WO2022264442A1

WO2022264442A1 - Current-limiting device

Info

Publication number: WO2022264442A1
Application number: PCT/JP2021/037225
Authority: WO
Inventors: 敬丸島; 芳明網田; 慧小川; 和長金谷; 暁斗齊藤
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: 2021-06-15
Filing date: 2021-10-07
Publication date: 2022-12-22
Also published as: JP2022191008A

Abstract

A current-limiting device according to an embodiment has a closed container, a fixed electrode, a movable electrode, and an operation mechanism. The closed container is filled with a filler. The fixed electrode is fixedly provided inside the closed container. The movable electrode is disposed to face the fixed electrode. The operation mechanism causes the movable electrode to come into contact with and separate from the fixed electrode. The operation mechanism has an operation unit, a control unit, an accumulator, a drainage tank, and a pump. The operation unit switches the movable electrode on and off by supply and discharge of a working fluid. The control unit has an electromagnetic repulsion mechanism that starts the supply of the working fluid, and controls the supply and discharge of the working fluid to and from the operation unit. The accumulator holds the pressure of the working fluid. The drainage tank stores the working fluid discharged by the operation unit. The pump supplies the working fluid in the drainage tank to the accumulator.

Description

Current limiting device

An embodiment of the present invention relates to a current limiting device.

Current-limiting devices, for example, limit the short-circuit current that flows in the power supply line of the power system. placed. When a circuit breaker installed in a power system is opened, a pair of electrodes arranged in the circuit breaker are mechanically separated. However, since the voltage in the power system is high, arc current may continue to flow even after the pair of electrodes are mechanically disconnected. Current limiting devices are used to limit large currents, including arc currents, generated by system faults.

If an accident occurs in the power system or distribution system, for example, a short-circuit current will occur. For the purpose of providing more stable power supply, power systems and the like are interconnected over a wide area. However, in a power system that is interconnected over a wide area, if a short-circuit fault occurs in one of the systems, the current will concentrate from power sources in a wider area and flow into the fault point, so the maximum value of the short-circuit current will increase. .

Furthermore, depending on the timing of the short-circuit accident, the short-circuit current may be a DC component superimposed with an AC component. The maximum current value of the short-circuit current in which the AC component is superimposed on the DC component is excessive. Since the electric power system has a resistance component, the peak value of the first wave after the occurrence of the short-circuit current becomes the maximum current, and then the DC component attenuates with time.

A conventional current limiting device, for example, has a structure in which a pair of electrodes arranged to face each other is driven by a driving mechanism to bring the electrodes into contact and apart. For example, a spring is used as the drive source of the drive mechanism. However, in that case, since a complicated operation is required from the breaking command to the operation of the breaking section contact, the responsiveness is low and it is insufficient as a drive mechanism for the current limiting device.

JP 2020-150752 A JP 2016-12398 A

The problem to be solved by the present invention is to provide a highly responsive current limiting device.

The current limiting device of the embodiment has a closed container, a fixed electrode, a movable electrode, and an operating mechanism. The sealed container is filled with a filler. A fixed electrode is fixed inside the sealed container. A movable electrode is arranged to face the fixed electrode. The operating mechanism separates and contacts the movable electrode with respect to the fixed electrode. The operating mechanism has an operating section, a control section, an accumulator, a drain tank, and a pump. The operation part opens and closes the movable electrode by supplying and discharging working fluid. The control section has an electromagnetic repulsion mechanism that initiates supply of the hydraulic fluid, and controls supply and discharge of the hydraulic fluid to and from the operation section. An accumulator holds the pressure of the hydraulic fluid. A drain tank stores the hydraulic fluid discharged by the operation unit. A pump supplies hydraulic fluid in the drain tank to the accumulator.

The block diagram of the current limiting device 1 of 1st Embodiment. The block diagram of the current limiting device 1 of 1st Embodiment. The block diagram of the operation mechanism 4 in the current limiting device of 2nd Embodiment. The block diagram of the operation mechanism 4 in the current limiting device of 3rd Embodiment. The block diagram of the control part 60 in the current limiting device of 4th Embodiment.

The current limiting device of the embodiment will be described below with reference to the drawings.

(First embodiment)
1 and 2 are configuration diagrams of a current limiting device 1 of the first embodiment. FIG. 1 shows the closed state of the current limiting device 1 and FIG. 2 shows the open state of the current limiting device 1 . The closed state of the current limiting device 1 includes an energized state of the current limiting device 1, and the open state includes a non-energized state. The current limiting device 1 is installed, for example, in a power supply facility such as a substation. The current limiting device 1 includes, for example, a movable electrode 2, a fixed electrode 3, an operating mechanism 4, and a container 5.

A filler 6 is enclosed in the container 5 . A first power supply line 7 is connected to the movable electrode 2 , and a second power supply line 8 is connected to the fixed electrode 3 . The first power supply line 7 and the second power supply line 8 extend outside the container 5 and are connected to the power system. In the following description, when explaining the positional relationship and direction of each member, the direction in which the operation mechanism 4 is arranged as viewed from the container 5 in the current limiting device 1 is called the mechanism direction, and the opposite direction is called the counter-mechanism direction. Sometimes.

The movable electrode 2 is made of a conductor metal containing, for example, copper or tungsten. The movable electrode 2 is, for example, a solid cylindrical member. The movable electrode 2 is formed by, for example, cutting. The end portion of the movable electrode 2 in the anti-mechanical direction is, for example, chamfered to form a curved surface.

The movable electrode 2 is arranged inside the container 5 while being supported by an insulator. The movable electrode 2 is arranged in the filler 6 in the container 5 so as to face the fixed electrode 3 so as to be in contact with and separated from the fixed electrode 3 . The end of the movable electrode 2 in the mechanical direction is connected to the operating mechanism 4 . The movable electrode 2 is driven by the operating mechanism 4 to mechanically come into contact with or separate from the fixed electrode 3 .

The fixed electrode 3 is made of a conductor metal containing, for example, copper or tungsten. The fixed electrode 3 is, for example, a cylindrical member. The fixed electrode 3 is formed by, for example, cutting. An opening 11 is formed at the end of the fixed electrode 3 in the mechanical direction. A bottom portion 12 is provided at the end portion of the fixed electrode 3 in the direction opposite to the mechanism.

The fixed electrode 3 is arranged inside the container 5 while being supported by an insulator (not shown). The fixed electrode 3 is arranged in the filler 6 in the container 5 so as to face the movable electrode 2 so as to be in contact with and separated from the movable electrode 2 . The opening 11 of the fixed electrode 3 contacts the outer diameter portion of the movable electrode 2 when the current limiting device 1 is in the closed state. The movable electrode 2 slides into the opening 11 to mechanically separate the fixed electrode 3 when the current limiting device 1 is in an open circuit state.

