RU2287200C1 - High-voltage load circuit breaker - Google Patents

Abstract

FIELD: power engineering; three-phase high-voltage circuit-opening devices.

SUBSTANCE: proposed high-voltage load circuit breaker that can be used for handling separate sections of 6-10 kV distribution lines at load currents of several hundreds of amperes and in no-current situations to protect power mains against short-circuit currents has two support insulators carrying spatial frame that mounts top transfer arc-control chamber and bottom enclosed one, conducting rods affording electrical connection between top and bottom arc-control chambers, and cleat rigidly coupled with conducting rods. Cleat is mounted for displacement between top and bottom arc-control chambers. In addition, circuit breaker has cleat operating mechanism in the form of control rod and compression spring, both coupled on one end with cleat and on other, with control rod. Bottom end of control rod is coupled with cleat and top one, with springs for disconnection. Frame and cleat are made of insulating material.

EFFECT: enhanced operating reliability and reduced mass of circuit breaker.

1 cl, 2 dwg

Description

The invention relates to energy, in particular to three-phase devices, and can be used for switching individual sections of electric distribution networks of 6-10 kV at load currents up to several hundred amperes and in the absence of current, as well as for protecting electric networks from short circuit currents. In the latter case, high voltage fuses are sequentially connected to the load switch.

Known are high voltage switches containing an arcing chamber with a fixed contact, a lead and a current path for connecting the lead to the contact (Catalog of the company EIB No. 21.5 01e, 1975, FIG. 1).

In this switch, the position of the camera with the fixed contact is rigidly fixed, without the possibility of adjustment, which complicates the interaction of the fixed contact with the movable due to the possible misalignment of these elements, which reduces the reliability of the device.

A high voltage circuit breaker is known, comprising an arcing chamber with a fixed contact, a terminal and a current path connecting the terminal to a fixed contact, and the articulation of the two elements of the current conductor is made by working contacts in the form of bodies of revolution (SU 442525, 1975).

The disadvantage of this technical solution is the low reliability of operation, due to the fact that during repeated operations on and off, the adjustment and contact tension between the connected elements of the current lead can be violated.

Currently, two types of load breakers are known: autogas (for example, VNP-10 / 630-20) and vacuum (VNVP-10 / 320-2). The manufacture of vacuum circuit breakers requires a large expenditure of material, working time, equipment. Therefore, this type of circuit breaker is not widely used in the CIS countries.

The opening of the arcing contacts of the autogas load switches in these switches takes place in chambers made of plastic with organic glass inserts. The design of the chambers allows shutdowns up to 200 times at a current of 100 A and 3 times at a current of 400 A, after which replacement of the bushings is required, which requires complete removal of the circuit voltage and dismantling of the quenching chambers. In accordance with this main disadvantage of existing gas switches is:

- the need for frequent replacement of plexiglass inserts in interrupter chambers;

- Frequent accidents due to the failure of the arcing contacts in the narrow gap of the horn of the load switch, as well as the frequent jamming of the same contacts;

- the presence of only one contact gap per phase;

- the complexity of the support structure of the drive;

- heavy weight of the device.

In addition, the load switches described above are fixedly installed in the switchgear cubicles, i.e. stationary, which complicates their operation.

Known is a high voltage switch containing an arcing chamber, which consists of a fixed plate made of heat-resistant insulating material in the form of a truncated cone on which the contact system is mounted, and a movable cylinder made of the same insulating material, inside of which a conical shape corresponding to the truncated cone of a fixed plate. Contacts are mounted on the bottom of the movable cylinder (SU 729680, 1980). When triggered, moving on a fixed plate, and therefore on the arc, the movable cylinder performs a quick narrowing of the narrow gap with conical surfaces, thereby achieving cooling and extinction of the arc.

The disadvantage of this technical solution is:

- the presence of only one contact gap per phase;

- the complexity of the support structure of the drive;

- heavy weight of the device.

The technical result achieved by the invention is to increase the reliability of the circuit breaker while reducing weight.

The invention consists in achieving the technical result in a high voltage load switch, which contains two supporting insulators, a spatial frame mounted on the insulators, on which are placed the upper passage and lower closed arc quenching chambers, conductive rods, a strap rigidly connected to conductive rods and installed with the possibility of movement between the upper and lower chambers of the extinction of the arc, and the drive moving the strap, made in the form of tension springs, one to ntsom associated with a rod, and the other - with the thrust, the lower end of the link is rigidly connected with a rod, the top - with springs detachably, and the frame and strap are made of an insulating material

The invention is illustrated by drawings, where in Fig.1 shows a high voltage load switch; figure 2 - conductive rod.

