JPH0594741A - Resistance breaking system circuit breaker operating device - Google Patents

Abstract

PURPOSE:To realize highly reliably an operational time difference between a main breaking section and a resistance breaking section necessary for resistance breaking and resistance input even in a hydraulic operating device suitable for a large capacity circuit breaker. CONSTITUTION:An oil pressure change in a hydraulic operating device 4 for a main breaking section in the case of breaking operation, is used as an operation starting signal of a hydraulic operating device 5 for a resistance breaking section. The oil pressure change in the hydraulic operating device 4 for the main breaking section is introduced to a pressure directional control valve 7 of the hydraulic operating device 5 for the resistance breaking section through a throttle section 6, and is used as the operation starting signal of the hydraulic operating device 5 for the resistance breaking section. Since an excellent operational delay time can be realized even to incompressible operating oil, there is no need to use a complicated delay circuit in an electric circuit section, so that malfunction or failure caused by opening/closing surge generated when operating a circuit breaker can be avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance breaker type circuit breaker operating device.

[0002]

2. Description of the Related Art A resistance closing and resistance breaking technology is known as a means for suppressing a switching surge which is generated when a circuit breaker operates and which is not preferable for insulation of a power system. That is, this resistance breaking type circuit breaker has a main breaking unit 1 as shown in FIG.
And a resistor 2 arranged so as to commutate the breaking current by the main breaking unit 1 at the time of breaking the current, and a resistance breaking unit 3 for breaking the resistance current flowing through the resistor 2. In order to realize this resistance cutoff, in order to secure an appropriate energization time to the resistor 2, the cutoff time is 30 ms and the closing time is 1 ms.
It is necessary to secure a difference in operating time between the main breaking unit 1 and the resistance breaking unit 3 of about 0 ms.
-53331 publication. Among them, the one using compressed air as the working medium is shown, but for a large capacity circuit breaker, a hydraulic operating device using high pressure oil is more advantageous. This is because it is non-compressible, the operation speed can be easily increased, and the pressure can be increased, so that the same operation force can be generated by a small operation device.

[0003]

On the contrary, in order to realize the operation time difference between the resistance closing and the resistance breaking in the above-mentioned prior art, on the contrary, the incompressibility is equivalent to the delay of the charging characteristic of the air operating device. Without, delay operation becomes difficult. Therefore, a specific problem arises in order to implement the delay operation with the hydraulic operating device.

In addition to this, in order to easily obtain the operation time difference, it is considered that an electric delay circuit is used to delay the interruption command signal issued from the control system of the electric power system to the circuit breaker. However, in the field where the circuit breaker is installed, it is undesired from the viewpoint of ensuring reliability because it receives a surge induced when the circuit breaker is opened and closed, etc., and the delay method by the electric circuit causes malfunction or failure.

The present invention has been made in view of the above points, and even in a hydraulic operating device suitable for a large-capacity circuit breaker, the difference in operating time between the main breaking portion and the resistance breaking portion required for resistance breaking and resistance closing is highly reliable. It is an object of the present invention to provide a resistance interrupting type circuit breaker operating device that can be realized in the above.

[0006]

SUMMARY OF THE INVENTION The above-mentioned object is to make a hydraulic pressure change in a hydraulic operating device for a main shutoff portion during a shutoff operation be an operation start signal of a hydraulic operating device for a resistance shutoff portion, and to perform a hydraulic operation for a main shutoff portion. This is achieved by guiding the change in hydraulic pressure in the device through the throttle portion to the pressure switching valve of the hydraulic operating device for the resistance cutoff portion to be the operation start signal of the hydraulic operating device for the resistance cutoff portion.

[0007]

Since the above-mentioned means is provided, a good operation delay time can be realized even for incompressible hydraulic oil, and it is not necessary to use a complicated delay circuit in the electric circuit portion, and the circuit breaker It is possible to avoid malfunction or failure due to the influence of switching surges that occur during operation.

[0008]

EXAMPLES Next, the present invention will be specifically described by way of examples.

