EP-4738415-A1 - AN ELECTRIC ARC INTERRUPTION ARRANGEMENT

EP4738415A1EP 4738415 A1EP4738415 A1EP 4738415A1EP-4738415-A1

Abstract

An electric arc interruption arrangement comprising: a movable, electrically insulating barrier (102) arranged to move from a first position to a second position, wherein in the second position, the movable, electrically insulating barrier is positioned within an arc zone (118) between a first electrode (106) and a second electrode (108), an electrically conducting coil (104) comprising at least one turn about an axis (122), the coil having a first end (112) and a second end (114), wherein the first end is positioned closer to the first and second electrodes compared to the second end, and second end (114) is electrically connected to one of the first electrode (106) and the second electrode (108) without passing through the coil, wherein the movement of the electrically insulating barrier (102) from the first position to the second position is parallel to the axis of the coil from the first end to the second end, wherein the electrically insulating barrier is arranged to push, by its movement, an arc (116) formed in the arc zone between the first electrode and the second electrode into the coil at its first end, whereby the arc induces an electric current through the electrically conducting coil, thereby generating a magnetic field that acts on the arc.

Inventors

Becerra, Marley
MANNEKUTLA, James
BERGAMINI, ALESSIO

Assignees

ABB SCHWEIZ AG

Dates

Publication Date: 20260506
Application Date: 20241029

Claims (15)

An electric arc interruption arrangement comprising: a movable, electrically insulating barrier (102) arranged to move from a first position to a second position, wherein in the second position, the movable, electrically insulating barrier is positioned within an arc zone (118) between a first electrode (106) and a second electrode (108), an electrically conducting coil (104) comprising at least one turn about an axis (122), the coil having a first end (112) and a second end (114), wherein the first end is positioned closer to the first and second electrodes compared to the second end, and second end (114) is electrically connected to one of the first electrode (106) and the second electrode (108) without passing through the coil, wherein the movement of the electrically insulating barrier (102) from the first position to the second position is parallel to the axis of the coil from the first end to the second end, wherein the electrically insulating barrier is arranged to push, by its movement, an arc (116) formed in the arc zone between the first electrode and the second electrode into the coil at its first end, whereby the arc induces an electric current through the electrically conducting coil, thereby generating a magnetic field that acts on the arc.
The electric arc interruption arrangement according to claim 1, comprising an auxiliary contact (126) connected to the first end of the electrically conducting coil.
The electric arc interruption arrangement according to claim 2, configured such that, in the presence of an arc between the first electrode and the second electrode, when the movable, electrically insulating barrier reaches an axial position between the first end and the second end of the electrically conducting coil, the arc forms between the one of the first electrode or the second electrode, and the auxiliary contact (126) at the first end of the electrically conducting coil.
The electric arc interruption arrangement according to any one of claims 1-2, wherein the magnetic field generated by the electrically conducting coil is configured to cause the arc to move in the azimuthal direction (Θ) of the electrically conducting coil.
The electric arc interruption arrangement according to any one of claims 1-4, wherein the electrically conducting coil is configured to generate a radial magnetic field component that pushes the arc against the inner and/or outer surface(s) of the electrically insulating barrier.
The electric arc interruption arrangement according to any one of claims 1-5, the electrically insulating barrier is arranged to move to a location inside the coil.
The electric arc interruption arrangement according to any one of claims 1-6, wherein the movable electrically insulating barrier is tubular.
The electric arc interruption arrangement according to claim 7, wherein the electrically conducting coil is a single layer solenoid that is coaxially arranged with the tubular and movable electrically insulating barrier.
The electric arc interruption arrangement according to any one of claims 1-8, comprising an insulating wall (132) separating the movable electrically insulating barrier and the electrically conducting coil.
The electric arc interruption arrangement according to any one of claims 1-9, comprising more than one electrically conducting coil (104a, 104b) interleaved or layered with each other.
The electric arc interruption arrangement according to claim 10, the more than one electrically conducting coils are connected to the same second electrode (108).
The electric arc interruption arrangement according to any one of claims 1-11, further comprising an auxiliary contact ring (126) connected to the first end (112) of the electrically conducting coil (104), the contact ring (126) comprising slots (140) that reach radially from an inner side towards an outer side of the contact ring (126).
The electric arc interruption arrangement according to any one of claims 1-12, comprising an iron core (130) inside the electrically conducting coil(s).
The electric arc interruption arrangement according to any one of claims 1-13, wherein the electrically conducting coil comprises multiple turns of variable pitch with increasing density towards the second end.
The electric arc interruption arrangement according to any one of claims 1-14, configured for direct current applications.

