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DE102005007334B4 - Summation current transformer for all-current sensitive detection of an electrical differential current - Google Patents

Summation current transformer for AC / DC sensitive detection of an electrical residual current Download PDF

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Publication number
DE102005007334B4
DE102005007334B4DE102005007334ADE102005007334ADE102005007334B4DE 102005007334 B4DE102005007334 B4DE 102005007334B4DE 102005007334 ADE102005007334 ADE 102005007334ADE 10200500ADE4334 ADE102005007334 ADE 102005007334500 B4DE 102005007334 ADE102005007337
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DE
Germany
Prior art keywords
current transformer
current
winding
summation current
summation
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Fee Related
Application number
DE102005007334A
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English (en)
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DE102005007334A1 (de
Inventor
Jürgen Bross
Bernhard Schmid
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Siemens AG
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Siemens AG
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Publication of DE102005007334A1publicationCriticalpatent / DE102005007334A1 / de
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Expired - Fee Relatedlegal-statusCriticalCurrent
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Left

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Classifications

    • H-ELECTRICITY
    • H01 — BASIC 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 / 38 — Instruments transformers for polyphase ac
    • H-ELECTRICITY
    • H01 — BASIC 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
    • H01F38 / 30 — Constructions
    • H-ELECTRICITY
    • H01 — BASIC ELECTRIC ELEMENTS
    • H01H-ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H83 / 00 — Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current
    • H01H83 / 14 — Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by unbalance of two or more currents or voltages, e.g. for differential protection
    • H01H83 / 144 — Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by unbalance of two or more currents or voltages, e.g. for differential protection with differential transformer
    • H-ELECTRICITY
    • H01 — BASIC 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 / 288-Shielding
    • H-ELECTRICITY
    • H01 — BASIC ELECTRIC ELEMENTS
    • H01F — MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27 / 00 — Details of transformers or inductances, in general
    • H01F27 / 34 — Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H01F27 / 36 — Electric or magnetic shields or screens
    • H-ELECTRICITY
    • H01 — BASIC 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

