EP4254461A1 - Elektromagnetisches stellglied - Google Patents

Elektromagnetisches stellglied Download PDF

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Publication number
EP4254461A1
EP4254461A1 EP22165825.5A EP22165825A EP4254461A1 EP 4254461 A1 EP4254461 A1 EP 4254461A1 EP 22165825 A EP22165825 A EP 22165825A EP 4254461 A1 EP4254461 A1 EP 4254461A1
Authority
EP
European Patent Office
Prior art keywords
armature
actuator
previous
inner housing
electromagnetic actuator
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.)
Pending
Application number
EP22165825.5A
Other languages
English (en)
French (fr)
Inventor
Lukasz Bachorz
Timothy John HEEMSKERK
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Energy Ltd
Original Assignee
Hitachi Energy Switzerland AG
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 Hitachi Energy Switzerland AG filed Critical Hitachi Energy Switzerland AG
Priority to EP22165825.5A priority Critical patent/EP4254461A1/de
Publication of EP4254461A1 publication Critical patent/EP4254461A1/de
Pending legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H50/00—Details of electromagnetic relays
    • H01H50/16—Magnetic circuit arrangements
    • H01H50/18—Movable parts of magnetic circuits, e.g. armature
    • H01H50/30—Mechanical arrangements for preventing or damping vibration or shock, e.g. by balancing of armature
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
    • H01F7/088—Electromagnets; Actuators including electromagnets with armatures provided with means for absorbing shocks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
    • H01F7/16—Rectilinearly-movable armatures
    • H01F7/1607—Armatures entering the winding
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
    • H01F7/16—Rectilinearly-movable armatures
    • H01F2007/1692—Electromagnets or actuators with two coils