The circuit breaker according to the invention comprises two insulators 1, a spatial frame 2 mounted on insulators, having an upper 3 and a lower 4 crosspiece. On the upper cross member 3, passage chambers 5 for extinguishing the arc are installed, on the lower cross member 4, lower closed chambers 6 for extinguishing the arc. Between the upper and lower arc quenching chambers, conductive rods 7 are installed, having contact (without hatching) and coated with insulation (for example, fluoroplastic) of the required thickness (shaded) part. In addition, the conductive rods from the side of the upper arc quenching chambers end with a conical shape ending of the same insulating material. The length of the rods is such that after moving them down when the device is turned off, visible gaps form at the upper chambers.

Inside the support frame 2 there is a strap 8 rigidly connected to the conductive rods 7. The strap 8 is mounted to move between the upper and lower crossbars 3 and 4, respectively, by means of a drive for moving the strap, which consists of a rod 9 and compression springs 10, with the springs having a lower end connected to the bar 8. The thrust of the displacement drive is made in the form of a U-shaped structure, while the legs of the structure are rigidly connected to the bar 8, and the cross member with springs installed on both sides of the legs. The springs and the tie rod 9 are connected with the possibility of separation by means of a release 11. To control autogas load switches of the Soviet (currently Russian) production, manual drives of types PR-17 and PRA-17 are used. These drives are equipped with free trip mechanisms that ensure the operation of the apparatus by tempering (uncoupling) the spring system. The specified drives can be used for this switch of loading.

The switch has three upper passage and three lower closed arc quenching chambers and, accordingly, three conductive rods.

The arc extinction chamber consists of a contact system, of a fixed plate of heat-resistant material, inside of which a cylindrical surface is cut, having a diameter slightly larger than the diameter of the movable current-carrying rod (to create the effect of a narrow gap). The upper chamber is made in the form of a passage channel in order to provide a visible gap. The lower chamber, somewhat elongated in length, does not structurally differ from the upper one, but is made with a dead-end glass-shaped channel and provides complete isolation of the lower contact after the circuit breaker is turned off.

The whole structure is located during storage on base 12. During operation, the load switch is installed directly in the cabinet (for example, KSO-366) on insulators.

The switch according to the invention operates as follows.

In the on state of the switch, the bar 8 and the conductive rods 7 rigidly connected to it are in the upper position, providing electrical communication between the contact systems of the upper passage 3 and the lower 4 of the closed arc extinction chambers. The cross member of the rod 9 is connected with the springs 10 in a compressed state.

To turn off the load switch, the rod 9 is released from adhesion with the springs, under the action of the springs, the bar 8 together with the conductive rods 7 moves downward, ensuring the extinction of arcs in the chambers of each phase with the simultaneous isolation of live parts. After shutdown, visible gaps form in the upper chambers.

The presented design has a common frame for three phases of insulating material (insulators 1, frame 2 and strip 8), for example, asbogetinaks or asbestos-laminate, and for each phase there are two contact systems - upper and lower. In addition, the design presented provides arc quenching simultaneously with the complete isolation of all conductive parts from each other, which eliminates the possibility of re-ignition of the arc regardless of the electrical strength of the gap.

Due to the simplicity of the design and the small number of parts included in it, the circuit breaker has a small weight of about 14 kg, which allows it to be equipped with plug-in contacts and made withdrawable by means of rollers (not shown in the drawing) without using a trolley.

Claims (1)

A high voltage load switch comprising two support insulators on which a spatial frame is installed, characterized in that the upper passage and lower closed arc extinction chambers are placed on the frame, between which conductive rods are installed that provide electrical communication between the contact systems of the upper and lower arc extinction chambers, with which the bar is installed rigidly connected with the possibility of moving between the upper and lower arc quenching chambers, the movement drive of which consists of traction and compression springs, the lower ends of the springs connected to the bar, and the upper ends to the rod, while the lower end of the rod is rigidly connected to the bar, and the upper end is connected to the springs with the possibility of separation, and the frame and bar are made of insulating material.

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