WO2023119453A1

WO2023119453A1 - Switch

Info

Publication number: WO2023119453A1
Application number: PCT/JP2021/047439
Authority: WO
Inventors: 幸三田村; 将人小林; 寛之白井
Original assignee: 株式会社日立産機システム
Priority date: 2021-12-21
Filing date: 2021-12-21
Publication date: 2023-06-29

Abstract

The purpose of the present invention is to provide a switch the size of which can be reduced.　In order to achieve the purpose, this switch is configured to have: a main circuit section which is formed from a vacuum interrupter equipped with an opening/closing part formed from a stationary electrode and a movable electrode to be separated from or brought into contact with the stationary electrode, a first bushing conductor electrically connected to a stationary conductor connected to the stationary electrode and pulled out to the outside of the vacuum interrupter, and a second bushing conductor electrically connected to a movable conductor connected to the movable electrode and pulled out to the outside of the vacuum interrupter; and an operation unit which is directly connected to the movable conductor pulled out to the outside of the vacuum interrupter and carries out operation of the opening/closing part by moving the movable electrode, wherein the operation unit is integrally molded with the main circuit section by using a solid insulating member.

Description

switch

The present invention relates to a high-voltage switch that is molded with resin.

Switches that handle high voltage, including vacuum circuit breakers, disconnectors, load switches, etc., are molded with resin to protect the surroundings from the high electric field around the equipment and improve insulation performance.

As a prior art document in this technical field, there is Patent Document 1, for example. In Patent Document 1, a vacuum interrupter comprising a fixed electrode and a movable electrode that contacts or dissociates with the fixed electrode, an insulated operating rod arranged coaxially with a movable conductor connected to the movable electrode, and a vacuum interrupter that is insulated A vacuum switchgear is disclosed which is molded with solid insulation surrounding the operating rod.

JP 2019-32994 A

In Patent Document 1, an insulating operating rod is used to connect a main circuit portion, which is a high-potential switch portion, and a ground-potential operating device connected to the insulating operating rod. In order to ensure sufficient insulation performance, it is necessary to increase the dimension of the insulation operating rod to ensure the insulation distance. Therefore, there is a problem that the size cannot be reduced. In addition, for miniaturization, it is possible to secure insulation performance by shortening the dimensions of the insulating operating rod by using a medium with high insulating strength such as insulating gas or vacuum in the space of the insulating operating rod portion. However, there was a problem that it was not sufficient and was expensive.

In view of the above problems, an object of the present invention is to provide a switch that can be miniaturized.

An example of the present invention is a switch, which is a vacuum interrupter having an opening/closing portion composed of a fixed electrode and a movable electrode that contacts or dissociates with the fixed electrode, and a vacuum interrupter connected to the fixed electrode. A first bushing conductor electrically connected to a fixed conductor drawn out of the vacuum interrupter, and a second bushing conductor connected to the movable electrode and electrically connected to the movable conductor drawn out of the vacuum interrupter. and a main circuit section composed of a bushing conductor and an operating device that is directly connected to a movable conductor pulled out of the vacuum interrupter and moves the movable electrode to operate the opening and closing section, and the operating device and the main circuit The parts are integrally molded with a solid insulating member.

According to the present invention, it is possible to provide a switch that can be miniaturized.

FIG. 3 is a cross-sectional view taken along a plane including the central axis of the vacuum circuit breaker in the example. FIG. 3 is a schematic functional configuration diagram of a vacuum circuit breaker in an embodiment; It is another functional structure schematic diagram of the vacuum circuit breaker in an Example. FIG. 3 is a cross-sectional view of a conventional vacuum circuit breaker cut along a plane including the central axis;

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In this embodiment, a vacuum circuit breaker for railway vehicles will be used as an example of the switch. FIG. 4 is a cross-sectional view cut along a plane including the central axis of a conventional vacuum circuit breaker, which is the premise of the present invention.