[Embodiment 1] FIG. 1 shows an embodiment of the present invention. Since the same parts as those in the past are designated by the same reference numerals, the description thereof will be omitted. A main breaking unit 1 composed of a pair of movable electrodes 1a and a fixed electrode 1b, a resistor 2 (see FIG. 8) arranged so as to commutate the breaking current by the main breaking unit 1 at the time of breaking the current, and this resistor 2 Is provided with a pair of movable electrodes 3a and a fixed electrode 3b for interrupting a resistance current flowing through the movable electrode 3a. 3 is a resistance interrupting type circuit breaker operating device in which the movable electrode 3a of No. 3 is driven by the resistance interrupting part hydraulic operating device 5. As a signal for starting the operation of the hydraulic operating device 5 for the resistance breaker,
A pressure change valve (main valve) of the hydraulic shut-off device 5 for operating the resistance shut-off unit is adapted to change the hydraulic pressure in the main shut-off hydraulic device 4 through the throttle unit 6.
7 was used as an operation start signal for the hydraulic operating device 5 for the resistance breaking unit. By doing this, it is possible to achieve a good operation delay time even with incompressible hydraulic oil, and it is not necessary to use a complicated delay circuit in the electric circuit part, which occurs when the circuit breaker operates. This makes it possible to avoid malfunctions or failures due to the effects of switching surges, and even in hydraulic operating devices suitable for large-capacity circuit breakers, there is a high operating time difference between the main circuit breaker and the resistance circuit breaker, which is necessary for resistance breaking and resistance closing. It is possible to obtain a resistance interrupting type circuit breaker operating device that can be realized with reliability.

That is, FIG. 1 shows the closed state of the circuit breaker, and hydraulic operating devices 4 and 5 are mechanically connected to the main circuit breaker 1 and the resistance circuit breaker 3, respectively. The normal pressure oil 9 in the oil tank 8 is pressurized to about 300 atm by the hydraulic pump 10, and the nitrogen gas 12 in the accumulator 11 is compressed and accumulated as the working oil 13 during operation.

The initial hydraulic pressure condition corresponding to the closed state of the circuit breaker shown in the figure is that the shut-off pilot valve 1 communicating with the oil tank 8
4, except for the low-pressure pipes 15, 16 and 17 connected to the main valves 7a and 7 of both the operation devices 4 and 5, respectively, all have high pressure.

When an electric signal of a shutoff command is issued to the shutoff electromagnetic hook mechanism 18 from the illustrated closed state, the pilot valve spool 19 moves downward in the figure against the force of the spring 20 to open the valve 21, The high pressure oil in the main valve operating cylinder 22 flows out to the oil tank 8 at normal pressure through the low pressure pipe 15.
As a result, the high pressure oil acts on the main valve spool 23 only from the left side and moves to the right side, the valve 24 is closed and the valve 25 is opened, and the hydraulic pressure of the cylinder 28 acting on the right side of the piston 27 in the operation cylinder 26 is changed. Switch from high pressure to low pressure. Therefore, the piston 27 coupled to the movable electrode 1a of the main cutoff portion 1 receives a hydraulic operating force determined by the area and the pressure difference between the two surfaces, and the movable electrode 1a
Are driven in the blocking direction S. At the same time, the hydraulic pressure in the cylinder 28 is connected to the cylinder 29 of the main valve 7 of the resistance cutoff hydraulic operating device 5 via the throttle 6. Since the oil in the cylinder 29 flows out at a flow rate determined by the opening area of the throttle portion 6, the main valve spool 31 moves to the right at a speed determined by the area of the piston 30 and the oil outflow rate. As a result, similarly to the case of the main shutoff unit 1, the hydraulic pressure acting on the right side of the piston 33 in the cylinder 32 of the hydraulic shutoff unit hydraulic operation device 5 is switched from high pressure to low pressure, and the piston 33 connected to the movable electrode 3a is switched. Receives a hydraulic operating force determined by the area and the pressure difference between the two surfaces, and is driven in the shutoff direction S. Therefore, since the operation start time of the main valve spool 31 is determined by the area of the piston 30, that is, the cylinder 29 and the opening area of the throttle portion 6, these relationships are appropriately set so that the pressure in the cylinder 32 switches after a preset time. Must be set to.

As a result of the above, it is possible to delay the resistance breaking unit 3 with respect to the main breaking unit 1 with the operation time difference initially set for the breaking operation.