Description

Field of the Invention The present invention relates to an electric arc interruption arrangement. Background Electrical switching devices, such as circuit breakers and disconnect switches, are widely used in power distribution and electrical systems to control and interrupt electrical currents. These electrical switching devices are importantly able to interrupt fault currents and protect the electrical system from damage caused by overcurrent or short circuits. During the interruption of high fault currents, an electric arc forms between the contacts of the electrical switching device. This arc can generate significant heat and damage the components of the switching device if not properly controlled and extinguished. Summary In view of the above-mentioned and other drawbacks of the prior art, it is an object of the present invention to provide an electric arc interruption arrangement that at least partly alleviates the deficiencies with prior art. According to a first aspect of the invention, there is provided a movable, electrically insulating barrier arranged to move from a first position to a second position, wherein in the second position, the movable, electrically insulating barrier is positioned within an arc zone between a first electrode and a second electrode, an electrically conducting coil comprising at least one turn about an axis, the coil having a first end and a second end, wherein the first end is positioned closer to the first and second electrodes compared to the second end, and second end is electrically connected to one of the first electrode and the second electrode without passing through the coil, wherein the movement of the electrically insulating barrier from the first position to the second position is parallel to an axis of the coil from the first end to the second end, wherein the electrically insulating barrier is arranged to push, by its movement, an arc formed in the arc zone between the first electrode and the second electrode into the coil at its first end, whereby the arc induces an electric current through the electrically conducting coil, thereby generating a magnetic field that acts on the arc. The present invention is at least partly based on the realization of a coil which is activated by the arc itself. That is, the arc energizes the coil when the arc is formed between the first electrode and the second electrode without the need for additional switches or power supplies. The magnetic field produced by the coil causes elongation and motion of the arc such that arc stagnation is prevented which may otherwise cause damage or wear on components of the electric switch comprising the electric arc interruption arrangement, or the electric arc interruption arrangement itself. The arc zone is the area or volume or location where the arc is formed and from which the electrically insulation barrier pushes the arc into the coil. The coil comprises at least one winding of electrically conducting material such as a metal wire or thread. As electric current is passed through the windings of the coil, a magnetic field is generated in the coil. When the electrically insulating barrier push the arc into the coil, the arc will at some time, once the electrically insulating has moved the arc sufficiently long, jump from the first- or second-second electrode to an auxiliary contact connected to first end of the electrically conducting coil. The electric current in the arc then travel through the coil before it reaches the second end of the coil and the second electrode. The magnetic field produced by the coil due to the electric current travelling though it acts on the arc to elongate and move the arc to prevent stagnation. In other words, in embodiments, the electric arc interruption arrangement may be configured such that, in the presence of an arc between the first electrode and the second electrode, when the movable, electrically insulating barrier reaches an axial position between the first end and the second end of the electrically conducting coil, the arc forms between the first electrode or the second electrode and the auxiliary contact at the first end of the electrically conducting coil. Hereby, a magnetic field is advantageously generated at the right time, when the arc is inside the coil, to act on the arc. In embodiments, the magnetic field generated by the electrically conducting coil may be configured to cause the arc to move in the azimuthal direction of the electrically conducting coil. The azimuthal direction being "around the curve" of the coil advantageously provides for maximizing the length of the elongation and motion of the arc in the space at hand. In embodiments, the electrically conducting coil may be configured to generate a radial magnetic field component that pushes the arc against the inner and/or outer surface(s) of the electrically insulating barrier. This advantageously further enhances the arc elongation. In embodiments, the electrically insulating bar