WO2023139643A1

WO2023139643A1 - Changeover switch for on-load tap changer, and on-load tap changer

Info

Publication number: WO2023139643A1
Application number: PCT/JP2022/001585
Authority: WO
Inventors: 真一郎阿部; 直紀江口
Original assignee: 株式会社東芝; 東芝エネルギーシステムズ株式会社
Priority date: 2022-01-18
Filing date: 2022-01-18
Publication date: 2023-07-27
Also published as: JPWO2023139643A1

Abstract

In the present invention, a changeover switch for an on-load tap changer according to an embodiment holds a resistance switch. The resistance switch has a first terminal and a second terminal that are capable of making contact with each other. The first terminal is able to move in a first direction and make contact with the second terminal at a first contact surface and a second contact surface. The first contact surface and the second contact surface are positioned in plane symmetry with each other relative to a first plane that is parallel to the first direction, and both assume a plane symmetrical configuration relative to a second plane that is orthogonal to the first plane. The cross-sectional shape of the first contact surface in the second plane is an arc centered on the opposite side from the first contact surface across the first plane. The cross-sectional shape of the second contact surface in the first plane is an arc centered on the opposite side from the second contact surface across the first plane.

Description

Change-over switch and on-load tap-changer for on-load tap-changers

Embodiments of the present invention relate to a switching switch for an on-load tap changer and an on-load tap changer.

The on-load tap changer is a device that switches the taps while the transformer is in operation (under load). Generally, an on-load tap changer has a tap selector and a switching switch. A tap selector selects a running tap in the transformer tap winding. A switching switch switches the circuit to the selected tap. A changeover switch has a valve, a current limiting resistor and a resistive switch. Resistive switches are consumed by chattering arcs when closed. It is required to suppress consumption of the resistance switch.

WO2020/240781

The problem to be solved by the present invention is to provide a switching switch for an on-load tap changer and an on-load tap changer capable of suppressing wear of the resistance switch.

The switching switch of the on-load tap changer of the embodiment has a tap terminal, a valve, and a current limiting resistor. The tap terminals are connected to tap selectors of an on-load tap changer. A valve is connected to the tap terminal via a valve switch. A current limiting resistor is connected to the tap terminal through a resistive switch. A current limiting resistor is connected in parallel with the valve to the tap terminal. The resistive switch has a first terminal and a second terminal that are abuttable with each other. The first terminal can move in the first direction to abut the second terminal on the first abutment surface and the second abutment surface. The first contact surface and the second contact surface are arranged plane-symmetrically with respect to a first plane parallel to the first direction, and are plane-symmetrical with respect to a second plane orthogonal to the first plane. The cross-sectional shape of the first contact surface on the second plane is an arc shape with the center located on the side opposite to the first contact surface across the first plane. The cross-sectional shape of the second contact surface on the second plane is an arc shape whose center is located on the side opposite to the second contact surface across the first plane.

The perspective view of the on-load tap changer of embodiment. The circuit diagram per phase of the switching switch of embodiment. The perspective view of the switching switch of embodiment. The perspective view of a switching unit. The perspective view of a cam unit. FIG. 4 is a perspective view of a fixing portion of the switch assembly of the first embodiment; FIG. 2 is a perspective view of the resistance switch terminal of the first embodiment; The perspective view of the 2nd movable part of 1st Embodiment. FIG. 2 is a side view of the resistive switch of the first embodiment; The timing chart of the switching operation of the switching switch. FIG. 5 is an explanatory diagram of changes in the energized state in the switching operation from the first tap terminal to the second tap terminal; FIG. 5 is an explanatory diagram of a change in energization state in the reversal switching operation from the second tap terminal to the first tap terminal; The side view of the resistive switch of 2nd Embodiment. The perspective view of the 2nd movable part of 2nd Embodiment. The perspective view of the fixing|fixed part of the switch assembly of 2nd Embodiment. FIG. 8 is a perspective view of a resistor switch fixed terminal and a resistor switch common terminal according to the second embodiment; Explanatory drawing of the common contact member of 2nd Embodiment. The perspective view of the common contact member of the modification of 2nd Embodiment.

Hereinafter, the switching switch of the on-load tap changer and the on-load tap changer of the embodiment will be described with reference to the drawings.
FIG. 1 is a perspective view of the on-load tap changer 1 of the embodiment. The on-load tap changer 1 is a device that adjusts the voltage by changing the turns ratio (transformation ratio) of the transformer during operation. The on-load tap changer 1 has a tap selector 2 , a drive mechanism 5 and a switching switch 10 .

A tap selector 2 performs a selection operation to select a running tap in the transformer tap windings. The drive mechanism 5 drives the tap selector 2 with a drive force transmitted from an electric operating device (not shown) via a drive shaft 6 .
Switching switch 10 performs the switching action of switching the circuit to the selected tap. The switching switch 10 is arranged inside a cylindrical container 10a and immersed in insulating oil.

The switching switch 10 of the embodiment will be described in detail.
FIG. 2 is a circuit diagram of the switching switch 10 of the embodiment, showing one phase of three-phase alternating current. Hereinafter, the configuration of each phase of switching switch 10 will be described unless otherwise specified. The switching switch 10 is a small-capacity switching switch having one valve V. FIG. The changeover switch 10 switches the circuit between the first tap terminal T1 and the second tap terminal T2.

As shown in FIG. 2, the switching switch 10 has a valve V, a first valve switch SV1 and a second valve switch SV2. The switching switch 10 further comprises a first current limiting resistor R1, a first resistive switch SR1, a second current limiting resistor R2 and a second resistive switch SR2. The switching switch 10 further has a first energization switch SM1 and a second energization switch SM2.

