CN118280757A - Magnetic blowing-air blowing combined arc extinguishing device and method for quick grounding switch - Google Patents

Abstract

The invention discloses a magnetic blowing-air blowing combined arc extinguishing device and method for a quick grounding switch. Coils are arranged on the moving contact and the fixed contact of the quick grounding switch to generate a magnetic field acting on the moving contact to break an arc, so that the arc rotates under electromagnetic force; a piston is arranged in the moving contact, the moving contact presses the piston to spray gas when being grounded, and the electric arc generated when the moving contact is opened is blown away; the magnetic field and the air blowing jointly act to rotate and elongate the arc, so that the contact area of the arc and surrounding gas is rapidly increased in a short time, the instantaneous cooling power of the arc is enhanced, the arc extinguishing capability is improved in an auxiliary manner, and the electromagnetic induction current switching-on and switching-off performance of the quick grounding switch is improved.

Description

A magnetic-air-blowing combined arc-extinguishing device and method for a fast grounding switch

Technical Field

The invention belongs to the technical field of fast grounding switches, and in particular relates to a magnetic-blow-air-blow combined arc extinguishing device and method for a fast grounding switch.

Background technique

When developing key components of high-voltage gas-insulated switchgear (GIS), there is a technical problem that the fast earthing switch (FES) for GIS is difficult to interrupt the Class B electromagnetic induction current.

The fast earthing switch is used to cut off the fault current and protect the safety of equipment and personnel. In the market environment led by the concept of environmental protection, it is more urgent to overcome the electromagnetic induction breaking problem of the fast earthing switch for environmentally friendly GIS. As a component of GIS, the volume and insulation performance of the fast earthing switch need to be designed in a matching way. Therefore, it is not suitable for designing complex or large structures for arc extinguishing, so as not to excessively increase the space cost and structure cost.

At present, the existing patent document CN202311343776.9 discloses a method and device for magnetic arc extinguishing of a fast grounding switch, which can insert a transverse magnetic field between the moving and static contacts of the fast grounding switch, so that the arc surface is subjected to tangential force everywhere and rotates. However, the method of using a magnet to generate a magnetic field will cause the direction of the magnetic field to not change with the current alternation cycle. This solution may cause the arc rotation direction to reverse every half cycle of the power frequency current, resulting in insufficient cooling effect. In addition, the magnetic field strength will decay as the spatial distance increases. When the moving contacts of the fast grounding switch are pulled apart by a certain distance, the magnetic field in the middle of the moving and static contacts is almost zero. Therefore, the arc cooling effect generated by the magnetic field rotation will decay with the movement of the moving contact, and the cooling intensity is still insufficient.

At present, the existing patent document CN201420753586.4 discloses a fast grounding switch device with a compressed air structure, which adds a closed air chamber and sprays a strong airflow through the nozzle to play a role in blowing out the arc. However, for the integrity of the combined electrical appliance, the additional volume generated by the additional cylinder is large, and more space costs and other structural costs must be considered. In addition, the high-pressure airflow generated by the cylinder is pressed into the chamber where the fast grounding switch contact is located, which will greatly increase the air pressure and cause the pressure of the cavity to be unbalanced, and also increase the requirements for the cavity's ability to withstand air pressure.

Summary of the invention

In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a magnetic blowing-air blowing combined arc extinguishing device and method for a fast grounding switch, which assists in gas arc cooling and heat dissipation without occupying additional space, thereby achieving the purpose of improving the electromagnetic induction current breaking capacity of the fast grounding switch.

In order to achieve the above object, the present invention adopts the following technical solution:

A magnetic-blow-air-blow combined arc extinguishing device for a fast grounding switch, wherein a moving end coil 6 and a static end coil 9 are respectively installed on a moving contact 2 of the fast grounding switch and a static contact 7 of the fast grounding switch, and when the moving contact 2 of the fast grounding switch and the static contact 7 of the fast grounding switch are disconnected, a current flows to generate a rotating arc magnetic field; wherein the moving end coil 6 is installed in the moving contact 2 of the fast grounding switch and has a gap in the middle, the static end coil 9 is installed outside the static contact 7 of the fast grounding switch, and an arc-starting ring 8 and a cooling ring 10 are installed in sequence inside the static end coil 9; a piston 3, a spring 4 and an insulating member 5 connected in sequence are installed on the upper part of the moving end coil 6 in the moving contact 2 of the fast grounding switch, and there is also a gap in the middle of the insulating member 5 at a position corresponding to the gap of the moving end coil 6, and a fixing member 1 fixed to the housing of the fast grounding switch is installed on the top of the moving contact 2 of the fast grounding switch;

