Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
  • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
  • G01R15/146—Measuring arrangements for current not covered by other subgroups of G01R15/14, e.g. using current dividers, shunts, or measuring a voltage drop
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4401—Optical cables
  • G02B6/4415—Cables for special applications
  • G02B6/4416—Heterogeneous cables
  • G02B6/4417—High voltage aspects, e.g. in cladding
  • G02B6/442—Insulators

Definitions

• Measuring device for measuring electrical currents in a power conductor under load
• the invention relates to a device for measuring electrical currents in at least one current conductor loaded with mechanical forces.
• a current measuring system is known with a high-potential sensor head which is tensioned in the power lines and thus absorbs the forces in the lines and one Air core coil with a burden for measuring the current and an analog-digital converter and a transmitter unit with LED for the digital optical transmission of the measurement signals via an optical waveguide to ground potential.
• the sensor head is optically over the same light wave conductor supplied with energy.
• the optical waveguide is guided in a flexible insulator.
• the invention is based on the object of specifying a measuring device for measuring electrical currents in at least one current conductor loaded with mechanical forces.
• the device for measuring electrical currents in at least one current conductor loaded with mechanical forces comprises at least one current sensor device and a separating part which is connected to the current conductor in an electrically insulating manner , that is to say electrically interrupts the current conductor, and which also absorbs the forces in the current conductor.
• the current sensor device is connected in a current branch (line branch) which is electrically connected in parallel with the separating part. Since the separating part absorbs the forces in the at least one current conductor, the current sensor device no longer has to bear these forces and can therefore be made mechanically simpler.
• the separating part is fastened via a flexible insulator to an anchorage which is at ground potential.
• the at least one current conductor is attached to an anchoring to earth potential via a flexible insulator.
• At least one light guide is preferably guided in the flexible isolator for the optical transmission of a measurement signal the current sensor device and for the optical transmission of supply power (supply energy) for the current sensor device.
• the weight of the current sensor device is generally absorbed by the current conductor.
• the separating part can also electrically interrupt several current conductors loaded with forces at the same time and absorb the forces acting in these current conductors.
• 1 shows a device for measuring electrical currents in power lines with a measuring resistor
• FIG. 2 shows a measuring device for measuring electrical currents in a tubular current conductor with a measuring resistor
• FIG. 3 shows a measuring device for measuring electrical currents in power lines with an inductive current transformer are each shown schematically. Corresponding to each other
• Parts ⁇ have the same reference numerals.
• the power lines 2 generally hang between two power poles, not shown, to which they are attached. Due to the dead weight of the power lines 2 and due to thermal expansion in the power lines 2, mechanical forces act in the power lines 2, particularly tensile forces in their longitudinal direction. The power lines 2 are now electrically separated with the aid of the separating part 3.
• the separating part 3 is in terms of its dimensions and its material s designed so that it effectively interrupts the power lines 2, that is, there is no current flow through the separating part 3, and at the same time absorbs the mechanical forces in the power lines 2.
• the separating part 3 comprises two elongated parts 30 and 31 which run essentially parallel to the longitudinal direction of the power lines 2 and which are connected to one another via a dielectric glass cap 32.
• a supply line 7 is mechanically fastened to the first part 30 and is electrically connected to the associated power line 2.
• a supply line 8 is also fastened for each power line 2 and is electrically connected to the associated power line 2.
• the measuring resistor 4 and the waveguide 5 are electrically connected in series between the leads 7 and the leads 8.
• the leads 7 are electrically connected to the waveguide 5 and the leads 8 to the measuring resistor 4.
• An electrically tapped voltage at the measuring resistor 4 as a measure of an electrical current flowing through the measuring resistor 4 is not shown as a measuring signal via put electrical measuring cable into the waveguide 5, in which a measuring electronics, not shown, is arranged for the measuring signal.
• the series circuit comprising the measuring resistor 4 and the waveguide 5 is electrically connected in parallel with the separating part 3 and the currents flowing in the power lines 2 flow through it. Because of the arrangement in the waveguide 5, the measuring electronics are practically not influenced by the magnetic field of the electric current or the electric currents in the power lines 2.