The valve V is a vacuum circuit breaker that uses vacuum as an insulating and arc-extinguishing medium. A first end of the valve V is connected to a first tap terminal T1 through a first valve switch SV1. A first end of the valve V is connected to a second tap terminal T2 via a second valve switch SV2. A second end of valve V is connected to neutral terminal 18 .

A first end of the first current limiting resistor R1 is connected to the first tap terminal T1 via the first resistance switch SR1. A second end of the first current limiting resistor R1 is connected to the neutral terminal 18 . A first current limiting resistor R1 is connected in parallel with the valve V to the first tap terminal T1. A first end of the second current limiting resistor R2 is connected to the second tap terminal T2 via a second resistive switch SR2. A second end of the second current limiting resistor R2 is connected to the neutral terminal 18 . A second current limiting resistor R2 is connected in parallel with the valve V to the second tap terminal T2.

The first resistance switch SR1 has a resistance switch fixed terminal 35R, a resistance switch common terminal 32R, and a resistance switch conductor 55R. The resistance switch fixed terminal 35R is connected to the first end of the first current limiting resistor R1. The resistive switch common terminal 32R is part of the common terminal 32 connected to the first tap terminal T1. The resistance switch conductor 55R can be brought into contact with and separated from the resistance switch fixed terminal 35R and the resistance switch common terminal 32R. When the resistance switch conductor 55R contacts the resistance switch fixed terminal 35R and the resistance switch common terminal 32R, the first resistance switch SR1 is closed. When the resistance switch conductor 55R is separated from the resistance switch fixed terminal 35R and the resistance switch common terminal 32R, the first resistance switch SR1 is opened. The second resistance switch SR2 is formed similarly to the first resistance switch SR1.

The first energization switch SM1 is connected in parallel with the valve V to the first tap terminal T1. The second energization switch SM2 is connected in parallel with the valve V to the second tap terminal T2.

FIG. 3 is a perspective view of the switching switch 10 of the embodiment. The switching switch 10 shown in FIG. 3 is arranged inside the cylindrical container 10a shown in FIG.
In the present application, the Z direction, R direction and θ direction of the polar coordinate system are defined as follows. The Z direction is the direction of the central axis of the switching switch 10 . For example, the Z direction is vertical and the +Z direction is upward. The R direction is the radial direction of the switching switch 10 . The +R direction is the radially outer direction (the direction away from the central axis). The θ direction is the circumferential direction of the central axis of switching switch 10 . The +θ direction is the direction of rotation of a right-hand screw that advances in the +Z direction. For example, the R direction and the θ direction are horizontal directions.

The switching switch 10 has a first mounting plate 12 , a second mounting plate 13 and a support 14 .
The first mounting plate 12 , the second mounting plate 13 and the struts 14 are made of a conductive metal material and connected to a neutral point terminal 18 .

The switching switch 10 has an energy storage mechanism 15 .
The energy accumulating mechanism 15 is arranged in the −Z direction of the second mounting plate 13 . The accumulating mechanism 15 includes an accumulating spring 15s. In parallel with the selection operation of the tap selector 2, the drive mechanism 5 shown in FIG. 1 expands or compresses the accumulating spring 15s (accumulating operation) shown in FIG. After the selection operation of the tap selector 2 is completed, the accumulating mechanism 15 releases the energized accumulating spring 15s. The accumulating mechanism 15 rotates the shaft 61 (see FIG. 5) at the center of the cam unit 60 by a predetermined angle by the restoring force (release of the accumulating force) of the accumulating spring 15s. As a result, the accumulating mechanism 15 instantaneously performs the switching operation of the switching switch 10 .

The switching switch 10 has a first current limiting resistor R1 and a second current limiting resistor R2. A first current limiting resistor R1 and a second current limiting resistor R2 are fixed to the +Z surface of the first mounting plate 12 .

The switching switch 10 has a switching unit 20 .
The switching unit 20 is arranged between the first mounting plate 12 and the second mounting plate 13 and supported by both. A switching unit 20 is formed for each phase of a three-phase alternating current. Three-phase switching units 20 are arranged side by side in the θ direction. The switching unit 20 comprises the previously mentioned valve V, a first switch assembly S1 and a second switch assembly S2. The valve V is arranged in the +R direction at the center of the switching unit 20 in the θ direction.

The first switch assembly S1, as shown in FIG. 2, includes a first energization switch SM1, a first valve switch SV1 and a first resistance switch SR1. The second switch assembly S2 includes a second energization switch SM2, a second valve switch SV2 and a second resistance switch SR2. As shown in FIG. 3, the first switch assembly S1 and the second switch assembly S2 are arranged across the valve V in the θ direction. The first switch assembly S1 is arranged in the -.theta. direction of the valve V, and the second switch assembly S2 is arranged in the +.theta.

FIG. 4 is a perspective view of the switching unit 20 viewed from the central axis side of the switching switch 10. FIG. The switching unit 20 has a unit base 21 and a valve opening/closing mechanism 22 .
The unit base 21 has a bottom plate portion 21a and a pillar portion 21b. The unit base 21 supports the aforementioned valve V, first switch assembly S1 and second switch assembly S2.

The first switch assembly S1 has a fixed portion 30 and

movable portions

40 and 50 . The second switch assembly S2 is formed symmetrically with the first switch assembly S1.
The fixed portion 30 is arranged in the +R direction of the switching unit 20 and fixed to the bottom plate portion 21 a of the unit base 21 . The

movable parts

40 and 50 are arranged in the −R direction of the fixed part 30 . The

movable parts

40 and 50 are supported by the pillars 21b of the unit base 21 via

parallel links

42 and 52, respectively. The

movable parts

40 and 50 are movable in substantially the R direction with respect to the fixed part 30 . The

movable parts

40 and 50 have a first movable part 40 arranged in the +Z direction and a second movable part 50 arranged in the -Z direction.

