WO2021176687A1 - Gas-insulated switchgear and cable withstand voltage testing method for gas-insulated switchgear - Google Patents

Abstract

Provided is a gas-insulated switchgear (1) provided with: a grounding switch-equipped disconnector (5) and a breaker (6) that are stored in a tank (2); and a charging terminal (9) that is connected to the grounding switch-equipped disconnector (5) and provided outside the tank (2) for grounding the grounding switch-equipped disconnector (5). One end of the breaker (6) is connected to a cable (8) outside the tank (2) so as to be electrically connectable. A grounding bar (10) is provided so as to be inserted into and connected with the charging terminal (9) in the horizontal direction with one end thereof serving as the rotational axis. The charging terminal (9) is grounded via a grounding conductor (11) connected to the rotational axis side. During withstand voltage testing of the cable (8), a testing terminal (31) is connected to the charging terminal (9), and a prescribed voltage is supplied from a testing power source (32).

Description

Cable withstand voltage test method for gas-insulated switchgear and gas-insulated switchgear

This application relates to a cable withstand voltage test method for a gas-insulated switchgear and a gas-insulated switchgear.

Conventionally, a gas-insulated switchgear is provided with a power charging terminal for a withstand voltage test or the like (see, for example, Patent Document 1). In Patent Document 1, the power charging terminal provided on the gas-insulated switch is always used as a ground terminal, and at the time of the withstand voltage test, the insulating gas is sealed in the gas sealing chamber formed in the bushing, and this power charging terminal is used. A test bushing is attached so as to cover the above.

However, when conducting a cable withstand voltage test on site after installing the gas-insulated switchgear, a structure that makes it easy to apply voltage to the cable is required. Therefore, in the structure of Patent Document 1, complicated work such as gas treatment is required on site, and the manufacturing cost of the test bushing is also high.

On the other hand, Patent Document 2 describes a grounding switch and the ground in a gas-insulated switch in which a grounding switch is housed in a tank and a grounding circuit led out from the grounding switch to the ground is led out to the outside of the tank. A disconnecting portion connected between them is provided so that a test terminal can be connected to a terminal provided on the grounding switch side of the disconnecting portion. By the operation of opening and closing the disconnector, the terminals for the test can be easily connected, and the test can be easily carried out.

Jikkenhei 3-63014 Japanese Unexamined Patent Publication No. 7-2223115

In Patent Document 2, the three-phase blade of the disconnector moves upward and is opened by rotating around the rotation shaft, but the rotation shaft remains near the terminal, so that the insulation distance is increased during the withstand voltage test. There is a risk of inadequacy.

The present application discloses a technique for solving the above-mentioned problems, and an object of the present application is to provide a gas-insulated switchgear in which test terminals can be connected with a simple structure and an insulation distance can be secured. ..

The gas-insulated switch according to the present disclosure includes a circuit breaker and a circuit breaker with a grounding switch housed inside the tank, and a circuit breaker with a grounding switch connected to the circuit breaker with a grounding switch to ground the circuit breaker with a grounding switch. A gas-insulated switch provided with a power charging terminal, one end of the circuit breaker is connected to a cable outside the tank so that it can be electrically connected, and one end is used as a rotation shaft. It has a grounding bar that is horizontally inserted and connected to the power charging terminal, and grounds the power charging terminal via a grounding conductor connected to the rotation shaft side of the grounding bar. ..

The cable withstand voltage test method for a gas-insulated switch according to the present disclosure is the cable withstand voltage test method for the gas-insulated switch described above, wherein the disconnector with a grounding switch is connected to the power charging terminal and grounded. The step, the step of turning on the disconnector to make a closed circuit, and forming a circuit from the power charging terminal to the cable, and the step of rotating the grounding bar horizontally from the power charging terminal to open it. It is provided with a step of retracting from the power charging terminal and a step of connecting a test instrument to the power charging terminal and performing a withstand voltage test of the cable.

According to the present disclosure, it is possible to provide a cable withstand voltage test method for a gas-insulated switchgear and a gas-insulated switchgear in which test terminals can be connected with a simple structure and an insulation distance can be secured.