The container 5 is, for example, a cylindrical closed container made of metal, insulator, or the like. Inside the container 5, the movable electrode 2 is movably arranged via an insulator (not shown), and the fixed electrode 3 is fixed via an insulator (not shown). The inside of the container 5 is filled with a filler 6 . Water, for example, is used as the filler 6 . If the container 5 is made of metal, it is connected to ground potential. The filler 6 between the spaced apart movable electrode 2 and fixed electrode 3 acts as a current limiting impedance.

The operation mechanism 4 is a hydraulic operation mechanism using liquid. The operating mechanism 4 causes the movable electrode 2 to move in and out of contact with the fixed electrode 3 by moving the movable electrode 2 in the direction of the mechanism or in the direction opposite to the mechanism. The operating mechanism 4 includes, for example, an operating section 20, an accumulator 30, a drainage tank 40, a pump unit 50, and a control section 60.

The operation part 20 opens and closes the movable electrode 2 . The operation unit 20 includes, for example, a drive cylinder 21, a drive piston 22, and a drive rod 23. The drive piston 22 is slidably inserted inside the drive cylinder 21 . A drive rod 23 connects the drive piston 22 and the movable electrode 2 .

A first drive fluid chamber 24 and a second drive fluid chamber 25 are formed by the drive piston 22 in the space inside the drive cylinder 21 . The first drive liquid chamber 24 is a liquid chamber on the drive rod 23 side (movable electrode 2 side) with respect to the drive piston 22 . The second driving fluid chamber 25 is a fluid chamber on the opposite side of the driving piston 22 from the first driving fluid chamber 24 . The drive cylinder 21 is an example of a cylinder. Drive piston 22 is an example of a piston. Drive rod 23 is an example of a rod.

The accumulator 30 maintains the pressure of the hydraulic fluid, here it is maintained at a high pressure. The accumulator 30 includes, for example, an accumulator container 31 and an accumulator piston 32 . The accumulator piston 32 is housed in the accumulator container 31 . The interior of the accumulator container 31 is partitioned into a nitrogen gas chamber 33 and a liquid storage chamber 34 by an accumulator piston 32 . The nitrogen gas chamber 33 is formed inside the accumulator container 31 at a position opposite to the mechanism direction of the accumulator piston 32 and is filled with high-pressure nitrogen gas. The nitrogen gas chamber 33 may be formed at any position, for example, it may be formed at a position in the mechanism direction of the accumulator piston 32 . The liquid storage chamber 34 is formed inside the accumulator container 31 at a position in the direction of the mechanism of the accumulator piston 32, and stores hydraulic fluid.

The drainage tank 40 stores the hydraulic fluid discharged by the operation part 20. The pump unit 50 pressurizes the working fluid in the drain tank 40 and supplies it to the accumulator 30 . Between the operation unit 20, the control unit 60, the accumulator 30, the waste liquid tank 40, and the pump unit 50, there are a first high-pressure flow path 52, a second high-pressure flow path 53, a control flow path 54, and a waste flow. A path 55 is provided. Hydraulic fluid stays in and flows through these channels. These flow paths will be described after the control unit 60 is described.

The control unit 60 controls the supply and discharge of hydraulic fluid to and from the operation unit 20 . The control unit 60 supplies high-pressure hydraulic fluid to the operating unit 20 and discharges the hydraulic fluid in the operating unit 20 to the drain tank 40 . A first control liquid chamber 61, a second control liquid chamber 62, and a third control liquid chamber 63 are formed in the control unit 60, for example. The control unit 60 includes, for example, a switching valve 64, an electromagnetic repulsion mechanism 70, and a position holding mechanism 80.

The switching valve 64 includes a connecting portion 64A, a valve body 64B, a blocking portion 64C, and a shaft portion 64D. The connection portion 64A, the valve body 64B, and the closing portion 64C are integrally formed by the shaft portion 64D. The connection portion 64A is connected to the electromagnetic repulsion mechanism 70 . A first through portion 65</b>A that penetrates from the first control liquid chamber 61 to the outside of the control portion 60 is formed at the end portion of the control portion 60 in the direction opposite to the mechanism. The first through portion 65A allows the first control liquid chamber 61 and the outside of the control portion 60 to communicate with each other. The connecting portion 64A is provided to close the first through portion 65A. The connection portion 64A is movable along the first penetration portion 65A while closing the first penetration portion 65A.

The valve body 64B is arranged inside the second control liquid chamber 62 . The valve body 64B includes a first communication passage 66A formed between the first control liquid chamber 61 and the second control liquid chamber 62 and a communication passage 66A formed between the second control liquid chamber 62 and the third control liquid chamber 63. to open or close the second communication path 66B formed by . The first communication path 66A communicates the first control fluid chamber 61 and the second control fluid chamber 62, and the second communication path 66B communicates the second control fluid chamber 62 and the third control fluid chamber. 63. When the switching valve 64 moves to the position closest to the anti-mechanism direction, the valve body 64B closes the first communication path 66A and opens the second communication path 66B. When the switching valve 64 moves to the position closest to the mechanism direction, the valve body 64B closes the second communication path 66B and opens the first communication path 66A. When the switching valve 64 is in a position other than these positions, the valve body 64B opens the first communication path 66A and the second communication path 66B.

A second through portion 65B that penetrates from the third control liquid chamber 63 to the outside of the control portion 60 is formed at the end portion of the control portion 60 in the mechanism direction. The second through portion 65B allows the third control liquid chamber 63 and the outside of the control portion 60 to communicate with each other. The closing portion 64C is provided to close the second through portion 65B. The closing portion 64C is movable along the second penetration portion 65B while closing the second penetration portion 65B. The second through portion 65B is an example of a through portion.

The first drive liquid chamber 24 in the operation section 20 is connected to the third control liquid chamber 63 in the control section 60 via the first high-pressure flow path 52 . The liquid storage chamber 34 in the accumulator 30 is connected to the first drive liquid chamber 24 in the operation section 20 via the second high-pressure flow path 53 . Hydraulic fluid stays at high pressure in the first high-pressure flow path 52 and the second high-pressure flow path 53 .

The second control liquid chamber 62 in the control section 60 is connected to the second drive liquid chamber 25 in the operation section 20 via the control channel 54 . When the current limiting device 1 is in the closed state, the hydraulic fluid stays in the control flow path 54 at high pressure. When the current limiting device 1 changes from the closed state to the open state, the hydraulic fluid in the second drive fluid chamber 25 flows into the second control fluid chamber 62 through the control flow path 54 .

The first control liquid chamber 61 in the control unit 60 is connected to the drainage tank 40 via the drainage channel 55 . When the current limiting device 1 is in the closed state, the hydraulic fluid stays in the drain channel 55 at a pressure as low as the atmospheric pressure. When the current limiting device 1 changes from the closed state to the open state, the first control liquid chamber 61 and the second control liquid chamber 62 communicate with each other, and the second control liquid chamber 62 is connected via the first control liquid chamber 61. The working fluid inside flows into the drain tank 40 through the drain channel 55 .