Abstract

Description

  • The invention relates to a summation current converter for the all-current sensitive detection of an electrical differential current.
  • In the case of a summation current transformer, the differential current is determined by adding the currents in several, for example two to four, primary conductors in the correct phase. The inductive principle is used here, so that initially only currents with an alternating component, i.e. alternating differential currents and pulsating direct differential currents, can be recorded. An AC / DC-sensitive summation current transformer is known from, which, in conjunction with an electronic unit, is also suitable for detecting smooth DC differential currents. The specially designed summation current transformer comprises two magnetic cores, one of which is intended for the alternating components and the other for the direct components.
  • In addition to the wide frequency range, AC / DC sensitive summation current transformers are also designed to require as little space as possible, since the installation space available for applications in installation technology is usually limited. In contrast, the nominal current of AC / DC-sensitive summation current transformers, i.e. the permissible current in a primary conductor, is often limited to a value of 80 A. Even lower nominal current values ​​are quite common.
  • Further features, advantages and details of the invention emerge from the following description of an exemplary embodiment based on the drawing. It shows:
  • an embodiment of a summation current transformer for AC / DC sensitive residual current detection in a longitudinal section,
  • the summation current transformer according to without external conversion in a perspective view and
  • the summation current transformer according to in a perspective view.
  • Corresponding parts are provided with the same reference numerals in FIGS.
  • In the following, an exemplary embodiment of an all-current-sensitive summation current transformer for detecting electrical differential currents is described with reference to FIGS. Universal current sensitive means that the frequency range of the recorded differential current can be in the range between 0 Hz and a few 10 kHz.
  • From the longitudinal sectional illustration according to FIG. 1, it can be seen that the essentially cylindrical summation current transformer contains two magnetic cores, namely an FI core and a DI core. The FI core is mainly intended to record currents with alternating components, whereas the DI core is mainly used to record direct currents. Both magnetic cores are tape cores made of crystalline or amorphous NiFe tapes. To protect against mechanical damage, they are arranged in an FI trough or in a DI trough. Both troughs and are designed as snap-in troughs with a snap-in lid. They are made of an electrically insulating material. In the exemplary embodiment, a plastic is provided.
  • The FI trough is wound with an FI secondary winding and the DI trough with a DI secondary winding. A thin enamel-insulated secondary winding wire is provided for each of the FI and DI secondary windings.
  • The FI secondary winding is surrounded by an FI insulating film and an FI shield. The DI secondary winding is surrounded by a DI insulating film and a DI shield. The FI and DI insulating film or as well as the FI and DI shielding or are each made in two parts in the exemplary embodiment for easier assembly. The FI and DI insulating film or is a deep-drawn plastic film that can be prefabricated in your later form and can then be easily pushed onto the relevant FI and DI secondary winding. The FI and DI shields are made of a magnetic metal. In the exemplary embodiment, a steel material with a wall thickness of 0.5 mm is provided. In principle, a wall thickness in the range between 0.2 mm and 2.0 mm can be selected. Then there is a good compromise between the greatest possible shielding effect and the smallest possible geometric dimensions.
  • The FI and DI insulating film or effect additional insulation of the secondary winding wire from the metallic FI shield or DI shield. During the winding process, the lacquer insulation on the secondary winding wire can be damaged in the edge area. The FI and DI insulating film or prevent electrical contact with the FI shield or DI shield at these points.
  • The cores wound and shielded in this way are arranged one behind the other in the direction of a central axis of the summation current transformer. A small axial distance is provided between the FI shield and the DI shield. This distance is at least so large that a test winding, which has its connections outwards, can be placed around at least one of the two shields and. In the exemplary embodiment, the test winding surrounds the DI shield.
  • An extension is provided on the FI trough, in which two metal pins are embedded, for example, cast in such a way that their free ends protrude a little from the extension and also from the outer circumferential wall of the summation current transformer. The metal pins are oriented radially, i.e. perpendicular to the central axis. Correspondingly, an extension into which metal pins are embedded is also arranged on the DI trough. The metal pins are oriented axially, that is, in the direction of the central axis. They protrude from an outer end wall of the summation current transformer. The loose ends of the FI secondary winding are each electrically connected to one of the metal pins. The loose ends of the DI secondary are each electrically connected to one of the metal pins. According to the illustration in FIG. 1, a recess for the extension and the metal pins is provided in the FI shield, as well as a recess in the DI shield for the extension and the metal pins.
  • The summation current transformer has a partition as an outer casing and protective cover, which consists of a partition middle part and two partition covers fitted on the side. The outer wall is designed in such a way that in the center of the cylinder shape, i.e. in the area of ​​the central axis, a total of four through openings in the form of longitudinal channels (see) for receiving and guiding primary conductors (not shown in detail) are formed. Apart from recesses and for the metal pins and / or for the connections of the test winding, the outer casing completely closes off the summation current transformer. In addition, the outer wall also separates the sub-units provided on the FI and DI side from one another.
  • In the area in which the metal pins protrude from the circumferential surface of the outer wall, four supports and two snap hooks are also molded onto the outer wall. The outer wall consists of a plastic material so that the supports and the snap hooks can easily be molded on in connection with the injection molding of the outer wall. The arrangement of the supports and the snap hooks on the outer wall can be seen in particular from the illustration in FIG. The supports and the snap hooks are used to mount and fasten an evaluation unit (not shown in more detail) directly on or on the summation current transformer.
  • The evaluation unit is provided for the further processing of the output signals of the summation current transformer that can be tapped at the metal pins. In this way, in particular, a smooth direct differential current can also be detected in the primary conductors to be monitored. A flat module of the evaluation unit can advantageously be plugged directly onto the metal pins and electrically connected by means of a soldered connection. The metal pins create a very stable structure, so that the flat module can be put on without fear of mechanical damage to this electrical connection. The metal pins are also intended for electrical connection to the evaluation unit.
  • Overall, the summation current transformer has a very compact design, which can also be used in applications with only a small amount of available installation space. On the one hand, the closely spaced arrangement of the FI and DI-side sub-units saves space, as does the possibility of placing the evaluation unit directly on the summation current transformer.
  • Due to the FI shielding and the DI shielding, such a close arrangement of the electronic evaluation unit does not stand in the way of the magnetic field that would otherwise also extend into the outside area. In addition, interference in the voltages induced in the FI secondary winding and in the DI secondary winding is prevented by magnetic fields generated outside the summation current transformer. These external magnetic fields are effectively shielded. Due to the shielding effect, no functional impairments due to magnetic fields are to be feared in the evaluation unit. The good shielding effect also enables the summation current transformer to be operated with higher permissible nominal current values ​​in the primary conductors. In the embodiment of the summation current transformer, a nominal current of 125 A is possible without any problems. In addition, even higher nominal current values ​​can generally be achieved.

