High-voltage earthing switch

Abstract

A high-voltage earthing switch is disclosed. A static contact of the earthing switch is connected with the first end of a conductive copper busbar. The second end of the conductive copper busbar is connected with a transformer. The conductive copper busbar includes a first segment and a second segment connected with the first segment. The first segment is one straight segment and an end is taken as an end of the first end of the conductive copper busbar. The first segment extends from the static contact in the direction opposite to the instantaneous action direction of the moving contact when the moving contact engages the static contact. The second segment is connected with the other end of the first segment, and extends towards the side of the first segment facing away from the moving contact.

Claims

1. A high-voltage earthing switch, comprising a moving contact, a contacting finger, a rack, an insulator, a static contact, a conductive copper busbar, and a transformer; wherein the moving contact is fixedly connected with the contacting finger, the contacting finger is swingably connected with the rack, the static contact is fixedly connected with the rack via the insulator, the static contact is connected with a first end of the conductive copper busbar, a second end of the conductive copper busbar is connected with the transformer, the conductive copper busbar comprises a first segment and a second segment connected with the first segment, the first segment is one straight segment, an end of the first segment is the first end of the conductive copper busbar, the first segment is parallel to an instantaneous action direction of the moving contact when the moving contact engages the static contact, the first segment extends from the static contact in a direction opposite to the instantaneous action direction of the moving contact when the moving contact engages the static contact, the second segment is connected with the other end of the first segment, the second segment extends towards a side of the first segment, which faces away from the moving contact, and the second segment is located at one side of an extended line of one end of the contacting finger connected with the moving contact when the earthing switch switching-on in the direction opposite to the instantaneous action direction of the moving contact when the moving contact engages the static contact.

2. The high-voltage earthing switch according to claim 1, wherein the second segment comprises a straight segment, and the straight segment of the second segment is perpendicular to the first segment.

3. The high-voltage earthing switch according to claim 1, wherein the second segment consists a first straight segment and a second straight segment, the first straight segment is connected with the first segment, the second straight segment is connected with the first straight segment, the second straight segment is perpendicular to the first segment, an angle between the first straight segment and the first segment is an obtuse angle, and an angle between the first straight segment and the second straight segment is an obtuse angle.

4. The high-voltage earthing switch according to claim 1, wherein the moving contact is a circular moving contact, the static contact comprises a body and a plurality of contacting finger strips provided in a circular hole on the body, the plurality of contacting finger strips are arranged in a circular array along a side wall of the circular hole, and a leaf spring is provided between a contacting finger strip of the plurality of contacting finger strips and the side wall of the circular hole.

5. The high-voltage earthing switch according to claim 4, wherein the static contact is fixed to the insulator through an L-shaped right-angle connector, the body of the static contact comprises four side surfaces, one of the four side surfaces of the body of the static contact is a plane, the first end of the conductive copper busbar is fixedly connected to the plane, another side surface of the four side surfaces opposite to the plane is an arc surface, the arc surface has a smooth transition with each of the other two of the four side surfaces of the body of the static contact, one right-angle edge of the L-shaped right-angle connector is fixedly connected with an end surface of the insulator, the other right-angle edge of the L-shaped right-angle connector is fixedly connected with a bottom surface of the body of the static contact.

6. The high-voltage earthing switch according to claim 5, wherein a gap of 2.5 mm to 5.5 mm is provided between neighboring contacting finger strips of the plurality of the contacting finger strips of the static contact.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a diagram of an overall structure of a earthing switch of the present invention.

(2) FIG. 2 is a top view of a static contact.

(3) FIG. 3 is a structural diagram of a single contacting finger of a static contact and a reed of an earthing switch.

(4) FIG. 4 is a diagram of an engagement state of a moving contact and a contacting finger strip.

(5) FIG. 5 is an analysis diagram of an electromotive force of an earthing switch.

(6) FIG. 6 is an analysis diagram of an electromotive force between a front end portion of a contacting finger and a second straight segment of a second segment of a conductive copper busbar.

(7) FIG. 7 is an analysis diagram of an electromotive force between a front end portion of a contacting finger and a first segment of a conductive copper busbar.

(8) In the FIGS.: Moving Contact 1, Contacting Finger 2, Spring 3, Rack 4, Insulator 6, Static Contact 7, Conductive Copper Busbar 8, Transformer 9, Leaf spring 10, L-shaped right-angle connector 11, First segment of the conductive copper busbar 81, Second segment of the conductive copper busbar 82, First straight segment of the second segment of the conductive copper busbar 821, Second straight segment of the second segment of the conductive copper busbar 822, instantaneous action direction of the moving contact when the moving contact engages the static contact 12, extended line of one end of the contacting finger connected with the moving contact when the earthing switch switching-on 13, Contacting finger strip 14.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(9) As shown in FIGS. 1-4, an earthing switch of the invention comprises a moving contact 1, a contacting finger 2, a spring 3, a rack 4, an insulator 6, a static contact 7, a conductive copper busbar 8, and a transformer 9. The moving contact 1 is fixedly connected with the contacting finger 2. The contacting finger 2 is connected with the rack 4. The spring 3 is connected between the contacting finger 2 and the rack 4. One end of the insulator 6 is fixed with the rack 4. The static contact 7 is fixed on the other end of the insulator 6 via an L-shaped right-angle connector 11. The first end of the conductive copper busbar 8 is fixed with the static contact 7, and a second end of the conductive copper busbar 8 is connected with the transformer 9.

