to external arrester of transformer balancing winding, at first to solve the technology realization that high-voltage variable is changed to low-voltage, comprise that needs consider parameters such as the dielectric level of dropping equipment, accuracy rating, low-voltage output institute bringing onto load size.Because it is on-the-spot to be applied to different open-air operations, also to consider factors such as gradation for surface pollution, sea level elevation, environment temperature during the dropping equipment design.Because the limitation of installation site, dropping equipment will accomplish as far as possible that volume is little, in light weight, profile is exquisite attractive in appearance, and this just need take all factors into consideration the relation between the parameters such as no-load voltage ratio, accuracy rating of dropping equipment.Next is to solve the technical matters that low voltage signal is transformed to 4～20mA industrial standard current signal, because the restriction of structural requirement, the secondary voltage of dropping equipment can not be too low.

For solving the technical matters of high-voltage variable being changed to low-voltage, voltage transmitter among the present invention adopts insulating property good insulation material and high performance siliconized plate, under the condition that guaranteed performance requires, produce that compact conformation, volume are little, in light weight, good looking appearance, the low dropping equipment of loss.This dropping equipment technical parameter is as follows:

Rated insulation level: 12/42/75kV;

Gradation for surface pollution: IV level;

Accuracy rating: 10P;

Sea level elevation: 1000m;

Environment temperature :-40～+ 55 ℃.

Transformer balance winding is generally delta connection, and each terminal is drawn with sleeve pipe, and passes through arrester ground, as shown in drawings, being example at b phase lightning arrester two ends cross-over connection voltage transmitter, during the lightning arrester operate as normal, voltage-to-ground that Pa, Pb, Pc are 3 is balance winding wire voltage

Doubly, the voltage at voltage transmitter two ends also is balance winding wire voltage

Doubly; When being short-circuited fault when the damage of b phase lightning arrester, the voltage transmitter both end voltage will reduce to zero; And when a mutually or c phase lightning arrester damage when being short-circuited fault, the voltage at voltage transmitter two ends will rise to balance winding wire voltage.As long as,, just can make judgement to the operation conditions of three-phase lightning protector according to the situation of change of voltage transmitter both end voltage at arbitrary phase lightning arrester two ends cross-over connection voltage transmitter of balance winding.

Therefore, to be example at b phase lightning arrester two ends cross-over connection voltage transmitter, the determination methods of running state of external arrester of transformer balancing winding provided by the invention is specific as follows:

When the voltage transmitter both end voltage is a balance winding wire voltage

Times the time, the three-phase lightning protector operational excellence;

When the voltage transmitter both end voltage was 0, b phase lightning arrester damaged;

When the voltage transmitter both end voltage was the line voltage of balance winding, one in a phase or the c phase lightning arrester damaged mutually.

According to judged result, in time change the fault lightning arrester, avoid because two-phase is damaged the transformer short-circuit accident that causes simultaneously.

Claims (1)

1. the determination methods of a running state of external arrester of transformer balancing winding, it is characterized in that, voltage transmitter is connected across the two ends of any phase of three-phase lightning protector, judges the running status of three-phase lightning protector by the voltage at monitoring voltage transmitter two ends, concrete state is judged as follows:

(1) when the voltage transmitter both end voltage be transformer balance winding wire voltage

Times the time, the three-phase lightning protector operational excellence;

(2) when the voltage transmitter both end voltage is 0, a connected phase lightning arrester damages;

(3) when the voltage transmitter both end voltage is the line voltage of transformer balance winding, one in the two-phase lightning arrester damages mutually in addition.

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