Instrument Transformer and Method for an Instrument Transformer

Abstract

Instrument transformer and method for isolating parts. The present invention relates to an instrument transformer (1) for high current and / or high voltage conversion, comprising a housing and at least one active part, which is electrically isolated by an insulating material. The insulating material comprises or is a paste and / or pulp (14). A method for the instrument transformer (1) comprises filling a housing of the instrument transformer (1) with paste and / or pulp (14), specifically with paste and / or pulp (14) comprising paper and / or cellulose material, dissolved in a solvent, specifically at least one ionic liquid.

Description

Instrument Transformer and Method for an Instrument Transformer

[0001] The present invention relates to an instrument transformer and a method for high current and / or high voltage conversion, comprising a housing and at least one active part, which is electrically isolated by an insulating material.

[0002] An oil-insulated instrument measuring transformer is, for example, known from US 5,391,835 A. Instrument transformers are used to measure high currents and / or voltages, specifically in the range of up to a few hundred Amperes and / or up to 1200 kV. An instrument transformer comprises a housing and at least one active part, which includes a measuring assembly. The measuring assembly comprises, for example, windings arranged around an electrical conductor, which can be used to measure a current in the conductor by magnetic induction in the windings. The active part is electrically insulated by an insulating material from the instrument transformer housing. The entire measuring assembly or parts of the measuring assembly are wrapped in kraft paper sheets and the housing is filled with oil to electrically insulate the active parts.

[0003] Isolation of the measuring assembly by kraft paper, specifically paper tape respectively sheets of paper, is performed manually by wrapping adhesive tape around the measuring assembly. A manual tape wrapping procedure is time-consuming, expensive due to labor costs, and prone to human error. Due to the complex shapes of the measuring assembly parts, automating tape wrapping procedures is difficult and costly.

[0004] One object of the present invention is to overcome the problems Petition 870260055254, dated 08 / 06 / 2026, page 6 / 47 2 / 13 described above. Specifically, an object of the present invention is to describe a method for isolating parts of an instrument transformer and an instrument transformer with electrically isolated parts, with an insulation that is easy to produce and economical.

[0005] The above objects are achieved by an instrument transformer for high current and / or high voltage conversion according to claim 1 and / or by a method for an instrument transformer, specifically for an instrument transformer described above, according to claim 12.

[0006] An instrument transformer for high current and / or high voltage conversion according to the present invention comprises a housing and at least one active part, which is electrically insulated by an insulating material. The insulating material comprises or is a paste and / or pulp.

[0007] The paste and / or pulp is easy to handle, especially easy to fill a housing, for example, by a machine. The use of insulation material being or at least comprising a paste and / or pulp allows for production automation, saves costs and is easy to perform, with little or no probability of failure. There is no manual tape winding procedure required to insulate the measuring assembly, where tape winding cannot be fully automated, is expensive, time-consuming and difficult to perform. Human contribution during the manufacturing process can be reduced by introducing respectively fully automated filling processes, leading to reductions in cost, time and failures.

[0008] The paste and / or pulp may comprise a solvent with dissolved particles, specifically powder of more than 80% w / w partially and / or totally dissolved in less than 20% w / w of Petition 870260055254, dated 08 / 06 / 2026, page 7 / 47 3 / 13 solvent. A relatively high particle size and small solvent size result in good electrical properties, i.e., good insulation properties, keeping the paste and / or pulp manageable during production, specifically during filling into a housing, for example, by a machine, reducing manufacturing time and costs.

[0009] The pulp and / or slurry may comprise particles with a size in the micro and / or nanometer range, partially and / or totally dissolved in the solvent. This small size provides good dissolution properties and results in good handling with advantages as previously described. A high filling factor is possible, with little space between the particles, easily produced from, for example, paper and / or cellulose material, easily filled into a housing, specifically fully automated.