Claims (9)

  1. Summation current transformer for AC / DC sensitive detection of an electrical differential current comprising a) an outer wall (), b) at least one passage opening () which runs in the direction of a central axis () and which is intended to accommodate at least two primary conductors monitored with regard to the differential current, c) one with a first secondary winding () wound and the through opening () surrounding the first magnetic core (), d) a second magnetic core () wound with a second secondary winding () and surrounding the through opening () and e) one between the outer wall () on the one hand and the first and second magnetic cores (12, 12) arranged on the other hand, made of a magnetic metal with a wall thickness between 0.2 mm and 2.0 mm.
  2. Summation current transformer according to claim 1, characterized in that the shielding contains a first partial shielding surrounding the first magnetic core and the first secondary winding and a second partial shielding surrounding the second magnetic core and the second secondary winding.
  3. Summation current transformer according to Claim 2, characterized in that the first and second partial shields (12, 14) are each made in at least two parts.
  4. Summation current transformer according to one of the preceding claims, characterized in that electrical insulation (12, 12) is provided between the magnetic shield (12, 12) and the secondary windings (12).
  5. Summation current transformer according to Claim 4, characterized in that the electrical insulation is designed as an insulating film (12, 14), in particular as a deep-drawn plastic insulating film.
  6. Summation current transformer according to one of the preceding claims, characterized in that the first and the second magnetic core (12,) are each designed as a tape core which is arranged in a first and in a second trough (12,).
  7. Summation current transformer according to claim 6, characterized in that two connecting pins () are attached to the first trough (), which protrude perpendicular to the central axis () from the outer wall () and to which one of the two loose ends of the first secondary winding () is electrically connected is.
  8. Summation current transformer according to one of the preceding claims, characterized in that support elements (14) for mounting an evaluation unit are provided on the outer wall (14).
  9. Summation current transformer according to one of the preceding claims, characterized in that fastening elements () for fastening an evaluation unit are provided on the outer wall (14).
DE102005007334A2005-02-172005-02-17 Summation current transformer for AC / DC sensitive detection of an electrical differential current Expired - Fee RelatedDE102005007334B4 (de)

Priority Applications (1)

Application NumberPriority DateFiling dateTitle
DE102005007334ADE102005007334B4 (de) 2005-02-172005-02-17Summation current transformer for all-current sensitive detection of an electrical differential current

Applications Claiming Priority (3)

Application NumberPriority DateFiling dateTitle
DE102005007334ADE102005007334B4 (de) 2005-02-172005-02-17Summation current transformer for all-current sensitive detection of an electrical differential current
EP06101331AEP1696444B1 (de) 2005-02-172006-02-06Summation current transformer for all-current sensitive detection of an electrical differential current
AT06101331TAT527672T (de) 2005-02-172006-02-06Summation current transformer for all-current sensitive detection of an electrical differential current

Publications (2)

ID = 36675886

Family Applications (1)

Application NumberTitlePriority DateFiling date
DE102005007334AExpired - Fee RelatedDE102005007334B4 (de) 2005-02-172005-02-17Summation current transformer for all-current sensitive detection of an electrical differential current

Country Status (3)

Cited By (2)