The electromagnetic repulsion mechanism 70 causes the working fluid to be supplied to and discharged from the operating portion 20 by moving the valve body 64B. The electromagnetic repulsion mechanism 70 includes, for example, a movable shaft 71, an opening coil 72, a closing coil 73, a drive plate 74, a repulsion ring 75, an opening damper 76, a closing damper 77, and an opening damper receiver 78. , and a closing damper receiver 79 . The circuit-opening coil 72, the circuit-closing coil 73, the drive plate 74, the repulsion ring 75, the circuit-opening damper 76, the circuit-closing damper 77, the circuit-opening damper receiver 78, and the circuit-closing damper receiver 79 are housed in the case 70A.

The movable shaft 71 is a long member. The end of the movable shaft 71 facing away from the mechanism is connected to the connection portion 64A of the switching valve 64 in the control portion 60 . The movable shaft 71 operates the switching valve 64 . The electromagnetic repulsion mechanism 70 drives the switching valve 64 by operating the switching valve 64 with the movable shaft 71 .

The circuit opening coil 72 is arranged surrounding the axis along the movable axis 71 . The circuit opening coil 72 is fixed to the case 70A via a base 72A attached to the case 70A, for example. The closing coil 73 is arranged around the axis along the movable axis 71 . The closing coil 73 is fixed to the case 70A via a pedestal 73A attached to the case 70A, for example.

The drive plate 74 is fixed to the movable shaft 71 . The drive plate 74 is composed of, for example, a disk-shaped light metal. The drive plate 74 is arranged between the circuit-opening coil 72 and the circuit-closing coil 73 (closer to the switching valve 64 than the circuit-opening coil 72). The repulsion ring 75 comprises an annular shaped good conductor material fixed to the drive plate 74 . A repulsion ring 75 is arranged for each of the opening coil 72 and the closing coil 73 .

When a current is applied to the circuit opening coil 72 , it generates an induced current in the opposite direction to the repulsion ring 75 and applies a repulsive force to the driving plate 74 in a direction away from the circuit opening coil 72 . In this way, the circuit-opening coil 72 moves the switching valve 64 in the mechanism direction (circuit-opening direction) via the movable shaft 71, thereby connecting the closed first control liquid chamber 61 and the second control liquid chamber 62. .

When a current is applied to the circuit closing coil 73 , it generates an induced current in the opposite direction to the repulsion ring 75 and applies a repelling force to the drive plate 74 in a direction away from the circuit closing coil 73 . In this manner, the closing coil 73 moves the switching valve 64 in the direction of the mechanism via the movable shaft 71, thereby allowing the closed second control liquid chamber 62 and the third control liquid chamber 63 to communicate with each other.

The circuit-opening damper 76 generates a braking force when the circuit-opening operation ends. The open circuit damper 76 contacts the open circuit damper receiver 78 to decelerate the movable shaft 71 when the movable shaft 71 moves toward the mechanism. The open circuit damper 76 is, for example, an oil damper. The open circuit damper 76 includes, for example, an outer cylinder 76A and a piston rod 76B.

The piston rod 76B protrudes from the outer cylinder 76A toward the open circuit damper receiver 78. The tip of the piston rod 76B is separated from the open circuit damper receiver 78 when the current limiting device 1 is in the closed circuit state. The open circuit damper 76 further includes a biasing member that biases the piston rod 76B toward the open circuit damper receiver 78 .

The closing damper 77 generates a braking force at the end of the closing operation. The closed circuit damper 77 contacts the closed circuit damper receiver 79 and decelerates the movable shaft 71 when the movable shaft 71 moves in the anti-mechanism direction (circuit closing direction). The closed circuit damper 77 is, for example, an oil damper. The closing damper 77 includes, for example, an outer cylinder 77A and a piston rod 77B.

The piston rod 77B protrudes from the outer cylinder 77A toward the closing damper receiver 79. The tip of the piston rod 77B is separated from the closing damper receiver 79 when the current limiting device 1 is in the open state. The closing damper 77 further includes a biasing member that biases the piston rod 77B toward the closing damper receiver 79 .

The open circuit damper receiver 78 has elasticity such as rubber and has a disk shape. The open circuit damper receiver 78 is fixed to a position closer to the mechanism direction than the position to which the drive plate 74 is fixed on the movable shaft 71 . The circuit-opening damper receiver 78 contacts the circuit-opening damper 76 when the circuit-opening operation ends. The open circuit damper receiver 78 is made of, for example, an elastic member such as rubber. The open-circuit damper receiver 78 dampens contact with the open-circuit damper 76 when contacting the open-circuit damper 76 .

The closing damper receiver 79 is fixed to the surface of the drive plate 74 opposite to the surface to which the movable shaft 71 is connected (the surface facing away from the mechanism). The closing damper receiver 79 comes into contact with the opening damper at the end of the closing operation. The closing damper receiver 79 is made of, for example, an elastic member such as rubber. The closed circuit damper receiver 79 dampens contact with the closed circuit damper 77 when contacting the closed circuit damper 77 .

The position holding mechanism 80 holds the position of the switching valve 64 and further the position of the valve body 64B. The position holding mechanism 80 has, for example, a swing link 81 and a biasing member 82 . The swing link 81 swings as the movable shaft 71 moves, and regulates the moving direction of the movable shaft 71 . The urging member 82 urges the swing link 81 so that the movable shaft 71 is urged in the anti-mechanical direction when the valve body 64B is positioned to close the first communication passage 66A. The movement of the shaft 71 is blocked, and the closed state of the first communication path 66A is maintained. The biasing member 82 biases the swing link 81 so that the movable shaft is biased in the direction of the mechanism when the valve body 64B is positioned to close the second communication path 66B. is prevented from moving, and the state in which the second communication path 66B is blocked is maintained.

The current limiting device 1 is in either an open circuit state or a closed circuit state. The operation of the current limiting device 1 from the closed state to the open state is called opening operation, and the operation of the current limiting device 1 from the open state to the closed state is called closing operation. Further, the anti-mechanism direction is also referred to as the circuit opening operation direction, and the mechanism direction is also referred to as the circuit closing operation direction. Next, the state and state change of the current limiting device 1 will be described.

First, the closed state of the current limiting device 1 will be described.
When the current limiting device 1 is in the closed state, the pump unit 50 pressurizes the working fluid in the drain tank 40 and supplies it to the fluid storage chamber 34 in the accumulator 30 . Since the compressibility of the nitrogen gas in the nitrogen gas chamber 33 acts on the fluid storage chamber 34 via the accumulator piston 32, the fluid storage chamber 34 stores the pressurized hydraulic fluid. . Hydraulic pressure from the fluid storage chamber 34 always acts on the surface of the driving piston 22 on the side of the first driving fluid chamber 24 via the hydraulic fluid staying in the first high-pressure flow path 52 .

On the other hand, in the control unit 60, the position holding mechanism 80 moves the movable shaft of the electromagnetic repulsion mechanism 70 at a position where the valve body 64B of the switching valve 64 closes the first communication path 66A and opens the second communication path 66B. Hold 71. Therefore, the first control liquid chamber 61 and the second control liquid chamber 62 are blocked, and the second control liquid chamber 62 and the third control liquid chamber 63 are communicated.

