CN111430174A - High-voltage switch - Google Patents

Abstract

The invention provides a high-voltage switch, which relates to the technical field of electric power. The high-voltage switch provided by the present invention includes: an insulating casing, two sets of coils, a pair of contacts, a metal shield and an adjustable DC power supply; wherein, the insulating casing is located outside the metal shield, and the contacts are located on the Inside the metal shield, two sets of coils are arranged between the metal shield and the insulating shell, and the two sets of coils are located on both sides of the contacts respectively; the two sets of coils are respectively connected to the adjustable DC power supply, After power-on, the sides of the two sets of coils close to the contacts are the N pole and the S pole, respectively, and the magnetic field formed between the two sets of coils can enter the inside of the metal shield. The technical scheme of the present invention enables the high-voltage switch to have a better arc extinguishing effect.

Description

a high voltage switch

technical field

The invention relates to the field of electric power technology, in particular to a high-voltage switch.

Background technique

High-voltage switch (also known as circuit breaker) is an important part of power transmission and transformation projects, and its arc extinguishing ability is related to the performance of high-voltage switch. Among them, an important step in the arc extinguishing process is to lengthen the arc to make it less difficult to extinguish. One of the ways to lengthen the arc is to use a magnetic field to subject the arc to electromagnetic force, increasing the path between the contacts and extinguishing the arc.

In the prior art, the magnetic field generated by the use of a magnetic field to extinguish the arc is generated by the short-circuit current (the current flowing through the switch when a short-circuit fault occurs in the power system) itself, and the magnetic field strength decreases as the current becomes smaller, so that the electromagnetic field received by the arc is reduced. The force is reduced, and the arc extinguishing effect is not good.

SUMMARY OF THE INVENTION

The invention provides a high-voltage switch, which can make the high-voltage switch have better arc extinguishing effect.

The present invention provides a high-voltage switch, which adopts the following technical solutions:

The high-voltage switch includes: an insulating casing, two sets of coils, a pair of contacts, a metal shield and an adjustable DC power supply; wherein the insulating casing is located outside the metal shield, and the contacts are located on the metal shield Inside the cover, two sets of coils are arranged between the metal shield and the insulating shell, and the two sets of coils are located on both sides of the contacts respectively; the two sets of coils are respectively connected with the adjustable DC power supply, and after power-on One side of the two sets of coils close to the contacts is the N pole and the S pole, respectively, and the magnetic field formed between the two sets of coils can enter the inside of the metal shield.

Optionally, the contacts are circular plate contacts.

Further, the edge portion of the contact has a chamfer.

Optionally, the coil is wound on a support column, and an end of the support column close to the contact is provided with a disc, and the diameter of the disc is larger than that of the support column.

Further, the support column, the disc and the insulating shell are integrally formed.

Optionally, the diameter of the support column is 0.05m-0.15m, and the number of turns of the coil is 100-300.

Optionally, the adjustable DC power supply is arranged outside the insulating housing.

Optionally, the adjustable DC power supply has a positive electrode and a negative electrode, one end of the two sets of coils is connected to the positive electrode, and the other end is connected to the negative electrode.

Optionally, the adjustment range of the adjustable DC power supply is 0-100A.

Optionally, the metal shield is made of non-ferromagnetic metal, and the metal shield is an integral structure.

Optionally, the metal shield is made of ferromagnetic metal, and the metal shield includes openings or slits corresponding to the two sets of coils.

Optionally, the metal shield is made of copper or stainless steel.

Optionally, the insulating shell is made of tempered glass or special ceramics.

The invention provides a high-voltage switch. The high-voltage switch includes an insulating shell, two sets of coils, a pair of contacts, a metal shield and an adjustable DC power supply. When the high-voltage switch needs to disconnect the line, the adjustable DC power supply is turned on, Then, a stable current is provided to the two sets of coils. After the two sets of coils are energized, the sides of the two sets of coils close to the contacts are the N pole and the S pole, respectively, and a magnetic field is formed between the two. Under the action of the magnetic field, the arc is effectively elongated, making the The arc is quickly extinguished, so that the high-voltage switch has a better arc extinguishing effect.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a front view of a high-voltage switch provided by an embodiment of the present invention;

2 is a side view of a high-voltage switch provided by an embodiment of the present invention;

3 is a top view of a high-voltage switch provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of a process of disconnecting an alternating current by a high-voltage switch according to an embodiment of the present invention;

5 is a schematic diagram of a process of disconnecting a DC current by a high-voltage switch according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a coil winding method according to an embodiment of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that each technical feature in the embodiments of the present invention can be combined with each other without conflict.

