WO2015155270A1 - Procédé et dispositif de détermination du taux d'humidité de l'isolation d'un transformateur de courant et de séchage de l'isolation - Google Patents

Procédé et dispositif de détermination du taux d'humidité de l'isolation d'un transformateur de courant et de séchage de l'isolation Download PDF

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Publication number
WO2015155270A1
WO2015155270A1 PCT/EP2015/057676 EP2015057676W WO2015155270A1 WO 2015155270 A1 WO2015155270 A1 WO 2015155270A1 EP 2015057676 W EP2015057676 W EP 2015057676W WO 2015155270 A1 WO2015155270 A1 WO 2015155270A1
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WO
WIPO (PCT)
Prior art keywords
insulation
current transformer
moisture content
dielectric response
drying
Prior art date
Application number
PCT/EP2015/057676
Other languages
German (de)
English (en)
Inventor
Stephanie Uhrig
Martin Anglhuber
Original Assignee
Omicron Electronics Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Omicron Electronics Gmbh filed Critical Omicron Electronics Gmbh
Publication of WO2015155270A1 publication Critical patent/WO2015155270A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
    • G01N27/223—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance for determining moisture content, e.g. humidity
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/32—Insulating of coils, windings, or parts thereof
    • H01F27/324—Insulation between coil and core, between different winding sections, around the coil; Other insulation structures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/40—Structural association with built-in electric component, e.g. fuse
    • H01F27/402—Association of measuring or protective means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
    • H01F38/20—Instruments transformers
    • H01F38/22—Instruments transformers for single phase ac
    • H01F38/28—Current transformers

