CN103983859A

CN103983859A - Transformer dielectric loss and capacitance on-line measurement device

Info

Publication number: CN103983859A
Application number: CN201410241940.XA
Authority: CN
Inventors: 于啸; 吴仕哲; 郭宇维; 孙振
Original assignee: State Grid Corp of China SGCC; State Grid Tianjin Electric Power Co Ltd
Current assignee: State Grid Corp of China SGCC; State Grid Tianjin Electric Power Co Ltd
Priority date: 2014-06-03
Filing date: 2014-06-03
Publication date: 2014-08-13

Abstract

The invention discloses a transformer dielectric loss and capacitance on-line measurement device. The voltage output end of a dielectric loss instrument is electrically connected with the primary of a test transformer, and the secondary of the test transformer is electrically connected with a cable copper bar which is connected with the high voltage side of the transformer to be measured. The transformer dielectric loss and capacitance on-line measurement device has the advantages that safety running and normal maintenance can be achieved, manpower and material resources are saved, and the requirements of innovation and effect improvement are well met. By the adoption of the transformer dielectric loss and capacitance on-line measurement device, a lead in the transformer can be prevented from being dismantled in the test process, the physical connection status of equipment in a transformer substation is not changed, the problems that oil of a transformer casing pipe is prone to leakage in the recovery process, and a connector is hot after power supply is recovered due to the fact that the voltage cable lead on the high voltage side of the transformer is dismantled are effectively avoided, working efficiency is improved, the risk of transformation test work is reduced, the safety of workers is improved, test work safety is improved, and safety running of a power grid is ensured.

Description

The on-line measurement device of transformer dielectric loss and electric capacity

Technical field

The present invention relates to power transformation operation professional skill field; Particularly relate to a kind of measurement mechanism that with inlet wire cable, transformer is carried out dielectric loss and electric capacity.

Background technology

At present, the local converting equipment of each power supply unit is increasing, and service work also increases thereupon, and this has just had higher requirement to staff's experiment work efficiency.Transformer is removed lead-in wire work and is had certain potential safety hazard always, as, reconnection work is careless slightly, will affect the normal operation after equipment test.Both at home and abroad, although just like where not removing the amount of literature data of in the situation of lead-in wire, transformer being carried out to every test.But, through the high voltage side of transformer of copper bar stube cable inlet wire, in the time carrying out dielectric loss and electric capacity measuring test, because the electric capacity of high-tension cable is larger, the in the situation that of without disconnecting power lead, high-tension cable produces a very large impact test findings, as obtained believable measurement data, the high-tension cable lead-in wire that must remove high voltage side of transformer, affects work efficiency.How to solve without disconnecting power lead such transformer is tested, tested, the research that must carry out in the work that becomes a reality.

Summary of the invention

Technical matters to be solved by this invention is that the on-line measurement device of a kind of transformer dielectric loss and electric capacity is provided.

The technical solution adopted in the present invention is, the on-line measurement device of a kind of transformer dielectric loss and electric capacity, comprise, dielectric loss instrument, testing transformer and transformer to be measured, the voltage output end of described dielectric loss instrument is connected with the primary electrical of testing transformer, and the cable copper bar secondary and that high voltage side of transformer to be measured is connected of testing transformer is electrically connected; When test, the cable copper bar of high voltage side of transformer to be measured is connected with the secondary of testing transformer, after step down side short circuit to be measured, is connected with the self-excitation p-wire on dielectric loss instrument, and long cable section of ingoing line switch is suitable for reading to be connected with the Cx on dielectric loss instrument.

Described testing transformer adopts nominal transformation ratio to be voltage transformer (VT).

The invention has the beneficial effects as follows, can reach the object using manpower and material resources sparingly of safe operation and conventional maintenance, also can fine satisfied innovation create the requirement of imitating.Adopt this device can avoid, in process of the test, transformer inlet wire is removed to lead processing, do not change the physical connection state of power transformation station equipment, effectively avoid due to the high-tension cable lead-in wire of removing high voltage side of transformer, and the bushing shell for transformer leakage of oil easily causing in rejuvenation, recover the problem of conductor joint heating after power transmission, increase work efficiency, reduce the risk of power transformation experiment work, strengthen operating personnel's security, improve experiment work security, ensured the safe operation of electrical network.

Brief description of the drawings

Fig. 1 is the on-line measurement device schematic diagram of transformer dielectric loss of the present invention and electric capacity.