For example, a railway car is composed of a plurality of cars, and a high-voltage lead-through cable is arranged on the roof of each car. receive power from Further, the high-voltage lead-through cables of the vehicles are connected between the vehicles by straight joints, and are branched in the vehicle floor direction by T-branch joints. The T-branch joint and the straight joint form an integrated switch. This switch is used by being attached to a fixed portion of a railway vehicle.

In FIG. 4, the vacuum circuit breaker 70 has

electrical connections

10A, 10B, and 10C, the

electrical connections

10B and 10C are electrically connected inside the vacuum circuit breaker 70, and the

electrical connections

10B and 10C constitute the T-branch joint. In addition, between the

electrical connection portion

10A and 10B and 10C, there is an opening/closing portion composed of a fixed electrode and a movable electrode, which will be described later, inside the vacuum circuit breaker 70. The

electrical connection portion

10A, 10B and 10C constitute a linear joint. Although not shown, the vacuum circuit breaker 70 is used with the T-shaped cable head connected to the

electrical connections

10A, 10B, and 10C. Also, the vacuum circuit breaker 70 is attached to the railcar while being fixed to the base 71 via a stay.

The vacuum interrupter 70 is composed of the fixed electrode 3, the movable electrode 5 that contacts or separates from the fixed electrode 3, the arc shield 6 that covers the fixed electrode 3 and the movable electrode 5, and the like. It has The outer container of the vacuum interrupter 1 maintains the interior in a vacuum state. The vacuum circuit breaker 70 extinguishes the arc within the vacuum vessel by utilizing the rapid diffusion of the arc into the vacuum. This configuration is also used in vacuum switches and is used from high pressure to extra high pressure. It is also used in high-voltage switchboards due to its durability and ease of maintenance.

The fixed electrode 3 is connected to a fixed conductor, which is pulled out of the vacuum interrupter 1 and electrically connected to the bushing conductors 12B and 12C on the fixed conductor side. The movable electrode 5 is connected to a movable conductor, which is pulled out of the vacuum interrupter 1 and electrically connected to the bushing conductor 12A on the movable conductor side.

Here, a high voltage of, for example, 25 kv to 30 kv is applied to the opening/closing part composed of the fixed electrode and the movable electrode. On the other hand, the operating device 40 required to move the movable electrode and operate the opening/closing portion composed of the fixed electrode and the movable electrode is at ground potential, and the electric circuit constituting the operating device 40 is a low-voltage circuit of DC 100 V, for example.

Therefore, in order to insulate the high-potential switching portion from the ground potential operating device, an insulating operating rod 30 is provided, one of which is connected to the movable conductor and the other of which is connected to the operating device 40 . By operating the insulated operating rod 30 with the operating device 40, the movable electrode is moved while maintaining the vacuum state of the vacuum interrupter 1, thereby operating the opening/closing portion composed of the fixed electrode and the movable electrode. The operating device 40 generates a driving force by, for example, combining a permanent magnet and an electromagnet with a spring and switching ON/OFF the energization of a coil that constitutes the electromagnet.

The main circuit section 20 composed of the vacuum interrupter 1, the bushing conductors 12B and 12C on the fixed conductor side, the bushing conductor 12A on the movable conductor side, and the like, and the air insulation space 31 around the insulation operating rod 30 are made of epoxy resin. A solid insulating member 15 made of a thermosetting resin such as a thermosetting resin is integrally molded so as to cover the outer peripheral portion, forming a molded insulator 50 indicated by a dashed line.

In this way, conventionally, an insulated operating rod is used to connect the high-potential main circuit section and the ground-potential operating device. Therefore, in order to ensure sufficient insulation performance, it is necessary to increase the dimension of the insulation operating rod to ensure the insulation distance. Therefore, there is a problem that the size cannot be reduced. In addition, for miniaturization, it is possible to shorten the dimensions of the insulating operation rod and secure the insulation performance by using a medium with high insulation strength such as insulating gas or vacuum in the space of the insulating operation rod part. However, there was a problem that it was not sufficient and was expensive.

Therefore, in the present embodiment, the air insulation space 31 is not required and the size is reduced by directly connecting the operating device to the main circuit section and molding it with resin. This embodiment will be described in detail below.

