阅读说明：本技术 一种基于铁磁材料的真空灭弧室纵磁触头 (Vacuum arc-extinguishing chamber longitudinal magnetic contact based on ferromagnetic material ) 是由 袁召 何俊磊 潘垣 陈立学 于 2020-12-14 设计创作，主要内容包括：本发明公开了一种基于铁磁材料的真空灭弧室纵磁触头,包括触头片、触头托、触头杯、支撑架、铁磁柱和导电杆；触头片和触头托上均匀开有沿径向的槽,其中一半为大槽,一半为小槽；触头杯上的开槽沿杯壁旋转90°形成杯指；支撑架固定在杯腔中心,主要起支撑作用；圆柱形的铁磁材料固定在支撑架和触头杯内壁之间,分布在靠近触头杯槽口处,其下端面通过杯腔底部的均匀分布的圆柱槽定位,上端面与触头托的下表面接触。该触头结构能改善真空灭弧室杯状纵磁触头的磁场分布,开距较小时触头边缘纵向磁场强度大于中心区域,开距较大时纵向磁场分布相对均匀,电流过零后剩余磁场较小,具有开断能力强、强度高、结构简单等优点。(The invention discloses a longitudinal magnetic contact of a vacuum arc extinguish chamber based on ferromagnetic materials, which comprises a contact blade, a contact support, a contact cup, a support frame, a ferromagnetic column and a conductive rod, wherein the contact blade is arranged on the contact support; radial grooves are uniformly formed in the contact blade and the contact support, wherein one half of the radial grooves are large grooves, and the other half of the radial grooves are small grooves; the open slot on the contact cup rotates 90 degrees along the cup wall to form a cup finger; the support frame is fixed in the center of the cup cavity and mainly plays a supporting role; the cylindrical ferromagnetic material is fixed between the support frame and the inner wall of the contact cup and distributed at the position close to the notch of the contact cup, the lower end surface of the ferromagnetic material is positioned by the uniformly distributed cylindrical grooves at the bottom of the cup cavity, and the upper end surface of the ferromagnetic material is contacted with the lower surface of the contact support. The contact structure can improve the magnetic field distribution of the cup-shaped longitudinal magnetic contact of the vacuum arc extinguish chamber, the longitudinal magnetic field intensity at the edge of the contact is larger than that in the central area when the opening distance is smaller, the longitudinal magnetic field distribution is relatively uniform when the opening distance is larger, the residual magnetic field after the current passes zero is smaller, and the contact structure has the advantages of strong breaking capacity, high strength, simple structure and the like.)

1. A vacuum interrupter indulges magnetic contact based on ferromagnetic material, its characterized in that includes: the contact device comprises a contact blade (1), a contact support (2), a support frame (3), a contact cup (4), a conductive rod (5) and a ferromagnetic column (7);

the contact blade (1), the contact support (2), the support frame (3), the contact cup (4) and the conductive rod (5) are sequentially arranged from top to bottom, and all contact surfaces are connected through high-conductivity solder;

the contact support (2) and the contact cup (4) form a cup cavity, the support frame (3) is positioned in the center of the cup cavity, the ferromagnetic columns (7) are uniformly distributed between the support frame (3) and the inner wall of the cup cavity, the lower end surface of the support frame (3) and the lower end surface of the ferromagnetic column (7) are both contacted with the bottom of the cup cavity through positioning grooves, and the upper end surface of the support frame (3) and the upper end surface of the ferromagnetic column (7) are both connected with the contact support (2);

the conducting rod (5) is arranged at the bottom of the contact cup (4) and used for connecting the contact and the vacuum arc-extinguishing chamber and conducting current.

2. Vacuum interrupter longitudinal magnetic contact according to claim 1, characterized in that a plurality of first slots are uniformly arranged in radial direction on the contact blade (1), which first slots serve to reduce eddy currents in the contact blade (1) and thus to reduce the hysteresis of the magnetic field during arcing and the residual magnetic field at the current zero crossing.

3. Vacuum interrupter longitudinal magnetic contact according to claim 2, characterized in that a plurality of second slots are uniformly arranged in the radial direction on the contact blade (1) and are arranged between two adjacent first slots, the length of the second slots being smaller than the length of the first slots, the width of the second slots being smaller than the width of the first slots; the second groove serves to further reduce eddy currents in the contact blade (1) while securing the movement path of the cathode spot during arcing.