It is a side view which shows the structure of the gas insulation switchgear which concerns on Embodiment 1, and is the figure which showed the partial cross section. It is a figure which shows the structure of the terminal chamber which housed the terminal for charge charge of the gas insulation switchgear which concerns on Embodiment 1, and is the figure which was seen from the direction AA in FIG. FIG. 2A is a diagram showing a state in which the door of the terminal chamber is opened. FIG. 2B is a diagram showing a state in which the ground bar is open. It is a figure which shows the connection state of the power charging terminal of the gas insulation switchgear which concerns on Embodiment 1, and the ground bar, and is the cross-sectional view seen from the direction BB in FIG. 2A. It is a top view which shows the structure of the tip part of the grounding bar. It is a side view which shows the structure of the tip part of the grounding bar. FIG. 2A is a view seen from the CC direction in FIG. 2A, showing the structure of the interlock device. FIG. 5A is a view seen from the EE direction in FIG. 5A. FIG. 2C is a view seen from the DD direction in FIG. 2C and shows the structure of the interlock device. It is a figure for demonstrating operation of the interlock device in the gas insulation switchgear which concerns on Embodiment 1. FIG. It is a figure for demonstrating operation of the interlock device in the gas insulation switchgear which concerns on Embodiment 1. FIG. It is a figure for demonstrating operation of the interlock device in the gas insulation switchgear which concerns on Embodiment 1. FIG. It is a figure for demonstrating operation of the interlock device in the gas insulation switchgear which concerns on Embodiment 1. FIG. It is a figure for demonstrating the procedure of attaching the test terminal to the power-imparting terminal of the gas insulation switchgear which concerns on Embodiment 1. FIG. It is a figure for demonstrating the procedure of attaching the test terminal to the power-imparting terminal of the gas insulation switchgear which concerns on Embodiment 1. FIG. 9 is a cross-sectional view seen from the FF direction in FIG. 9A. It is a top view which shows the structure of the test terminal attached to the power charging terminal of the gas insulation switchgear which concerns on Embodiment 1. FIG. It is a side view which shows the structure of the test terminal.

Hereinafter, the present embodiment will be described with reference to the drawings. In each figure, the same reference numerals indicate the same or corresponding parts.

Embodiment 1.
Hereinafter, the gas-insulated switchgear according to the first embodiment will be described with reference to the drawings.
FIG. 1 is a right side view showing the configuration of the gas-insulated switchgear according to the first embodiment. In the figure, the gas-insulated switchgear 1 has a plurality of compartments inside the housing. The bus 3 of the bus chamber 3a is connected to the conductor inside the tank 2 via the bus bushing 4. An insulating gas is sealed inside the tank 2, and a disconnector 5 with a grounding switch and a circuit breaker 6 connected to the disconnector 5 with a grounding switch are provided. The circuit breaker 6 is via a cable bushing 7. , It is connected to the cable 8 of the cable chamber 8a, and power is supplied from the cable 8 to the load. As long as the circuit breaker 6 is connected to the cable 8 in a state where it can be electrically connected, for example, a disconnector may be further connected between the circuit breaker 6 and the cable 8.

The disconnector 5 with a grounding switch is connected to the bus 3 side during the operation of the gas-insulated switch 1, but when the circuit breaker 6 is grounded, it is released from the bus 3 and power is applied outside the tank 2. It is connected to the terminal 9 side and is grounded via the ground conductor 11.
In the control equipment room 5b in front of the housing of the tank 2, a controller 5a for controlling the disconnector 5 with a grounding switch and a controller 6a for controlling the circuit breaker 6 are housed. The door 9a of the terminal chamber 9b, which is the compartment in which the power charging terminal 9 is housed, is opened, and test instruments such as a test terminal and a test power supply, which will be described later, are connected. The door 9a may also serve as the front door of the housing of the gas-insulated switchgear 1.

2A, 2B, and 2C are views showing the structure of the terminal chamber 9b in which the power charging terminal 9 is housed, and are views taken from the direction AA in FIG. 1, respectively. 2B is a diagram showing a state in which the door 9a is opened in FIG. 2A, and FIG. 2C is a diagram showing a state in which the grounding bar 10 is opened in FIG. 2B. FIG. 2A shows a state in which the ground bar 10 is connected to the power charging terminals 9 for three phases. One end of the grounding bar 10 is rotatably attached to the grounding bar support 12, and when connected to the power charging terminal 9, the other end is engaged in the interlock device 13. Further, a grounding conductor 11 is attached to the grounding bar support 12, and the grounding bar 10 is grounded via the grounding conductor 11.

FIG. 3 is a view seen from the direction BB in FIG. 2A. The connection portion 91 of the power charging terminal 9 has a junction structure, and the ground bar 10 is sandwiched and connected to the junction structure from the horizontal direction.

