CN200950390Y - Electromagnetic voltage potential transformer for superhigh voltage and extra-high voltage - Google Patents

Abstract

An electromagnetic voltage transformer used for UHV and EHV includes a single-stage SF6 gas-insulating voltage transformer and one or two composite single-stage SF6 gas-insulating voltage transformers which are communicated in series and superimposed. The top single-stage SF6 gas-insulating voltage transformer only has one core while the bottom composite single-stage SF6 gas-insulating voltage transformer has two cores with one for manufacturing the single-stage voltage transformer and the other for high-voltage isolation transformer. The first winding series compensated capacitor of the high-voltage isolation transformer is communicated with the first input terminal while the second winding is in series communication with the second winding of the single-stage voltage transformer and communicated with the second input terminal. The utility model overcomes the magnetic flux imbalance of each stem of the series voltage transformer and the vulnerability to the effects of ground capacitance leakage current; and improves the electromagnetic field distribution of UHV and EHV electromagnetic voltage transformer through series communication , thus reducing the manufacturing difficulties and the production cost and producing UHV and EHV electromagnetic voltage transformer by the present technology of producing gas-insulating voltage transformer.

Description

The electromagnetic potential transformer that is used for superhigh pressure and ultra high voltage

Technical field

The utility model relates to a kind of electromagnetic potential transformer, especially relates to the electromagnetic potential transformer that is used for superhigh pressure and ultra high voltage.

Background technology

Electric power system need be gathered voltage signal from the primary circuit with voltage transformer, offers electric measurement, electric energy metrical, relaying protection and automatics and uses.Electromagnetic potential transformer is mainly used in 220kV and following electric power system at present, and more high-tension electromagnetic potential transformer can't be extensive use of in superhigh pressure (500kV and 750kV) electric power system owing to cost height, manufacture difficulty are big.Electromagnetic potential transformer has single electrode voltage instrument transformer and two kinds of structures of tandem voltage transformer, 110kV and 220kV tandem voltage transformer use porcelain case insulation system, mechanical strength is low, innage is many and easily cracked in the porcelain case, is safe hidden danger, simultaneously after electric pressure rising, tandem winding number increase, iron core and coil direct-to-ground capacitance have also increased, be subjected to the distributed capacitance influence of leakage current, the error instability of instrument transformer, accuracy descends with the increase of tandem hop count.Near single-stage gas-insulated voltage transformer bushing end and the winding electric field is very concentrated, when being used for superhigh pressure, must use the balanced electric field of multistage capacitance plate, so complex structure, and the diameter of a winding is along with the proportional increase of the raising of primary voltage, make and to bear the casing of gas pressure and the difficulty that manufactures and designs of bushing is multiplied, be difficult to use in superhigh pressure and ultra high voltage (1100kV).

In addition, the Chinese invention patent of the applicant invention: 901003018 " voltage mutual inductor serial addition circuits ", a kind of measurement circuitry is disclosed, two earthed voltage transformers winding and secondary winding are connected respectively in this circuit.This tandem-type connection does not allow to change the earth point of instrument transformer, therefore can not be used to measure voltage relatively after the series connection.Because 110kV and above electric power system all are earth neutral systems, need to use earthed voltage transformer to measure phase-to-ground voltage, therefore the electromagnetic potential transformer made from this serial addition circuit can not satisfy the needs of superhigh pressure and extra-high voltage grid.

Summary of the invention

The purpose of this utility model is, overcomes the deficiencies in the prior art, and a kind of simple in structure, cost is low and security reliability is high electromagnetic potential transformer that is used for superhigh pressure and ultra high voltage is provided.

Technical solution of the present utility model is: a kind of electromagnetic potential transformer that is used for superhigh pressure and ultra high voltage is characterized in that: by a single-stage SF ₆Gas-insulated voltage transformer 12 and one or two combined type single-stage SF ₆Gas-insulated voltage transformer 13 placement that is composed in series and superposes, between every by last one secondary output terminals a and n and high-voltage earthing terminal N input terminal aa and nn and the sub-A of high voltage input terminal totally three pairs of corresponding connections of terminal with next; A uppermost single-stage SF ₆Gas-insulated voltage transformer 12 has only an iron core; Be placed on following combined type single-stage SF ₆Gas-insulated voltage transformer 13 has two iron cores, one of them iron core is a single-stage transformer iron core 3, be used to make the single electrode voltage instrument transformer, the iron core that increases newly is a high pressure isolation transformer iron core 6, be used to make the high pressure isolation transformer, winding 4 of high pressure isolation transformer be connected to input terminal aa and nn after compensation condenser 11 is connected, the secondary winding 5 of high pressure isolation transformer be connected to output secondary terminal a and n after the secondary winding 2 of single electrode voltage instrument transformer is connected.