The positive potential of the outlet ends of the moving end coil 6 and the static end coil 9 are both introduced from the side of the static contact 7 of the fast earthing switch, and the negative poles of the outlet ends are both grounded, so that when the moving contact 2 of the fast earthing switch and the static contact 7 of the fast earthing switch are disconnected, the moving end coil 6 and the static end coil 9 generate a rotating arc magnetic field whose direction alternates synchronously with the current, so that the arc rotates in the same direction in different AC current cycles; the piston 3 and the spring 4 cooperate to vertically press out the gas stored in the tube cavity of the moving contact of the fast earthing switch, and accelerate the flow rate through the gap between the insulating member 5 and the moving end coil 6 to vertically spray out the contact.

The moving end coil 6 and the static end coil 9 are designed with different shapes, different numbers of turns and different materials according to the specific structure of the fast grounding switch contact, and are protected by insulating paint and insulating shell to isolate the electric field between the coil and other structures when current flows through the coil; a gap is left in the middle of the moving end coil 6 structure as a gas flow channel, and the size of the gap is designed according to the required blowing intensity to control the gas circulation speed.

The insulating member 5 is fixed between the moving end coil 6 of the moving contact 2 of the fast earthing switch and the spring 4 to isolate the electric field between the conductors. The piston 3 is made of non-conductive and non-magnetic lightweight materials, so that the installation of various components inside the fast earthing switch does not affect the overall insulation performance of the fast earthing switch and does not impose additional weight burden on the moving contact 2 of the fast earthing switch.

The lengths of the piston 3 and the spring 4 are designed and adjusted according to the required jet volume, and the insulating member 5 is made of a material with heat insulation properties to prevent the spring 4 from being annealed by heat.

An arc-starting ring 8 is installed on the side of the static contact 7 of the fast earthing switch, which does not generate stress with other structures. The material of the embedded cooling ring 10 is ceramic or metal grid.

The arc starting ring 8 is grounded, and the material should be heat-resistant and non-isolated magnetic field capable.

The fast earthing switch moving contact 2 and the fast earthing switch static contact 7 are plug-in contacts, and the structure size and breaking speed are adjusted according to the required breaking current level.

The fixing member 1 is a structural member of any shape fixed to the moving contact 2 of the fast earthing switch, and is a column, a fixing screw or a baffle; the fixing member 1 is made of solid material and does not move with the movement of the moving contact 2 of the fast earthing switch.

The arc extinguishing method of the magnetic blowing-air blowing combined arc extinguishing device of the rapid grounding switch,

The moving contact 2 of the fast earthing switch and the static contact 7 of the fast earthing switch are vertically opposite to each other. When in contact, the circuit is connected, and an arc is generated when disconnected. Since the magnetic field of the moving end coil 6 and the static end coil 9 acts on the arc to make it rotate, a rotating arc magnetic field is generated. During the upward movement of the moving contact 2 of the fast earthing switch to ground, the piston 3 is pressed by the fixing part 1, pressing the spring 4 to compress it, and the gas stored in the moving contact pipeline of the fast earthing switch is ejected through the pores between the insulating part 5 and the moving end coil 6. The insulating part 5 isolates the electric field between the spring 4 and the moving end coil 6. The arc starting ring 8 installed outside the static contact 7 of the fast earthing switch The rotating arc magnetic field diffuses the arc to the edge of the arc striking ring installed outside the static contact 7 of the fast earthing switch, and then contacts the cooling ring 10 installed in the arc striking ring 8 and cools and dissipates the heat; the magnetic field and the air blowing act in combination on the arc generated when the moving contact 2 of the fast earthing switch and the static contact 7 of the fast earthing switch are disconnected, so that the arc rotates and lengthens the arc, and the contact area between the arc and the surrounding gas is rapidly increased in a short time, so that the arc is blown away while rotating, and the contact area between the arc and the surrounding gas is rapidly increased. The arc extinguishing performance is improved by instantaneous cooling of the arc temperature, so as to achieve the purpose of assisting in breaking the electromagnetic induction current of the fast earthing switch.