In the cutoff state, this state is maintained. In the subsequent closing operation, the electric signal of the closing command flows to the electromagnetic hook mechanism 34 for closing, and first, the pilot valve spool 35
Moves downward in the figure against the force of the spring 36 to connect high pressure oil to the main valve cylinder 29. As a result, driving force is generated in the main valve spool 31 due to the area difference between the valve 37 and the piston 30, and the main valve spool 31 moves leftward. As a result, the hydraulic pressure in the space on the right side of the piston 33 in the cylinder 32 of the hydraulic circuit for resistance interruption 5 is switched from low pressure to high pressure, and an operating force is generated by the differential pressure acting on the cross-sectional area of the shaft 38. Therefore, the piston 33
And the movable electrode 3 of the resistance interruption part 3 connected to the piston 33
a is driven in the closing direction N. At the same time, the high-pressure oil pressure in the cylinder 32 is guided to the main valve operating cylinder 22 of the main shutoff hydraulic operating device 4 via the throttle portion 6a. As in the shutoff operation, the main valve spool 23 moves leftward at a speed determined by the area of the cylinder 22 and the flow rate of hydraulic oil from the throttle portion 6a. As a result, in the main cutoff hydraulic operating device 4 as well, the hydraulic pressure in the space on the right side of the piston 27 in the cylinder 26 is switched from low pressure to high pressure after a preset time, and the piston 27 coupled to the movable electrode 1a disconnects its shaft 39. It receives the hydraulic operation force that acts on the area and is driven in the closing direction. In the figure, 40 is a valve.

As a result of the above, it is possible to delay the main breaking unit 1 with respect to the resistance breaking unit 3 with the initially set operation time difference in the closing operation.

In this embodiment, the main valve cylinder 22 of the main shut-off hydraulic operating device 4 is connected to the cylinder 32 of the resistance shut-off hydraulic operating device 5 via the throttle portion 6a, so that the pressure is low when shut off. , It is automatically maintained at high pressure in the input state. Similarly, since the main valve cylinder 29 of the resistance shutoff hydraulic operating device 5 is connected to the cylinder 26 of the main shutoff hydraulic operating device 4 via the throttle 6, the shutoff state is low and the main shutoff state hydraulic pressure is low. Automatically maintained at high pressure. Therefore, there is a feature that a special mechanism for maintaining the closed state and the closed state is unnecessary.

As described above, according to this embodiment, when the current is cut off, the change in the hydraulic pressure of the hydraulic circuit for the main circuit breaker is detected and used as a trigger signal for the resistance circuit breaker, and when the circuit is closed, the hydraulic circuit for the resistance circuit breaker is operated. Is used as a trigger signal for the hydraulic operating device for the main cutoff part, and a throttle part is provided in the hydraulic fluid flow path to mitigate the high-speed transmission characteristics of the operating signal due to the incompressibility of hydraulic fluid. Since the spilled hydraulic oil is used to operate the valve mechanism in the subsequent stage, there is no need to use a complicated delay circuit in the electric circuit part, and malfunctions or failures due to the effects of switching surges that occur when the circuit breaker operates can be avoided. In addition, since the throttle portion is provided in the hydraulic signal transmission path, a good operation delay time can be realized even for incompressible hydraulic oil.

[Embodiment 2] FIG. 2 shows another embodiment of the present invention. In this embodiment, the main cutoff portion 1 and the resistance cutoff portion 3 are connected to the hydraulic operating devices 4 and 5 via rotary levers 43 and 44 supported by fixed pins 41 and 42. The configuration of the hydraulic operating devices 4, 5 and the positional relationship of the valves, pistons, etc. are the same as in the above-mentioned case, but the figure corresponds to the shut-off position of the circuit breaker, and the upper part of the figure shows the hydraulic operating device 4 for the main shut-off part
The hydraulic operating device 5 for the resistance breaker is located below. The electromagnetic hook mechanism is also reversed, and the electromagnetic hook mechanism for shutting off the upper part 1
8, the lower part is the electromagnetic hook mechanism 34 for closing. The operation is the same as the above-mentioned case if the terms of making and shutting are read differently. In the present embodiment, the rise of the pressure of the cylinder 28 of the main cutoff hydraulic operating device 4 from the low pressure to the high pressure is guided to the resistance cutoff hydraulic operating device 5 and is used as a cutoff operation start signal. Since the fall of the pressure of the cylinder 32 of the device 5 from the high pressure to the low pressure is used as the closing operation start signal of the main cutoff hydraulic operating device 4, the characteristics can be reversed with respect to the above-described embodiment.