In figure:

10, dielectric loss instrument 20, testing transformer 30, transformer to be measured.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail:

As shown in Figure 1, the on-line measurement device of transformer dielectric loss of the present invention and electric capacity, comprise, dielectric loss instrument 10, testing transformer 20 and transformer to be measured 30, the voltage output end of described dielectric loss instrument 10 is connected with the primary electrical of testing transformer 20, and the cable copper bar secondary and that transformer to be measured 30 high-pressure sides are connected of testing transformer 20 is electrically connected; When test, the on high-tension side cable copper bar of transformer 30 to be measured is connected with the secondary of testing transformer 20, after transformer 30 low-pressure side short circuits to be measured, is connected with the self-excitation p-wire on dielectric loss instrument 10, and long cable section of ingoing line switch is suitable for reading to be connected with the Cx on dielectric loss instrument 10.Dielectric loss instrument 10 self-excitation voltage output ranges are generally less than 50V, can voltage be risen to by testing transformer 20 to the voltage of test request, are generally 10kV.Testing transformer 20 adopts nominal transformation ratio to be voltage transformer (VT).

Measuring principle is as follows, uses the mode of existing dielectric loss instrument compatibility test transformer 20 to realize, and obtains respectively dielectric loss and the electric capacity of transformer 30 to be measured and cable through twice measurement.

Dielectric loss instrument 10 of the prior art comprises a standard loop and a loop to be measured.Standard loop includes the standard capacitor of high stable, and loop to be measured is made up of Devices to test.In test process, respectively the sinusoidal signal that flows through standard loop and loop to be measured is sampled, obtain standard capacitance signal and testing medium signal.The phase place of standard capacitance is known, and the phase place of Devices to test is determined by product to be tested insulation situation.Respectively to two paths of signals amplify, after filtering processes, relatively its phase relation, thus calculate dielectric loss value and the capacitance value of product to be tested.

Measure for the first time transformer 30 electric capacitys to be measured and dielectric loss.When test, cable is connected with the standard capacitance of dielectric loss instrument 10 as loop to be measured standard capacitance, and transformer 30 to be measured forms loop to be measured.Because the electric capacity of cable is larger, and its dielectric loss value is relatively little, therefore, can be similar to and ignore cable to standard capacitance and test result impact in test process.By the phase relation of standard of comparison loop and loop signal to be measured, can draw transformer 30 dielectric loss values to be measured, and calculate transformer 30 electric capacitys to be measured.

Measure for the second time electric capacity and the dielectric loss that can obtain cable.With the transformer to be measured 30 of determining dielectric loss, electric capacity, as standard capacitance formation standard loop, cable is as tested loop.Can record so the when relative dielectric loss value of capacity of cable transformer 30 relatively to be measured, owing to measuring and the dielectric loss of transformer 30 to be measured and electric capacity being measured for the first time, just can extrapolate electric capacity and the dielectric loss value of cable by transformer 30 to be measured.

Of the present invention avoiding removed lead processing to transformer inlet wire to be measured in test process, do not change the physical connection state of power transformation station equipment, effectively avoid due to the high-tension cable lead-in wire of removing high voltage side of transformer, and the bushing shell for transformer leakage of oil easily causing in rejuvenation, recover the problem of conductor joint heating after power transmission, increase work efficiency, reduce the risk of power transformation test job, not only strengthen operating personnel's security, but also improved test job security, ensure the safe operation of electrical network.

Claims

1. the on-line measurement device of a transformer dielectric loss and electric capacity, comprise, dielectric loss instrument (10), it is characterized in that, also comprise testing transformer (20) and transformer to be measured (30), the voltage output end of described dielectric loss instrument (10) is connected with the primary electrical of testing transformer (20), and the cable copper bar secondary and that transformer to be measured (30) high-pressure side is connected of testing transformer (20) is electrically connected; When test, the secondary connection of the on high-tension side cable copper bar of transformer to be measured (30) and testing transformer (20), after transformer to be measured (30) low-pressure side short circuit, be connected with the self-excitation p-wire on dielectric loss instrument (10), long cable section of ingoing line switch is suitable for reading to be connected with the Cx on dielectric loss instrument (10).

2. the on-line measurement device of a kind of transformer dielectric loss according to claim 1 and electric capacity, is characterized in that, described testing transformer (20) adopts nominal transformation ratio to be voltage transformer (VT).