JPS58180801A - Oil pressure operating device for circuit breaker - Google Patents

Abstract

PURPOSE:To shorten the acting time of a main directional control valve, by a method wherein an accumulator for driving of a driving piston is made into a piston type hydro-pneumatic accumulator and an accumulator for driving of the directional control valve device is made into a bladder type hydro-pneumatic accumulator. CONSTITUTION:High hydraulic pressure connecting with a valve circuit of a main directional control valve 8 is only the hydraulic pressure to be supplied from a piston type hydro-pneumatic accumulator 17 and the high hydraulic pressure of a bladder type hydro-pneumatic accumulator 18 is supplied to a pilot valve 14 for breaking, a pilot valve 16 for making, a valve circuit of a breaking position holding valve 15, and introducing openings 10, 11, 12 and 13 of the hydraulic pressure of the main directional control valve through its valve circuit. As hydraulic pressure making the bladder type hydro-pneumatic accumulator into a hydraulic pressure source is applied at an acting time of the main directional control valve 8, a titled device is superior in its responsibility and is suitable for high speed action without having no transitional pressure variation at the time of changeover of the valve.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic operating device for a circuit breaker, and particularly to a hydraulic operating device with excellent high-speed response.

As the number of power grids increases, the responsibility of power circuit breakers to interrupt high-voltage, large-capacity short-circuit currents increases.
In addition, due to the need to increase system stability and reduce damage to power transmission and substation equipment due to failures, it has become necessary to satisfy specifications such as shortening failure duration time 7) rounding off time reduction. Recently, in order to meet these needs, 8
The performance of the buffer-type gas circuit breaker, which uses F gas as a medium and has a simple structure and high reliability, has significantly improved performance. Buffer-type gas interconnectors use the breaking principle of compressing gas during the breaking operation and extinguishing the arc by blowing that gas onto the arc. An operating line with high responsiveness is required.

In the past, there have been four types of human body operating devices: those that use pneumatic pressure and those that use hydraulic pressure, and each has been used to take advantage of its advantages.

However, when considering a large-capacity, high-speed environment, a hydraulic system is advantageous because it is compact, can obtain large force, and has a high force propagation speed.

First, if high-speed response is required, the hydraulically operated unit must be compact, lightweight, and have high-speed propagation characteristics. For this reason, the hydraulic system is excellent when the target is a breaking time of 1 cycle, or when applied to a circuit breaker that can replace a round fault current limiter that separates the system at high speed and completely reduces the fault current.

As an example of a circuit breaker that aims to meet the cycle at the time of interruption, the first
There is one shown in the figure. This figure shows the entire closed state of the circuit breaker.

The operating piston 2, which is connected to the shutoff part l at the 1'rIL position via an insulator, reciprocates in the cylinder 3, and is constantly connected to the chamber 4 above the piston from the hydraulic source 5 via the accumulator 6fr. High pressure hydraulics are installed. On the other hand, the high pressure of the accumulator is introduced into the chamber 7 below the piston via the main switching valve 8. In this state, since the same high pressure oil is introduced to both sides of the piston 20, the piston is chipped in the closing direction by a force corresponding to the IiT product of the piston lower side 9. In this state, accumulator pressure is introduced into the main switching valve 8 through the hydraulic pressure inlet ports 10 and 11, and no hydraulic pressure is present in the inlet ports 12 and 13. In this state, the main switching valve 8Vi valve circuit left 1st place nt
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When the valve circuit of the shutoff phase pilot valve 14 is switched from the right side to the left side by the shutoff command fC, the accumulator oil pressure fri+ that had been introduced into the inlet 11 until then! Switch the inlet port 11t to the tank. Switch the valve circuit of the main switching valve 8 to the right side from VC. Then, the oil in the lower chamber 7 of the piston, where the C accumulator oil pressure had been introduced, is released to the tank, eliminating the force on the lower side of the piston, and at the same time supplying the htm i%l14 hair accumulator oil pressure of the piston. Then, the am driving operation is performed to the lower side of the piston assembly.

After the shutoff operation, the valve circuit of the shutoff position it holding valve 15 is
By switching to 11, the accumulator hydraulic pressure is introduced into the hydraulic pressure inlet 12, and the valve circuit of the main switching valve 8 is maintained in the right position 114. As a result, the shutoff pilot valve 1
Even if the valve circuit No. 4 is switched back to the right side and the accumulator hydraulic pressure is introduced into the hydraulic pressure introduction port 11, the main switching switch 98 maintains the cut-off state 1lll.

In the closing operation, when the closing pilot valve 16 is driven by the closing command flow resistance and the valve circuit is switched to the left side, the accumulator hydraulic pressure is applied to the hydraulic pressure inlet 13, and the valve circuit is switched to the left side of the main switching valve 8. , pressure oil is introduced from the hair accumulator in the chamber 7 below the piston, and a charging operation is performed.

There are two types of hydraulic power accumulators for circuit breaker operating devices: plug type and piston type. The former uses a rubber bag to separate gas and oil, while the latter uses a piston inside a cylinder to separate gas and oil. Therefore, while the former has excellent responsiveness and is suitable for high-speed operation,
Volume and discharge flow are small. In the rear part, the response is poor because the piston needs to move, but it is easy to increase the volume and discharge flow rate by 1°.

When adopting bladder type accumulators, by arranging many in parallel, it is possible to compensate for the small volume and discharge flow. However, the disadvantage is that there are many accumulators. In the case of a piston type accumulator, can you achieve the specified 8 degrees and discharge by arranging one or several in parallel? However, it is difficult to improve responsiveness.