In this state, the hydraulic pressure from the fluid accumulating chamber 34 flows through the second high-pressure flow path 53, the first high-pressure flow path 52, and the control flow path 54 to the second driving fluid chamber 25 side of the driving piston 22. always works on the side of Thus, the hydraulic pressure of the hydraulic fluid acts on the driving piston 22 not only on the surface on the first driving fluid chamber 24 side but also on the surface on the second driving fluid chamber 25 side. On both sides of the drive piston 22, there is a difference in hydraulic pressure action area where the hydraulic pressure of the hydraulic fluid acts, and the area on the first drive fluid chamber 24 side is narrower than the area on the second drive fluid chamber 25 side. . Due to the difference in hydraulic active areas on opposite sides of the drive piston 22, the current limiting device 1 is held in the closed position as shown in FIG.

Next, the circuit opening operation until the current limiting device 1 in the closed state shown in FIG. 1 changes to the open circuit state shown in FIG. 2 will be described.
In the current limiting device 1 in the closed state shown in FIG. A current is generated.

The generated eddy current flows in the direction opposite to the current flowing in the repulsion ring 75 , so an electromagnetic repulsion force is generated in the repulsion ring 75 . The electromagnetic repulsive force generated in the repulsive ring 75 is larger than the urging force in the direction opposite to the opening operation direction of the switching valve 64 by the position holding mechanism 80 . Therefore, the repulsion ring 75 , the drive plate 74 and the movable shaft 71 start moving in the opening operation direction of the switching valve 64 . As the movable shaft 71 moves, the switching valve 64 also moves in the opening operation direction.

By moving the switching valve 64, the first communication path 66A is opened, and the first control liquid chamber 61 and the second control liquid chamber 62 are communicated with each other. The communication between the first control liquid chamber 61 and the second control liquid chamber 62 reduces the liquid pressure in the second drive liquid chamber 25 of the operation unit 20 . As a result, the driving piston 22 is driven in the direction of the mechanism by the hydraulic pressure of the high-pressure hydraulic fluid in the first driving fluid chamber 24, and the movable electrode 2 connected to the driving piston 22 via the driving rod 23 opens the circuit. conduct.

When the movable shaft 71 is displaced by a certain distance, the open circuit damper receiver 78 abuts against the piston rod 76B of the open circuit damper 76, and then the piston rod 76B is pushed into the outer cylinder 76A so that the open circuit damper 76 brakes the movable shaft 71. A braking force is generated. The braking force of the open circuit damper 76 is applied to all moving parts including the movable shaft 71 and the switching valve 64 .

The switching valve 64 moves to a position where it blocks the second control liquid chamber 62 and the third control liquid chamber 63 and stops. After that, the position holding mechanism 80 holds the position of the switching valve 64 via the movable shaft 71 . During the circuit opening operation, as the drive piston 22 moves, part of the hydraulic fluid in the second drive fluid chamber 25 is drained, and is discharged by the drain tank 40 via the control channel 54 and the drain channel 55. be recovered. During the opening operation, the second control liquid chamber 62 and the third control liquid chamber 63 are shut off by the switching valve 64 . Therefore, since the high-pressure hydraulic fluid does not flow out to the drainage channel 55, the consumption of the hydraulic fluid can be reduced.

Next, the open circuit state of the current limiting device 1 will be described.
When the current limiting device 1 is in the open circuit state, the pump unit 50 increases the pressure of the hydraulic fluid in the drain tank 40 and supplies it to the liquid storage chamber 34 in the accumulator 30, similarly to when the current limiting device 1 is in the closed circuit state. supply. For this reason, hydraulic fluid that has been pressurized and pressurized is stored in the fluid storage chamber 34 , and the surface of the drive piston 22 on the side of the first drive fluid chamber 24 is filled with high-pressure fluid from the fluid storage chamber 34 . Pressure is constantly acting through the hydraulic fluid residing in the first high pressure flow path 52 .

On the other hand, in the control unit 60, the position holding mechanism 80 moves the movable shaft 71 of the electromagnetic repulsion mechanism 70 at the position where the valve body 64B of the switching valve 64 opens the first communication path 66A and closes the second communication path 66B. hold. Therefore, the first control liquid chamber 61 and the second control liquid chamber 62 are communicated, and the second control liquid chamber 62 and the third control liquid chamber 63 are blocked.

Therefore, since the working fluid at about atmospheric pressure stays in the control channel 54, the drain channel 55, and the second driving fluid chamber 25, the surface of the driving piston 22 on the second driving fluid chamber 25 side is A low hydraulic pressure of about atmospheric pressure always acts on the . Therefore, on both sides of the drive piston 22, a pressure difference is generated in which the pressure applied to the first drive fluid chamber 24 side of the drive piston 22 is higher than the pressure applied to the second drive fluid chamber 25 side. , the current limiting device 1 is held in the open circuit position as shown in FIG.

Next, the circuit closing operation until the current limiting device 1 in the open circuit state shown in FIG. 2 changes to the closed circuit state shown in FIG. 1 will be described.
In the current limiting device 1 in the open circuit state shown in FIG. A current is generated.

The generated eddy current flows in the direction opposite to the current flowing in the repulsion ring 75 , so an electromagnetic repulsion force is generated in the repulsion ring 75 . The electromagnetic repulsive force generated in the repulsive ring 75 is larger than the urging force in the opposite direction to the closing operation direction of the switching valve 64 by the position holding mechanism 80 . As a result, the repulsion ring 75 , the drive plate 74 and the movable shaft 71 start moving in the closing operation direction of the switching valve 64 . As the movable shaft 71 moves, the switching valve 64 also moves in the closing direction.

By moving the switching valve 64, the second communication path 66B is opened, and the second control liquid chamber 62 and the third control liquid chamber 63 communicate with each other. By connecting the second control fluid chamber 62 and the third control fluid chamber 63, the driving piston 22 operates not only on the surface of the first driving fluid chamber 24 but also on the surface of the second driving fluid chamber 25. A high hydraulic pressure is applied by the liquid.

When the same high hydraulic pressure acts on both sides of the driving piston 22, the driving piston 22 is driven in the counter-mechanical direction due to the difference in the hydraulic pressure acting area. When the drive piston 22 is driven in the counter-mechanical direction, the movable electrode 2 connected to the drive piston 22 via the drive rod 23 performs the closing operation of moving in the closing operation direction.

When the movable shaft 71 is displaced by a certain distance, the closing damper receiver 79 comes into contact with the piston rod 77B of the closing damper 77, and then the piston rod 77B is pushed into the outer cylinder 77A so that the closing damper 77 brakes the movable shaft 71. A braking force is generated. The braking force of the closing damper 77 is applied to all moving parts including the movable shaft 71 and the switching valve 64 .