FIG. 5 is a perspective view of the cam unit 60. FIG. In addition to the cam unit 60, only the one-phase switching unit 20 is shown in FIG. Cam unit 60 is arranged along the central axis of switching switch 10 . The switching unit 20 is arranged in the +R direction of the cam unit 60 . One cam unit 60 implements the switching operation of the three-phase switching unit 20 . The cam unit 60 has a shaft 61, a first cam 70 arranged in the +Z direction, a valve cam 65 arranged in the center in the Z direction, and a second cam unit 80u arranged in the -Z direction. The first cam 70 moves the first movable portion 40 . The valve cam 65 operates the valve opening/closing mechanism 22 . The second cam unit 80u moves the second movable portion 50. As shown in FIG.

(First embodiment)
FIG. 6 is a perspective view of the fixing portion 30 of the first switch assembly S1 of the first embodiment viewed from the -R direction. The fixed part 30 has a switch base 31 . The switch base 31 is made of an insulating material such as resin. The switch base 31 is formed in a rectangular parallelepiped shape whose longitudinal direction is the Z direction.

The first switch assembly S1 further has a first tap terminal T1 and a common terminal 32. The first switch assembly S1 further has an energization switch fixed terminal 35M, a valve switch fixed terminal 35V and a resistance switch fixed terminal 35R. The common terminal 32 is made of a metal material such as brass or copper-tungsten alloy. The energizing switch fixed terminal 35M, the valve switch fixed terminal 35V, and the resistance switch fixed terminal 35R are also made of the same material as the common terminal 32.

The first tap terminal T1 is arranged on the +R surface of the switch base 31. A first tap terminal T1 is connected to the common terminal 32 . A first tap terminal T1 is arranged on the fixing portion 30 of the first switch assembly S1, and a second tap terminal T2 is arranged on the fixing portion 30 of the second switch assembly S2. The first tap terminal T1 and the second tap terminal T2 are connected by wiring 3 to the tap selector 2 shown in FIG.

The common terminal 32 extends in the Z direction. The common terminal 32 is arranged in the -θ direction of the -R surface of the switch base 31 . An energization switch common terminal 32M and a valve switch common terminal 32V are formed at the end of the common terminal 32 in the +Z direction. A resistive switch common terminal 32R is formed at the end of the common terminal 32 in the -Z direction. The energization switch common terminal 32M, the valve switch common terminal 32V, and the resistance switch common terminal 32R are part of the common terminal 32 and are integrally formed with the common terminal. The energization switch common terminal 32M, the valve switch common terminal 32V, and the resistance switch common terminal 32R have the same shape.

The energization switch fixed terminal 35M, the valve switch fixed terminal 35V and the resistance switch fixed terminal 35R are arranged on the -R surface of the switch base 31 in the +θ direction. The energization switch fixed terminal 35M, the valve switch fixed terminal 35V, and the resistance switch fixed terminal 35R are arranged side by side in the Z direction along the common terminal 32. As shown in FIG. The energization switch fixed terminal 35M is arranged side by side with the energization switch common terminal 32M in the θ direction. The valve switch fixed terminal 35V is arranged side by side with the valve switch common terminal 32V in the θ direction. The resistance switch fixed terminal 35R is arranged side by side with the resistance switch common terminal 32R in the θ direction. The energizing switch fixed terminal 35M, the valve switch fixed terminal 35V and the resistance switch fixed terminal 35R have the same shape.

FIG. 7 is a perspective view of the second movable part 50 of the first embodiment. The second movable portion 50 has a frame 51, a parallel link 52, a first roller (cam follower) 53, a second roller (cam follower) 54, and a resistance switch conductor (first terminal) 55R.

The frame 51 has a movable terminal support portion 51a, a central portion 51b, and a roller support portion 51c.
A first end of the parallel link 52 is connected to the central portion 51 b of the frame 51 . A second end of the parallel link 52 is connected to the support 21b of the unit base 21, as shown in FIG. Thereby, the second movable part 50 can move in the substantially R direction with respect to the fixed part 30 . The resistance switch conductor 55R contacts and separates from the resistance switch common terminal 32R and the resistance switch fixed terminal 35R at the same time.

The resistance switch conductor 55R is made of a metal material such as brass or copper-tungsten alloy. The resistance switch conductor 55R is formed in a substantially cylindrical shape. The resistance switch conductor 55R is supported by the movable terminal support portion 51a of the frame 51. As shown in FIG. An opening 57R is formed in the side wall of the movable terminal support portion 51a in the .theta. direction. The center axis of the resistance switch conductor 55R is inserted through the opening 57R. A resistance switch spring 56R is arranged between the side wall of the movable terminal support portion 51a in the -R direction and the resistance switch conductor 55R. The resistance switch spring 56R biases the resistance switch conductor 55R in the +R direction.

As shown in FIG. 5, the cam unit 60 has a second cam unit 80u. The second cam unit 80u moves the second movable portion 50. As shown in FIG. The second cam unit 80 u has a second cam 80 and a second cam rotation control mechanism 90 . A second cam rotation control mechanism 90 controls the rotation of the second cam 80 .