Definitions

  • the present invention relates to a method and a device for measuring the moisture content of an insulation of a current transformer and, on the other hand, for drying this insulation.
  • a current transformer is understood in particular to be a measuring transducer for the potential-free measurement of alternating currents of great magnitude (power range greater than 1 MW).
  • Such a current transformer operates like a special transformer in that the current flowing in a primary conductor and to be measured is transformed by means of a secondary winding to measure the secondary current flowing in the secondary winding, the magnitude of which is proportional to the magnitude of the primary current.
  • the present invention has the object to improve the measurement of a moisture content of an insulation of a current transformer and the drying of the insulation of a current transformer.
  • a method for determining the moisture content of an insulation of a current transformer comprises the following steps:
  • the temperature of the insulation has an influence on the dielectric response of the specimen or the insulation.
  • the current transformer should not be in operation in the practice of the present invention. In other words, the current transformer should be taken offline prior to performing the present invention.
  • Measurement of the dielectric response of the isolation may be performed for multiple frequencies (e.g., from 0.1MHz to 100Hz) so that the measurement of the dielectric response may include the steps of:
  • the determination of the dielectric response at various frequencies in addition to the above-described frequency domain spectroscopy (FDS) in the present invention can also be carried out by polarization and depolarization current measurement (PDC) or by a combination of FDS and PDC.
  • PDC polarization and depolarization current measurement
  • a voltage jump is applied and the resulting current profile is converted into the frequency range, for example by means of a Fourier transformation.
  • the FDS is preferably used at high frequencies and the PDC at low frequencies.
  • the dielectric losses can be determined, for example, by determining the loss factor of the current transformer or by determining the complex permittivity of the current transformer.
  • determining the temperature of the insulation comprises, in particular, measuring an electrical resistance of a secondary winding of the current transformer.
  • the electrical resistance of the secondary winding changes with the temperature, so that, for example, based on the measured electrical resistances, the temperature of the secondary winding can be fully automatically deduced based on the reference measurements made previously. Since the secondary winding within the insulation or in the immediate vicinity of the Insulation, the temperature determined by the electrical resistance of the secondary winding corresponds to the tempera- the insulation.
  • measuring the electrical resistance ie, determining the temperature of the insulation
  • measuring the dielectric response is continuously alternating so that the measurement of the electrical resistance is followed by measuring the dielectric response, which in turn is followed by further measuring the electrical resistance etc.
  • the moisture content of the insulation can advantageously be determined continuously depending on the respective current values for the temperature of the insulation and the dielectric response of the insulation.
  • existing, conductive components of the current transformer can be used to measure the dielectric response.
  • the dielectric response may be measured by applying a voltage between a shield of the current transformer and a high voltage pad of the current transformer.
  • the dielectric response can be measured by applying a voltage between the shield of the current transformer and the primary conductor of the current transformer.
  • the high-voltage coating which consists of a conductive material, the function of uniforming the electromagnetic field of the primary conductor.
  • the use of existing electrodes or components of the current transformer to measure the dielectric response is a cost effective embodiment.
  • the dielectric measurement is advantageously performed on that portion of the insulation which is also heavily stressed during operation of the current transformer and includes much of the paper's insulation.
  • a capacitive coating of a leadthrough part of the current transformer can be connected in parallel to the high-voltage coating, so that the voltage between the screen on one side and the parallel circuit of the high-voltage coating and the capacitive coating on the other side is applied when measuring the dielectric response.
  • geometry information is also determined which indicates an influence of a geometry of the insulation on the dielectric response.
  • the moisture content of the insulation is thus determined depending on the temperature, the dielectric response and the geometry information in this embodiment.
  • the dielectric responses are measured and stored in advance.
  • the geometry information may be determined based on the currently measured dielectric response.
  • the moisture content of the insulation may be determined according to the invention as follows.
  • the measured dielectric response of the isolation is compared with the dielectric responses from those known combinations that have the measured temperature and the determined geometry information. These comparisons determine the dielectric response from the known combinations that best matches the measured dielectric response.
  • the sought moisture content of the insulation is then determined as the moisture content corresponding to the moisture content of that combination whose dielectric response best matches the measured dielectric response.
  • the dielectric response is measured in each case.
  • the known combinations are therefore determined by measurements to be carried out beforehand and are stored, for example, in a database.
  • the already described model of the current transformer or the insulation of the current transformer which has a relationship between the geometry of the insulation, the temperature of the insulation, the moisture content of the insulation and the dielectric response of the Insulation modeled.
  • This model can be used to create the known combinations.