[Embodiment 3] FIG. 3 shows an embodiment relating to oil temperature control. The range of temperature change of the environment in which the circuit breaker is installed is large, for example, about +40 to -20 ° C. The viscosity of the hydraulic oil applied to the hydraulic operating device changes depending on the temperature, and when the flow rate is controlled by using the throttle portion as in the present invention, the change in the viscosity causes a large variation in the operation.
In this embodiment, an oil sump 45 is provided in front of the throttle portion 6a, and the temperature of the oil 47 inside is controlled to be constant by heating with a heater 46. For this reason, a temperature sensor 48 is provided in the oil sump 45 to detect the temperature, and a temperature controller 49
The heater current is controlled by. The volume of the oil sump 45 may be about several times the amount of oil passing through the throttle portion 6a during operation, that is, a product of the diameter of the piston 50 of the main valve spool 23 and the moving distance thereof. The figure shows the case where the main valve 7a is located downstream of the throttle portion 6a, but when the main valve 7a is located upstream, the positional relationship between the oil sump 45 and the throttle portion 6a may be reversed. It is also effective to provide oil sumps 45, 45a on both sides of the throttle portion 6a, as shown in FIG. 4, considering that high speed operation is repeated by shutting off and closing.

[Embodiment 4] FIG. 5 shows the case where a small-scale accumulator is installed at the connecting portion between the throttle portion and the main valve cylinder. As shown in the figure, an accumulator 52 is installed between the cylinder 29 of the main valve 7 of the hydraulic operating device for the resistance cutoff portion and the throttle portion 6 of the pipe 51 connecting the cylinder 29. Accumulator 5
The inside of 2 is filled with nitrogen gas 12, and the high pressure oil 53
Is compressed by. When the pressure in the pipe 51 drops due to the shut-off operation, the oil in the accumulator 52 first becomes the throttle portion 6.
As shown in FIG. 6, the pressure inside the cylinder 29 is gradually discharged through the compressive action of the nitrogen gas 12.
It drops almost linearly. That is, curve A in the figure
As shown in FIG. 5, when the pressure in the pipe 51 decreases from the high pressure Ph to the low pressure Pl, the pressure in the cylinder 29 also gradually decreases as indicated by a straight line B in the figure until the operation start pressure Pw of the main valve spool 31. When lowered, the main valve spool 31 starts to move. In the present embodiment, since the main valve spool 31 is stopped from the operation start time t ₁ to t ₂ of the main shutoff portion, it is possible to prevent wasteful outflow of the high pressure hydraulic oil from the valve 37 during this period. Further, the amount of oil flowing out from the throttle portion 6 by the time t ₂ becomes the amount of oil which the piston 54 of the accumulator 52 eliminates, so that it is easy to increase the delay time. Accordingly, it is possible to increase the opening area of the throttle portion 6 for the same delay time, the main valve spool 31 after the time t ₂ in FIG. 6 (these pipes, cylinders, the main valve spool, a valve,
It is possible to increase the operating speed of the throttle, accumulator, piston, etc. (see FIG. 5).

In FIG. 7, the piping portion of the accumulator 52 shown in FIG. 5 is further provided with a throttle portion 6b.
It is necessary that the flow rate of the throttle portion 6b be several times or more that of the throttle portion 6 and that the throttle portion 6 is dominant with respect to the delay time. By doing so, it is possible to prevent the volume of the accumulator 52 from causing a delay in operation with respect to the high voltage signal transmitted from the pipe 55 at the time of input.

[0022]

As described above, according to the present invention, even in a hydraulic operating device suitable for a large capacity circuit breaker, a difference in operating time between a main circuit breaker and a resistance circuit breaker necessary for resistance breaking and resistance closing can be realized with high reliability. Therefore, even for hydraulic operating devices suitable for large-capacity circuit breakers, it is possible to realize with high reliability the operating time difference between the main circuit breaker and the resistance circuit breaker required for resistance breaking and resistance closing. An operating device can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of a resistance interrupting type circuit breaker operating device of the present invention.

FIG. 2 is an explanatory view of another embodiment of the operating device for a resistance interrupting type circuit breaker of the present invention.

FIG. 3 is an explanatory view showing an embodiment relating to temperature control of the operating device for a resistance interruption type circuit breaker of the present invention.

FIG. 4 is an explanatory view showing another embodiment relating to temperature control of the operating device for a resistance interruption type circuit breaker of the present invention.

FIG. 5 is an explanatory view showing an embodiment of a hydraulic operating mechanism section of the operating device for a resistance interruption type circuit breaker of the present invention.

6 is a characteristic diagram showing characteristics of the hydraulic operating mechanism section shown in FIG.

FIG. 7 is an explanatory view showing another embodiment of the hydraulic operating mechanism section of the operating device for a resistance interruption type circuit breaker of the present invention.

FIG. 8 is a circuit diagram of a resistance interrupting type circuit breaker.