[0010] The particles can be spherical in shape, and / or the particles can be fibrous in shape. Both shapes allow for a high surface area to volume ratio with advantages as previously described. Spherical particles are easy to produce, with low cost and ease of maintenance. Fibrous particles provide additional stability and are especially used in the paper industry, with special properties after a drying process such as good particle bonding and directional properties.

[0011] The pulp and / or cellulose may comprise paper and / or cellulose and / or silicon material. Paper, cellulose and / or silicon material are good insulating materials, especially at high voltages up to 1200 kV, are environmentally friendly, economical and easy to handle. Paper, cellulose and / or silicon material particles can be easily handled in fully automated ways and are easy to produce in specific sizes. Petition 870260055254, dated 08 / 06 / 2026, p. 8 / 47 4 / 13

[0012] The paste and / or pulp may comprise as a solvent at least one ionic liquid, specifically 1-butyl-3-methylimidazolium chloride [C4mim]Cl, N-methylmorpholine oxide (NMMO), N,N-dimethylacetamide / lithium chloride (DMAc / LiCl), 1,3-dimethyl-2-imidazolidinone / lithium chloride (DMI / LiCl), N,N-dimethylformamide / nitrous tetroxide (DMF / N2O4), dimethyl sulfoxide (DMSO) / tetrabutylammonium fluoride (TBAF), imidazolium phosphates and / or phosphonates, specifically [C2mim](MeO)2PO2, [C2mim](MeO)MePO2, -(MeO)MePO2, and [C2mim](MeO)HPO2, 1-butyl3-methylimidazolium acetate [C4mim]OAc, 1-ethyl-3-methylimidazolium acetate [C2mim] OAc, 1-(3,6,9-trioxadecyl)-3-ethylimidazolium acetate [Me(OEt)3-Et-Im] OAc, and / or molten salt hydrates, specifically LiClO4^3H2O and / or LiSCN^2H2O. These liquids are capable of dissolving or partially or totally dissolving particles, specifically paper and / or cellulose and / or silicon material, with advantages as previously described.

[0013] Paste and / or pulp comprises, as an insulating fluid, oil, specifically mineral oil and / or synthetic oil, and / or ester, specifically vegetable esters. Oil as an insulating fluid as part of the paste and / or pulp is a good insulating material, especially at high voltages up to 1200 kV.

[0014] The solvent portion in the paste and / or pulp can be reduced and / or replaced by an insulating fluid. The insulating properties of the paste and / or pulp can be increased by reducing and / or replacing the solvent with an insulating fluid.

[0015] The paste and / or pulp may be in the form of or comprise a gel. The gel is easy to handle, good for production and allows for an automated filling process, respectively fully automated, leading to reductions in cost, time and defects.

[0016] Insulation material with paste and / or pulp can be Petition 870260055254, dated 08 / 06 / 2026, p. 9 / 47 5 / 13 disposed within the housing, specifically the head and / or insulator and / or base housing, specifically disposed between the housing and the active parts, specifically the measuring assembly and the housing. The free space can be easily, automatically and economically filled, specifically completely with a paste and / or slurry, resulting in good electrical insulation of parts and / or between parts of the instrument transformer, especially at high voltages up to 1200 kV.

[0017] The paste and / or pulp insulation material can fill, specifically can completely fill the space between the housing, specifically the head and / or insulator and / or base housing, and active parts, specifically the measuring assembly, with advantages as previously described.

[0018] A method for an instrument transformer, specifically for an instrument transformer as previously described, comprises that an instrument transformer housing is filled with paste and / or pulp, specifically with paste and / or pulp comprising a paper and / or cellulose material, dissolved in a solvent, specifically at least one ionic liquid.

[0019] The solvent portion in the paste and / or pulp may be reduced and / or the solvent in the paste and / or pulp may be replaced by an insulating fluid, specifically oil, specifically mineral oil and / or synthetic oil, and / or ester, specifically vegetable esters.

[0020] Insulation material, specifically paste and / or pulp, can be filled into the instrument transformer housing, especially after degassing.