4. Vacuum interrupter longitudinal magnetic contact according to any of claims 1 to 3, characterized in that a third radial slot is arranged uniformly on the contact carrier (2), which third slot serves to reduce eddy currents in the contact carrier (2), to reduce the hysteresis of the magnetic field during arcing and the residual magnetic field at the current zero crossing; and the position of the third groove is the same as that of the first groove.

5. Vacuum interrupter longitudinal magnetic contact according to claim 4, characterized in that a plurality of fourth slots are uniformly arranged in the radial direction on the contact carrier (2) and are arranged between two adjacent third slots, the length of the fourth slots being smaller than the length of the third slots, and the width of the fourth slots being smaller than the width of the third slots; the position of the fourth groove is the same as that of the second groove; the fourth groove is used for further reducing eddy currents in the contact carrier (2).

6. Vacuum interrupter longitudinal magnetic contact according to claim 5, characterized in that the number of first slots is the same as the number of third slots, and the number of second slots is the same as the number of fourth slots; and the number of the first slots is the same as the number of cup fingers of the contact cup (4).

7. Vacuum interrupter longitudinal magnetic contact according to any of the claims 1 to 6, characterized in that the material of the support frame (3) is a stainless steel material.

8. Longitudinal magnetic contact for vacuum interrupter according to claim 1, characterized in that the contact cup (4) is slotted and turned 90 ° along the cup wall to form a cup finger, the notch in the contact cup (4) corresponding to the third slot in the contact holder (2).

9. The longitudinal magnetic contact of the vacuum arc-extinguishing chamber according to claim 8, characterized in that the ferromagnetic columns (7) are fixed between the supporting frame (3) and the inner wall of the contact cup (4), the number of the ferromagnetic columns (7) is the same as the number of cup fingers of the contact cup (4), a plurality of the ferromagnetic columns (7) are uniformly distributed in the diameter direction corresponding to the third slot of the contact holder (2), the lower end faces of the ferromagnetic columns (7) are uniformly arranged in positioning slots through the bottom of the cup cavity, and the upper end faces of the ferromagnetic columns (7) are in contact with the lower surface of the contact holder.

10. Longitudinal magnetic contact for vacuum interrupter according to claim 9, characterized in that the ferromagnetic column (7) is cylindrical and the positioning slot is cylindrical.

Technical Field

The invention belongs to the technical field of vacuum arc-extinguishing chambers, and particularly relates to a longitudinal magnetic contact of a vacuum arc-extinguishing chamber based on a ferromagnetic material.

Background

In a high-voltage direct-current transmission system, a direct-current circuit breaker is used as important control and protection equipment and is a guarantee for safe and reliable power supply of the high-voltage direct-current transmission system. The vacuum arc-extinguishing chamber is used as a key element for generating and extinguishing electric arc, and the opening and closing performance of the vacuum arc-extinguishing chamber is closely related to the contact structure used.

The high-voltage direct-current transmission system has the characteristics of high fault current rising speed, no natural zero crossing point and the like, and is a main obstacle for restricting the development of the direct-current transmission technology. The direct current circuit breaker based on the artificial zero crossing principle generates high-frequency reverse current through the current converting branch circuit and superposes the high-frequency reverse current on the current of the main loop, so that the electric arc in the vacuum arc extinguish chamber is extinguished due to zero crossing of the current, the arc burning time of the direct current electric arc is shorter than that of the power frequency alternating current electric arc, and higher requirements are provided for the diffusion of the electric arc in the vacuum arc extinguish chamber.

The traditional cup-shaped longitudinal magnetic contact generates a longitudinal magnetic field distributed in a bell shape, the diffusion of the electric arc in the initial stage of the arc burning is dominant in a restraining effect, and the control effect on the direct current vacuum electric arc is limited.

Disclosure of Invention

Aiming at the defects of the conventional cup-shaped longitudinal magnetic contact, the invention provides a longitudinal magnetic contact of a vacuum arc extinguish chamber based on a ferromagnetic material, and aims to solve the problem that the diffusion of electric arc at the initial stage of arc burning is dominant in a suppression effect because the cup-shaped longitudinal magnetic contact generates a longitudinal magnetic field distributed in a bell shape, so that the control effect on a direct current vacuum electric arc is limited in the prior art; the invention aims to ensure that the longitudinal magnetic field intensity at the edge of the contact is larger than that in the central area when the opening distance is small in the initial stage of opening, the longitudinal magnetic field distribution is relatively uniform when the opening distance is large, and the residual magnetic field after the current passes zero is small.