[Explanation of symbols]

1 ... Main interruption part, 1a ... Movable electrode (for main interruption part), 1b ...
Fixed electrode (for main interruption part), 2 ... Resistor, 3 ... Resistance interruption part, 3a ... Movable electrode (for resistance interruption part), 3b ... Fixed electrode (for resistance interruption part), 4 ... Hydraulic operation for main interruption part Device, 5 ...
Hydraulic operating device for resistance cutoff section, 6 ... throttle section, 7 ... pressure switching valve (main valve).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Koyanagi 4026 Kuji Town, Hitachi City, Hitachi, Ibaraki Prefecture, Hitachi Research Institute, Ltd. Hitachi Research Laboratory (72) Inventor Yukio Kurosawa 4026, Kuji-machi, Hitachi City, Ibaraki Prefecture Hitachi Research Institute, Ltd.

Claims (11)

[Claims] 1. A main cutoff portion composed of a pair of movable electrodes and a fixed electrode, a resistor arranged so as to commutate the cutoff current by the main cutoff portion when the current is cut off, and a resistance current flowing through the resistor. A resistance cutoff unit composed of a pair of movable electrodes and a fixed electrode for cutoff is provided, and the movable electrode of the main cutoff unit is driven by a hydraulic operation device for the main cutoff unit to move the movable electrode of the resistance cutoff unit to a hydraulic pressure for the resistance cutoff unit. In a resistance interrupting type circuit breaker operating device that is driven by an operating device, a hydraulic pressure change in the main circuit breaker hydraulic operating device at the time of a circuit breaking operation is used as an operation start signal of the resistance circuit breaking hydraulic operating device, A resistance characterized in that a change in hydraulic pressure in the main cutoff hydraulic operating device is guided to a pressure switching valve of the resistance cutoff hydraulic operating device through a throttle portion and used as an operation start signal of the resistance cutoff hydraulic operating device. Cutoff method Sectional operating device. 2. The circuit breaker operating device guides a rising portion of a change in hydraulic pressure in the main circuit breaking hydraulic pressure device from a low pressure to a high pressure to the resistance circuit breaking hydraulic operating device, and the resistance circuit breaking hydraulic pressure. The operating device for a resistance breaking type circuit breaker according to claim 1, which is used as an operation start signal of the operating device. 3. The circuit breaker operating device guides the falling portion of the hydraulic pressure change in the main circuit breaker hydraulic operating device from a high pressure to a low pressure to the resistance circuit hydraulic operating device for the resistance circuit breaking part. The operating device for a resistance breaking type circuit breaker according to claim 1, which is used as an operation start signal of the hydraulic operating device. 4. The circuit breaker operating device uses a change in hydraulic pressure in the resistance interrupting part hydraulic operating device during closing operation as an operation start signal of the main disconnecting part hydraulic operating device. Operating device for the circuit breaker of the resistance breaking method described. 5. The circuit breaker operating device guides a change in hydraulic pressure in the resistance interrupting part hydraulic operating device through a throttle part to a pressure switching valve of the main disconnecting part hydraulic operating device. The operating device for a resistance interrupting type circuit breaker according to claim 4, wherein the operating device is an operation start signal. 6. The circuit breaker operating device guides the rising portion of the hydraulic pressure change in the resistance switching part hydraulic operating device from a low pressure to a high pressure to the main switching part hydraulic operating device. The operating device for a resistance interrupting type circuit breaker according to claim 4, which is used as an operation start signal of the operating device. 7. The circuit breaker operating device guides the falling portion of the hydraulic pressure change in the resistance circuit breaking hydraulic operating device from a high pressure to a low pressure to the main circuit breaking hydraulic operating device for the main circuit breaking part. The operating device for a resistance interruption type circuit breaker according to claim 4, which is used as an operation start signal of the hydraulic operating device. 8. The circuit breaker operating device according to claim 1 or 5, wherein an oil sump is provided on the upstream side of the throttle portion to control the temperature of the oil in the oil sump. Operation device for resistance breaker type circuit breaker. 9. The circuit breaker according to claim 1, wherein the operating device for the circuit breaker has an accumulator installed at a connecting portion between the throttle portion and the pressure switching valve of the hydraulic operating device for the resistance breaking portion. Manual operation device. 10. The resistance interruption type circuit breaker according to claim 5, wherein the circuit breaker operating device has an accumulator installed at a connection portion between the throttle portion and the pressure switching valve of the main circuit breaker hydraulic operating device. Manual operation device. 11. The resistance interrupt type circuit breaker operating device according to claim 9 or 10, wherein the circuit breaker operating device has a throttle portion installed in a connection pipe portion of the accumulator.