[0021] The insulation material, specifically paste and / or pulp, in the instrument transformer housing can electrically isolate the live parts of the instrument transformer, Petition 870260055254, dated 08 / 06 / 2026, page 10 / 47 6 / 13 specifically the measuring assembly, of the instrument transformer housing.

[0022] The advantages in connection with the method described for an instrument transformer according to the present invention are similar to the advantages previously described in connection with the instrument transformer for high current and / or high voltage conversion.

[0023] The present invention will be further described hereafter with reference to the illustrated embodiments shown in the accompanying drawings, in which:

[0024] Figure 1 illustrates an instrument transformer 1 for high current and / or high voltage conversion in section view, comprising a housing and at least one active part, which is electrically insulated by an insulating material 9, and

[0025] Figure 2 illustrates a sectional view of the head 2 of the instrument transformer 1 of Figure 1 according to the state of the art, and

[0026] Figure 3 illustrates in sectional view the head 2 of an instrument transformer 1 according to the present invention, with paste and / or pulp 14 as insulation material for the active part.

[0027] Figure 1 shows in sectional view an instrument transformer 1 for high current and / or high voltage conversion. The instrument transformer 1 comprises a housing and at least one active part, which is electrically insulated by an insulation material 9. In the embodiment of Figure 1, an active part of the instrument transformer 1 includes a measuring assembly 11 with, for example, windings arranged around an electrical conductor. The windings can be used to measure a current in the conductor by magnetic induction in the windings. Additional active parts are, for example, control electrodes and / or Petition 870260055254, dated 08 / 06 / 2026, page 11 / 47 7 / 13 a discharge pipe.

[0028] The active part, specifically the measuring assembly 11, is located within the instrument transformer housing 1. The instrument transformer 1, for example, comprises a head 2, an insulator 3 and a base 4, which are specifically mounted by a head housing 12 with a bellows cover 6, which includes an oil level indicator 7, by an insulator 3 specifically composed of a hollow cylindrical body and by a base 4, for example, in the form of a cast iron pedestal. The insulator 3 is, for example, a hollow body of ceramic, silicon and / or composite material with plate fins on the outer sheath to increase the leakage current length.

[0029] The insulator 3 is, for example, columnar with two column ends, arranged with the base 4 on one end and the head 2 on the other end. The head 2 is on top of the vertical columnar insulator 3, which comprises high-voltage terminals 8 for electrically connecting the instrument transformer 1 with high-voltage lines, electric generators and / or electric consumers, to measure current / voltage of high-voltage lines and / or electrical devices. A measuring assembly 11 as an active part within the housing of the instrument transformer 1 measures the current and / or voltage between the high-voltage terminals 8. Transferred through active parts such as, for example, a discharge tube and / or primary, secondary windings of the VT and core of the VT, the measurement results can be recorded and / or read from meters within terminal boxes 5, specifically arranged in the base 4.

[0030] The live part is electrically isolated by an insulating material from the instrument transformer housing. In the prior art, kraft paper sheets are used as insulating material. The entire live part or parts of the live part are wrapped. Petition 870260055254, dated 08 / 06 / 2026, page 12 / 47 8 / 13 in kraft paper and the housing is filled with oil to electrically insulate the live parts. The oil impregnates the kraft paper and improves the insulation properties. The live part is covered by kraft paper in the form of insulating tape, respectively sheets wrapped around the live part, which absorbs the oil. The oil is, for example, transformer oil 10, which comprises mineral oil.

[0031] The winding or application of tape to active parts with kraft paper sheets is done manually, leading to an expensive and time-consuming production process. Due to the complex shapes of active parts, such as the measuring assembly 11, automating the tape application procedures is difficult and expensive. Manual tape application is prone to failures and requires high precision. Failures can lead to short-circuit currents and complete failure of the instrument transformer 1, specifically irreversible damage to the instrument transformer 1.