Normally, the power charging terminal 9 is short-circuited to the ground by the ground bar 10 in all three phases, and is used as the ground terminal of the disconnector 5 with a ground switch. At the time of the withstand voltage test of the cable 8, the disconnector 5 with a grounding switch is turned on to the power charging terminal 9, the circuit breaker 6 is turned on (the circuit breaker is closed), and then the grounding bar 10 is opened for power charging. The terminal 9 and the test instrument will be connected. FIG. 2B shows a state in which the disconnector 5 with a grounding switch is inserted into the power charging terminal 9 side, the circuit breaker 6 is inserted (the circuit breaker is closed), and then the door 9a is opened. Subsequently, in FIG. 2C, the grounding bar 10 is disengaged from the interlocking device 13 side, rotated horizontally around the grounding bar support 12 side, and the grounding bar 10 is released from the power charging terminal 9. Will be done.

FIG. 4A is a plan view showing the structure of the tip of the grounding bar 10, and FIG. 4B is a side view showing the structure of the tip of the grounding bar. As shown in the figure, an L-shaped metal fitting 10a protruding upward and an engaging metal fitting 10b having a hook-shaped tip are attached to the tip of the grounding bar 10, and the tip of the engaging metal fitting 10b is inside the interlock device 13. Engage.

Next, the structure of the interlock device 13 will be described. FIG. 5A is a diagram showing the structure of the interlock device 13, and is a view seen from the CC direction in FIG. 2A. FIG. 5B is a view seen from the EE direction in FIG. 5A. Further, FIG. 6 is a view seen from the DD direction in FIG. 2C, and shows a state in which the ground bar 10 is opened. As shown in the figure, when the grounding bar 10 is connected to the power charging terminal 9, the L-shaped metal fitting 10a of the grounding bar 10 hits the frame of the interlock device 13 due to the horizontal rotation of the grounding bar 10. It touches and acts as a stopper. Further, the actuator of the microswitch 13a protrudes from the surface of the frame of the interlock device 13 that comes into contact with the L-shaped metal fitting 10a, and detects the insertion state, that is, the connected state and the open state of the grounding bar 10 into the power charging terminal 9. It plays the role of a sensor. The detected signal is output as an interlock signal to the controller 5a that controls the disconnector 5 with a grounding switch and the controller 6a that controls the circuit breaker 6.

When the grounding bar 10 is inserted into the power charging terminal 9, the L-shaped metal fitting 10a comes into contact with the frame of the interlock device 13 and pushes the actuator of the microswitch 13a protruding from the contact surface. Further, the tip of the engaging metal fitting 10b engages with the solenoid movable iron core 13b1 below the solenoid 13b. The solenoid 13b of the interlock device 13 receives an interlock signal from the controller 5a that controls the disconnector 5 with a grounding switch and the controller 6a that controls the circuit breaker 6, and the circuit breaker 6 is turned on (the circuit breaker is closed). And only when the disconnector 5 with a grounding switch is in the grounded state, it is excited and the solenoid movable iron core 13b1 rises. When the solenoid movable iron core 13b1 rises, the engagement of the tip of the engaging metal fitting 10b is released, and the grounding bar 10 can be opened from the power charging terminal 9. When the circuit breaker 6 is turned on (the circuit breaker is closed) and the disconnector 5 with a grounding switch is not in the grounded state, the solenoid 13b is not excited and the solenoid movable iron core 13b1 is engaged with the tip of the engaging metal fitting 10b. Is maintained and the grounding bar 10 cannot be opened.

The details of the operation of the interlock device 13 will be described with reference to FIGS. 7A to 7D.
7A to 7D are views showing the relationship between the interlock device 13 having the microswitch 13a and the solenoid 13b and the ground bar. FIG. 7A shows a state in which the tip of the engaging metal fitting 10b of the grounding bar is engaged with the solenoid movable iron core 13b1. This indicates that, for example, the gas-insulated switchgear 1 is in operation during normal operation, the grounding bar 10 is inserted into the power charging terminal 9, and the power charging terminal 9 is grounded. The circuit breaker 6 is closed, the disconnector 5 with a grounding switch is connected to the bus 3, the solenoid 13b is not excited, and the grounding bar 10 cannot be opened. It prevents the grounding of the power charging terminal 9 from being inadvertently released.

FIG. 7B shows the state when the cable withstand voltage test is performed. When conducting a cable withstand voltage test, the circuit breaker 6 is turned on (the circuit breaker is closed), the disconnector 5 with a grounding switch is connected to the power charging terminal 9, and the power charging terminal 9 is connected to the cable 8. Form a circuit. At this time, the solenoid 13b receives an interlock signal from each of the controllers 5a and 6a and is excited, and the solenoid movable iron core 13b1 rises, so that the grounding bar 10 can be opened.