  • different dielectric responses for different moisture contents of the insulation are generated and compared with the measured dielectric response.
  • that dielectric response of a characteristic of the model is sought or determined which best matches the measured dielectric response.
  • the moisture content of the insulation of this expression of the model then corresponds to the moisture content of the insulation to be determined.
  • a preferred field of application for the method according to the invention for determining the moisture content of a component is the drying of the current transformer.
  • a method for drying an insulation of a current transformer is also provided.
  • the moisture content of the insulation is determined using the method according to the invention described above.
  • the drying of the insulation is then carried out as a function of the moisture content determined in accordance with the invention.
  • a device for determining the moisture content of an insulation of a current transformer comprises measuring means and processing means.
  • the measuring means are designed to measure, on the one hand, a dielectric response of the insulation of the current transformer and, on the other hand, to determine or measure a temperature of the insulation.
  • the measuring means may comprise, for example, a first measuring device for measuring the dielectric response and a second measuring device for measuring the temperature.
  • the processing means are configured to determine the moisture content of the insulation depending on the dielectric response and the temperature.
  • the advantages of the device according to the invention essentially correspond to the advantages of the method according to the invention for determining the moisture content, which have been carried out in detail in advance, so that a repetition is dispensed with here.
  • the device comprises a device (in particular a circuit or switching matrix).
  • This device is configured such that the device with the device either measures an electrical resistance of a secondary winding of the current transformer or applies a voltage between a screen of the current transformer and a high voltage pad of the current transformer or a primary line of the current transformer.
  • the switching matrix provides the connection of the device to the current transformer required for the respective measurement function (resistance measurement or measurement of the dielectric response).
  • the present invention also provides a drying apparatus for drying insulation of a power converter.
  • the drying device according to the invention comprises the device described above for determining the moisture content.
  • the drying device according to the invention comprises the advantages of the invention Method according to the invention for drying insulation, which are carried out in advance in detail, so that a repetition is dispensed with here.
  • the moisture content of the insulation of a current transformer can be accurately determined.
  • the invention is suitable for all processes in which paper insulation of current transformers are dried.
  • the drying process according to the invention can be automated since the present invention requires no switching action (for example for a dew point measurement) due to the continuous determination of the moisture content. Also, an interruption of the drying process to determine a residual moisture is not necessary.
  • the water content in insulation of a current transformer can be determined.
  • a drying process during manufacture and after the repair or maintenance of a current transformer can be optimized in terms of time.
  • the present invention is particularly suitable for processes in which paper insulation of a power converter is dried which is not in operation. This includes, for example, the manufacture and repair of current transformers both locally and in stationary systems (ovens).
  • the drying processes in which the present invention can be used are known in the art as "hot-air”, “vapor-phase”, “hot-oil-spray” and "low-frequency-heating” processes known.
  • FIGS. 1 to 3 show different types of current transformers.
  • FIG. 4 the current transformer type of Fig. 2 is shown again.
  • FIGS. 5 to 8 the current transformer type from FIG. 1 is shown in detail.
  • FIGS. 9 to 1 show a geometric model of an insulation of a current transformer.
  • Figures 12 and 13 illustrate how to measure either a resistance or a dielectric response with a switching matrix.
  • 14 schematically shows a drying device according to the invention with a device according to the invention for determining the moisture content.
  • FIG. 1 the most common types of current hikes are shown.
  • the current transformer type shown in Fig. 1 is very common in Europe.
  • the primary conductor 5 in the current transformer type shown in FIG. 1 traverses the current transformer 1 in a straight line over a short distance
  • the primary conductor 5 in the current transformer shown in FIG. 2 is U-shaped in the current transformer 1.
  • the secondary winding 6 is located in the foot part of the current transformer 1.
  • a shield or a screen 8 is arranged in the lower portion of the U-shape.
  • the current transformer type shown in Fig. 3 has similarities with the current transformer type shown in Fig. 2. While the primary conductor 5 in FIG. 2 is U-shaped, in FIG. 3 the forward conductor and the return conductor of the primary conductor 5 are usually arranged closer to one another, wherein the primary conductor 6 forms a circular shape only in the lowermost portion, where the secondary winding 6 and the Screen 8 are arranged so that here the distance between the forward conductor and return conductor increases to the diameter of the circle. While the primary conductor 6 in the current transformer type shown in Fig. 1 can be added to the current transformer 1 only after the production of the remaining current transformer 1, this is only possible with difficulty in the current transformer types shown in Figures 2 and 3. Therefore, in the present invention, the primary conductor in a current transformer 1 of the current transformer type shown in Fig. 1 should not be used as a dielectric response measuring electrode, while it is possible with the current transformer types shown in Figs.
  • the insulation 7 is also arranged between the forward conductor and the return conductor of the primary conductor 5.