[0032] In Figure 2, the head 2 of the instrument transformer 1 of Figure 1 is shown in sectional view. Kraft paper in the form of insulating tape 13 is wrapped around the measuring assembly 11 resulting in an insulating envelope around the active part, which is impregnated with oil, specifically transformer oil 10 filled in the instrument transformer housing 1. The space between the housing and the active part with wrapped kraft paper is filled with oil after assembly. The instrument transformer housing 1 is airtight, except for an overpressure outlet. High currents during the operation of the instrument transformer produce waste heat, increasing the oil temperature and leading to high pressure inside the instrument transformer 1. The overpressure and / or oil can dissipate through the overpressure outlet in an upward direction, to prevent destruction and / or explosion of the instrument transformer 1 and / or injury to Petition 870260055254, dated 08 / 06 / 2026, page 13 / 47 9 / 13 workers on duty.

[0033] As described above, winding the active parts of the instrument transformer 1 with insulating tape and kraft paper sheets is time-consuming, expensive, and prone to failure. In the prior art, winding is done manually, making automation difficult. Winding the active parts before assembling the instrument transformer 1 leads to a free space between the wound parts and the housing, which is filled with oil. The space between the active parts, such as the measuring assembly 11 and the housing, specifically the head housing 12, cannot be effectively used for insulation with kraft paper, since production tolerances and the assembly of the instrument transformer parts lead to a free space that must be filled with oil.

[0034] In Figure 3, the head 2 of an instrument transformer according to the present invention is shown in sectional view, with paste and / or pulp 14 as insulation material for the active part. The instrument transformer 1 in Figure 3 is as described for Figures 1 and 2, except for the winding of active parts with kraft paper in the form of insulating tape 13. Instead, the free space between the housing and the active parts is filled with paste and / or pulp 14 of insulation material, specifically comprising a solvent with dissolved particles, specifically powder of more than 80% w / w partially and / or totally dissolved in less than 20% w / w of solvent. The particles comprise, for example, paper and / or cellulose and / or silicon material, and are, for example, spherical in shape, and / or the particles are, for example, fibrous in shape, specifically with a size in the micro and / or nanometer range, partially and / or totally dissolved in the solvent.

[0035] The solvent comprises, for example, at least one ionic liquid, specifically 1-butyl-3-methylimidazolium chloride. Petition 870260055254, dated 08 / 06 / 2026, page 14 / 47 10 / 13 [C4mim]Cl, N-methylmorpholine oxide (NMMO), N,N-dimethylacetamide / lithium chloride (DMAc / LiCl), 1,3-dimethyl-2-imidazolidinone / lithium chloride (DMI / LiCl), N,N-dimethylformamide / nitrous tetroxide (DMF / N2O4), dimethyl sulfoxide (DMSO) / tetrabutylammonium fluoride (TBAF), imidazolium phosphates and / or phosphonates, specifically [C2mim](MeO)2PO2, [C2mim](MeO)MePO2, -(MeO)MePO2, and [C2mim](MeO)HPO2, 1-butyl-3-methylimidazolium acetate [C4mim]OAc, 1-ethyl-3-methylimidazolium acetate [C2mim]OAc, acetate 1-(3,6,9-trioxadecyl)-3-ethylimidazolium [Me(OEt)3-Et-Im]OAc, and / or molten salt hydrates, specifically LiClO4^3H2O and / or LiSCN-2H2O.

[0036] The particles 14 are composed of or comprise paper and / or cellulose and / or silicon material. These materials exhibit good dielectric properties, specifically good electrical insulation properties. To improve the insulation properties, the pulp 14 comprises an insulating fluid, oil 10, specifically mineral oil and / or synthetic oil, and / or ester, specifically vegetable esters. Alternatively, the fluid comprises a gas, for example, synthetic air and / or SF6. The solvent portion in the pulp 14 is reduced and / or replaced by insulating fluid for a further increase in electrical insulation. The pulp 14 may be in the form of or comprise a gel, for easy handling during production.