Publication numberPriority datePublication dateAssigneeTitle
WO2014104982A1 (en) 2012-12-242014-07-03Razvojni Center Enem Novi Materiali D.O.O.Electronic device for residual current circuit breakers of type b and its derivative
DE102016225879A1 (de) 2016-12-212018-06-21Siemens AktiengesellschaftUniversal current sensitive summation current transformer, electromechanical protective switching device and manufacturing process

Families Citing this family (4)

Publication numberPriority datePublication dateAssigneeTitle
DE102011075456B4 (de) 2011-05-062015-06-25Siemens AktiengesellschaftSummation current transformer and residual current circuit breaker
DE102012201002A1 (de) 2012-01-242013-07-25Siemens AktiengesellschaftSummation current transformer housing, summation current transformer and residual current circuit breaker
DE102012203337B4 (de) 2012-03-022020-04-23Siemens AktiengesellschaftSummation current transformer and electrical circuit breaker
EP2940702A1 (de) *2014-04-162015-11-04Bender GmbH & Co. KGResidual current measuring module

Citations (7)

Publication numberPriority datePublication dateAssigneeTitle
DE3021768A1 (de) *1980-01-181981-07-23Felten & Guilleaume Ag OesterResidual current circuit breaker with summation current transformer
DE4036275A1 (de) *1990-11-141992-05-21Zumtobel AgRing-shaped bobbin for small and safety transformers and processes for its production
DE4106034A1 (de) *1991-02-221992-08-27Siemens AGPower converter
EP0603857A1 (de) *1992-12-241994-06-29Limited partnership Ritz Messwandler GmbH & amp; Co.Toroidal core converter with interference voltage protection
DE4111236C2 (de) *1991-04-081999-04-08Abb Patent GmbHSummation current transformer for a residual current circuit breaker
DE19944043A1 (de) *1999-09-142001-03-15Siemens AGResidual current protective device and method for operating a residual current protective device
EP1267467A2 (de) *2001-06-122002-12-18DOEPKE & amp; CO. SCHALTGERÄTEFABRIK GmbH & amp; CO. KGDevice for detecting electrical differential currents

Family Cites Families (3)

Publication numberPriority datePublication dateAssigneeTitle
DE3543985A1 (de) *1985-12-121987-06-19Siemens AGArrangement for detecting fault currents
EP0531554B1 (de) *1991-09-061994-12-07Siemens AktiengesellschaftTransformers, for example summation current transformers
DE19822515C2 (de) *1998-05-192000-07-06Siemens AGShielding for summation current transformer arrangement for residual current circuit breakers

Patent Citations (7)

Publication numberPriority datePublication dateAssigneeTitle
DE3021768A1 (de) *1980-01-181981-07-23Felten & Guilleaume Ag OesterResidual current circuit breaker with summation current transformer
DE4036275A1 (de) *1990-11-141992-05-21Zumtobel AgRing-shaped bobbin for small and safety transformers and processes for its production
DE4106034A1 (de) *1991-02-221992-08-27Siemens AGPower converter
DE4111236C2 (de) *1991-04-081999-04-08Abb Patent GmbHSummation current transformer for a residual current circuit breaker
EP0603857A1 (de) *1992-12-241994-06-29Limited partnership Ritz Messwandler GmbH & amp; Co.Toroidal core converter with interference voltage protection
DE19944043A1 (de) *1999-09-142001-03-15Siemens AGResidual current protective device and method for operating a residual current protective device
EP1267467A2 (de) *2001-06-122002-12-18DOEPKE & amp; CO. SCHALTGERÄTEFABRIK GmbH & amp; CO. KGDevice for detecting electrical differential currents

Cited By (3)

Publication numberPriority datePublication dateAssigneeTitle
WO2014104982A1 (en) 2012-12-242014-07-03Razvojni Center Enem Novi Materiali D.O.O.Electronic device for residual current circuit breakers of type b and its derivative
DE102016225879A1 (de) 2016-12-212018-06-21Siemens AktiengesellschaftAC / DC sensitive summation current transformer, electromechanical protective switching device and manufacturing process
EP3340272A1 (de) *2016-12-212018-06-27Siemens AktiengesellschaftAC / DC sensitive summation current transformer, electromechanical protective switching device and manufacturing process

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