Definitions

  • the invention relates to an electromagnetic actuator for an electrical switching apparatus, the electromagnetic actuator comprising an actuator housing defining a longitudinal axis and having an upper inner housing surface and a lower inner housing surface, an armature comprising ferromagnetic material and arranged within the actuator housing axially movable between a first position and a second position, and at least one electromagnetic coil coaxially arranged within the actuator housing in respect to and for actuating the armature.
  • Electromagnetic actuators due to their simplicity and high efficiency are widely used for providing motion in electrical switching apparatuses, such as for example MV, medium voltage, circuit breakers, reclosers, switches and contactors.
  • electrical switching apparatuses such as for example MV, medium voltage, circuit breakers, reclosers, switches and contactors.
  • electromagnetic actuators comprise a permanent magnet with either a single or double electromagnet coil for driving a movable contact of the electrical switching apparatus for closing and tripping respectively opening.
  • Both alternative designs provide high reliability and fast operation with contact speeds reaching at least 1 m/s, which is critical for proper operation of the electrical switching apparatus in some electrical applications, such as for example capacitor switching.
  • the drive rod is equipped with an overtravel spring, which works like a bumper and decreases shocks being generated during closing, thereby changing some of the kinetic energy into potential energy that provides additional opening speed during tripping.
  • an overtravel spring which works like a bumper and decreases shocks being generated during closing, thereby changing some of the kinetic energy into potential energy that provides additional opening speed during tripping.
  • Said operation is a source of massive tensions, vibrations and noise and may lead to premature mechanical failures of the device due to material fatigue.
  • an electromagnetic actuator for an electrical switching apparatus comprising
  • the damping element in particular for tripping operation constitutes a key point of the proposed solution.
  • Said damping element reduces mechanical shocks generated during switch tripping.
  • moving mass kinetic energy may compress the damping element so that at least a part of the kinetic energy will be transformed directly into potential energy, which will be then available when the electrical switching apparatus will be requested to close.
  • the proposed solution decreases significantly mechanical shock generated during tripping of electrical switching apparatus, reduces noise and extends mechanical life due to reduced material fatigue.
  • the damping element is not intended to provide a permanent separation between the armature and the actuator housing, as in the second position the armature preferably tangentially contacts the lower inner housing surface.
  • the damping element dissipates energy when the armature moves into the second position, whereby the damping element becomes in particular fully compressed.
  • With a metallic actuator housing magnetic latching can be achieved in said second position. In result electrical switching apparatus lifetime is significantly extended.
  • the actuator housing may be made of metal and/or may comprise a closed tube-like and/or cylinder-like shape, in particular with openings only at deck surfaces for a rod and/or a stem mentioned below.
  • the upper inner housing surface and/or the lower inner housing surface may thus be defined by an inner deck surface of the cylinder.
  • the armature may also comprise a respective closed tube-like and/or cylinder-like shape, in particular sharing the axis of the actuator housing.
  • the term that the armature in the first position contacts the upper inner housing surface and in the second position contacts the lower inner housing surface means preferably that at least a part of a deck surface of the armature contacts the respective inner housing surface in a touching manner.
  • the second position preferably at least a part of the deck surface of the armature contacts the lower inner housing surface, for example 10, 20, 30 or 50% of the deck surface of the armature facing the lower inner housing surface.
  • the armature can be understood as an electrically conducting member of which a part is adjacent to the electromagnetic coil such that the armature is subject to a repulsive force upon application of a current pulse to the electromagnetic coil.
  • the current pulse in the electromagnetic coil generates a varying magnetic flux, which in turn generates a current with opposite direction in the armature, which generates a magnetic force between the electromagnetic coil and the armature for effecting movement of the armature relatively to the electromagnetic coil.
  • the armature may comprise a continuous aluminium body, since aluminium has a relatively good conductivity and also a relatively light but robust structure.
  • Ferromagnetic material means that the material comprises a kind of magnetism that is associated with materials such as for example iron, cobalt, nickel, and some alloys or compounds containing one or more of these elements.
  • the at least one electromagnetic coil may radially surround the armature such that, when a current is applied to the least one electromagnetic coil, the armature is axially moved within the actuator housing from the first position into the second position.
  • the damping element may be provided as a flat pad, may be permanently attached to the bottom end of the armature or to the lower inner housing surface and/or may comprise a round diameter extending around the longitudinal axis.
  • the bottom end of the armature or the lower inner housing surface comprises a recess and the damping element is provided in the recess.
  • the recess may be provided as an opening, as a cavity, as a gap and/or as a notch, in which the damping element is arranged.
  • the recess preferably comprises an axial depth smaller than an axial extension of the damping element.
  • the recess is preferably dimensioned such that the damping element axially overtops the recess.
  • the recess extends ring-like, rectange-like or square-like around the longitudinal axis.
  • the recess may comprise a shape in a form of a flat washer.
  • the recess may comprise an axial depth or 2, 5, 10 or 20 mm, with a width being 2, 5 or 10 times the depth.
  • the recess may comprise, in a side view, a rectangle-like shape, a V-shape or a rounded shape.
  • the recess comprises a radially extending surface smaller than a radially extending surface of the bottom end of the armature.
  • the recess is preferably smaller in size than the bottom end of the armature so that in the second position at least a part of the armature contacts the lower inner housing surface.
  • the radially extending surface of the recess is 50, 70, 80 or 90% of the radially extending surface of the bottom end of the armature.
  • At least a part of the bottom end or the lower inner housing surface is provided damping element-free and, in the second position, the damping element-free part tangentially contacts the lower inner housing surface or the bottom end.
  • the damping element-free part in the second position, is in preferably touching contact between the armature and the lower inner housing surface.
  • no damping element is present.
  • the part preferably extends radially.
  • the part may have a ring-like or square-like shape extending around the damping element.
  • the part may have the same outer form as the axial side of the armature.
  • the damping element may be provided as any kind of shock absorber for converting kinetic energy of the moving armature into another form of energy.
  • the damping element comprises a pad made of compressible porous material.
  • the damping element and/or the pad may comprise an axial thickness of 0.2, 0.5, 1, 2, 5 or 10 cm.
  • the damping element may consist of a microcellular foam, such as for example urethane foam, a viscoelastic PUR-material, nitrile, polyurethane, polyvinyl chloride, rubber or a combination thereof.
  • the damping element comprises a foamed EPDM and/or rubber elastomeric material, in particular with closed or open structures filled with air.
  • EPDM ethylene propylene diene monomer rubber
  • ethylene propylene diene monomer rubber is usually known as a type of synthetic rubber comprises elastomers having a saturated chain of the polyethylene type.
  • EPDM is typically made from ethylene, propylene, and a diene comonomer that enables crosslinking via sulfur vulcanization, and often has a hardness, Shore A, between 30 to 90. Rubber is typically referred to a material consisting of polymers of an organic compound isoprene, with minor impurities of other organic compounds.
  • the electromagnetic actuator comprises two electromagnetic coils arranged axially distant to each other.