A second groove 80a is formed at the end of the outer circumference 83 of the second cam 80 in the -Z direction. The second roller 54 of the second movable portion 50 is accommodated in the second groove portion 80a. The first roller 53 of the second movable portion 50 contacts the outer circumference (+R surface) 83 of the second cam 80 . As a result, the position of the second movable portion 50 in the R direction is regulated. A first outer peripheral portion 86 and a second outer peripheral portion 87 are formed on the outer periphery 83 of the second cam 80 at different positions in the R direction. The first outer peripheral portion 86 is arranged in the -R direction, and the second outer peripheral portion 87 is arranged in the +R direction.

When the second cam 80 rotates in the θ direction, the second movable portion 50 is arranged adjacent to the first outer peripheral portion 86 in the +R direction. At this time, the second movable portion 50 is arranged at the end in the -R direction in the movable range in the R direction. As a result, the resistance switch conductor 55R is separated from the resistance switch common terminal 32R and the resistance switch fixed terminal 35R, and the first resistance switch SR1 is opened.

When the second cam 80 rotates in the θ direction, the second movable portion 50 is arranged adjacent to the second outer peripheral portion 87 in the +R direction. At this time, the second movable portion 50 is arranged at the +R-direction end of the R-direction movable range. As a result, the resistance switch conductor 55R comes into contact with the resistance switch common terminal 32R and the resistance switch fixed terminal 35R, and the first resistance switch SR1 is closed.

The first movable portion 40 shown in FIG. 4 is formed in the same manner as the second movable portion 50. Instead of the resistance switch conductor 55R of the second movable part 50, the first movable part 40 has an energization switch conductor 45M and a valve switch conductor 45V. The valve switch conductor 45V is arranged in the +R direction from the energization switch conductor 45M. By changing the position of the first movable portion 40 in the R direction, various combinations of opening and closing of the first energizing switch SM1 and the first valve switch SV1 are realized.

FIG. 8 is a side view of the resistive switch of the first embodiment. The first resistance switch SR1 and the second resistance switch SR2 (hereinafter referred to as resistance switch SR) have a resistance switch conductor (first terminal) 55R that can contact each other, a resistance switch fixed terminal (second terminal) 35R, and a resistance switch common terminal 32R. The resistor switch common terminal 32R is the same as the resistor switch fixed terminal 35R. The resistance switch fixed terminal 35R will be described below as a representative.

The resistance switch conductor 55R can move in the +R direction and come into contact with the resistance switch fixed terminal 35R. The resistance switch conductor 55R can contact the resistance switch fixed terminal 35R on the first contact surface C1 and the second contact surface C2. The first contact surface C1 and the second contact surface C2 are plane-symmetrical to each other with respect to the first plane F1 parallel to the +R direction. For example, the first plane F1 is a horizontal plane.

The width in the θ direction of the first contact surface C1 and the second contact surface C2 of the resistance switch conductor 55R is the same range as the width in the θ direction of the resistance switch fixed terminal 35R. The first contact surface C1 and the second contact surface C2 are plane-symmetrical with respect to a second plane F2 orthogonal to the first plane F1. For example, the second plane F2 is an RZ plane passing through the center of the resistance switch fixed terminal 35R in the θ direction.

The cross-sectional shape of the first contact surface C1 on the second plane F2 is the shape of the first circular arc A1. A center P1 of the first arc A1 is arranged on the side opposite to the first contact surface C1 across the first plane F1. The shape of the first arc A1 is the same regardless of the position of the second plane F2 in the θ direction. That is, the shape of the first contact surface C1 is the shape of the outer peripheral surface of a cylinder extending parallel to the central axis of the resistance switch conductor 55R.

The cross-sectional shape of the second contact surface C2 on the second plane F2 is the shape of the second arc A2. A center P2 of the second arc A2 is arranged on the side opposite to the second contact surface C2 across the first plane F1. The shape of the second arc A2 is the same regardless of the position of the second plane F2 in the θ direction. That is, the shape of the second contact surface C2 is the shape of the outer peripheral surface of a cylinder extending parallel to the central axis of the resistance switch conductor 55R.

The cross-sectional shape on the second plane F2 of the outer peripheral surface of the resistance switch conductor 55R excluding the first contact surface C1 and the second contact surface C2 is the shape of an arc A0. The center P0 of arc A0 is located on the central axis of resistive switch conductor 55R. That is, the radii of curvature of the first arc A1 and the second arc A2 are larger than the curvature radius of the arc A0. The radius of curvature of the first contact surface C1 and the second contact surface C2 is greater than the radius of curvature of the outer peripheral surface of the resistive switch conductor 55R.

FIG. 9 is a perspective view of the resistance switch fixed terminal 35R of the first embodiment. The resistance switch fixed terminal 35R has a substantially V shape opening in the -R direction when viewed from the θ direction. The resistance switch fixing terminal 35R can contact the first contact surface C1 and the second contact surface C2 of the resistance switch conductor 55R at the third contact surface C3 and the fourth contact surface C4.

The third contact surface C3 and the fourth contact surface C4 are plane-symmetrical with respect to the first plane F1. The third contact surface C3 and the fourth contact surface C4 are plane-symmetrical with respect to the second plane F2.

The cross-sectional shape of the third contact surface C3 on the second plane F2 is the shape of the third straight line L3. The cross-sectional shape of the third contact surface C3 on a third plane (not shown) orthogonal to the third straight line L3 is the shape of the third arc A3. The center of the third arc A3 is arranged on the side opposite to the first plane F1 across the third contact surface C3. The shape of the third arc A3 is the same regardless of the position on the third straight line L3 on the third plane. That is, the shape of the third contact surface C3 is the shape of the outer peripheral surface of a cylinder extending parallel to the third straight line L3. The third contact surface C3 has a convex shape toward the first plane F1. A ridgeline of the third contact surface C3 coincides with the third straight line L3.