FIG. 1 is a cross-sectional view taken along a plane including the central axis of the vacuum circuit breaker in this embodiment. In FIG. 1, the same components as those in FIG. 4 are denoted by the same reference numerals, and descriptions thereof are omitted. 1 differs from FIG. 4 in that the operating device 40 and the main circuit section 20 are directly connected to each other and the entirety is integrated with the resin-made solid insulating member 15 without the insulating operating rod 30 and the air insulating space 31. It is a point that it is mold-molded.

As shown in FIG. 1, the vacuum circuit breaker 80 in this embodiment connects the movable conductor pulled out of the vacuum interrupter 1 of the main circuit section 20 to the operating device 40, and connects the operating device 40 to the main circuit section 20. Concatenate directly. This eliminates the need for an insulation distance between the main circuit section and the operating section, and thus the insulating operating rod 30 and the air insulating space 31 are not required, so that miniaturization is possible. By directly connecting the operating device 40 to the main circuit section 20, the operating device 40 also becomes the same charging section as the main circuit section 20. FIG. Therefore, since it is not a conducting path, current does not flow, but insulation is required. Therefore, the operation device 40 and the main circuit section 20 as a whole are molded to form a mold insulator 51, and the surface of the mold insulator 51 is grounded.

In addition, since the operation unit will be operated by the low voltage circuit, it is necessary to avoid contact with the high voltage part of the main circuit. For that reason, the driving circuit, auxiliary circuit, and other parts are separated from the operating device, and only the mechanical part is molded.

FIG. 2 is a schematic diagram of the functional configuration of the vacuum circuit breaker in this embodiment. In FIG. 2, conventionally, the components in the operating device are a mechanical part 42, a drive source 43 such as an electromagnet consisting of a drive coil, an auxiliary circuit 44 such as a proximity sensor or a magnetic sensor for monitoring the state of the contact of the switching part, and an operating device. Among other parts 45 such as a counter and a thermometer, parts other than the mechanical part 42 are arranged outside the solid insulating member 15 . As a result, even if the operating device is operated on a low-voltage circuit, the electrical circuit portion is outside the mold, so it is possible to avoid contact with the high-voltage portion of the main circuit portion. In FIG. 2, the mechanical part 42 is arranged inside the case 41 and used as a mold for molding the case 41, and the periphery thereof is molded. Also, the case 41 and the mechanical portion 42 are fixed by the main circuit portion 20 . As the fixing structure, a screw or pin structure may be used.

FIG. 3 is another functional configuration schematic diagram of the vacuum circuit breaker in this embodiment. In FIG. 3, the same components as in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted. 3 differs from FIG. 2 in that it has an electromagnet 46 as a driving source 43 and has a plunger 47 , a contact pressure spring 48 for connecting parts, and a breaking spring 49 as a mechanical part 42 .

　In order to insulate the main circuit from the high voltage part, if the mechanical part inside the controller is placed outside the mold, the electric circuit part of the controller cannot be physically connected to the mechanical part. Therefore, by using a non-contact type electromagnet 46 as the driving source 43 and driving the plunger 47 as the mechanical section 42 in a non-contact manner, the opening/closing section of the main circuit section can be operated. In addition, by adopting non-contact type auxiliary circuits 44 such as a proximity sensor and a magnetic sensor, and other parts 45 such as an operation counter and a thermometer, the state inside the mold can be detected.

In addition, in this embodiment, since the main circuit part and the mechanical part are entirely covered with a mold, there is concern about the influence of heat generation when energized. For this reason, the case 41 is made of cast aluminum, for example, and the heat is dissipated in the case 41 to suppress the heat generation of the conductor.

Also, as a method of connecting the movable conductor pulled out of the vacuum interrupter 1 of the main circuit section 20 and the bushing conductor 12A, Copel, braided wire, multi-contact, or the like is used.