The switching valve 64 moves to a position where it blocks the first control liquid chamber 61 and the second control liquid chamber 62 and stops. After that, the position holding mechanism 80 holds the position of the switching valve 64 via the movable shaft 71 . During this closing operation, the switching valve 64 blocks the first control liquid chamber 61 and the second control liquid chamber 62, and the high-pressure liquid may flow out to the drainage flow path 55 as in the opening operation. Therefore, the consumption of high-pressure liquid can be reduced.

The current limiting device 1 of the first embodiment uses the operation mechanism 4, which is a hydraulic operation mechanism using liquid. Therefore, when the movable shaft 71 in the operating mechanism 4 is moved to change the state from the closed state to the open state, the responsiveness of the operation can be enhanced.

In the current limiting device 1 of the first embodiment, by using the electromagnetic repulsion mechanism 70, the responsiveness of operation is enhanced. However, the movable electrode 2 used in the current limiting device 1 is made of, for example, a conductive metal containing copper or tungsten, and is therefore heavy. Furthermore, in order to operate the movable electrode 2, a certain stroke length, for example, a stroke length of about several hundred mm is required. When the electromagnetic repulsion mechanism 70 is used, the responsiveness of the operation can be improved, but it becomes difficult to increase the stroke length of the movable electrode 2 .

In this regard, the current limiting device 1 of the first embodiment moves the movable electrode 2 using the operating mechanism 4, which is a hydraulic operating mechanism using liquid. Using the operation mechanism 4, which is a hydraulic operation mechanism, it is possible to easily increase the output by adjusting the cylinder diameter and the axial dimension of the drive cylinder 21. FIG.

Furthermore, the high-pressure hydraulic fluid in the second driving fluid chamber 25 of the operation unit 20 can be rapidly discharged and introduced via the control flow path 54, and the driving piston 22 can be moved with high response. . Therefore, the current limiting device 1 can quickly move even the heavy movable electrode 2 . By providing the operation mechanism 4, a large output, a high response, and a long stroke can be achieved.

(Second embodiment)
Next, a second embodiment will be described. The current limiting device of the second embodiment differs from that of the first embodiment mainly in the configuration of the electromagnetic repulsion mechanism in the operating portion. In the following description of the second embodiment and subsequent embodiments, the same reference numerals may be assigned to elements and the like common to those of the first embodiment, and the description thereof may be omitted.

FIG. 3 is a configuration diagram of the operating mechanism 4 in the current limiting device of the second embodiment. The operating mechanism 4 of the second embodiment includes, in the control unit 60, a first unidirectional electromagnetic repulsion mechanism 110 and a second single-direction driving mechanism instead of the electromagnetic repulsion mechanism 70 in the first embodiment. A directional electromagnetic repulsion mechanism 120 is provided. The first unidirectional electromagnetic repulsion mechanism 110 and the second unidirectional electromagnetic repulsion mechanism 120 are provided on both sides of the switching valve 64, respectively.

The first unidirectional electromagnetic repulsion mechanism 110 includes, for example, a movable shaft 111, a coil 112, a drive plate 113, a repulsion ring 114, a damper 115, and a damper receiver 116. The movable shaft 111 is connected to the switching valve 64 . Each element of the first unidirectional electromagnetic repulsion mechanism 110 except for the movable shaft 111 is housed in a case 110A.

The coil 112 is arranged surrounding the movable shaft 111 . The coil 112 is fixed to the case 110A, for example, via a pedestal 112A attached to the case 110A. The drive plate 113 is made of, for example, a disk-shaped light metal and fixed to the movable shaft 111 . The drive plate 113 is arranged at a position closer to the mechanism direction of the coil 112 . The repulsion ring 114 includes an annular good conductor material fixed to the surface of the drive plate 113 facing away from the mechanism.

The damper 115 decelerates the movable shaft 111 by coming into contact with the damper receiver 116 when the movable shaft 111 moves in the anti-mechanism direction. Damper 115 is, for example, an oil damper. The damper 115 includes, for example, an outer cylinder 115A and a piston rod 115B. The damper 115 is configured in the same manner as the open circuit damper 76 of the first embodiment, and is arranged facing the opposite side of the open circuit damper 76 of the first embodiment in relation to the control unit 60 .

The damper receiver 116 is connected to the surface of the driving plate 113 opposite to the surface to which the movable shaft 111 is connected (the surface facing away from the mechanism). The damper receiver 116 is made of, for example, an elastic member such as rubber. The damper receiver 116 dampens the contact with the damper 115 when it contacts the damper 115 .

The second unidirectional electromagnetic repulsion mechanism 120 includes, for example, a movable shaft 121, a coil 122, a drive plate 123, a repulsion ring 124, a damper 125, and a damper receiver 126. Each element of the second unidirectional electromagnetic repulsion mechanism 120 is configured similarly to each element of the first unidirectional electromagnetic repulsion mechanism 110 . The second unidirectional electromagnetic repulsion mechanism 120 is arranged symmetrically with respect to the first unidirectional electromagnetic repulsion mechanism 110 with the position holding mechanism 80 and the control unit 60 interposed therebetween.

Next, the circuit opening operation and the circuit closing operation in the current limiting device of the second embodiment will be described. First, the circuit opening operation of the current limiting device of the second embodiment will be described.
When a pulse current is passed through the coil 112 from a drive power supply (not shown), a magnetic field is generated between the coil 112 and the repulsion ring 114 , and an eddy current is generated in the repulsion ring 114 .

The generated eddy current flows in the direction opposite to the current flowing in the repulsion ring 114 , so an electromagnetic repulsion force is generated in the repulsion ring 114 . The electromagnetic repulsive force generated in the repulsive ring 114 is larger than the urging force in the direction opposite to the opening operation direction of the switching valve 64 by the position holding mechanism 80 . Therefore, the repulsion ring 114 , the drive plate 113 and the movable shaft 111 start moving in the opening operation direction of the switching valve 64 . As the movable shaft 111 moves, the switching valve 64 also moves in the opening operation direction.

By moving the switching valve 64, the first communication path 66A is opened, and the first control liquid chamber 61 and the second control liquid chamber 62 are communicated with each other. By connecting the first control liquid chamber 61 and the second control liquid chamber 62, the movable electrode 2 (see FIG. 1) opens the circuit, as in the first embodiment.

When the movable shaft 111 is displaced by a certain distance, the damper receiver 116 comes into contact with the piston rod 115B of the damper 115, and then the piston rod 115B is pushed into the outer cylinder 115A so that the damper 115 exerts a braking force to brake the movable shaft 111. Occur. The damping force of damper 115 is applied to all moving parts including movable shaft 111 and switching valve 64 .

The switching valve 64 moves to a position where it blocks the second control liquid chamber 62 and the third control liquid chamber 63 and stops. After that, the position holding mechanism 80 holds the position of the switching valve 64 via the movable shaft 111 . By moving the switching valve 64, the current limiting device is opened in the same manner as in the first embodiment.

Next, the closing operation of the current limiting device of the second embodiment will be described.
When a pulse current is passed through the coil 122 from a drive power supply (not shown), a magnetic field is generated between the coil 122 and the repulsion ring 124 , and an eddy current is generated in the repulsion ring 124 .