An embodiment of the present invention provides a high-voltage switch. Specifically, as shown in FIGS. 1 , 2 and 3 , FIG. 1 is a front view of a high-voltage switch provided by an embodiment of the present invention, and FIG. 2 is a high-voltage switch provided by an embodiment of the present invention. The side view of the switch, FIG. 3 is a top view of the high-voltage switch provided by the embodiment of the present invention, the high-voltage switch includes: an insulating casing 1, two sets of coils 2, a pair of contacts 3, a metal shield 4 and an adjustable DC power supply 5; wherein , the insulating shell 1 is located outside the metal shield 4, the contacts 3 are located inside the metal shield 4, the two sets of coils 2 are arranged between the metal shield 4 and the insulating shell 1, and the two sets of coils 2 are located on the two sides of the contact 3. The two sets of coils 2 are respectively connected to the adjustable DC power supply 5. After power-on, the sides of the two sets of coils 2 close to the contacts 3 are the N pole and the S pole, respectively, and the magnetic field formed between the two sets of coils 3 can enter the metal shield. 4 inside.

It should be added that the above-mentioned metal shield 4 is used to prevent the damage of the insulating casing 1 by particles (electrons or positive ions).

When the high-voltage switch needs to disconnect the line, the adjustable DC power supply 5 is turned on, and then a stable current is provided to the two sets of coils 2. After power-on, the sides of the two sets of coils 2 close to the contact 3 are the N pole and the S pole, respectively. A magnetic field is formed between them. Under the action of the magnetic field, the arc is effectively elongated, so that the arc is quickly extinguished, and the extinguishing time can be less than 10ms, so that the high-voltage switch has a better arc extinguishing (arc extinguishing or arc prevention) effect. In addition, since the current provided by the adjustable DC power supply 5 is adjustable, the strength of the magnetic field formed between the two sets of coils can be adjusted for different voltage levels and short-circuit currents, so that the arc can be quickly extinguished or the arc can be avoided to achieve the best opening breaking ability.

The high-voltage switch in the embodiment of the present invention is suitable for disconnecting alternating current and direct current at the same time, and its working mode when disconnecting alternating current and direct current is as follows:

When the AC current is disconnected: before the high-voltage switch disconnects the line, the adjustable DC power supply 5 sends power to the two sets of coils 2, and a constant magnetic field is established between the two sets of coils. When the two contacts 3 are separated, such as As shown in FIG. 4, FIG. 4 is a schematic diagram of the process of disconnecting the alternating current of the high-voltage switch provided by the embodiment of the present invention. An arc is generated between the contacts 3, the direction of the arc current is substantially perpendicular to the direction of the magnetic field, and the electrons and positive ions in the arc are in the magnetic field. Under the action of electromagnetic force, it moves to the outside of the contact 3, and is elongated at the same time, and the arc is extinguished at the zero-crossing point. After the arc is extinguished, the adjustable DC power supply 5 is turned off, and the high-voltage switch completes an operation of cutting off the AC current. In Figure 4, E is the electric field, B is the magnetic field, F is the total force on electrons or positive ions, F _B is the magnetic field force on electrons or positive ions, F _E is the electric field force on electrons or positive ions, v1 is the moving speed of positive ions, and v2 is the moving speed of electrons.

In the above process, according to different voltage levels and short-circuit currents, the output current of the adjustable DC power supply can be adjusted to adjust the current in the coil 2, so that the arc can be quickly extinguished. It should be emphasized that in this process, the current in the coil 2 should not be too large or too small. If it is too large, the coil 2 will be heated and damaged, and the magnetic force between the two sets of coils 2 will be too large, resulting in structural damage. If it is small, the purpose of quickly extinguishing the arc cannot be achieved. Therefore, the appropriate coil current range should be selected according to the voltage level, the required duration of the breaking process and the stability of the switch structure, so that the high-voltage switch can achieve the best breaking capacity corresponding to different voltage levels.

When the DC current is disconnected: take the vacuum switch as an example, before the high-voltage switch disconnects the line, the adjustable DC power supply 5 sends power to the two sets of coils 2, and a constant magnetic field is established between the two sets of coils at this time, as shown in the figure 5, FIG. 5 is a schematic diagram of the process of disconnecting the DC current of the high-voltage switch provided by the embodiment of the present invention. When the two contacts 3 are separated, there are orthogonal electric fields and magnetic fields in the space between the two contacts 3. , after the high-voltage switch is turned off, the electric field existing between the two contacts 3 can be regarded as a uniform electric field in the longitudinal direction, and a uniform magnetic field in the transverse direction. The electrons emitted by the cathode (one contact 3) will be affected by the electric field force and Loran The combined action of these forces makes the electrons accelerate in the direction parallel to the electrode axis (the direction of the electric field), and at the same time make circular motions in the direction perpendicular to the magnetic field lines, that is, the trajectory of the electrons in the uniform orthogonal electromagnetic field is a cycloid. The movement trajectory is offset to the space outside the anode (another contact 3), so that all or most of the electrons emitted by the cathode move to the height of the anode and are horizontally deflected beyond the space range of the anode, and arcs will not occur due to a large number of electrons hitting the anode. . In Figure 5, E is the electric field, _B is the magnetic field, F is the total force on the electrons, FB is the magnetic force on the electrons, _FE is the electric field force on the electrons, and v is the moving speed of the electrons.