When the grounding bar 10 is opened, the microswitch 13a detects the opening of the grounding bar 10 as shown in FIG. 7C, and outputs an interlock signal indicating that the grounding is released to the controllers 5a and 6a. .. When the grounding bar 10 is open and the power charging terminal 9 is not grounded, the controllers 5a and 6a cannot operate the disconnector 5 with a grounding switch and the circuit breaker 6, and the grounding bar 10 is again operated. Until it is inserted, the disconnector 5 with a grounding switch and the circuit breaker 6 cannot be operated carelessly.

When the circuit breaker 6 is manually operated at the end of the cable withstand voltage test while the grounding bar 10 is open, the solenoid 13b is de-excited and the solenoid movable iron core 13b1 is released as shown in FIG. 7D. Goes down. Therefore, the tip of the engaging metal fitting 10b cannot be inserted so as to engage with the solenoid movable iron core 13b1, and the grounding bar 10 cannot be operated. Unless the circuit breaker 6 is turned on (the circuit breaker is closed), the disconnector 5 with a grounding switch is connected to the power charging terminal 9 side, and the solenoid 13b is not excited, the power charging terminal 9 is grounded. You can't do that.

Next, the cable withstand voltage test will be described with reference to the figure. FIG. 8 is a diagram showing a configuration in which a pedestal 30 composed of insulating parts is arranged in front of and in front of the power charging terminal 9 in a state where the ground bar 10 of FIG. 2C is open. FIG. 9A shows a state in which the test terminals 31 corresponding to each phase are arranged on the pedestal 30 shown in FIG. 8 and the test terminals 31 are inserted into the junction of the connection portion 91 of the power charging terminal 9. It is a figure. Further, FIG. 9B shows a cross-sectional view seen from the FF direction in FIG. 9A. The ground conductor 11 in FIGS. 8 and 9A is omitted. FIG. 10A is a plan view showing the structure of the test terminal 31, and FIG. 10B is a side view showing the structure of the test terminal 31. The test terminal 31 is made of a conductive material and has a plug portion 31b made of a rod-shaped part and a power connection portion 31a made of a plate-shaped part. As shown in FIGS. 9A and 9B, the plug portion 31b of the test terminal 31 is inserted into the junction of the connection portion 91 of the power charging terminal 9, and the power supply connection portion 31a fixed by the pedestal 30 is tested outside the housing. It is connected to the power supply 32. At this time, it is necessary to secure an insulating distance sufficient to withstand the test voltage between the connected phases of the test terminals 31 and the distance between the terminals of each phase and the ground metal such as the ground bar 10 and the housing. A predetermined voltage (DC voltage) is applied to the cable from the test power supply 32, and a withstand voltage test is performed. When the cable withstand voltage test is completed, the test power supply 32 is removed from the test terminal 31, and the plug portion 31b of the test terminal 31 is pulled out from the connection portion 91 of the power charging terminal 9. The pedestal 30 arranged in front of the power charging terminal 9 is removed to prepare for the connection of the ground bar 10.

In the present embodiment, after the grounding bar 10 for grounding the power charging terminal 9 rotates in the horizontal direction and retracts from the power charging terminal 9, the test terminal 31 is moved to the power charging terminal 9. Since the cable withstand voltage test is performed by connecting to the cable, it is possible to secure the insulation distance between each phase of the test terminal 31 and the ground bar. Further, in FIGS. 2C, 9A, and 9B, if the grounding bar 10 is fastened to the rotating shaft of the grounding bar 10 and the grounding bar support 12 so that the grounding bar 10 can be removed from the grounding bar support 12, the insulation distance can be obtained. It is effective in securing the above, and the operation of the withstand voltage test becomes easy. Alternatively, a rail may be provided inside the grounding bar support 12 so that the grounding bar 10 can be stored along the grounding bar support 12.

Further, in the present embodiment, since the interlock device 13 that regulates the grounding and opening operations of the grounding bar 10 is provided, the grounding and opening states of the grounding bar 10 and the circuit breaker 5 with the grounding switch and the circuit breaker are cut off. Since the controllers 5a and 6a of the device 6 are interlocked with each other to regulate the operation of the grounding bar 10 or the circuit breaker 5 with the grounding switch and the circuit breaker 6, careless operation can be avoided and a short circuit occurs. It is possible to avoid accidents and the like, and it is possible to provide a highly reliable gas-insulated switchgear.

Further, in the above description, the interlock device 13 is provided with the solenoid 13b, and the tip of the grounding bar 10 engages the hook-shaped engaging metal fitting 10b with the solenoid movable iron core 13b1, but the present invention is not limited to this. Even if the tip of the engaging metal fitting 10b is not hook-shaped, it may have a hole shape that can be engaged and disengaged by raising and lowering the solenoid movable iron core 13b1.