It is characterized in that: combined type single-stage SF ₆Gas-insulated voltage transformer 13 is made up of high pressure bearing 7, bushing 8, high-pressure conduit 9, steel casing 10, once input terminal aa and nn and the sub-A of high voltage input terminal on the high pressure bearing 7, secondary output terminals a and n and high-voltage earthing terminal N are arranged at the bottom of steel casing 10; Square shape single-stage transformer iron core 3 with the manufacturing of cold-rolled orientation silicon steel sheet is installed in steel casing 10 bottoms, on iron core column above the iron core 3, be equipped with single-stage instrument transformer secondary winding 2 and a winding 1, winding 4 of high pressure isolation transformer is installed on winding 1 of single-stage instrument transformer, on a winding 4, high-pressure conduit 9 is installed, the high-voltage terminal of two outlets of a winding 4 of high pressure isolation transformer and a winding 1 of single-stage instrument transformer passes from high-pressure conduit 9, building-out capacitor 11 is installed in the high pressure bearing 7, and high-pressure conduit 9 external mounting have bushing 8; High pressure isolation transformer iron core 6 is high magnetic permeability iron cores, is installed in the side of casing 10, is equipped with secondary winding 5 on the high pressure isolation transformer iron core 6, uses SF between winding 4 of high pressure isolation transformer and the secondary winding 5 ₆Gas-insulated, casing 10 and bushing 8 have gas-tight design, and the SF with 0.35MPa～0.4MPa pressure is filled in inside ₆Gas.

This series system makes every single electrode voltage instrument transformer can both independent reliably working on the one hand, and total on the other hand primary voltage is shared by each voltage transformer of series connection, has reduced the separate unit insulating requirements.The shortcoming that the utility model has overcome each stem stem magnetic flux imbalance of tandem voltage transformer and has been subject to the direct-to-ground capacitance influence of leakage current, improved the Electric Field Distribution of superhigh pressure and ultra high voltage electromagnetic potential transformer with series connection method, alleviated manufacture difficulty and reduced production cost, made and to produce superhigh pressure and ultra high voltage electromagnetic potential transformer with the technology of present manufacturing gas-insulated voltage transformer.

Description of drawings

Fig. 1 is a basic circuit diagram of the present utility model.

Fig. 2 is a structural representation of the present utility model.

Fig. 3 is combined type single-stage SF ₆The profile construction schematic diagram of 13 1 embodiment of gas-insulated voltage transformer.

Among the figure: 1. winding of single-stage instrument transformer, 2. single-stage instrument transformer secondary winding, 3. single-stage transformer iron core, 4. winding of high pressure isolation transformer, 5. high pressure isolation transformer secondary winding, 6. high pressure isolation transformer iron core, 7. high pressure bearing, 8. bushing, 9. high-pressure conduit, 10. casing, 11. compensation condensers, 12. single-stage SF ₆The gas-insulated voltage transformer, 13. combined type single-stage SF ₆The gas-insulated voltage transformer

Embodiment

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1 is a basic circuit diagram of the present utility model, and Fig. 2 is a structural representation of the present utility model, when the utility model is used for electric pressure and is the 1100kV ultra high voltage, by a single-stage SF ₆Gas-insulated voltage transformer 12 and two combined type single-stage SF ₆Gas-insulated voltage transformer 13 placement that is composed in series and superposes, between every by last one secondary output terminals a and n and high-voltage earthing terminal N input terminal aa and nn and the sub-A of high voltage input terminal totally three pairs of corresponding connections of terminal with next; A uppermost single-stage SF ₆Gas-insulated voltage transformer 12 has only an iron core; Be placed on following combined type single-stage SF ₆Gas-insulated voltage transformer 13 has two iron cores, one of them iron core is a single-stage transformer iron core 3, be used to make the single electrode voltage instrument transformer, the iron core that increases newly is a high pressure isolation transformer iron core 6, be used to make the high pressure isolation transformer, winding 4 of high pressure isolation transformer be connected to input terminal aa and nn after compensation condenser 11 is connected, the secondary winding 5 of high pressure isolation transformer be connected to output secondary terminal a and n after the secondary winding 2 of single electrode voltage instrument transformer is connected.This series system, from the secondary voltage of a bottom output is secondary voltage (by the high pressure isolation transformer) sum of each single electrode voltage instrument transformer, make every single electrode voltage instrument transformer can both independent reliably working so on the one hand, total on the other hand primary voltage is shared by each single electrode voltage instrument transformer of series connection, has reduced the separate unit insulating requirements.When electric pressure was the 750kV ultra high voltage, the utility model then was by a single-stage SF ₆Gas-insulated voltage transformer 12 and a combined type single-stage SF ₆Gas-insulated voltage transformer 13 placement that is composed in series and superposes.