In the above process, when the electrons move to the height of the anode in the direction of the electrode axis, the horizontal displacement increases with the increase of the magnetic induction intensity. If the magnetic induction intensity is too small, most of the electrons emitted by the cathode move to the height of the anode, and the horizontal deflection increases. Before exceeding the space range of the anode, a large number of electrons emitted by the cathode will still hit the anode, and further development will form an arc. Similarly, considering the heating and stability requirements of the coil and switch structure, the magnetic induction intensity should not be too large. Therefore, the appropriate coil current range should be selected according to the voltage level, the required duration of the breaking process and the stability of the switch structure, so that the high-voltage switch can achieve the best breaking capacity corresponding to different voltage levels.

In order to facilitate those skilled in the art to better understand and implement the high-voltage switch in the embodiments of the present invention, the following embodiments of the present invention illustrate various structures in the high-voltage switch.

A pair of contacts in the embodiment of the present invention includes a stationary contact and a moving contact, and the distance between the two can be adjusted through the movement of the moving contact, so as to realize the contact or disconnection of the two. Before separation, the two are in contact. When separating, the moving contact is facing away from the static contact, and it moves to a set distance (such as 5mm to 10mm) to stand still. Optionally, the contact 3 in the embodiment of the present invention is a circular plate contact. It can be seen from the above that the high-voltage switch in the embodiment of the present invention utilizes the current provided by the adjustable DC power supply 5 to the coil 2 to generate a magnetic field to extinguish the arc. The current is stable in magnitude and the magnetic field is stable. Therefore, there is no need to perform special The arc-extinguishing effect can be achieved by adopting the circular plate contact with simple structure. In the prior art, the magnetic field generated by the use of a magnetic field to extinguish the arc is generated by the short-circuit current (the current flowing through the switch when a short-circuit fault occurs in the power system) itself. Considering the need to generate a magnetic field, the shape of the switch contact needs to be specially designed. , such as opening a plurality of grooves on it, not only makes the contact processing more difficult, but also aggravates the electric field distortion near the contact, which is prone to discharge phenomenon, which is unfavorable for arc extinguishing.

Further, in the embodiment of the present invention, preferably, the edge portion of the contact 3 has a chamfer. Chamfering the edge portion of the contact 3 during the processing can improve the electric field distribution in the space around the high-voltage switch contact 3, and help further improve the arc extinguishing effect of the high-voltage switch.

Optionally, as shown in FIG. 6 , which is a schematic diagram of a coil winding method provided in an embodiment of the present invention, the coil 2 in the embodiment of the present invention is wound on a support column 6 , and one end of the support column 6 close to the contact 3 is provided with The disk 7, the diameter of the disk 7 is larger than the diameter of the support column, and the support column 6 with the disk 7 at the top can effectively fix the coil 2. Further, in the embodiment of the present invention, the support column 6 , the disk 7 and the insulating shell 1 are preferably integrally formed, which can not only simplify the manufacturing process, but also improve the structural stability between the support column 6 , the disk 7 and the insulating shell 1 .

The inventor found that the number of turns and the diameter of the coil 2 are important factors affecting the strength of the magnetic field generated by the coil 2. Specifically, the more the number of turns of the coil 2, the greater the strength of the magnetic field generated by the same current, which is beneficial to the improvement of the performance of the high-voltage switch. The larger the diameter, the less the number of turns of the same length of the coil 2, and the weaker the magnetic field generated by the same current, which is not conducive to the improvement of the switching performance. Optionally, in the embodiment of the present invention, the diameter of the support column 6 is 0.05m-0.15m, such as 0.1m, and the number of turns of the coil is 100-300, such as 200, so that the coil 2 can generate a larger magnetic field strength, In addition, the support column 6 can provide sufficient support for the coil 2, and those skilled in the art can make a reasonable selection according to the voltage level of the high-voltage line within this range. In addition, the coil 2 can be wound on the support column 6 in a multi-layer winding manner to avoid the reduction of structural stability caused by the excessive length of the support column 6, affecting other structures or increasing the occupied space of the high-voltage switch.

Optionally, the adjustable DC power supply 5 in the embodiment of the present invention is disposed outside the insulating housing 1 to reduce the difficulty of operating the adjustable DC power supply 5 and improve safety.