Compared with the prior art, the present invention has the following advantages:

In order to assist in extinguishing the arc generated when the contacts are disconnected under high-voltage conditions, the present invention combines the advantages of magnetic blowing and air blowing, blows away the arc with airflow while it rotates, and uses the principles of heat conduction and heat convection to improve the instantaneous cooling power of the arc. This scheme takes into account the insulation characteristics, heating characteristics and spatial structure characteristics of the fast grounding switch, and has the potential and feasibility to continuously improve the breaking performance.

When the fast earthing switch is disconnected, the coils installed at both ends of the contacts are connected in series to the arc path and current flows through them. The magnetic field generated by the coils acts on the arc to make it rotate. The internal piston of the moving contact end is compressed and gas is ejected. The cathode arc root area and the arc middle area are further dispersed by gas convection, thereby strengthening the cooling intensity of the cathode arc root area and compensating for the defect that the magnetic field attenuates with distance, resulting in insufficient electromagnetic force on the arc middle area, thereby increasing the contact area between the arc and the gas. The arc in the anode arc root area on the static contact side will be dispersed into the cooling ring, increasing the cooling intensity of the anode arc root area.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of an embodiment of a magnetic-blow-air-blow combined arc-extinguishing device for a fast grounding switch of the present invention, showing the overall structure of the embodiment.

FIG2 is a schematic diagram of the details of the static contact structure of an embodiment of a magnetic-blow-air-blow combined arc-extinguishing device for a fast grounding switch of the present invention, showing the details of the static contact structure of the example.

3a and 3b are schematic diagrams of the magnetic blowing principle of an embodiment of a magnetic blowing-air blowing combined arc extinguishing method for a fast grounding switch of the present invention, in which two coils are wound in the same direction and the positive and negative poles of the outlet terminals are opposite.

FIG4 is a schematic diagram of the gas blowing principle of an embodiment of a magnetic blowing-gas blowing combined arc extinguishing method for a fast grounding switch of the present invention.

Explanation of reference numerals: 1. Fixing part; 2. Moving contact of fast earthing switch; 3. Piston; 4. Spring; 5. Insulating part; 6. Moving end coil; 7. Static contact of fast earthing switch; 8. Arc starting ring; 9. Static end coil; 10. Cooling ring.

Detailed ways

The present invention is further described in detail below in conjunction with the accompanying drawings. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. That is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments.

As shown in Figures 1 and 2, the magnetic blowing-air blowing combined arc extinguishing device of the fast grounding switch provided by the present invention includes a fixing part 1, a fast grounding switch moving contact 2, a piston 3, a spring 4, an insulating part 5, a moving end coil 6, a fast grounding switch static contact 7, an arc-starting ring 8, a static end coil 9 and a cooling ring 10, wherein the fast grounding switch moving contact 2 and the fast grounding switch static contact 7 are vertically opposite to each other, and the two contacts are in contact and connected when the fast grounding switch is closed, and the fast grounding switch moving contact 2 moves upward when disconnected to generate an arc between the two contacts.

The moving end coil 6 is installed inside the moving contact 2 of the fast earthing switch, and the static end coil 9 is installed outside the static contact 7 of the fast earthing switch. This method conforms to the conventional structure of the fast earthing switch for GIS, and no additional space is required. The positive poles of the two coil outlets are introduced from the static contact 7 of the fast earthing switch. Figures 3a and 3b respectively show the schematic diagram of the magnetic field generated by the coils in the positive and negative cycles of the alternating current, which makes the arc subjected to force. It can be seen that the direction of the electromagnetic force on the arc remains unchanged, and the arc always rotates in the same direction when the two coils are wound in the same direction and the positive and negative poles of the outlets are opposite (such as the upper side of the outlet of the moving end coil 6 is connected to the potential and the lower side is grounded, and the lower side of the outlet of the static end coil 9 is connected to the potential and the upper side is grounded).