The generated eddy current flows in the direction opposite to the current flowing in the repulsion ring 124 , so an electromagnetic repulsion force is generated in the repulsion ring 124 . The electromagnetic repulsive force generated in the repulsive ring 124 is larger than the urging force in the opposite direction to the closing operation direction of the switching valve 64 by the position holding mechanism 80 . As a result, the repulsion ring 124 , the drive plate 123 and the movable shaft 121 start to move in the closing operation direction of the switching valve 64 . As the movable shaft 121 moves, the switching valve 64 also moves in the closing direction.

By moving the switching valve 64, the second communication path 66B is opened, and the second control liquid chamber 62 and the third control liquid chamber 63 communicate with each other. By connecting the second control liquid chamber 62 and the third control liquid chamber 63, the movable electrode 2 (see FIG. 1) performs the closing operation as in the first embodiment.

When the movable shaft 121 is displaced by a certain distance, the damper receiver 126 comes into contact with the piston rod 125B of the damper 125, and then the piston rod 125B is pushed into the outer cylinder 125A, and the damper 125 exerts a braking force to brake the movable shaft 121. Occur. The damping force of damper 125 is applied to all moving parts including movable shaft 121 and switching valve 64 .

The switching valve 64 moves to a position where it blocks the first control liquid chamber 61 and the second control liquid chamber 62 and stops. After that, the position holding mechanism 80 holds the position of the switching valve 64 via the movable shaft 121 . By moving the switching valve 64, the closing operation of the current limiting device is executed in the same manner as in the first embodiment.

The current limiting device of the second embodiment has the same effects as the first embodiment, and can improve the responsiveness of the operation when trying to change the state from the closed state to the open state. Furthermore, the current limiting device of the second embodiment comprises a first unidirectional electromagnetic repulsion mechanism 110 and a second unidirectional electromagnetic repulsion mechanism 120 . Therefore, it is possible to contribute to simplification and cost reduction of the components.

In the second embodiment, the first unidirectional electromagnetic repulsion mechanism 110 and the second unidirectional electromagnetic repulsion mechanism 120 are provided on both sides of the control unit 60, but the mechanism for moving the switching valve 64 in the closing direction is , a mechanism other than the second unidirectional electromagnetic repulsion mechanism 120 may be used. Alternatively, when moving the switching valve 64 in the closing direction, another mechanism may be connected or the switching valve 64 may be moved by human power or the like without providing a mechanism for moving the switching valve 64 in the closing direction.

(Third embodiment)
Next, a third embodiment will be described. The current limiting device of the third embodiment differs from that of the first embodiment mainly in the configuration of the electromagnetic repulsion mechanism in the operating portion.

FIG. 4 is a configuration diagram of the operating mechanism 4 in the current limiting device of the third embodiment. The control unit 60 of the operating mechanism 4 of the third embodiment includes a first automatic return electromagnetic repulsion mechanism 130 and a second automatic repulsion mechanism 130 driven in one direction instead of the electromagnetic repulsion mechanism 70 in the first embodiment. A return electromagnetic repulsion mechanism 140 is provided. A first automatic return electromagnetic repulsion mechanism 130 and a second automatic return electromagnetic repulsion mechanism 140 are provided on both sides of the switching valve 64, respectively.

The first automatic return electromagnetic repulsion mechanism 130 includes, for example, a movable shaft 131, a coil 132, a drive plate 133, a repulsion ring 134, a stopper 135, a closing damper 136, an opening damper receiver 137, and an opening damper 138. and a return spring 139 . Each element in the first automatic return electromagnetic repulsion mechanism 130 is housed in a case 130A.

The movable shaft 131 is an elongated member, and is arranged at a distance from the switching valve 64 when the current limiting device is in the closed state, and the end in the mechanism direction is near the end in the counter-mechanism direction of the switching valve 64 . placed in The movable shaft 131 is movable in the direction of the mechanism. When the current limiting device changes from the closed circuit state to the open circuit state, the movable shaft 131 protrudes outside the case 130A.

The coil 132 is arranged surrounding the movable shaft 131 . Coil 132 is fixed to case 130A, for example, via a pedestal (not shown) attached to case 130A. The drive plate 133 is made of, for example, a disk-shaped light metal and is fixed to the movable shaft 131 . The drive plate 133 is arranged at a position closer to the mechanism direction of the coil 132 . The repulsion ring 134 includes an annular good conductor material fixed to the surface of the driving plate 133 facing away from the mechanism.

The stopper 135 is provided at the end of the movable shaft 131 in the direction opposite to the mechanism. The stopper 135 moves as the movable shaft 131 moves. The stopper 135 is made of, for example, an elastic member such as rubber. The stopper 135 buffers the contact with the closing damper 136 when contacting the closing damper 136 . The stopper 135 is arranged so as to pass through a position avoiding the coil 132 and the pedestal when the movable shaft 131 moves.

The closing damper 136 decelerates the movable shaft 131 upon contact with the stopper 135 when the movable shaft 131 moves in the direction opposite to the mechanism. The closed circuit damper 136 is, for example, an oil damper. The closing damper 136 includes, for example, an outer cylinder 136A and a piston rod 136B. The closing damper 136 is configured similarly to the damper 115 of the second embodiment.

The open circuit damper receiver 137 has elasticity such as rubber and has a disk shape. The open circuit damper receiver 137 is fixed to a position closer to the mechanism direction than the position to which the drive plate 133 is fixed on the movable shaft 131 . The circuit-opening damper receiver 137 contacts the circuit-opening damper 138 when the circuit-opening operation ends. The open-circuit damper receiver 137 dampens contact with the open-circuit damper 138 when contacting the open-circuit damper 138 .

The return spring 139 is stretched between the opening damper receiver 137 and the support member 138A. Return spring 139 is a compression spring. The return spring 139 contracts between the opening damper receiver 137 and the support member 138A as the movable shaft 131 moves in the mechanism direction. The contracted return spring 139 urges the open circuit damper receiver 137 in the anti-mechanical direction (the direction of widening the space between the open circuit damper receiver 137 and the support member 138A).

The second automatic return electromagnetic repulsion mechanism 140 includes, for example, a movable shaft 141, a coil 142, a drive plate 143, a repulsion ring 144, a stopper 145, a damper 146, a closing damper receiver 147, and a closing damper 148. , and a return spring 149 . Each element of the second auto-return electromagnetic repulsion mechanism 140 is configured similarly to each element of the first auto-return electromagnetic repulsion mechanism 130 . The second automatic return electromagnetic repulsion mechanism 140 is arranged symmetrically with respect to the first automatic return electromagnetic repulsion mechanism 130 with the position holding mechanism 80 and the control section 60 interposed therebetween.

Next, the circuit opening operation and the circuit closing operation in the current limiting device of the third embodiment will be described. First, the circuit opening operation of the current limiting device of the third embodiment will be described.
When a pulse current is passed through the coil 132 from a drive power source (not shown), a magnetic field is generated between the coil 132 and the repulsion ring 134 , and an eddy current is generated in the repulsion ring 134 .