In order to achieve the above object, the present invention provides a longitudinal magnetic contact of a vacuum interrupter based on ferromagnetic material, comprising: the contact device comprises a contact blade, a contact support, a support frame, a contact cup, a conductive rod and a ferromagnetic column; the contact blade, the contact support, the support frame, the contact cup and the conductive rod are sequentially arranged from top to bottom, and all contact surfaces are connected through high-conductivity solder; the contact support and the contact cup form a cup cavity, the support frame is positioned in the center of the cup cavity, the ferromagnetic columns are uniformly distributed between the support frame and the inner wall of the cup cavity, the lower end surface of the support frame and the lower end surface of the ferromagnetic columns are both contacted with the bottom of the cup cavity through the positioning grooves, and the upper end surface of the support frame and the upper end surface of the ferromagnetic columns are both connected with the contact support; the conducting rod is arranged at the bottom of the contact cup and used for connecting the contact and the vacuum arc-extinguishing chamber and conducting current.

Furthermore, a plurality of first slots are uniformly arranged on the contact blade in the radial direction, and the first slots are used for reducing eddy currents in the contact blade, so that the hysteresis of a magnetic field during arcing and the residual magnetic field at the moment of zero crossing of current are reduced. A plurality of second grooves are uniformly arranged on the contact piece along the radial direction, the second grooves are arranged between two adjacent first grooves, the length of each second groove is smaller than that of each first groove, and the width of each second groove is smaller than that of each first groove; the second slot serves to further reduce eddy currents in the contact blade while securing the path of movement of the cathode spot during arcing.

Furthermore, the contact holder is uniformly provided with third grooves in the radial direction, the positions of the third grooves are the same as those of the first grooves, and the third grooves are used for reducing eddy currents in the contact holder and reducing the hysteresis of a magnetic field during arcing and the residual magnetic field at the zero crossing moment of the current. A plurality of fourth grooves are uniformly arranged on the contact carrier along the radial direction, the fourth grooves are arranged between two adjacent third grooves, the length of each fourth groove is smaller than that of each third groove, and the width of each fourth groove is smaller than that of each third groove; the position of the fourth slot is the same as the position of the second slot, and the fourth slot is used for further reducing the eddy current in the contact carrier.

The number of the first grooves is the same as that of the third grooves, and the number of the second grooves is the same as that of the fourth grooves; and the number of first slots is the same as the number of cup fingers of the contact cup.

Furthermore, the support frame can be made of stainless steel materials and plays a supporting role in the center of the cup cavity, so that the deformation of the contact blade, the contact holder and the contact cup is reduced, and the mechanical strength of the contact is improved.

Furthermore, the structure of the contact cup is the same as that of a common cup-shaped longitudinal magnetic contact, a groove is formed in the cup wall of the contact cup and is rotated by 90 degrees along the cup wall to form a cup finger, and a notch in the contact cup corresponds to a third groove in the contact support; a longitudinal magnetic field can be generated when current flows through the contact cup.

Furthermore, the ferromagnetic columns are fixed between the support frame and the inner wall of the contact cup, the number of the ferromagnetic columns is the same as that of cup fingers of the contact cup, the ferromagnetic columns are uniformly distributed in the diameter direction corresponding to the third groove of the contact support, the lower end faces of the ferromagnetic columns are uniformly arranged in the positioning grooves through the bottoms of the cup cavities, and the upper end faces of the ferromagnetic columns are in contact with the lower surface of the contact support. The contact structure can improve the longitudinal magnetic field distribution of the contact gap, the residual magnetic field after the current zero-crossing is smaller, the rapid diffusion of the arc plasma is facilitated, and the contact structure is suitable for the direct current on-off working condition based on the artificial zero-crossing principle.

Further preferably, the ferromagnetic column may be cylindrical, and the positioning groove is cylindrical; is convenient for processing.

In the embodiment of the invention, each part mainly playing a conductive role in the contact comprises a contact blade, a contact support, a contact cup, a conductive rod and a backing ring from top to bottom in sequence, and a cup cavity is formed by the contact support and the contact cup; the support frame is located the cup chamber center, and ferromagnetic post is the evenly distributed area between support frame and contact cup wall, and the lower terminal surface of support frame and ferromagnetic post all passes through constant head tank and cup chamber bottom contact, and the contact holds in the palm is connected to the up end.