The cross-sectional shape of the fourth contact surface C4 on the second plane F2 is the shape of the fourth straight line L4. The cross-sectional shape of the fourth contact surface C4 on a fourth plane (not shown) perpendicular to the fourth straight line L4 is the shape of a fourth arc A4. The center of the fourth arc A4 is arranged on the side opposite to the first plane F1 across the fourth contact surface C4. The shape of the fourth arc A4 is the same regardless of the position on the fourth straight line L4 on the fourth plane. That is, the shape of the fourth contact surface C4 is the shape of the outer peripheral surface of a cylinder extending parallel to the fourth straight line L4. The fourth contact surface C4 has a convex shape toward the first plane F1. A ridgeline of the fourth contact surface C4 coincides with the fourth straight line L4.

As shown in FIG. 8, the first contact surface C1 of the resistance switch conductor 55R and the third contact surface C3 of the resistance switch fixed terminal 35R are in contact. Similarly, the second contact surface C2 of the resistance switch conductor 55R and the fourth contact surface C4 of the resistance switch fixed terminal 35R are in contact. Below, contact between the first contact surface C1 and the third contact surface C3 will be described as a representative.

As described above, the shape of the third contact surface C3 of the resistance switch fixed terminal 35R is the shape of the outer peripheral surface of a cylinder extending parallel to the third straight line L3. The shape of the first contact surface C1 of the resistance switch conductor 55R is the shape of the outer peripheral surface of a cylinder extending parallel to the central axis of the resistance switch conductor 55R. The ridgeline of the first contact surface C1 and the ridgeline of the third contact surface C3 are twisted by 90 degrees. Therefore, the contact between the first contact surface C1 and the third contact surface C3 is point contact first.

The position of the resistance switch conductor 55R may shift in the direction of the central axis due to expansion and contraction of the constituent members of the second movable portion 50, or the like. Even in this case, the contact position between the first contact surface C1 and the third contact surface C3 does not change. The opening and closing timings of the resistance switch SR are less likely to change. This improves the operational reliability of the switching switch 10 of the on-load tap changer 1 .

The resistance switch conductor 55R is pressed against the resistance switch fixed terminal 35R by the resistance switch spring 56R (see FIG. 7). The resistance switch conductor 55R and the resistance switch fixed terminal 35R are elastically deformed. The contact between the first contact surface C1 and the third contact surface C3 changes from point contact to surface contact.

As described above, the radius of curvature of the first contact surface C1 is larger than the radius of curvature of the outer peripheral surface of the resistance switch conductor 55R. Therefore, the area of the contact surface between the first contact surface C1 and the third contact surface C3 is increased. The radius of the contact surface (Herz radius) is 0.2 mm or more. The pressure on the contact surface is reduced, and wear of the first contact surface C1 and the third contact surface C3 is suppressed.

A switching operation (sequence) of the switching switch 10 will be described. As described above, the switching operation of the switching switch 10 is instantaneously performed when the shaft 61 (see FIG. 5) rotates due to the release of the stored force of the energy storing spring 15s (see FIG. 3).
10 is a timing chart of the switching operation of the switching switch 10. FIG. Each chart in FIG. 10 shows the closed (ON) state on the upper side and the open (OFF) state on the lower side. 11A and 11B are explanatory diagrams of changes in the energization state in the switching operation from the first tap terminal T1 to the second tap terminal T2. 12A and 12B are explanatory diagrams of changes in the energization state in the reversal switching operation from the second tap terminal to the first tap terminal.

A second cam rotation control mechanism 90 shown in FIG. 5 controls the rotation of the second cam 80 .
The second cam rotation control mechanism 90 rotates the second cam 80 by a predetermined angle to move the second movable portion 50 when the switching operation of the switching switch 10 is started. As a result, the first resistance switch SR1 is opened and the second resistance switch SR2 is closed from time b to time C of the switching operation shown in FIG. After that, at time D, the valve V opens. As described above, prior to the opening of the valve V in the switching operation, the second current limiting resistor R2 to which the tap is switched is energized. As shown in FIG. 10, the second cam rotation control mechanism 90 keeps the second cam 80 in a non-rotating state after time C until the end of the switching operation.

The second cam rotation control mechanism 90 reversely rotates the second cam 80 by a predetermined angle to move the second movable portion 50 in the reverse direction when the reverse switching operation of the switching switch 10 is started. As a result, the first resistance switch SR1 is closed and the second resistance switch SR2 is opened from time point p to time point Q of the reversal switching operation shown in FIG. After that, the valve V is opened at time r. As described above, prior to the opening of the valve V in the reversal switching operation, the first current limiting resistor R1 of the tap switching destination is energized. As shown in FIG. 10, the second cam rotation control mechanism 90 keeps the second cam 80 in a non-rotating state from time point Q until the end of the reverse switching operation.

At time b of the switching operation shown in FIG. 11, a potential difference is generated between the resistance switch fixed terminal 35R of the second resistance switch SR2 and the resistance switch conductor 55R. When the second resistance switch SR2 is closed from time b to time C, a chattering arc may occur between the resistance switch fixed terminal 35R and the resistance switch conductor 55R. The same applies to the first resistance switch SR1 from time point p to time point Q of the reversal switching operation.

As described above, the resistance switch conductor 55R can move in the +R direction and come into contact with the resistance switch fixed terminal 35R. The resistance switch conductor 55R can contact the resistance switch fixed terminal 35R on the first contact surface C1 and the second contact surface C2. The first contact surface C1 and the second contact surface C2 are arranged plane-symmetrically with respect to the first plane F1 parallel to the +R direction. A center P1 of the first arc A1 of the first contact surface C1 is arranged on the opposite side of the first plane F1 from the first contact surface C1. A center P2 of the second arc A2 of the second contact surface C2 is arranged on the opposite side of the second contact surface C2 across the first plane F1.