  • the secondary winding 6 surrounds the primary conductor 5, wherein the secondary winding 6 is shown only on the left side in Fig. 4, while in reality is also present on the right side ,
  • FIGS. 5 to 8 the current transformer type illustrated in FIG. 1 is shown in detail.
  • Fig. 5 shows a current transformer 1 from the outside with a device 10 according to the invention for determining the moisture content of the insulation.
  • the current transformer 1 shown in Fig. 5 is shown schematically in Figures 6 to 8 in detail.
  • the primary conductor 5 and the secondary winding 6 are located in the actual current transformer part 12, which is arranged above a feedthrough part 13.
  • Within the secondary winding 6 is an annular iron core 14 which surrounds the primary conductor 5.
  • the secondary winding 6 is in turn surrounded by a screen 8, which in turn is surrounded by the insulation 7, which in turn is surrounded by a high-voltage coating 9 made of a conductive material.
  • the right part of the current transformer part 12 is shown in cross section.
  • the passage member 13 is shown in detail.
  • the lead-through part 13 is constructed symmetrically to the central metal rod 15.
  • This metal rod 15 is surrounded in a cylindrical shape by capacitive coverings, the outer capacitive covering being designated by the reference numeral 16 and the inner capacitive covering by the reference numeral 17.
  • Fig. 9 a section 24 of the insulation 7 is shown in detail. It can be seen that the insulation 7 is made up of different paper layers 25 and that there are 7 microscopically small air holes 4 in the insulation. These air holes 4 are gaps which form between the individual paper layers 25. Therefore, the insulation 7 should not be modeled as compact paper.
  • the paper insulation 7 is modeled according to the X / Y model illustrated in FIG. 10, which is known for modeling the isolation of other high power electrical equipment (eg, transformers).
  • the reference numeral 21 and paper structures within the insulation 7, which are parallel to the paper layers similar to barrier in transformer insulations extend, designated by the reference numeral 22.
  • the dielectric properties depend on geometry parameters X, Y, so that these geometry parameters X, Y also influence values of resistors Ri, R 2 and capacitors C1-C3 of the X / Y model illustrated in FIG. 11.
  • the air gap is modeled here as an ideal capacity, since an air gap has almost no losses.
  • values of the resistors R 1 , R 2 and capacitors C 1 -C 3 and thereby the dielectric response for a moisture value can be calculated.
  • the dielectric response calculated with the dielectric response measured by the respective current transformer 1 can be used to determine the most suitable geometry parameters X, Y for the respectively measured current transformer 1.
  • the temperature of the insulation 7 can also be taken into account, for example by determining the resistors Ri, R 2 and capacitors C Css not only as a function of the geometry parameters X, Y, but additionally as a function of the temperature.
  • variable X is, for example, according to the invention for current transformer in a range of 75% to 95% (0.75 to 0.95), while the variable Y is in a range of 40% to 50% (0.4 to 0.5) ,
  • FIGS. 12 and 13 describe how, on the one hand, the temperature of the insulation 7 and, on the other hand, the dielectric response of the insulation 7 are determined.
  • a direct current is passed through the secondary winding 6 with the aid of a current source 26, and the voltage measuring device 27 measures a voltage dropping as a function of the direct current across the secondary winding 6. Based on the strength of the direct current and the measured voltage, the resistance of the secondary winding 6 can be determined. Since this resistance changes with temperature, the temperature of the secondary winding 6 can be determined based on the measured resistance. Since the secondary winding 6 is located within the insulation or in the immediate vicinity of the insulation 7, thereby the temperature of the insulation 7 can be determined.
  • a voltage generated by a voltage source 28 is applied to the shield 8 and to the high voltage pad 9 and the outer capacitive pad 16 by means of the circuit 18.
  • the current flowing through the insulation 7 depending on the applied voltage is measured by the current meter 29 to determine the dielectric response of the insulation 7.
  • the switching matrix 18 thus has two states, wherein in the first state it couples the current source 26 and the voltmeter to the electrodes of the secondary winding 6 and in the second state couples the voltage source 28 and the current eater 29 to the current transformer 1 the dielectric response is measured.
  • the drying device 20 comprises an apparatus 10 according to the invention for determining the moisture content of an insulation 7 and a furnace 19. In this furnace 11 there is a current transformer 1, so that the insulation of the current transformer 1 is dried.
  • the device 10 comprises a measuring device 2, processing means 3, a circuit 18 and a memory 30. With the aid of the circuit 18 and the measuring device 2, the device 10 according to the invention is capable of, on the one hand the resistance of the secondary winding 6 and thus the temperature of the insulation and to determine the dielectric response of the insulation as described above. Based on the dielectric response and the temperature of the insulation, the moisture content of the insulation is determined by comparing the dielectric response with dielectric responses stored in the memory 30.
  • the moisture content of the insulation is determined based on the stored dielectric response most consistent with the measured dielectric response.
  • the moisture content of the insulation of the current transformer 1 can be constantly monitored without having to interrupt the drying process of the current transformer 1, as is the case in the prior art, for example in the dew point measurement.
  • the drying process in the furnace 1 1 it is possible by the constant determination of the moisture content, the drying process in the furnace 1 1 to control such that a predetermined target moisture content is achieved accurately, without the insulation is damaged by a too long drying.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Measurement Of Resistance Or Impedance (AREA)

