RU1778805C - Hydromechanical operating mechanism of sulfur hexafluoride switch - Google Patents

Abstract

Usage: in switching equipment, in particular in SF6 circuit breakers. Essence: when the switch is turned on, a command is given to the electromagnet of valve 10. This opens the valve and the working fluid 6 from the accumulator 5 enters the under-cavity of the working cylinder 1. On both sides of the piston 2, the pressure is equalized and it moves upward due to that the active area of the lower part of the piston 2 exceeds the active area of the upper part of the piston. There is a short circuit of contacts 3 of the switch. At the end of the switching operation by the block contacts, the electric voltage is removed from the electromagnet of the valve 10 and the valve returns to its original position by its spring. When the switch is turned off, a command is issued to the solenoid of valve 11. At the same time, w e VJ 00 00

Description

the piston cavity of the working cylinder 1 communicates with the low-pressure cavity 8, due to the resulting pressure difference, the piston 2 moves to the lower position, causing the contacts 3 to open and the arcing devices of the switch to trip. When the piston 2 is moved to the lower position, the cylinder 1 is fed with hydraulic fluid 6 from the accumulator 5. The energy absorber 12 provides a constant pressure of the hydraulic fluid 6, moving the piston 7 due to the pressure of the compressed gas on the cover 15. When the bellows 13 reaches a predetermined height, automatic activation of the hydraulic pump 9, which, pumping the spent liquid from the cavity 8 into the hydraulic accumulator 5, returns the hydraulic accumulator-energy carrier system to its original position. 1 ill.

The invention relates to high-voltage apparatus engineering, in particular to hydromechanical drives of gas-insulated circuit breakers with autocompression arcing devices.

It is known that the drive of gas-insulated circuit breakers with autocompression-type arcing devices must have a relatively high power, because he needs both to perform the work of transferring the contacts of the switch from one position to another, while providing a speed of their movement during shutdown of about 7 m / s, and also to perform work on compression of the SF6 gas in the cylinders of the arcing devices with the purpose of creating a flow of SF6 directed into the burning zone of the electric arc.

This requirement is fully met by hydraulic drive devices, characterized by a relatively small occupied volume, low weight, and flexible regulation of dynamic characteristics.

Hydromechanical actuators for SF6 circuit breakers are known, comprising a working power cylinder, the piston of which is mechanically connected to the movable contacts of the arcing devices, a hydraulic accumulator filled with a working fluid (oil) at a pressure of about 30 MPa, which is constantly in fluid communication with the piston cavity of the working cylinder; control valves with electromagnetic actuators, by means of which the piston cavity of the working cylinder communicates (when operating with an SF6 circuit breaker) or with a hydraulic accumulator or with a cavity in which the working fluid is under low pressure and a hydraulic pump for pumping the spent working fluid from the low pressure cavity into the hydraulic accumulator .

As a carrier of stored energy for creating a high pressure of a working fluid in a hydraulic accumulator, known devices use either

compressed nitrogen at a pressure of about 30 MPa, acting through the working piston of the hydraulic accumulator on the working fluid, or a pack of compressed disk springs, constantly acting on the moving piston of the hydraulic accumulator.

The disadvantages of such devices are: the relative complexity and, therefore, reduced reliability of the seal assemblies of the movable piston of the hydraulic accumulator separating the high pressure cavities with the working fluid and nitrogen; the high complexity and complexity of manufacturing plate-shaped springs of large diameter, as well as a significant change in the mechanical characteristics of the energy carrier depending on the stroke, which in turn negatively affects the stability of the SF6 circuit breaker.

The purpose of the invention is to increase the reliability of the SF6 circuit breaker by increasing the stability of the hydraulic drive characteristics.

To this end, in the hydromechanical drive of a gas-insulated circuit breaker with arcing devices

autocompression type containing a working power cylinder, the piston of which is mechanically connected to the movable contacts of the arcing devices, and

nadporshnevoy cavity is constantly associated with a hydraulic accumulator filled with high pressure working fluid; carrier of stored energy; control valves with electromagnetic actuators and a hydraulic pump; a bellows is selected as a carrier of stored energy;

filled with compressed gas, the pressure of which is significantly lower than the pressure of the hydraulic accumulator fluid.

The hydromechanical drives of SF6 circuit breakers with the above distinguishing features are unknown.

The drawing shows a General view of the proposed hydromechanical drive.

The drive contains a working power cylinder 1, the piston 2 of which is mechanically connected to the movable contacts 3 of the arcing devices (not shown in the drawing). The supra-piston cavity 4 of the working cylinder 1 is constantly connected to the hydraulic accumulator 5, which is filled with a working fluid 6 under high pressure. The hydraulic accumulator cylinder 5 contains a movable piston 7, which divides the cylinder into two cavities of high pressure 6 and low pressure 8. The low pressure cavity 8 is used to collect the waste fluid, which is pumped into the high pressure cavity 6 by means of a hydraulic pump 9. The drive is controlled by electromagnetic valves 10 and 11. A constant high pressure of the working fluid 6 in the accumulator 5 is supported by the energy carrier 12, which is a bellows 13, the internal cavity of which is filled with compressed gas a pressure of about 2 MPa, sealed at the ends caps 14 and 15. The energy carrier 12 is mechanically connected to the piston 7 torus pressure reservoir 5 via the rod 16.

The operation of the drive is as follows.

In the initial position, the switch is open. In this case, valve 11 closes the communication of the working cylinder 1 with the low-pressure cavity 8.

When the switch is turned on, a command is given to the electromagnet of valve 10. In this case, the valve opens and the working fluid 6 from the accumulator 5 enters the piston cavity of the working cylinder 1. On both sides of the piston 2, the pressure is equalized and it moves upward due to the active area of the lower part piston 2 exceeds the active area of the upper part of the piston.

There is a short circuit of contacts 3 of the switch. At the end of the switching operation by block contacts (not shown in the drawing)

the electrical voltage is removed from the electromagnet of the valve 10 and its valve

spring returns to its original position.

When the switch is turned off, a command is given to the valve electromagnet 11. In this case, the piston cavity of the working cylinder 1 communicates with the low-pressure cavity 9, due to the resulting pressure difference, the piston 2 moves to the lower position, causing the opening of contacts 3 and the operation of the arcing

switch device.

When the piston 2 is moved to the lower position, the cylinder 1 is energized by the working fluid G from the hydraulic accumulator torz 5. The energy carrier 12 provides a constant pressure of the working fluid 6 by moving the piston 7 due to the pressure of the compressed gas on the cover 25. When the bellows 13 reaches a predetermined height, automatic the inclusion of a hydraulic pump 9, which, pumping the spent liquid from the cavity 8 into the hydraulic accumulator 5, returns the hydraulic accumulator-energy carrier system to its original position.

The use of an SF6 circuit breaker in the form of a bellows in a hydromechanical drive. filled with compressed gas, allows fairly simple means to achieve stability

characteristics of the circuit breaker, and therefore increase its reliability.

Claims (1)

SUMMARY OF THE INVENTION Hydromechanical drive of a gas-gas circuit breaker with autocompression-type arcing devices, comprising a working power cylinder, the piston of which is mechanically connected to the movable contacts of the arrester devices, and the nadporshne cavity is constantly associated with a hydraulic accumulator filled with a high-pressure working fluid, a carrier of stored energy, control valves with electromagnetic actuators and a hydraulic pump, characterized in that, in order to increase reliability by increasing the stability of the drive characteristics, a bellows sealed with an end cap and filled with compressed gas, the pressure of which is significantly lower than the pressure of the working fluid Torah.