The radius of curvature of the first contact surface C1 is larger than the radius of curvature of the outer peripheral surface of the resistance switch conductor 55R. This increases the area of the contact surface between the first contact surface C1 and the third contact surface C3. As described above, even if a chattering arc occurs during the switching operation and reverse switching operation of the switching switch 10, the damage acting on the first contact surface C1 and the third contact surface C3 is dispersed. The same applies to the second contact surface C2 and the fourth contact surface C4. Therefore, consumption of the resistance switch SR can be suppressed.

(Second embodiment)
FIG. 13 is a side view of the resistance switch of the second embodiment. In the second embodiment, the shape of the terminals of the resistance switch SR is different from that in the first embodiment. Descriptions of the second embodiment that are the same as those of the first embodiment may be omitted.

FIG. 14 is a perspective view of the second movable part of the second embodiment. Instead of the resistance switch conductor 55R of the first embodiment, the switching switch of the second embodiment has a resistance switch movable terminal (first terminal) 55R. The resistance switch movable terminal 55R has a first contact member B1 including a first contact surface C1, a second contact member B2 including a second contact surface C2, and a first support member 252 that supports the first contact member B1 and the second contact member B2.

The first support member 252 is made of a metal plate such as iron, aluminum or brass. The first support member 252 is formed by stamping or bending a metal plate. The first support member 252 has a base portion 253 , an arm portion 254 , a first inclined portion 256 and a second inclined portion 257 .

A normal line of the base portion 253 is parallel to the R direction. The base portion 253 is biased in the +R direction by the resistance switch spring 56R.
The arm portion 254 extends in the −R direction from both ends of the base portion 253 in the θ direction. A support shaft 255 is erected at the tip of the arm portion 254 . The support shaft 255 extends outward in the θ direction. The support shaft 255 is inserted into the opening 57R of the movable terminal support portion 51a of the frame 51. As shown in FIG. The movable terminal support portion 51a supports the first support member 252 so as to be movable in the R direction.

The first inclined portion 256 extends in the +Z direction and the -R direction from the +Z direction edge of the base portion 253 . A normal line of the first inclined portion 256 intersects the Z direction and the R direction. A first contact member B1 is attached to the +Z direction and +R direction surfaces of the first inclined portion 256 . The first contact member B1 is fixed to the first inclined portion 256 by a fastening member or the like. A first contact member that contacts the resistance switch common terminal 32R is mounted next to the first contact member B1 that contacts the resistance switch fixed terminal 35R in the θ direction.

As shown in FIG. 14, the second inclined portion 257 extends in the -Z direction and the -R direction from the -Z direction edge of the base portion 253 . A normal line of the second inclined portion 257 intersects the Z direction and the R direction. A second contact member B2 is attached to the surface of the second inclined portion 257 in the −Z direction and the +R direction. The second contact member B2 is fixed to the second inclined portion 257 by a fastening member or the like. A second contact member that contacts the resistance switch common terminal 32R is mounted next to the second contact member B2 that contacts the resistance switch fixed terminal 35R in the θ direction.

FIG. 15 is a perspective view of the fixing portion 30 of the second switch assembly S2 of the second embodiment viewed from the -R direction. The common terminal 32 of the second switch assembly S2 is arranged on the −R surface of the switch base 31 in the +θ direction. The shape of the resistance switch common terminal 32R of the second embodiment differs from that of the energization switch common terminal 32M and the valve switch common terminal 32V. The energization switch fixed terminal 35M, the valve switch fixed terminal 35V, and the resistance switch fixed terminal 35R of the second switch assembly S2 are arranged in the +θ direction of the −R surface of the switch base 31 . The shape of the resistance switch fixed terminal 35R of the second embodiment differs from that of the energization switch fixed terminal 35M and the valve switch fixed terminal 35V. The resistor switch common terminal 32R and the resistor switch fixed terminal 35R have the same shape. The resistance switch fixed terminal 35R will be described below as a representative.

FIG. 16 is a perspective view of the resistance switch fixed terminal 35R and the resistance switch common terminal 32R of the second embodiment. The resistance switch fixed terminal 35R has a third contact member B3 including a third contact surface, a fourth contact member B4 including a fourth contact surface, and a second support member 232 that supports the third contact member B3 and the fourth contact member B4.

The second support member 232 is made of a metal plate such as iron, aluminum or brass. The second support member 232 is formed by stamping or bending a metal plate. The second support member 232 has a base portion 233 , a first inclined portion 236 and a second inclined portion 237 .

The normal line of the base portion 233 is parallel to the R direction. The base portion 233 is fixed to the switch base 31 (see FIG. 15) by a fastening member or the like.

The first inclined portion 236 extends in the +Z direction and the -R direction from the +Z direction edge of the base portion 233 . A normal line of the first inclined portion 236 intersects the Z direction and the R direction. A third contact member B3 is attached to the -Z direction and -R direction surfaces of the first inclined portion 236 .

The second inclined portion 237 extends in the -Z direction and the -R direction from the -Z direction edge of the base portion 233 . A normal line of the second inclined portion 237 intersects the Z direction and the R direction. A fourth contact member B4 is attached to the +Z direction and -R direction surfaces of the second inclined portion 237 .

FIG. 17 is an explanatory diagram of the common contact member B of the second embodiment. A common contact member B constitutes the first contact member B1, the second contact member B2, the third contact member B3, and the fourth contact member B4. The common contact member B is made of a metal material such as brass or copper-tungsten alloy. The common abutment member B has a common abutment surface C which is a first abutment surface C1, a second abutment surface C2, a third abutment surface C3 and a fourth abutment surface C4. The shape of the common contact surface C of the common contact member B of the second embodiment is a cylindrical surface.