Abstract

La présente invention concerne un procédé et un dispositif de mesure de la réponse diélectrique de l'isolation (7) d'un transformateur de courant (1) pour déterminer la température de l'isolation (7) et pour déterminer un taux d'humidité de l'isolation (7) en fonction de la réponse diélectrique et de la température.
PCT/EP2015/057676 2014-04-10 2015-04-09 Procédé et dispositif de détermination du taux d'humidité de l'isolation d'un transformateur de courant et de séchage de l'isolation WO2015155270A1 (fr)

Applications Claiming Priority (2)

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AT502702014 2014-04-10
ATA50270/2014 2014-04-10

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104714100A (zh) * 2015-04-01 2015-06-17 国家电网公司 一种用于含水量分析的绝缘电阻测量数据处理方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20010017053A1 (en) * 2000-02-29 2001-08-30 Alan Rynhart Moisture meter with impedance and relative humidity measurements
EP2026062A1 (fr) * 2007-08-17 2009-02-18 Omicron electronics GmbH Procédé et dispositif destinés à la détermination de la teneur en humidité d'une isolation de transformateur

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20010017053A1 (en) * 2000-02-29 2001-08-30 Alan Rynhart Moisture meter with impedance and relative humidity measurements
EP2026062A1 (fr) * 2007-08-17 2009-02-18 Omicron electronics GmbH Procédé et dispositif destinés à la détermination de la teneur en humidité d'une isolation de transformateur

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
"Diagnostic Testing Solutions for Power Transformers", 30 May 2013 (2013-05-30), pages 1 - 32, XP055196347, Retrieved from the Internet <URL:https://www.omicron.at/fileadmin/user_upload/pdf/literature/Transformer-brochure-ENU.pdf> [retrieved on 20150617] *
"We have the answer", OMICRON MAGAZINE, 1 January 2012 (2012-01-01), pages 11 - 13, XP055196549, Retrieved from the Internet <URL:https://www.omicron.at/fileadmin/user_upload/pdf/papers/OM-02-2012-we-have-the-answer.pdf> [retrieved on 20150617] *
JOHN A. DEDAD: "The basics of transformers, part 2.", 1 December 1999 (1999-12-01), pages 1 - 3, XP055196495, Retrieved from the Internet <URL:http://ecmweb.com/print/content/basics-transformers-part-2> [retrieved on 20150617] *
MAIK KOCH ET AL: "A Comparative Test and Consequent Improvements on Dielectric Response Methods", PROCEEDINGS OF THE XVTH INTERNATIONAL SYMPOSIUM ON HIGH VOLTAGE ENGINEERING, ISH, 1 January 2007 (2007-01-01), XP055062377 *
MAIK KOCH ET AL: "IMPROVED MOISTURE ANALYSIS OF POWER TRANSFORMERS USING DIELECTRIC RESPONSE METHODS", 3RD EUROPEAN CONFERENCE ON HV & MV SUBSTATION EQUIPMENT, 16 November 2007 (2007-11-16), XP055062360 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104714100A (zh) * 2015-04-01 2015-06-17 国家电网公司 一种用于含水量分析的绝缘电阻测量数据处理方法
CN104714100B (zh) * 2015-04-01 2018-08-07 国家电网公司 一种用于含水量分析的绝缘电阻测量数据处理方法

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