[0037] The particles in the paste and / or pulp 14 are, for example, spherical and / or fibrous in shape. The described shape allows for a high filling factor and a high surface area to volume ratio of particles, for example, at least twice, specifically at least ten times higher than for the same material in sheet form. This can also allow for good solution and / or dissolution, resulting in a paste and / or pulp that is easy to fill and / or Petition 870260055254, dated 08 / 06 / 2026, page 15 / 47 11 / 13 handle, specifically in gel form. A high surface area to volume ratio enhances impregnation with, for example, oil, and increases insulation properties with a high fill factor.

[0038] The paste and / or pulp 14 is filled into the housing, for example, through a paste / pulp filling inlet 15. The filling process can be fully automated, saving time, cost and reducing insulation failures in active parts of the instrument transformer 1. A portion of solvent in the paste and / or pulp 14 is reduced and / or solvent in the paste and / or pulp 14 is replaced by an insulating fluid, specifically oil 10, specifically mineral oil and / or synthetic oil and / or ester, specifically vegetable esters, before or after filling into the housing. After filling into the housing, it may be possible to change the properties of the paste / pulp, reducing its viscosity and handling properties, but increasing its insulation properties.Alternatively, further solvent reduction in the paste and / or pulp 14, made before filling the paste / pulp into the housing, can increase the handling and / or filling properties of the paste / pulp and / or make the replacement process easier. Over time, a paste / pulp can coagulate, consolidate and / or solidify or remain fluid. The insulation material made of, respectively comprising paste / pulp 14, specifically particles dissolved in solvent and / or oil, results in good electrical insulation of live parts in the direction of the instrument transformer housing 1.

[0039] The embodiments described above of the present invention can also be used in combination and combined with known embodiments of the prior art. For example, the instrument transformer 1 can be a current transformer, an inductive voltage transformer, a voltage transformer Petition 870260055254, dated 08 / 06 / 2026, page 16 / 47 12 / 13 capacitive, a combined current and voltage transformer, a power voltage transformer and / or an optical current transformer. The active parts may be located in a head housing 2, in an isolator 3 and / or in a base 4. The measuring assembly 11 is, for example, arranged in the head housing 2. Alternative instrument transformer designs comprise an isolator 3 and a base 4 without a head housing, for example, with the measuring assembly 11 arranged in the base 4.

[0040] The insulating material slurry 14 comprises paper and / or cellulose material, and / or silicon or combinations thereof. Alternative insulating materials in particle form may also be used, specifically oil-soluble materials such as plastics and / or porous materials such as zeolite, and / or materials such as silicon oxide. The slurry 14 may be spherical, porous and / or fibrous in shape. An impregnation of particles 14, for example with oil or an oil and solvent exchange may be carried out before filling the slurry 14 into the instrument transformer 1 or after filling the slurry 14 into the instrument transformer 1. The insulating fluid may be or may comprise oil, specifically mineral oil and / or a synthetic oil, and / or ester, specifically vegetable esters, or gas, for example clean air and / or SF6. The slurry 14 may be degassed.

[0041] The pulp / pulp insulation material 14 may be disposed within the housing, specifically in the head housing 12 and / or insulator 3 and / or base 4. The insulation material may consist of pulp / pulp 14. Alternatively, the insulation material may consist of and / or comprise pulp / pulp 14 and paper sheets in combination, specifically kraft paper sheets. The insulation material may be disposed between the housing and active parts, specifically the measuring assembly 11 and the housing, to Petition 870260055254, dated 08 / 06 / 2026, p. 17 / 47 13 / 13 electrically insulate the parts from each other. The insulating material consisting of paste / pulp 14 can be disposed within the head housing 12 and / or the insulating material consisting of paper sheets can be disposed within the insulator 3. Alternatively, the insulating material consisting of paste / pulp 14 can be disposed within the insulator 3 and / or the insulating material consisting of paper sheets can be disposed within the head housing 12. Within the insulator 3, all free space can be filled with insulating material or only parts, specifically field electrodes and / or electrical conductors, especially in tube form, are filled and / or wrapped and / or coated with insulating material. Within the head housing 12, all free space can be filled with insulating material. LIST OF REFERENCE CHARACTERS instrument transformer heads insulator base terminal box bellows cover oil level indicator high voltage terminals high voltage insulation transformer oil measuring assembly, specifically core / secondary windings head housing insulating tape, kraft paper pulp / slurry pulp / slurry filler inlet