Therefore, if a bladder type 'f is used as the accumulator 6 in the hydraulic operating device shown in Fig. 1, there will be no delay in knitting speed [6], but if a piston type accumulator is used, the high-speed response or You will be killed.

Fig. 2 C: Accumulator pressure P when using a histone type accumulator and hydraulic pressure inlet 11 of main switching valve 8
This figure shows the change in pressure P over time. When the shutoff pilot valve 14 is switched in response to a shutoff command, P rapidly decreases to zero. This vc# main switching valve 8 is supplied with oil from the accumulator to the hydraulic pressure inlet lO, and is switched to the right valve circuit. At this time, the amount of oil consumed to fully switch the main valve is small, but if a piston-type accumulator is used, the oil pressure will drop until a sufficient amount of force is obtained to drive the piston. The pressure of the round P, where the piston / is to operate, decreases transiently, and the flow of oil stops when the main switching valve switches, so the oil pressure increases due to inertia. When piston 2 starts moving,
In order to supply oil to the upper chamber 4 of the piston, the accumulator oil pressure also decreases transiently.

As can be seen from this figure, when a piston-type accumulator is used, the hydraulic pressure when effectively working is low compared to the static hydraulic pressure, and when high-speed response is required, the main switching The delay in the valve switching operation results in dead time for the operating piston operation, which is a significant drawback for the circuit breaker's single-speed operation.

The purpose of the present invention is to shorten the operating time of the main switching valve in a hydraulic operation position #C with a piston-type accumulator, and to shorten the dead time of the operation piston, thereby achieving hydraulic operation with increased response. The goal is to provide equipment.

”The oil wax required for the operation of the switching valve is the operating piston drive@VC
Since the amount of oil consumed is very small compared to the amount of oil consumed, by supplying only the high-pressure oil consumed for this purpose from the bladder type accumulator force, it is possible to eliminate one cycle delay of the main switching valve. . In addition, the high pressure oil F of the bladder type accumulator
The i4 piston is connected to the piston type accumulator via a check valve or a stop valve to prevent consumption.

An embodiment of the present invention will be described below with reference to FIG. The structure and operation of the hydraulic operating device are the same as those shown in FIG. 1, so a description thereof will be omitted. In this embodiment, in addition to the piston type accumulator 17, a bladder type accumulator 18i is provided, which is connected to the piston type accumulator via a bladder type accumulator 18U and a check 9f19, and the same hydraulic pressure as the piston type accumulator is supplied from the hydraulic pressure source 5. ing. The high-pressure oil pressure connected to the valve circuit of the main switching valve 8 is only the oil pressure supplied from the piston-type accumulator 17;
ji disconnection pilot valve 14. input pilot valve 17;
The hydraulic pressure inlet L]10°11.12.13 of the main switching valve 8 is supplied through the valve circuit of the shutoff position holding valve 15 and its entire valve circuit.

According to this embodiment, when the main switching valve is operated, hydraulic pressure from the bladder-type accumulator is used as the hydraulic source, so responsiveness is excellent, and there is no transient force change when switching the valve, and the sieve chain 1・It is possible to provide a hydraulic operation device that is suitable for operations.

In this embodiment, if there is no check 4'P19, the hydraulic pressure of the bladder type accumulator, which has good response when operating the piston body, will be consumed first, so the bladder type accumulator L
・If we do not increase the capacity, we will be responsible for continuous production [against! 2
From the second operation onward, the piston-type actuator will depend only on the high-pressure oil, and its quick response will be lost.

However, by providing 19 check valves, the high pressure oil in the bladder type accumulator can be limited to only the main switching valve operation.
Bladder type accumulators can be reduced in number and small in size.

FIG. 4 shows the piston/type accumulator hydraulic pressure P1 and the bladder type accumulator hydraulic pressure P in the embodiment shown in FIG.
z fluctuation and the pressure P at the hydraulic pressure inlet 11 of the main switching valve 8.

In response to the Nyu trace disconnection command, the V drops drastically and the main switching valve operates, but there is no pressure because it is in communication with the pressure oil of the PZIX bladder type accumulator. On the other hand, since there is no necessity to supply oil when the main switching valve operates, P decreases only when the operating piston operates.

According to the present invention, the switching valve operation of the hydraulic operating device can be performed at high speed, so that the operation delay time of the hydraulic operating device can be shortened.

[Brief explanation of drawings]

Figure 1 is a hydraulic circuit diagram of a conventional IC-hydraulic operating device.
Is Figure 2 the pressure characteristic in Figure 1? 3 is a hydraulic circuit diagram of a hydraulic operating device according to an embodiment of the present invention,
FIG. 4 is a route map showing the pressure characteristics in the example shown in FIG. 2... Operating piston, 3... Cylinder, 6... Accumulator, 8... Main switching valve, 14... Pilot valve for shutoff, 16... Pilot valve for closing, 17...
・Piston type accumulator, 18...Prada type accumulator-7 (JJ1 bundle・Fig. 1 PcI m- Fig. 3 V 4 Fig. PcI m-4

Claims (1)

[Scope of Claims] 1. Using an incompressible fluid as a driving force transmission medium, a drive piston for driving the flow cutoff device and a switching valve device #t for switching the operating direction of the drive piston are provided. In the hydraulic operating device for a circuit breaker, the pressure accumulator for driving the drive piston is a piston type pressure accumulator, and the pressure accumulator for driving the switching valve device is a bladder type pressure accumulator.
Hydraulic operating device for S disconnection with # value. 2. Claim 1g4 is characterized in that the piston-type pressure accumulator and the bladder type pressure device rIIL are communicated with each other by a check valve or a squeeze valve that allows free flow from the piston type to the bladder type. Hydraulic operating device for circuit breakers.