At combined type single-stage SF shown in Figure 3 ₆In the profile construction schematic diagram of an embodiment of gas-insulated voltage transformer 13, combined type single-stage SF ₆Gas-insulated voltage transformer 13 is made up of high pressure bearing 7, bushing 8, high-pressure conduit 9, steel casing 10, the sub-A of secondary input terminal aa and nn and high voltage input terminal is arranged on the high pressure bearing 7, and secondary output terminals a and n and high-voltage earthing terminal N are arranged at the bottom of steel casing 10; Square shape single-stage transformer iron core 3 with the manufacturing of cold-rolled orientation silicon steel sheet is installed in steel casing 10 bottoms, on iron core column above the iron core 3, be equipped with single-stage instrument transformer secondary winding 2 and a winding 1, winding 4 of high pressure isolation transformer is installed on winding 1 of single-stage instrument transformer, on a winding 4, high-pressure conduit 9 is installed, the high-voltage terminal of two outlets of a winding 4 of high pressure isolation transformer and a winding 1 of single-stage instrument transformer passes from high-pressure conduit 9, building-out capacitor 11 is used to compensate winding leakage reactance of high pressure isolation transformer, be installed in the high pressure bearing 7, high-pressure conduit 9 external mounting have bushing 8, and bushing 8 is high strength china sleeve pipe or compound insulating sleeve; High pressure isolation transformer iron core 6 is high magnetic permeability iron cores, is installed in the side of casing 10, is equipped with secondary winding 5 on the high pressure isolation transformer iron core 6, uses SF between winding 4 of high pressure isolation transformer and the secondary winding 5 ₆Gas-insulated, casing 10 and bushing 8 have gas-tight design, and the SF with 0.35MPa～0.4MPa pressure is filled in inside ₆Gas.

Claims (2)

1, a kind of electromagnetic potential transformer that is used for superhigh pressure and ultra high voltage is characterized in that: by a single-stage SF ₆Gas-insulated voltage transformer (12) and one or two combined type single-stage SF ₆Gas-insulated voltage transformer (13) placement that is composed in series and superposes, between every by last one secondary output terminals a and n and high-voltage earthing terminal N input terminal aa and nn and the sub-A of high voltage input terminal totally three pairs of corresponding connections of terminal with next; A uppermost single-stage SF ₆Gas-insulated voltage transformer (12) has only an iron core; Be placed on following combined type single-stage SF ₆Gas-insulated voltage transformer (13) has two iron cores, one of them iron core is single-stage transformer iron core (3), be used to make the single electrode voltage instrument transformer, the iron core that increases newly is a high pressure isolation transformer iron core (6), be used to make the high pressure isolation transformer, a winding (4) of high pressure isolation transformer be connected to input terminal aa and nn after compensation condenser (11) is connected, the secondary winding of high pressure isolation transformer (5) be connected to output secondary terminal a and n after the secondary winding (2) of single electrode voltage instrument transformer is connected.

2, the electromagnetic potential transformer that is used for superhigh pressure and ultra high voltage according to claim 1 is characterized in that: combined type single-stage SF ₆Gas-insulated voltage transformer (13) is made up of high pressure bearing (7), bushing (8), high-pressure conduit (9), steel casing (10), once input terminal aa and nn and the sub-A of high voltage input terminal on the high pressure bearing 7, secondary output terminals a and n and high-voltage earthing terminal N are arranged at the bottom of steel casing (10); The square shape single-stage transformer iron core made from the cold-rolled orientation silicon steel sheet (3) is installed in steel casing (10) bottom, on the top iron core column of iron core (3), be equipped with a single-stage instrument transformer secondary winding (2) and a winding (1), go up an installation high pressure winding of isolation transformer (4) at a winding of single-stage instrument transformer (1), go up installation high-pressure conduit (9) at a winding (4), the high-voltage terminal of two outlets of a winding (4) of high pressure isolation transformer and a winding (1) of single-stage instrument transformer passes from high-pressure conduit (9), building-out capacitor (11) is installed in the high pressure bearing (7), and high-pressure conduit (9) external mounting has bushing (8); High pressure isolation transformer iron core (6) is the high magnetic permeability iron core, is installed in the side of casing (10), is equipped with secondary winding (5) on the high pressure isolation transformer iron core (6), uses SF between a winding of high pressure isolation transformer (4) and the secondary winding (5) ₆Gas-insulated, casing (10) and bushing (8) have gas-tight design, inside to fill SF with 0.35MPa～0.4MPa pressure ₆Gas.

Images