In the embodiment of the invention, a plurality of radial slots are uniformly formed on the contact blade and the contact support, and the slots on the two parts are in the same position. The contact is characterized in that the position corresponding to the notch on the contact cup is provided with a groove with larger length and width, the number of the grooves is equal to the index of the contact cup, the structure of the contact is the same as that of the existing cup-shaped longitudinal magnetic contact blade, and the purpose is to reduce the residual magnetic field of the contact caused by eddy current when the current passes zero. Because the added ferromagnetic material increases the residual magnetic field, a groove with smaller length and width is arranged between every two adjacent large grooves, so that the residual magnetism can be reduced as much as possible, and the cathode spots during the arcing process can have enough space to diffuse outwards.

In an embodiment of the invention, the ferromagnetic posts are fixed between the support frame and the inner wall of the contact cup. The magnetic field generated by the contact cup mainly distributes the areas with the strongest magnetizing action on the ferromagnetic materials in the cup cavity at the positions close to the notches of the contact cup, and meanwhile, the whole contact is not too heavy, so that the ferromagnetic columns are only placed at the positions close to the notches of the contact cup, the number of the ferromagnetic columns is the same as the index of the cup, and the cylindrical shape is convenient to process. The lower end surface of the contact holder is positioned by evenly distributed cylindrical grooves at the bottom of the cup cavity, and the upper end surface of the contact holder is contacted with the lower surface of the contact holder. When current flows through the contact cup and generates a longitudinal magnetic field, the ferromagnetic posts are easily magnetized to generate longitudinal magnetic fields in the same direction, and the longitudinal magnetic field intensity at the edge of the contact is enhanced.

Compared with the prior art, the technical scheme of the invention can obtain the following beneficial effects:

(1) at the initial stage of switching-off, the contact is small in opening distance, the ferromagnetic material added at a specific position on the periphery of the contact is magnetized, a longitudinal magnetic field in the same direction as the original contact structure is generated in a gap, the longitudinal magnetic field intensity at the edge of the contact at the initial diffusion stage of the electric arc can be obviously improved on the basis of not increasing the contact quality too much, and the rapid diffusion of the electric arc is facilitated.

(2) After the rated open distance is reached, the open distance is relatively large, the longitudinal magnetic field generated by the ferromagnetic material distributed in the cup cavity in the gap is weaker, the longitudinal magnetic field which is uniformly distributed along the radial direction is mainly generated by the contact cup, and the contact cup can be kept at a certain strength to generate an effective control effect on electric arcs, thereby being beneficial to uniform distribution of electric arc plasma and reducing concentration.

(3) The contact piece is processed by the big and small grooves, so that larger eddy current caused by ferromagnetic materials can be effectively reduced, the residual magnetic field in gaps is smaller, and meanwhile, the outward diffusion path of cathode spots moving on the cathode contact piece during arcing is not blocked, the diffusion of arc plasma is facilitated, and the breaking performance is improved.

Drawings

Fig. 1 is a schematic structural diagram of a longitudinal magnetic contact of a vacuum arc-extinguishing chamber based on ferromagnetic materials, which is provided by the invention;

fig. 2 is a structural plan view of a contact blade in a longitudinal magnetic contact of a vacuum arc-extinguishing chamber provided by the embodiment of the invention;

fig. 3 is a top view of a contact holder in a longitudinal magnetic contact of a vacuum arc-extinguishing chamber according to an embodiment of the present invention;

fig. 4 is a structural cross-sectional view of a support frame in a longitudinal magnetic contact of a vacuum arc-extinguishing chamber according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a contact cup in a longitudinal magnetic contact of a vacuum arc-extinguishing chamber provided in an embodiment of the present invention;

fig. 6 is a structural cross-sectional view of a ferromagnetic column in a longitudinal magnetic contact of a vacuum arc-extinguishing chamber according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 1, the core components of the longitudinal magnetic contact of the vacuum arc-extinguishing chamber based on ferromagnetic materials comprise a contact blade 1, a contact holder 2, a support frame 3, a contact cup 4, a conductive rod 5, a backing ring 6 and a ferromagnetic pole 7; the contact blade 1 is made of CuCr50 which is widely applied to a high-voltage vacuum arc-extinguishing chamber, namely the mass fractions of Cu and Cr both account for 50%, the requirements of the contact on higher conductivity and mechanical strength can be met, and the arc ablation resistance is strong; the contact holder 2, the contact cup 4, the conductive rod 5 and the backing ring 6 are made of TU1 oxygen-free copper so as to reduce the through-current loss when the contact is closed; the support frame 3 is made of stainless steel 022Cr17Ni12Mo2, and has high strength and strong corrosion resistance; the ferromagnetic post 7 is made of electrically pure iron DT4, which has a permeability of about 7000 in the mT range of the field generated by the contact and is easily magnetized.