The shape of the common contact member B of the second embodiment will be described.
A cuboid 240 is imaged. Both end faces in the thickness direction of the rectangular parallelepiped 240 are

main faces

241 and 246 of the rectangular parallelepiped 240 . The

major surfaces

241, 246 are square. The thickness of the cuboid 240 is smaller than the length of the edge 245 of the main surface 241 .

One principal surface 241 of the cuboid 240 is changed from a flat surface to a cylindrical surface 242 . Cylindrical surface 242 is the outer peripheral surface of a cylinder or cylinder. A ridgeline 243 of the cylindrical surface 242 passes through the center 244 of the main surface 241 and is parallel to the edge 245 of the main surface 241 .

An inscribed circle 247 with respect to the other main surface 246 of the cuboid 240 is imaged. A rectangular parallelepiped 240 is punched out by a cylinder whose cross section is the inscribed circle 247 . The portion remaining inside the cylinder becomes the common abutment member B. A peripheral edge portion 248 of the cylindrical surface 242 of the common contact member B is chamfered (not shown). The inner cylindrical surface 242 of the chamfer is the common abutment surface C. As shown in FIG.

A mounting portion (not shown) is formed on the other main surface 246 . The attachment portion is used to attach the common contact member B to the first support member 252 or the second support member 232 .
The above description does not necessarily match the manufacturing process of the common contact member B. The constituent material of the common contact member B is expensive. The common abutment member B is machined into its final shape from a disc-shaped blank rather than from a cuboid 240 . As a result, the constituent material of the common contact member B is saved, and the manufacturing cost is suppressed.

The common contact member B is attached to the first support member 252 to form the first contact member B1 and the second contact member B2. A common contact surface C of the common contact member B is a cylindrical surface. The common contact member B is attached to the first support member 252 so that the ridge line 243 of the cylindrical surface of the common contact surface C is parallel to the Rθ plane (horizontal plane).

As shown in FIG. 13, the first contact surface C1 and the second contact surface C2 are arranged plane-symmetrically with respect to the first plane F1 parallel to the +R direction. The first contact surface C1 and the second contact surface C2 are plane-symmetrical with respect to a second plane F2 perpendicular to the first plane F1. The cross-sectional shape of the first contact surface C1 on the second plane F2 is the shape of the first circular arc A1. The cross-sectional shape of the second contact surface C2 on the second plane F2 is the shape of the second arc A2. The center of the first arc A1 of the first contact surface C1 is arranged on the opposite side of the first plane F1 from the first contact surface C1. The center of the second arc A2 is arranged on the side opposite to the second contact surface C2 across the first plane F1.

This increases the radius of curvature of the first contact surface C1. The area of the contact surface between the first contact surface C1 and the third contact surface C3 is increased. Even if a chattering arc occurs during the switching operation and reverse switching operation of the switching switch 10, the damage acting on the first contact surface C1 and the third contact surface C3 is dispersed. The same applies to the second contact surface C2 and the fourth contact surface C4. Therefore, consumption of the resistance switch SR can be suppressed.

The resistance switch movable terminal 55R has a first support member 252 formed of a metal plate and supporting the first contact member B1 and the second contact member B2. The resistance switch fixed terminal 35R has a second support member 232 formed of a metal plate and supporting the third contact member B3 and the fourth contact member B4.

This facilitates the manufacture of the resistance switch movable terminal 55R and the resistance switch fixed terminal 35R. The weight of the resistance switch movable terminal 55R attached to the second movable portion 50 is reduced, and vibration of the resistance switch movable terminal 55R is suppressed. The opening and closing timings of the resistance switch SR are less likely to change. This improves the operational reliability of the switching switch 10 of the on-load tap changer 1 .

A common contact member B constitutes the first contact member B1, the second contact member B2, the third contact member B3, and the fourth contact member B4.
This reduces the cost of the resistive switch SR.

The common contact member B is attached to the first support member 252 to form the first contact member B1 and the second contact member B2. As shown on the left side of FIG. 17, the common contact member B is attached to the first support member 252 so that the ridge line 243 of the common contact surface C is parallel to the Rθ plane (horizontal plane). A ridge line 243 of the first contact surface C1 of the first contact member B1 is parallel to the Rθ plane. The same applies to the ridgeline 243 of the second contact surface C2 of the second contact member B2.

The common contact member B is attached to the second support member 232 to form the third contact member B3 and the fourth contact member B4. As shown on the right side of FIG. 17, the common contact member B is attached to the second support member 232 so that the ridgeline 243 of the common contact surface C is parallel to the RZ plane. A ridgeline 243 of the third contact surface C3 of the third contact member B3 is parallel to the RZ plane. The same applies to the ridge line 243 of the fourth contact surface C4 of the fourth contact member B4.

The Rθ plane and the RZ plane are orthogonal. The ridgeline 243 of the first contact surface C1 and the ridgeline 243 of the third contact surface C3 are twisted by 90°. The first contact member B1 and the third contact member B3 are arranged such that the ridgeline 243 of the first contact surface C1 and the ridgeline 243 of the third contact surface C3 are twisted by 90°. Similarly, the second contact member B2 and the fourth contact member B4 are arranged such that the ridgeline 243 of the second contact surface C2 and the ridgeline 243 of the fourth contact surface C4 are twisted by 90°.