When the fast earthing switch is disconnected, the moving contact 2 of the fast earthing switch moves upward. As can be seen from Figure 4, during the upward movement of the moving contact 2 of the fast earthing switch, the fixing member 1 is fixed on the housing of the fast earthing switch and does not move with the moving contact 2 of the fast earthing switch. The piston 3 in the tube cavity of the moving contact 2 of the fast earthing switch is held by the fixing member 1, and the insulating member 5 is lifted upward synchronously with the fast earthing switch 2. The piston 3 and the insulating member 5 are both solid rigid structures. The lower side of the piston 3 presses the spring 4, and the upper side of the insulating member 5 presses the spring 4. As the moving contact 2 of the fast earthing switch moves, the spring 4 is compressed to deform, thereby squeezing out the gas in the tube cavity between the piston 3 and the insulating member 5, and passing through the gap between the insulating member 5 and the moving end coil 6, it is ejected vertically from the moving contact, dispersing the arc part in the cathode arc root area, and blowing away the arc part in the arc middle area that is weakly affected by the magnetic fields of the moving end coil 6 and the static end coil 9.

On one side of the static contact 7 of the fast earthing switch, the anode arc root area is diffused to the arc starting ring 8 by the electromagnetic force, contacts the cooling ring 10 embedded in the arc starting ring and dissipates heat quickly, thereby increasing the cooling intensity.

This combination scheme uses air blowing and magnetic blowing to rotate and diffuse the arc, applies gas convection cooling on the moving contact 2 side of the fast earthing switch, and applies solid conduction heat dissipation on the static contact 7 side of the fast earthing switch, comprehensively cooling the gas between the contacts from a good electrical conductor (thermal plasma) to an electrical insulator (cold gas) in a short period of time, thereby helping to improve the arc extinguishing capability of high-voltage electrical equipment.

Claims (10)

1. A quick earthing switch magnetic blow-air blow combined arc-extinguishing device is characterized in that: a moving end coil (6) and a fixed end coil (9) are respectively arranged on a moving contact (2) of the quick grounding switch and a fixed contact (7) of the quick grounding switch, and when the moving contact (2) of the quick grounding switch and the fixed contact (7) of the quick grounding switch are disconnected, a rotating arc magnetic field is generated through current; the movable end coil (6) is arranged in the movable contact (2) of the quick grounding switch, a hole is formed in the middle of the movable contact, the static end coil (9) is arranged outside the static contact (7) of the quick grounding switch, and the arc striking ring (8) and the cooling ring (10) are sequentially arranged inside the static end coil (9); a piston (3), a spring (4) and an insulating part (5) which are sequentially connected are arranged on the upper part of a moving end coil (6) in a quick grounding switch moving contact (2), a hole is also formed in the middle of the insulating part (5) and at the position corresponding to a gap of the moving end coil (6), and a fixing part (1) fixed on a quick grounding switch shell is arranged at the top of the quick grounding switch moving contact (2).

2. The magnetic blow-through and air-blow combined arc extinguishing device of the fast grounding switch as recited in claim 1, wherein: the positive potentials of the wire outlet ends of the moving end coil (6) and the fixed end coil (9) are led in from the side of the fixed contact (7) of the quick grounding switch, and the negative poles of the wire outlet ends are grounded, so that when the moving contact (2) of the quick grounding switch and the fixed contact (7) of the quick grounding switch are opened, the directions of rotating arc magnetic fields generated by the moving end coil (6) and the fixed end coil (9) synchronously alternate with current, and the electric arc rotates around the same direction in different alternating current periods; the piston (3) and the spring (4) are matched to vertically extrude the gas stored in the tube cavity of the moving contact of the quick grounding switch, and the gas is vertically ejected out of the contact through the hole between the insulating piece (5) and the moving end coil (6) to speed up the flow speed.