As shown in fig. 2 and 3, 12 radial slots are uniformly formed in the contact blade 1 and the contact carrier 2, the slot positions of the two parts are the same, 6 of the two parts are large slots 8 and 10, 6 of the two parts are small slots 9 and 11, and the large slots and the small slots are distributed in a staggered manner. In a direct current circuit breaker based on an artificial zero crossing principle, taking the cut-off of 5kA direct current as an example, a longitudinal magnetic field of 20-25mT is generated on a contact middle plane at the moment of current peak; when the current rapidly passes through zero in hundred microseconds or even less time after the current conversion is applied, a residual magnetic field of 15-20mT can be generated in a contact gap due to eddy currents in the contact cup and the contact holder, the residual magnetism is further enhanced due to the existence of ferromagnetic materials, the diffusion of plasma after arc is inhibited, and the disconnection is not facilitated. The slotting process can effectively reduce the influence of eddy current, and meanwhile, partial slots are arranged into small slots, so that the cathode spots in the arcing stage have enough space to move outwards.

As shown in fig. 4, the support frame 3 is made of stainless steel. Because the contact blade 1, the contact support 2 and the contact cup 4 are provided with a plurality of grooves, the support frame 3 is needed to reduce the deformation of the contact blade 1, the contact support 2 and the contact cup 4 during rapid opening and closing, and the mechanical strength of the contact is improved.

As shown in fig. 5 and 6, the slots 12 in the contact cup 4 are rotated 90 ° along the cup wall to form cup fingers. When current flows, a circular current path is formed, and a longitudinal magnetic field is generated in the contact gap. The notches 13 in the contact cup 4 correspond to the macro-slots 10 in the contact carrier 2. Because the longitudinal magnetic field generated by the contact cup 4 has different magnetization effects on ferromagnetic materials at different positions in the cup cavity, if annular ferromagnetic materials or excessive ferromagnetic columns are directly placed, the enhancement effect on the longitudinal magnetic field at the edge is limited, but the quality of the contact can be greatly increased, and therefore the positions of the ferromagnetic columns need to be selected. The bottom of the inner cavity of the contact cup 4 is provided with 6 circular positioning holes 14 for fixing the ferromagnetic posts 7, and the circular positioning holes are uniformly distributed in the diameter direction corresponding to the notch 13. The lower end face of the ferromagnetic column 7 is positioned by 6 evenly distributed cylindrical grooves at the bottom of the cup cavity, and the upper end face of the ferromagnetic column is contacted with the lower surface of the contact holder. Because the magnetic conductivity of the ferromagnetic pole is high, the ferromagnetic pole is easy to be magnetized to generate a longitudinal magnetic field, and the direction of the longitudinal magnetic field is the same as that of the longitudinal magnetic field generated by the contact cup.

In the embodiment of the invention, the opening distance of the contact is smaller in the initial stage of opening, the longitudinal magnetic field in the same direction generated by the ferromagnetic material in the gap is more obvious, and the longitudinal magnetic field intensity at the edge of the contact in the initial diffusion stage of the electric arc can be obviously improved. Meanwhile, as the ferromagnetic column 7 is electrically connected with the contact holder and the contact cup through the solder, the conductivity of the ferromagnetic column is about 1 multiplied by 10⁷S/m, about 5.7X 10 relative to the contact cup⁷The conductivity of S/m can play a certain role in shunting, and the current flowing through the contact cup 4 is reduced, so that the contact cup can be contactedThe longitudinal magnetic field in the central area of the head is reduced by 0.5 mT-1 mT, which is beneficial to the rapid diffusion of electric arc. When the rated opening distance is reached, the opening distance is relatively large, the longitudinal magnetic field generated by the ferromagnetic material in the gap is relatively weak, the longitudinal magnetic field is relatively uniform in distribution, the sufficient strength can be kept to generate an effective control effect on the electric arc, the electric arc is maintained in a diffusion state, the uniform distribution of the electric arc plasma is facilitated, and the concentration is reduced.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.