Claims

1. Instrument transformer (1) for high current and / or high voltage conversion, comprising a housing and at least one active part disposed inside the housing and electrically isolated from the housing by an insulating material, characterized in that the insulating material comprises a paste or pulp introduced inside the housing and disposed between the housing and the active part, wherein the paste or pulp comprises a solvent capable of at least partially dissolving cellulosic material and particles comprising paper and / or cellulose material at least partially dissolved in the solvent, and wherein, after introduction into the housing, the solvent portion is reduced and / or replaced by an insulating fluid comprising mineral oil, synthetic oil and / or ester, so as to form the electrical insulating material.

2. Instrument transformer (1), according to claim 1, characterized in that the particles comprising paper and / or cellulose material at least partially dissolved in the solvent have a size in the micrometer and / or nanometer range.

3. Instrument transformer (1), according to claim 2, characterized in that the particles comprising paper and / or cellulose material at least partially dissolved in the solvent have a fibrous and / or spherical shape.

4. Instrument transformer (1), according to any one of claims 1 to 3, characterized in that the paste (14) or pulp comprises as solvent at least one ionic liquid, specifically 1-butyl-3-methylimidazolium chloride [C4mim]Cl, Petition 870260055254, dated 08 / 06 / 2026, p. 19 / 47 2 / 3 N-methylmorpholine oxide (NMMO), N,N-dimethylacetamide / lithium chloride (DMAc / LiCl), 1,3-dimethyl-2-imidazolidinone / lithium chloride (DMI / LiCl), N,N-dimethylformamide / nitrous tetroxide (DMF / N2O4), dimethyl sulfoxide (DMSO) / tetrabutylammonium fluoride (TBAF), imidazolium phosphates and / or phosphonates, specifically [C2mim](MeO)2PO2, [C2mim](MeO)MePO2, -(MeO)MePO2, and [C2mim](MeO)HPO2, 1-butyl-3-methylimidazolium acetate [C4mim]OAc, 1-ethyl-3-methylimidazolium acetate [C2mim]OAc, acetate 1-(3,6,9-trioxadecyl)-3-ethylimidazolium [Me(OEt)3-Et-Im]OAc, and / or molten salt hydrates, specifically LiClO4OH2O and / or USCN-2H2O.

5. Instrument transformer (1), according to any one of claims 1 to 4, characterized in that the paste or pulp is disposed within the housing and fills at least partially the space between the housing and the active part.

6. Instrument transformer (1), according to claim 5, characterized in that the instrument transformer (1) comprises a head housing (12), an insulator (3) and a base (4), wherein the paste or pulp is disposed in at least one of the head housing (12), the insulator (3) and the base (4), between the housing and the active parts.

7. Instrument transformer (1) according to any one of claims 5 or 6, characterized in that the insulation material with paste or pulp completely fills the space between the housing, specifically the head housing (12) and the insulator (3) and the base (4), and active parts, specifically the measuring assembly (11).

8. Method for an instrument transformer (1), as defined in any one of claims 1 to 7, characterized in that the housing of the instrument transformer (1) is filled with paste or pulp comprising particles of paper and / or cellulose material at least partially dissolved in the solvent.

9. Method according to claim 8, characterized in that the solvent portion in the paste or pulp is reduced by an insulating fluid, specifically oil (10), specifically mineral oil or synthetic oil, or ester, specifically vegetable esters.

10. Method according to claim 8, characterized in that the paste as insulation material is filled into the instrument transformer housing (1), specifically after degassing.

11. Method, according to any one of claims 8 to 10, characterized in that the insulation material in the instrument transformer housing (1) electrically isolates the active parts of the instrument transformer (1), specifically the measuring assembly (11), from the instrument transformer housing (1).

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