In the gas-insulated switch 1 according to the present embodiment, as a method of performing a withstand voltage test of the cable 8, first, the ground switch 5 and the circuit breaker 6 between the bus 3 and the cable 8 are grounded. The circuit breaker 5 with a device is opened 3 from the bus, grounded via the power charging terminal 9, the circuit breaker 6 is turned on (closed), and the circuit breaker 5 with a grounding switch and the circuit breaker are closed. A circuit to the cable 8 is formed via the cable 8, and then the grounding bar for grounding the power charging terminal 9 is horizontally rotated from the power charging terminal 9 in the terminal chamber to retract the power charging terminal 9, and then the unit is charged. Since the test equipment is connected to the electrical terminal 9, it is possible to easily switch to the withstand voltage test mode, and the insulation distance from the power charging terminal 9 of each phase can be secured in the terminal chamber 9b. , The withstand voltage test of the cable 8 can be easily carried out. Further, since the disconnector 5 with a grounding switch and the controllers 5a and 6a of the circuit breaker 6 are interlocked with each other by an interlock signal according to the closing and opening states of the grounding bar 10, the operation of the grounding bar 10 or the disconnecting with a grounding switch is performed. Regulate the operation of the device 5 and the disconnector 6. As a result, careless operation during the withstand voltage test can be avoided, a short circuit accident or the like can be avoided, and a highly reliable withstand voltage test method for the cable 8 of the gas-insulated switchgear can be provided. ..

Although the present disclosure describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are those of a particular embodiment. It is not limited to application, but can be applied to embodiments alone or in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1: Gas insulated switch, 2: Tank, 3: Bus, 3a: Bus room, 4: Busing for bus, 5: Breaker with grounding switch, 5a: Controller, 5b: Control equipment room, 6: Circuit breaker , 6a: Controller, 7: Busbar for cable, 8: Cable, 8a: Cable chamber, 9: Power charging terminal, 9a: Door, 9b: Terminal chamber, 10: Grounding bar, 10a: L-shaped metal fitting, 10b: Engagement bracket, 11: Ground conductor, 12: Ground bar support, 13: Interlock device, 13a: Micro switch, 13b: Solvent, 13b1: Movable iron core, 30: Pedestal, 31: Test terminal, 32 Test power supply , 91: Connection part

Claims (8)

1. A disconnector and a circuit breaker with a grounding switch housed inside the tank, and a power charging terminal provided outside the tank that is connected to the disconnector with a grounding switch and grounds the disconnector with a grounding switch. It is a gas-insulated switch that is equipped.
   One end of the circuit breaker is connected to a cable outside the tank so that it can be electrically connected.
   The power charging terminal has a grounding bar that is horizontally inserted and connected to the power charging terminal with one end as a rotating shaft, and is connected to the grounding shaft side of the grounding bar via a grounding conductor connected to the rotating shaft side. A gas-insulated switchgear that grounds.
2. The gas according to claim 1, wherein an engaging metal fitting is provided at the other end of the grounding bar, and an interlock device is provided to which the engaging metal fitting is engaged when the grounding bar is connected to the power charging terminal. Insulated switchgear.
3. The gas-insulated switchgear according to claim 2, wherein the interlock device includes a sensor that detects that the grounding bar is connected or open to the power charging terminal.
4. The interlock device transmits the state of the grounding bar detected by the sensor to the controller of the disconnector with a grounding switchgear and the controller of the circuit breaker, and the engaging metal fitting is based on a signal from each of the controllers. The gas-insulated switchgear according to claim 3, wherein the engagement of the gas-insulated switchgear is released.
5. The gas insulation according to claim 4, wherein the interlock device disengages the engaging metal fitting when the disconnector with a grounding switch is connected to the power charging terminal and the circuit breaker is closed. Switchgear.
6. The gas-insulated switchgear according to any one of claims 1 to 5, which has the power charging terminals for three phases.
7. The gas-insulated switchgear according to any one of claims 1 to 6, wherein a test terminal can be connected to the power charging terminal in a state where the grounding bar is open.
8. The cable withstand voltage test method for the gas-insulated switchgear according to any one of claims 1 to 6.
   The process of connecting the disconnector with a grounding switch to the power charging terminal and grounding.
   The process of turning on the circuit breaker to close the circuit and forming a circuit from the power charging terminal to the cable, and
   A step of rotating the grounding bar horizontally from the power charging terminal to open it and retracting it from the power charging terminal.
   A cable withstand voltage test method for a gas-insulated switchgear, comprising a step of connecting a test instrument to the power charging terminal and performing a withstand voltage test of the cable.

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