The position of the resistance switch movable terminal 55R may shift in the direction of the support shaft 255 shown in FIG. Even in this case, the position of the contact point G1 between the first contact surface C1 and the third contact surface C3 and the position of the contact point G2 between the second contact surface C2 and the fourth contact surface C4 do not change. The opening and closing timings of the resistance switch SR are less likely to change. This improves the operational reliability of the switching switch 10 of the on-load tap changer 1 .

The resistance switch SR is designed so that the distances from the support shaft 255 to the contact points G1 and G2 are short. As a result, the vibration of the second movable portion 50 is suppressed, so that the opening and closing timings of the resistance switch SR are less likely to change. Therefore, the operational reliability of the switching switch 10 of the on-load tap changer 1 is improved.

FIG. 18 is a perspective view of a common contact member B of a modified example of the second embodiment. The common contact member B of the modified example differs from the second embodiment in that the common contact surface C is spherical. The description of the modified examples that are the same as the second embodiment may be omitted.

The common contact member B constitutes the first contact member B1, the second contact member B2, the third contact member B3, and the fourth contact member B4. The common contact member B is made of a metal material such as brass or copper-tungsten alloy. The common abutment member B has a common abutment surface C which is a first abutment surface C1, a second abutment surface C2, a third abutment surface C3 and a fourth abutment surface C4. The shape of the common contact surface C of the common contact member B of the modified example of the second embodiment is spherical.

Also in the modified example of the second embodiment, the radius of curvature of the first contact surface C1 is increased. The area of the contact surface between the first contact surface C1 and the third contact surface C3 is increased. Even if a chattering arc occurs during the switching operation and reverse switching operation of the switching switch 10, the damage acting on the first contact surface C1 and the third contact surface C3 is dispersed. The same applies to the second contact surface C2 and the fourth contact surface C4. Therefore, consumption of the resistance switch SR can be suppressed.

Common contact member B is manufactured as follows. One end face of the disk-shaped material is processed into a spherical surface. The apex of the sphere is located in the center of the end face. A round chamfer is applied to the periphery of the spherical surface. A mounting portion is formed on the other end surface. The common contact member B is completed by the above.
Spherical processing is relatively easy. Therefore, the manufacturing cost of switching switch 10 is suppressed.

According to at least one embodiment described above, the center of the first arc A1 of the first contact surface C1 of the first contact member B1 is arranged on the opposite side of the first plane F1 from the first contact surface C1. The center of the second arc A2 of the second contact surface C2 of the second contact member B2 is arranged on the opposite side of the second contact surface C2 across the first plane F1. As a result, wear of the resistance switch SR can be suppressed.

Although several embodiments of the invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

A1... First arc, A2... Second arc, B... Common contact member, B1... First contact member, B2... Second contact member, B3... Third contact member, B4... Fourth contact member, C1... First contact surface, C2... Second contact surface, C3... Third contact surface, C4... Fourth contact surface, F1... First plane, F2... Second plane, P1... Center, P2... Center, R1... First current limiting resistor, R2... second current limiting resistor, SR1... first resistance switch, SR2... second resistance switch, SV1... first valve switch, SV2... second valve switch, T1... first tap terminal, T2... second tap terminal, V... valve, 1... on-load tap changer, 2... tap selector, 10... switching switch, 32R... resistance switch common terminal (second terminal), 35R... resistance switch fixed terminal (second terminal), 55R... resistance switch conductor ( first terminal), 55R... resistance switch movable terminal (first terminal), 232... second support member, 243... ridge line, 252... first support member.

Claims

a tap terminal connected to a tap selector of an on-load tap changer;
a valve connected to the tap terminal via a valve switch;
a current limiting resistor connected to the tap terminal via a resistance switch and connected in parallel with the valve to the tap terminal;
The resistance switch has a first terminal and a second terminal that can contact each other,
the first terminal is capable of moving in a first direction and contacting the second terminal on a first contact surface and a second contact surface;
The first contact surface and the second contact surface are arranged plane-symmetrically with respect to a first plane parallel to the first direction, and are plane-symmetrical with respect to a second plane orthogonal to the first plane,
The cross-sectional shape of the first contact surface on the second plane is an arc shape with the center located on the opposite side of the first plane from the first contact surface,
The cross-sectional shape of the second contact surface on the second plane is an arc shape whose center is located on the side opposite to the second contact surface across the first plane,
Change-over switch for on-load tap changers.
The first terminal has a first contact member including the first contact surface, a second contact member including the second contact surface, and a first support member formed of a metal plate and supporting the first contact member and the second contact member,
The second terminal includes a third contact member including a third contact surface capable of contacting the first contact surface, a fourth contact member including a fourth contact surface capable of contacting the second contact surface, and a second support member formed of a metal plate and supporting the third contact member and the fourth contact member.
2. A change-over switch for an on-load tap changer according to claim 1.
The first contact member, the second contact member, the third contact member and the fourth contact member are configured by a common contact member,
3. A change-over switch for an on-load tap changer according to claim 2.
the first contact surface, the second contact surface, the third contact surface and the fourth contact surface are cylindrical surfaces;
The first contact member and the third contact member are arranged such that the ridgeline of the first contact surface and the ridgeline of the third contact surface are twisted by 90°,
The second contact member and the fourth contact member are arranged such that the ridgeline of the second contact surface and the ridgeline of the fourth contact surface are twisted by 90°,
4. A switching switch for an on-load tap changer according to claim 2 or 3.
The first contact surface, the second contact surface, the third contact surface and the fourth contact surface are spherical surfaces,
4. A switching switch for an on-load tap changer according to claim 2 or 3.
a switching switch of the on-load tap changer according to any one of claims 1 to 5;
and the tap selector.
On-load tap changer.