  • the coil adjacent to the damping element can be referred to as open and/or trip coil, as said coil is intended for opening the electrical switching apparatus.
  • the other coil can be referred to as closing coil being intended for closing the electrical switching apparatus.
  • the respective coil is preferably arranged such that, exemplary to the open and/or trip coil, in the first position the open and/or trip coil and the armature axially only slightly overlap, while in the second position the armature axially preferably fully overlaps the open and/or trip coil.
  • the coils preferably circumferentially extends around a lateral surface of the armature.
  • the electromagnetic actuator comprises a permanent magnet coaxially arranged within the actuator housing in respect to and for actuating the armature and arranged axially distant to the at least one electromagnetic coil.
  • Said at least one electromagnetic coil and/or permanent magnet are intended for driving the armature and subsequently a movable contact connectable to the armature as described below for closing and tripping the electrical switching apparatus.
  • the at least one electromagnetic coil and/or permanent magnet are preferably designed such that the actuator provide high reliability and fast operation with armature and/or movable contact speeds reaching at least 1m/s.
  • the damping element is preferably designed to effectively damp and/or decelerate such speeds thereby avoiding noise and/or vibrations.
  • the electromagnetic actuator comprises a connecting rod extending along the longitudinal axis, fixed to the armature and configured for moving a moveable contact of the electrical switching apparatus in order to open and close the electrical switching apparatus.
  • the electromagnetic actuator comprises an overtravel spring axially connected to the connecting rod and configured for connecting the movable contact.
  • the overtravel spring is preferably connected in between the connecting rod and the movable contact in axial extension of the connecting rod.
  • the connecting rod also referred to as drive rod
  • the overtravel spring can work as a bumper reducing mechanical stresses on mechanical components of the electrical switching apparatus.
  • the electromagnetic actuator comprises a stem extending along the longitudinal axis such that the armature is arranged between the stem and the connecting rod.
  • the stem is preferably fixed to the armature and/or extends in parallel to the connecting rod.
  • the connecting rod and/or the stem may axially extend through an opening within the upper inner housing surface and/or the lower inner housing surface of the actuator housing.
  • the electromagnetic actuator comprises a trip assisting spring arranged between the stem and the actuator housing. Said trip assisting spring is preferably connected with one end to the actuator housing and with and never opposite end to an end of the stem facing away from the armature.
  • an electrical switching apparatus comprising a fixed contact, a movable contact and the electromagnetic actuator as described before, whereby the armature is connected to the movable contact in order to open and close the electrical switching apparatus.
  • the electrical switching apparatus is provided as medium voltage circuit breaker, recloser, switch or contactor.
  • the term medium voltage is preferably understood as 1 and 50 kV or lower than 72 kV AC and 100 kV DC.
  • So-called protection devices typically circuit breakers, are basically suitable for carrying, for a specified time, and breaking currents under specified abnormal circuit conditions, namely short circuits.
  • So called maneuvering switching devices, such as contactors are capable of making, carrying and breaking currents under normal circuit conditions including overload conditions.
  • Such contactors are widely used for example to switch on/off electric motors, are required to satisfy a number of conditions which are important to guarantee the proper functional performances during their service life in electrical networks.
  • Figs. 1 to 3 each show an electromagnetic actuator 1 for an electrical switching apparatus 2, only partially shown, with three different axial positions of an armature 3 made of a ferromagnetic material in a schematic sectional view according to different implementation.
  • the electrical switching apparatus 2 is provided as medium voltage circuit breaker, recloser, switch or contactor.
  • the electromagnetic actuator 1 is part of electrical switching apparatus 2, which comprises a two current carrying contacts, namely a fixed contact part 4 and a movable contact part 5.
  • a connecting respectively pull rod 6 connects the movable contact 5 via an overtravel spring 7 to the actuator 1 in order to open and close the electrical switching apparatus 2.
  • the pull rod 6 is made of an electrically insulating material in order to electrically insulate the contacts 4, 5 from the actuator 1.
  • the actuator 1 comprises a tube-like actuator housing 8 surrounding the tube-like armature 3 and defining a longitudinal axis 9.
  • the actuator housing 8 has two axial openings along the longitudinal axis 9, one upper opening where the pull rod 6 extends along the longitudinal axis through the actuator housing 8 being connected to an upper axial end of the armature 3 and one lower opening where a stem 10 extends along the longitudinal axis through the actuator housing 8 being connected to a lower axial end of the armature 3.
  • the actuator 1 further comprises at least one electromagnetic coil 11, 12 arranged within the actuator housing 8 coaxially in respect to the armature 3.
  • the actuator 1 of Figs. 1 and 2 comprise one electromagnetic coil 11 arranged close to a lower inner housing surface 13 of the actuator housing 8, whereby the actuator 1 of Fig. 3 comprises two electromagnetic coils 11, 12 arranged axially distant to each other. Axially between and distant to the two electromagnetic coils 11, 12 a permanent magnet 14 is coaxially arranged within the actuator housing 8 in respect to the armature 3.
  • the armature 3 is axially movable along the longitudinal axis 9 between a first position, shown in Figs. 1 to 3 in the left, and a second position, shown in Figs. 1 to 3 in the right.
  • the movable contact 5 electrically contacts the fixed contact 4 and the overtravel spring 7 is compressed, while the armature 3 tangentially contacts an upper inner housing surface 15 of the actuator housing 8.
  • the movable contact 5 In the second position the movable contact 5 does not electrically contact the fixed contact 4 and the overtravel spring 7 is expanded, while the armature 3 tangentially contacts the lower inner housing surface 13 of the actuator housing 8.
  • a middle position shown in Figs. 1 to 3 in the middle, the movable contact 5 still electrically contacts the fixed contact 4, while the overtravel spring 7 becomes expanded as the armature 3 is not in contact anymore with the upper inner housing surface 15, but also not yet in contact with the lower inner housing surface 13.
  • the actuator 1 further comprises a damping element 16, which is attached in Fig. 1 to the lower inner housing surface 13 thereby facing a bottom end of the armature 3.
  • the damping element 16 is attached to the bottom end of the armature 3 thereby facing the lower inner housing surface 13.
  • the damping element 16 comprises a ring-like radially extending shape arranged around the stem 10 respectively the longitudinal axis 9. Thereby a radially extending surface of the damping element 16 is smaller than a radially extending surface of the bottom end of the armature 3.
  • the damping element 16 is provided as a pad made of compressible porous material, such as a foamed EPDM and/or rubber elastomeric material with closed or open structures filled with air.
  • a trip assisting spring 19 is arranged in Figs. 1 and 2 between the stem 10 and the actuator housing 8, whereby the trip assisting spring 19 is most compressed in the first position and expanded in the second position.
  • Fig. 1 the lower inner housing surface 13 and in Figs. 2 and 3 the bottom end is provided with a radially extending recess 17 having a ring-like shape.
  • the damping element 16 is provided in the recess such that the damping element 16, as shown in Figs. 1 to 3 in the left and in the middle, overtop the recess 17.
  • moving mass kinetic energy compresses the damping element 16 until the armature 3 rests touching on the lower inner housing surface 13. Therefore, at least a part 18 of the bottom end or of the lower inner housing surface 13 is provided damping element-free so that, in the second position, the damping element-free part 18 tangentially contacts lower inner housing surface 13 or the bottom end of the armature 3.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Electromagnets (AREA)
EP22165825.5A 2022-03-31 2022-03-31 Elektromagnetisches stellglied Pending EP4254461A1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP22165825.5A EP4254461A1 (de) 2022-03-31 2022-03-31 Elektromagnetisches stellglied