The generated eddy current flows in the direction opposite to the current flowing in the repulsion ring 134 , so an electromagnetic repulsion force is generated in the repulsion ring 134 . The electromagnetic repulsion force generated in the repulsion ring 134 causes the movable shaft 131 to move in the direction of the mechanism, and the end of the movable shaft 131 in the direction of mechanism contacts the end of the switching valve 64 in the direction opposite to the mechanism. The electromagnetic repulsive force generated in the repulsive ring 134 is larger than the urging force in the direction opposite to the opening operation direction of the switching valve 64 by the position holding mechanism 80 . Therefore, the movable shaft 131 moves further in the opening operation direction of the switching valve 64 together with the driving plate 133 , the repulsion ring 134 , the stopper 135 and the opening damper receiver 137 . As the movable shaft 131 moves, the switching valve 64 also moves in the opening operation direction.

By moving the stopper 135 together with the movable shaft 131, the stopper 135 separates from the piston rod 136B provided on the outer cylinder 136A of the closing damper 136. As the open circuit damper receiver 137 moves together with the movable shaft 131, the return spring 139 contracts between the open circuit damper receiver 137 and the support member 138A.

When the movable shaft 131 is displaced by a certain distance, the open circuit damper receiver 137 comes into contact with the open circuit damper 138, and the piston rod of the open circuit damper 138 is pushed into the outer cylinder of the open circuit damper 138, so that the open circuit damper receiver 137 brakes the movable shaft 131. A braking force is generated. The braking force by the open circuit damper 138 is applied to all moving parts including the movable shaft 131 and the switching valve 64 .

The switching valve 64 moves to a position where it blocks the second control liquid chamber 62 and the third control liquid chamber 63 and stops, and the position holding mechanism 80 holds the position of the switching valve 64 . Thereafter, in the first automatic return electromagnetic repulsion mechanism 130, the operation of supplying current from the drive power source to the coil 132 is terminated, and the electromagnetic repulsion force by the repulsion ring 134 disappears.

When the electromagnetic repulsive force by the repulsive ring 134 disappears, the biasing force of the return spring 139 acts on the open circuit damper receiver 137, and the movable shaft 131 moves in the anti-mechanical direction. After that, the movable shaft 131 returns to the position before the operation by the stopper 135 coming into contact with the closing damper 136 . Thereafter, the circuit opening operation of the current limiting device is performed in the same manner as in the first embodiment.

Next, the closing operation of the current limiting device of the third embodiment will be described.
When a pulse current is passed through the coil 142 from a drive power source (not shown), a magnetic field is generated between the coil 142 and the repulsion ring 144 , and an eddy current is generated in the repulsion ring 144 . Due to the electromagnetic repulsive force generated in the repulsion ring 144 , the movable shaft 141 moves in the anti-mechanism direction, and the anti-mechanism direction end of the movable shaft 141 contacts the mechanism direction end of the switching valve 64 . The electromagnetic repulsive force generated in the repulsive ring 144 is larger than the urging force in the direction opposite to the direction of closing operation of the switching valve 64 by the position holding mechanism 80 . Therefore, the movable shaft 141 moves further in the closing operation direction of the switching valve 64 together with the drive plate 143 , the repulsion ring 144 , the stopper 145 and the closing damper receiver 147 . As the movable shaft 141 moves, the switching valve 64 also moves in the closing direction.

By moving the stopper 145 together with the movable shaft 141, the stopper 145 separates from the piston rod 146B provided on the outer cylinder 146A of the damper 146. When the closing damper receiver 147 moves together with the movable shaft 141, the return spring 149 contracts between the closing damper receiver 147 and the support member 148A.

When the movable shaft 141 is displaced by a certain distance, the closing damper receiver 147 comes into contact with the closing damper 148, and the piston rod of the closing damper 148 is pushed into the outer cylinder of the closing damper 148, so that the closing damper receiver 147 brakes the movable shaft 141. A braking force is generated. The braking force by the closing damper receiver 147 is applied to all moving parts including the movable shaft 141 and the switching valve 64 .

The switching valve 64 moves to a position where it blocks the first control liquid chamber 61 and the second control liquid chamber 62 and stops, and the position holding mechanism 80 holds the position of the switching valve 64 . After that, in the second automatic return electromagnetic repulsion mechanism 140, the operation of supplying current from the drive power supply to the coil 142 is terminated, and the electromagnetic repulsion force by the repulsion ring 144 disappears.

When the electromagnetic repulsive force by the repulsive ring 144 disappears, the biasing force of the return spring 149 acts on the closing damper receiver 147, and the movable shaft 141 moves toward the mechanism. After that, the stopper 145 abuts against the damper 146, whereby the movable shaft 141 returns to the position before the operation. Thereafter, the closing operation of the current limiting device is performed in the same manner as in the first embodiment.

The current limiting device of the third embodiment has the same effects as the first embodiment, and can improve the responsiveness of the operation when trying to change the state from the closed state to the open state. Furthermore, the current limiting device of the third embodiment comprises a first automatic return electromagnetic repulsion mechanism 130 and a second automatic return electromagnetic repulsion mechanism 140 . Therefore, the

movable shafts

131 and 141 can be quickly returned to the state before the operation. Furthermore, a distance from the switching valve 64 is provided before the

movable shafts

131 and 141 operate. Therefore, the

movable shafts

131 and 141 can contact the switching valve 64 with inertia force, so that the responsiveness can be improved. A mechanism for returning the movable shaft, such as a return spring or a damper, to the state before the return may be provided in the current limiting device of another embodiment.

(Fourth embodiment)
Next, a fourth embodiment will be described. The current limiting device of the fourth embodiment differs from that of the first embodiment mainly in the configuration of the operation section.

FIG. 5 is a configuration diagram of the controller 60 in the current limiting device of the fourth embodiment. In the control unit 60 of the fifth embodiment, the flow channel cross-sectional areas of the first control liquid chamber 61, the second control liquid chamber 62, and the third control liquid chamber 63 are the same as those of the current limiting device of the first embodiment. different from Hereinafter, in the current limiting device of the fourth embodiment, the cross-sectional area of the first communication passage in the second control liquid chamber 62 will be referred to as a first cross-sectional area S1. The cross-sectional area of the second control liquid chamber 62 on the side of the third control liquid chamber 63 is defined as a second cross-sectional area S2. The cross-sectional area of the atmosphere-side switching valve 64 in the third control liquid chamber 63 (opening cross-sectional area of the second through portion 65B) is defined as a third cross-sectional area S3.