3. The magnetic blow-through and air-blow combined arc extinguishing device of the fast grounding switch as recited in claim 1, wherein: the movable end coil (6) and the static end coil (9) adopt designs of different shapes, different turns and different materials according to the specific structure of the quick grounding switch contact, and are protected by insulating paint and an insulating shell to isolate the electric field effect between the coil and other structures when the coil flows through; and a hole is reserved in the middle of the structure of the movable end coil (6) and is used as a gas flow channel, the size of the hole is designed according to the required blowing strength, and the gas circulation speed is controlled.

4. The magnetic blow-through and air-blow combined arc extinguishing device of the fast grounding switch as recited in claim 1, wherein: the insulating piece (5) is fixed between the moving end coil (6) and the spring (4) of the moving contact (2) of the quick grounding switch, the electric field effect between conductors is isolated, the piston (3) is made of non-conductor and non-magnet light materials, so that the whole insulating performance of the quick grounding switch is not affected by all parts installed in the quick grounding switch, and extra weight load is not applied to the moving contact (2) of the quick grounding switch.

5. The magnetic blow-through and air-blow combined arc extinguishing device of the fast grounding switch as recited in claim 1, wherein: the lengths of the piston (3) and the spring (4) are designed and adjusted according to the required air injection amount, and the insulating piece (5) is made of a material with heat insulation performance, so that the spring (4) is prevented from being annealed by heating.

6. The magnetic blow-through and air-blow combined arc extinguishing device of the fast grounding switch as recited in claim 1, wherein: an arc striking ring (8) is arranged on the side of the fixed contact (7) of the quick grounding switch, stress is not generated between the fixed contact and other structures, and the embedded cooling ring (10) is made of ceramic or metal grid plates.

7. The magnetic blow-through and air-blow combined arc extinguishing device of the fast grounding switch as recited in claim 1, wherein: the arc striking ring (8) is grounded, and the material has heat resistance and magnetic field non-isolation performance.

8. The magnetic blow-through and air-blow combined arc extinguishing device of the fast grounding switch as recited in claim 1, wherein: the movable contact (2) and the fixed contact (7) of the quick grounding switch are plug-in contacts, and the structure size and the switching-on and switching-off speed are adjusted according to the required switching-off current level.

9. The magnetic blow-through and air-blow combined arc extinguishing device of the fast grounding switch as recited in claim 1, wherein: the fixing piece (1) is a structural piece with any shape and is fixed on the movable contact (2) of the quick grounding switch, and a column body, a fixing screw or a baffle plate is adopted; the fixing piece (1) is firm in material and does not move along with the action of the moving contact (2) of the quick grounding switch.

10. The arc extinguishing method of the combined magnetic blow-out and air blow-out arc extinguishing device for the fast grounding switch according to any one of claims 1 to 9, characterized in that: the moving contact (2) of the quick grounding switch is vertically opposite to the fixed contact (7) of the quick grounding switch, and is communicated with a circuit during contact and generates an electric arc during breaking; the magnetic fields of the moving end coil (6) and the static end coil (9) act on the electric arc to enable the electric arc to rotate, a rotating arc magnetic field is generated, in the process that the moving contact (2) of the quick grounding switch acts upwards to be grounded, the piston (3) is propped against the fixed piece (1) to press the spring (4) to compress the moving contact, gas stored in a moving contact pipeline of the quick grounding switch is sprayed out through a hole in the middle of the insulating piece (5) and the moving end coil (6), and the insulating piece (5) isolates the electric field effect between the spring (4) and the moving end coil (6); an arc striking ring (8) arranged outside the fast grounding switch fixed contact (7), and a rotating arc magnetic field diffuses an electric arc to the edge of the arc striking ring arranged outside the fast grounding switch fixed contact (7), and then contacts with a cooling ring (10) arranged in the arc striking ring (8) to cool and dissipate heat; the magnetic field and air blowing combination acts on the electric arcs generated when the moving contact (2) and the fixed contact (7) of the quick grounding switch are opened, so that the electric arcs rotate and are lengthened, the contact area between the electric arcs and surrounding gas is rapidly increased in a short time, the electric arcs are blown away while rotating, the contact area between the electric arcs and the surrounding gas is rapidly increased, the arc extinguishing performance is improved through instantaneous cooling of the arc temperature, and the aim of assisting in opening and closing electromagnetic induction current of the quick grounding switch is fulfilled.