Also, since the entire main circuit and mechanical parts are covered with a mold, maintenance of the mechanical parts inside the mold is difficult. In order to solve this problem, a low-friction material is used for the bearings, which eliminates the need for grease and adjustment. Alternatively, the molds for the main circuit section and the mechanical section may be divided, and a part of the mold may be removed for maintenance. When using a split type, it is necessary to configure so that dielectric breakdown does not occur at the joints of the resin. For this purpose, a structure in which the distance of the joint portion is increased or a structure in which the joint portion is fitted through an elastic body may be adopted so that the surface pressure at the joint of the resin is increased. Furthermore, a sealing material such as insulating grease or an O-ring may be used at the junction of the joints.

In addition, since the curing temperature at the time of casting the mold is, for example, 140°C, there is concern that the mechanical part of the operating device may be damaged at that curing temperature. This can be dealt with by selecting parts that match the temperature specifications.

Furthermore, as the overall sealing structure before molding, it is possible to cover the mechanical part with a case and seal the case with the mating surface of the conductor of the main circuit part.

In addition, the vacuum circuit breaker of this embodiment does not require the insulated operating rod 30, so it is possible to reduce the weight of the circuit breaker. Since the sound is confined by the mold, noise reduction is possible.

As described above, according to the present embodiment, the operating device is directly connected to the main circuit section and molded with resin, thereby eliminating the need for an insulated operating rod and providing a compact vacuum circuit breaker. .

Although the embodiments have been described, the present invention can reduce the amount of materials used by achieving miniaturization. Therefore, it is possible to reduce carbon emissions, prevent global warming, and contribute especially to item 7 energy for realizing SDGs (Sustainable Development Goals).

In addition, the present invention is not limited to the above-described examples, and includes various modifications. For example, in the above-described embodiments, a vacuum circuit breaker for railway vehicles was explained as an example, but it is also applicable to switches that handle high voltages, including disconnectors, load switches, and the like. Moreover, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations.

1: Vacuum interrupter, 3: Fixed electrode, 5: Movable electrode, 6: Arc shield, 10A, 10B, 10C: Electrical connection part, 12A, 12B, 12C: Bushing conductor, 15: Solid insulating member, 20: Main circuit part , 30: insulated operating rod, 31: air-insulated space, 40: operator, 41: case, 42: mechanical part, 43: drive source, 44: auxiliary circuit, 45: other parts, 46: electromagnet, 47: plunger , 48: connecting part contact pressure spring, 49: breaking spring, 50, 51: molded insulator, 70, 80: vacuum circuit breaker, 71: base

Claims

A vacuum interrupter having an opening/closing portion composed of a fixed electrode and a movable electrode that contacts or disengages from the fixed electrode, and a fixed conductor that is connected to the fixed electrode and drawn out of the vacuum interrupter is electrically connected. and a second bushing conductor connected to the movable electrode and electrically connected to the movable conductor drawn out of the vacuum interrupter;
an operating device that is directly connected to the movable conductor drawn out of the vacuum interrupter and moves the movable electrode to operate the opening/closing unit;
A switch, wherein the operating device and the main circuit unit are integrally molded with a solid insulating member.
The switch according to claim 1,
The mechanical part and the main circuit part of the operating device are molded with the solid insulating member,
A switch, wherein a drive circuit for driving the mechanical part is arranged outside the molding.
The switch according to claim 2,
A switch, wherein an auxiliary circuit for monitoring the state of the switch is arranged outside the molding.
The switch according to claim 2,
A switch, wherein parts other than the mechanical part of the operating device are arranged outside the molding.
The switch according to claim 4,
A switch, wherein the other part is an operation counter or a thermometer.
The switch according to claim 2,
The switch, wherein the drive circuit drives the mechanical portion in a non-contact manner.
The switch according to claim 1,
A switch characterized in that the molding is surface-grounded.
The switch according to claim 2,
A switch, wherein the mechanical part is arranged in a case, the case is sealed at a mating surface with the main circuit part, and the main circuit part and the case are integrally molded.
The switch according to claim 8,
The switch is characterized in that the case is made of aluminum and dissipates heat generated when energized.
The switch according to claim 1,
A switch, wherein the movable conductor drawn out of the vacuum interrupter of the main circuit section and the second bushing conductor are connected by any one of copel, braided wire, or multi-contact. .