In the current limiting device of the fourth embodiment, the first cross-sectional area S1 is larger than the third cross-sectional area S3, and the third cross-sectional area S3 is larger than the second cross-sectional area S2. Therefore, the following equation (1) holds between the first cross-sectional area S1, the second cross-sectional area S2, and the third cross-sectional area S3.
S1>S3>S2 (2)

Next, the closed circuit state and open circuit state of the current limiting device of the fourth embodiment will be described.
When the fourth current limiting device is in the closed state, in the control unit 60, the second control liquid chamber 62 and the third control liquid chamber 63 are filled with high-pressure hydraulic fluid. Therefore, hydraulic pressure acts in the direction of the closing operation from the second control liquid chamber 62 to the switching valve 64 (valve body 64B), and from the third control liquid chamber 63 to the switching valve (closed portion 64C). As a result, the hydraulic pressure acts in the opening direction.

At this time, the first cross-sectional area S1 is larger than the third cross-sectional area S3 (S1>S3). Therefore, since the hydraulic pressure applied to the valve body 64B is higher than the hydraulic pressure applied to the closing portion 64C, the switching valve 64 is always biased in the closing direction. Therefore, the switching valve 64 is held at the position where the valve body 64B closes the first communication path 66A.

On the other hand, when the fourth current limiting device is in the open circuit state, in the control section 60, the third control fluid chamber 63 is filled with high-pressure working fluid. Therefore, hydraulic pressure acts in the direction of the closing operation from the third control fluid chamber 63 to the switching valve 64 (valve body 64B), and the third control fluid chamber 63 acts on the switching valve (blocking portion 64C). As a result, the hydraulic pressure acts in the opening direction.

At this time, the third cross-sectional area S3 is larger than the second cross-sectional area S2 (S3>S2). Therefore, since the hydraulic pressure applied to the valve body 64B is smaller than the hydraulic pressure applied to the closing portion 64C, the switching valve 64 is always biased in the opening direction. Therefore, the switching valve 64 is held at the position where the valve body 64B closes the second communication path 66B.

The current limiting device of the fourth embodiment has the same effect as the first embodiment, and can improve the responsiveness of the operation when changing the state from the closed state to the open state. Furthermore, in the current limiting device of the fourth embodiment, the first cross-sectional area S1 is larger than the third cross-sectional area S3, and the third cross-sectional area S3 is larger than the second cross-sectional area S2. Therefore, the position of the switching valve 64 can be held by the high-pressure hydraulic fluid filled in the control section 60 . Therefore, the closed circuit state and the open circuit state of the current limiting device can be stabilized. Furthermore, since the position of the switching valve 64 can be held without the position holding mechanism 80, the number of components can be reduced.

In each of the above embodiments, the filler enclosed in the container 5 is water, but the filler may be a substance other than water. The filler may be, for example, an oil, a liquid metal, a fluorinated liquid, a substance in a supercritical state, or the like. Furthermore, a filter or the like may be provided at the inlet of the drain tank 40 on the drain channel 55 side and the outlet on the pump unit 50 side to remove foreign matter contained in the working fluid.

According to at least one embodiment described above, a closed container filled with a filler, a fixed electrode fixed inside the closed container, a movable electrode arranged opposite to the fixed electrode, and the movable an operating mechanism for separating and contacting the electrode with respect to the fixed electrode, wherein the operating mechanism includes an operating portion for opening and closing the movable electrode by supplying and discharging working fluid; and an electromagnetic repulsion for starting supplying the working fluid. a control unit having a mechanism for controlling the supply and discharge of the hydraulic fluid to and from the operation unit; an accumulator for holding the pressure of the hydraulic fluid; and a drain tank for storing the hydraulic fluid discharged by the operation unit. and a pump for supplying the hydraulic fluid in the drain tank to the accumulator, a highly responsive current limiting device can be provided.

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.

Claims

A closed container filled with a filler;
a fixed electrode fixed inside the sealed container;
a movable electrode arranged opposite to the fixed electrode;
an operation mechanism for separating and contacting the movable electrode with respect to the fixed electrode,
The operating mechanism is
an operation unit that opens and closes the movable electrode by supplying and discharging working fluid;
a control unit having an electromagnetic repulsion mechanism for starting supply of the hydraulic fluid and controlling supply and discharge of the hydraulic fluid to and from the operation unit;
an accumulator that holds the pressure of the hydraulic fluid;
a drain tank for storing the hydraulic fluid discharged by the operation unit;
a pump that supplies the hydraulic fluid in the drainage tank to the accumulator;
Current limiting device.
The operation unit is
a cylinder filled with the hydraulic fluid;
a piston slidably inserted inside the cylinder;
a rod connecting the piston and the movable electrode;
a first drive fluid chamber formed on the rod side of the piston in the cylinder, and a second drive fluid chamber formed on the opposite side of the rod of the piston in the cylinder,
The control unit
a first control liquid chamber connected to the drainage tank via a drainage channel;
a second control liquid chamber connected to the second driving liquid chamber via a control channel;
a third control liquid chamber connected to the second drive liquid chamber via a high-pressure flow path;
a valve body provided between at least one of the first control liquid chamber and the second control liquid chamber or between the second control liquid chamber and the third control liquid chamber; with
The electromagnetic repulsion mechanism drives the valve body,
A current limiting device according to claim 1 .
The electromagnetic repulsion mechanism is
a movable shaft that operates the valve body;
an opening coil and a closing coil arranged around the movable shaft;
a drive plate fixed to the movable shaft and arranged between the opening coil and the closing coil;
a repulsion ring provided on the drive plate and facing the opening coil and the closing coil;
an open circuit damper that generates a braking force at the end of the open circuit operation;
a closing damper that generates a braking force at the end of the closing operation;
an opening damper receiver fixed to the movable shaft and brought into contact with the opening damper when the opening operation is completed;
a closing damper receiver that is fixed to the movable shaft and contacts the closing damper when the closing operation is completed;
3. A current limiting device according to claim 2.
The electromagnetic repulsion mechanism includes a unidirectional electromagnetic repulsion mechanism provided on each side of the valve body,
The unidirectional electromagnetic repulsion mechanism is
a movable shaft that operates the valve body;
a coil arranged to surround the movable shaft;
a drive plate fixed to the movable shaft and arranged closer to the valve body than the coil;
a repulsion ring provided on the drive plate and facing the coil;
a damper that generates a braking force at the end of operation;
a damper receiver fixed to the movable shaft and brought into contact with the damper at the end of operation;
3. A current limiting device according to claim 2.
The electromagnetic repulsion mechanism is
Further comprising a return spring for returning the movable shaft after operating the valve body to a position before operating the valve body,
A current limiting device according to claim 3 or 4.
a first communication passage for communicating the first control liquid chamber and the second control liquid chamber;
a second communication passage for communicating the second control liquid chamber and the third control liquid chamber;
a through portion that penetrates the third control liquid chamber and the outside of the control portion is formed;
a channel cross-sectional area of the first communication passage in the second control liquid chamber is larger than an opening cross-sectional area of the through portion in the third control liquid chamber;
An opening cross-sectional area of the through portion in the third control liquid chamber is larger than a channel cross-sectional area of the second communication path in the second control liquid chamber,
Current limiting device according to any one of claims 2 to 5.
The control unit further includes a position holding mechanism that holds the position of the valve body,
Current limiting device according to any one of claims 2 to 6.