Optionally, as shown in FIG. 6 , the adjustable DC power supply 5 may have a positive pole and a negative pole. At this time, one end of the two sets of coils 2 is connected to the positive pole and the other end is connected to the negative pole. The adjustable DC power supply 5 may also have a positive pole and a negative pole. Multiple positive electrodes and multiple negative electrodes, at this time, two ends of one group of coils 2 are connected to one positive electrode and one negative electrode, and two ends of another group of coils 2 are connected to another positive electrode and another negative electrode. Wherein, when the adjustable DC power supply 5 has a positive pole and a negative pole, and the two sets of coils 2 are connected to the positive pole at one end and the negative pole at the other end, the currents in the two sets of coils 2 can be guaranteed to be consistent, and the adjustable DC current can be reduced. The structural and operational complexity of the power supply 5 .

Optionally, the adjustment range of the adjustable DC power supply 5 is 0-100A, so that the high-voltage switch can adapt to lines of different voltage levels. Exemplarily, taking a coil with a diameter of 0.1 m and a number of turns of 200 as an example, when the output current of the adjustable DC power supply 5 is 5A, the high-voltage switch can be applied to a 10kV line, and the output current of the adjustable DC power supply 5 is 15A. , the high-voltage switch can be applied to a 35kV line, and when the output current of the adjustable DC power supply 5 is 45A, the high-voltage switch can be applied to a 110kV line.

In addition, the metal shield 4 in the embodiment of the present invention may be made of ferromagnetic metal (eg, stainless steel), or may be made of non-ferromagnetic metal (eg, copper). It should be noted that, in order to ensure that the magnetic field formed between the two sets of coils 2 can enter the interior of the metal shield 4, when the material of the metal shield 4 is different, the corresponding structure will also be different.

In an example, the metal shield 4 is made of non-ferromagnetic metal, and the metal shield 4 does not block the magnetic field, so the metal shield 4 is selected as an integral structure to have a better shielding effect on particles.

In yet another example, as shown in FIG. 3 , the metal shield 4 is made of ferromagnetic metal, and the metal shield 4 will block the entry of the magnetic field, so the metal shield 4 is selected to include openings or gaps corresponding to the two sets of coils 2 41 to ensure that the magnetic field formed between the two sets of coils 2 can better enter the inside of the metal shield 4 . Specifically, when the metal shield 4 has gaps 41 corresponding to the two sets of coils 2 , the metal shield 4 can be formed by splicing two fan-shaped parts, and a gap is reserved between the two fan-shaped parts for the space between the two sets of coils 2 The formed magnetic field enters the inside of the metal shield 4 .

Optionally, the insulating housing 1 in the embodiment of the present invention is made of tempered glass or special ceramics.

Optionally, the arc extinguishing medium in the high-voltage switch in the embodiment of the present invention may be one of vacuum, sulfur hexafluoride, transformer oil, and the like.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (10)

1. A high-voltage switch, characterized in that it comprises: an insulating casing, two sets of coils, a pair of contacts, a metal shield and an adjustable DC power supply; wherein, the insulating casing is located outside the metal shield, and the The contact is located inside the metal shield, two sets of coils are arranged between the metal shield and the insulating shell, and the two sets of coils are located on both sides of the contact respectively; The DC power supply is connected, and the sides of the two sets of coils close to the contacts are N pole and S pole respectively after power-on, and the magnetic field formed between the two sets of coils can enter the inside of the metal shield. 2 . The high-voltage switch according to claim 1 , wherein the contacts are circular plate contacts. 3 . 3. The high-voltage switch according to claim 2, wherein the edge portion of the contact has a chamfer. 4 . The high-voltage switch according to claim 1 , wherein the coil is wound on a support column, an end of the support column close to the contact is provided with a disc, and the diameter of the disc is larger than the diameter of the The diameter of the support column. 5 . The high-voltage switch according to claim 4 , wherein the support column, the disk and the insulating housing are integrally formed. 6 . The high-voltage switch according to claim 4 or 5, characterized in that, the diameter of the support column is 0.05m-0.15m, and the number of turns of the coil is 100-300. 7 . The high-voltage switch according to claim 1 , wherein the adjustable DC power supply is arranged outside the insulating housing. 8 . 8 . The high-voltage switch according to claim 1 , wherein the adjustment range of the adjustable DC power supply is 0-100A. 9 . 9 . The high-voltage switch according to claim 1 , wherein the metal shield is made of non-ferromagnetic metal, and the metal shield is an integral structure. 10 . 10 . The high-voltage switch according to claim 1 , wherein the metal shield is made of ferromagnetic metal, and the metal shield includes openings or slits corresponding to the two sets of coils. 11 .

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