• the measuring electronics process the electrical measuring signal of the measuring resistor 4 further.
• the measuring electronics convert the electrical measuring signal into an optical measuring signal, which is transmitted via the light guide 9.
• the light guide 9 is guided through an opening in the waveguide 5.
• the measuring resistor 4 and the waveguide 5 with the measuring device arranged therein Electronics form a current sensor device 14, which delivers an (optical) measurement signal for the current in the power lines 2.
• the measuring electronics in the waveguide 5 are preferably also supplied with energy via the light guide 9 or also a further light guide, not shown.
• an optical energy supply system not shown, which is known per se, is provided with a light source, for example a laser, and a photoelectric converter.
• the two parts 30 and 31 of the separating part 3 can at least partially consist of dielectric material or also of a conductive material, for example of a metal.
• Separating part 3 is generally taken over by the one glass cap 32 or several such glass caps.
• the flexible insulator 6 is now fastened to the separating part 3 via the fastening device 11.
• the fastening device 11 can be, for example, a tensioning device with a rope and optionally a tension spring.
• the optical waveguide 9 runs inside the flexible insulator 6 up to the anchoring 10, which is at ground potential.
• the flexible insulator 6 is attached to the anchor 10.
• the fastening device 11 can also be provided at the base of the insulator 6 on the anchoring 10.
• the isolator 6 can also be clamped at the top and bottom.
• the optical measurement signal can be led from the anchoring 10 via optical fiber earth cables to a control room. The optical transmission ensures isolated transmission of the measurement signal.
• the flexible insulator 6 minimizes leakage currents between the current conductor 2 which is at high voltage potential and the anchor 10 which is at ground potential.
• the dead weight of the measuring resistor 4 and the waveguide 5 with the measuring electronics arranged therein is absorbed by the separating part 3 and thus by the power lines 2 via the feed lines 7 and 8.
• the flexible insulator 6 therefore does not have to bear any further mechanical forces apart from any tensioning forces by the fastening device 11, in particular also not the weight of the measuring resistor 4 provided as the current sensor and of the waveguide 5 or the mechanical forces in the power lines 2 - construction guarantees a high level of earthquake security.
• the flexible insulator 6 and the likewise flexible power lines 2 and the freely running light guide 9 simply follow the movements of the anchor 10, and destruction of the measuring device is thus prevented .
• the separating part 3 is preferably simply provided with a dielectric disk or a dielectric ring with a thickness sufficient for electrical insulation and sufficient strength to absorb the forces in the current conductor 2 '.
• a current sensor device 14 with a measuring resistor 4 and an associated waveguide 5, which contains the measuring electronics, is again provided, which is suspended via leads 7 and 8 from the current conductor 2 'and with the partial area of the current conductor 2', which by da ⁇ Part 3 is electrically interrupted, is electrically connected in parallel.
• the flexible insulator 6 is fastened to the current conductor 2 'via the fastening device 11 and is preferably tensioned again.
• the flexible insulator 6 must electrically isolate the entire potential difference between the current conductor 2 'and the earth potential at the anchor 10.
• hanging power lines 2 are again provided, which are again electrically interrupted by a separating part 3 as in FIG.
• an inductive current transformer 4 ' is provided instead of a measuring resistor 4.
• the current sensor device with the current transformer 4 'and the waveguide 5 is designated 14'.
• the measurement signal of the inductive current transformer 4 ' is fed via a measurement cable 12 into the associated waveguide 5, in which the associated measurement electronics are arranged.
• An optical measurement signal is again conducted to earth potential via a light guide 9 and the movable isolator 6.
• any suitable current sensor device can be used as the current sensor device connected in parallel to the separating part 3, in particular an electrical current sensor device that delivers an electrical measurement signal, but also a magneto-optical Faraday current converter that directly delivers an optical measurement signal.
• the waveguide 5 is generally no longer necessary.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7790562

Family Applications (1)

Country Status (7)

Families Citing this family (3)

Family Cites Families (7)

• 1996
  • 1996-04-04 DE DE19613664A patent/DE19613664A1/de not_active Withdrawn
• 1997
  • 1997-03-24 BR BR9708496A patent/BR9708496A/pt not_active Application Discontinuation
  • 1997-03-24 EP EP97920538A patent/EP0891557A1/de not_active Withdrawn
  • 1997-03-24 WO PCT/DE1997/000598 patent/WO1997038320A1/de not_active Application Discontinuation
  • 1997-03-24 CN CN97193693A patent/CN1215473A/zh active Pending
  • 1997-04-02 ZA ZA9702791A patent/ZA972791B/xx unknown
• 1998
  • 1998-10-02 NO NO984643A patent/NO984643L/no unknown

Non-Patent Citations (1)

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