(10) In the following description, as shown in FIG. 1, the instantaneous action direction 12 of the moving contact when the moving contact engages the static contact is downward, otherwise, being upward, the direction indicated by one end of the contacting finger connected with the moving contact in the engaged state is taken as the right, otherwise, as the left.

(11) The conductive copper busbar comprises a first segment 81 with an end taking as the first end of the conductive copper busbar and a second segment connected with the first segment 81, the first segment 81 is parallel to the instantaneous action direction 12 of the moving contact when the moving contact engages the static contact, the first segment 81 extends upward from the static contact 7; the second segment extends toward right side from the upper end of the first segment 81, the second segment is located above an extended line 13 of the contacting finger toward the right side in the switching-on state. the second segment consists of two straight segments, wherein the left end of the first straight segment 821 is connected with the upper end of the first segment 81, the second straight segment 822 is connected with the right end of the first straight segment 821, the second straight segment 822 is perpendicular to the first segment 81, the angle between the first straight segment 821 and the first segment 81 is an obtuse angle, the angle between the first straight segment 821 and the second straight segment 822 is also an obtuse angle.

(12) A circular hole is provided on the body of the static contact 7, 16 contacting finger strips 14 are arranged in a circular array along the side wall of the circular hole in the circular hole, a gap of 2.5 mm to 5.5 mm is provided between the respective contacting finger strips 14 of the static contact. A leaf spring 10 is provided between the contacting finger strip 14 and the side wall of the circular hole.

(13) The right side surface of the body of the static contact is one plane, and the first end of the conductive copper busbar 8 is fixedly connected to the plane. The left side surface of the body of the static contact 7 is an arc surface, and the arc surface has a smooth transition with front and back side surfaces of the body of the static contact 7. The vertical edge of the L-shaped right-angle connector 11 is fixed with the end surface of the insulator 6 via a bolt, and the horizontal edge of the L-shaped right-angle connector 11 is fixed with the bottom surface of the body of the static contact 7 via the bolt.

(14) The contacting finger 2 consists of a front end portion fixing the moving contact and a swing arm connecting the front end portion and the rack 4.

(15) As shown in FIGS. 5-7, a ladder is formed between the front end portion of the contacting finger and the second straight segment of the second segment of the conductive copper busbar. Two diagonals of the ladder are d1 and d2, respectively. Two waists thereof are s1 and s2, respectively. The height thereof is a. Preferably, the proportion of d1:d2:s1:s2:a is 1:2.2:1.22:1.61:1. The front end portion of the contacting finger and the first segment of the conductive copper busbar (excluding the portion contacted with the static contact, and the remaining portion is an effective portion) constitute two conductors perpendicular to each other. The length of the front end portion of the contacting finger is set as a. The length of the effective portion of the first segment of the conductive copper busbar is set as h. The widths of the front end portion of the contacting finger and the first segment of the conductive copper busbar are both 2r. Preferably, the proportion of a:h:r is 7.53:6.08:1.

(16) An electromotive force loop coefficient between the front end portion of the contacting finger and the second straight segment of the second segment of the conductive copper busbar is formulated as:

(17) $c=\frac{\left(d_1+d_2\right)-\left(s_2+s_1\right)}{a}.$

(18) An electromotive force loop coefficient between the front end portion of the contacting finger and the first segment of the conductive copper busbar is formulated as:

(19) $c=\ln \left[\frac{2\mathrm{ah}}{r(h+\sqrt{h^2+a^2)}}\right].$

(20) Therefore, distance between two wires a is increased would effectively reduce the coefficient of the electromotive force c, and thus being able to reduce the interference of the electromotive force on the earthing switch.

(21) The process of an action of the earthing switch is provided as follows. When it is needed to switch on, an operational mechanism drives the contacting finger to be rotated clockwise. When the contacting finger is rotated by a critical point of the spring, the contacting finger is rotated rapidly until the contacting finger is rotated clockwise by 90, then the moving contact is inserted into the contacting finger strip of the earthing static contact, and the moving contact engages the static contact to realize the earthing. When it is needed to switch off, the operational mechanism drives the contacting finger to be rotated counterclockwise. The moving contact disengages from the static contact. When the contacting finger is rotated by a critical point of the spring, the contacting finger is rotated rapidly until the contacting finger is rotated counterclockwise by 90, then the contacting finger keeps a set position under a limit position.