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP22165825.5A EP4254461A1 (de) 2022-03-31 2022-03-31 Elektromagnetisches stellglied

Publications (1)

Publication Number Publication Date
EP4254461A1 true EP4254461A1 (de) 2023-10-04

Family

ID=81328325

Family Applications (1)

Application Number Title Priority Date Filing Date
EP22165825.5A Pending EP4254461A1 (de) 2022-03-31 2022-03-31 Elektromagnetisches stellglied

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Country Link
EP (1) EP4254461A1 (de)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA999622A (en) * 1974-05-13 1976-11-09 United-Carr Divisions Of Trw Canada Limited Automotive bounceless contact relay structure
JPS58155706A (ja) * 1982-03-10 1983-09-16 Kamiya Denshi Kogyo Kk ソレノイド
FR2883408A1 (fr) * 2005-03-15 2006-09-22 Denso Corp Commutateur electromagnetique comportant un element tampon pour attenuer le choc de retour du noyau plongeur
DE102007039148A1 (de) * 2007-08-18 2009-02-26 Thomas Magnete Gmbh Schnellschaltmagnet
CN107331580A (zh) * 2017-08-25 2017-11-07 戴丁志 减震强密封式起动继电器

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA999622A (en) * 1974-05-13 1976-11-09 United-Carr Divisions Of Trw Canada Limited Automotive bounceless contact relay structure
JPS58155706A (ja) * 1982-03-10 1983-09-16 Kamiya Denshi Kogyo Kk ソレノイド
FR2883408A1 (fr) * 2005-03-15 2006-09-22 Denso Corp Commutateur electromagnetique comportant un element tampon pour attenuer le choc de retour du noyau plongeur
DE102007039148A1 (de) * 2007-08-18 2009-02-26 Thomas Magnete Gmbh Schnellschaltmagnet
CN107331580A (zh) * 2017-08-25 2017-11-07 戴丁志 减震强密封式起动继电器

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