JPH0354409B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a shingle breaker in which the arrangement structure of switching overvoltage suppressing resistors is improved.

[Technical background of the invention and its problems]

In order to suppress the switching overvoltage of a circuit breaker, especially the closing overvoltage when closing a circuit breaker, a resistor closing method is generally used in which a resistor is closed before the main contact.
This is used in power transmission systems of 500kV or higher. In this case, a link mechanism mechanically connected to the main contact is generally used as the contact for opening and closing the closing resistor. In addition, the shearing performance of the sheath disconnectors equipped with a closing resistor, especially the SF ₆ spray type sheath disconnectors, has recently been significantly improved, and models with a large width and a reduced number of shear disconnections have appeared, and 500 kV In power grids as well, two-point disconnects and disconnectors have begun to appear.

On the other hand, the value of the closing resistor that suppresses the closing overvoltage is determined by the insulation coordination level of the power transmission system, the system voltage, the system surge impedance, and the length of the power transmission line, and is not greatly affected by the short circuit capacity. Therefore, even if the performance of the breakers and breakers is improved and the number of breakouts is greatly reduced as described above, the closing resistor remains unchanged from the current state. However, the fact that the number of breakers is greatly reduced means that the number of closing resistor switching contacts is also reduced accordingly, and the space in which the breakers are installed is also greatly reduced. Therefore, efficient arrangement and configuration of resistors has become an important issue.

FIG. 1 shows an example of a conventional closing resistor and disconnector.

Conventional closing resistors and disconnectors have four disconnection units 2a, 2b, 2c, and 2 inside the tank 1.
d are connected in series, both ends of which are led out to the outside through bushings 3a and 3b, and 2a, 2b, 2c, and 2d of the four shear section units are connected in series.
The driving portions 4a and 4b are respectively configured to correspond to the driving portions 4a and 4b. Therefore, when the number of wire breaks is reduced as described above, the number of closing resistance contacts is reduced, but the resistor remains the same as the conventional one. In addition, as the rated voltage of the circuit breaker increases, the surge voltage also increases, making it necessary to increase the capacity of the resistor and the number of resistors compared to the past. Therefore, the conventional structure has the disadvantage that resistors cannot be arranged efficiently.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to replace the closing resistor and the closing resistor switching contact arranged in parallel with the bridge or break when the number of breaks or breaks decreases. It is an object of the present invention to provide a circuit breaker which can be arranged efficiently and which causes little thermal deterioration and mechanical strength deterioration of a resistor.

[Summary of the Invention] In order to achieve the above object, the present invention arranges the resistive switching contact and the main contact gap and the disconnecting portion almost horizontally, and the resistor is arranged between the resistive switching contact and the main contact gap and the disconnecting portion. The resistor is arranged with its central axis deviated upward from the longitudinal central axis of the gas-tight tank, and the resistor is attached to the upper inner wall of the gas-tight tank via an insulator.

[Embodiments of the invention]

The present invention will be explained below based on an embodiment shown in FIGS. 2 to 4. The sheath section unit 2 is
It is provided with a closing resistance contact 5 as a resistance switching contact and a main contact 6 as a main contact and a disconnection part. The closing resistance contact 5 includes a fixed contact 10 having a wipe spring 9 in a gap 8 formed by an insulating cylinder 7, and a lever 11.
A movable contact 13 is disposed that moves forward and backward by a drive mechanism 12 composed of, etc. The tip portion of the movable contact 13 is covered with a shield 15. Similarly, the end of the fixed contact 10 is also covered with a shield 16.

The main contacts 6 include a fixed contact 18 provided on a shield member 17 and a movable contact 21 provided on a puff cylinder 20 that moves a puff piston 19 of the fixed member. The movable contact 21 is moved forward and backward by a drive mechanism 23 composed of a lever 22 or the like, and is provided with a nozzle 24 made of an insulator at its tip. Also, the lever 11 of the resistance closing contact 5 and the lever 22 of the main contact 6
and are mechanically connected to each other by a shaft 25 as a connecting mechanism, so that they operate at the same angular velocity. Furthermore, the making resistance contact 5 is made of an insulating material and is connected to the tank 1.
The movable contact 13 is supported and fixed horizontally to the main contact 6 side, and the movable contact 13 is placed at a position where the axes of the main contact 6 and the making resistance contact 5 are different from each other, for example, at a position with a sufficient insulation distance on the upper side of the tank 1. It is electrically connected to metal fittings 37 of a plurality of resistors 33 supported and fixed from the side by insulators 36.

Therefore, in the above-mentioned configuration, the drive unit 4a,
When a closing command is applied to 4b, the driving force is transmitted to the sheath breakage lever 23 via the insulated operating rod 31, and at the same time as the sheath breakage portions 2a to 2d perform the closing operation, they are connected to the rotating shaft of the lever 23. The rotational force is transmitted to the lever 11 of the closing contact 5 through the insulating shaft 25, and the closing contact 5 starts the closing operation. At this time, since the electrodes are arranged and configured such that the closing time of the closing contact 5 is shorter than the closing time of the shingle break section 6, the closing contact 5 will close first even if the closing operations are started at the same time. Closing resistor 33
is first inserted in series into the power transmission system, and after being energized for a certain period of time, the shield breaker 6 is closed, the closing resistor 33 is short-circuited, and the closing operation is completed. The shrinking operation is performed through a process reverse to the above-mentioned closing operation. in this case,
Since the fixed side contact 10 of the contact 5 is wiped by the spring 9, it is unable to follow the opening speed of the bow break portion 6 and the closing contact movable contact 13, and the closing contact 5 is wiped before the tip break portion 6. Since the electrode is opened and the interelectrode insulation is restored in advance, the main current shear break occurs at the main sheath break portion 6. In a high-voltage, large-capacity shunt breaker, it is necessary to increase the number of resistors 33 and increase the capacitance of the resistors in order to suppress surges generated by such closing and shutting operations.

As mentioned above, since the axes of the main contact 6 and the resistance contact 5 are arranged at different positions, the extra space around the main contact 6 and the resistance contact 5 can be used, and a large number of resistors 33 can be installed in this extra space. can do. In addition, in the case of frequent cutting and cutting,
Since heat is easily generated from the resistor 33, placing it horizontally above the axis of the main contact 6 and the resistance contact 5 increases the heat dissipation effect and reduces thermal deterioration of the resistor 33. Furthermore, since the plurality of resistors 33 are not directly supported by the main contact 6 or the resistance contact 5 but are supported by an insulator from the tank 1, they are directly subjected to vibrations caused by the operation of the movable parts of the main contact 6 and the resistance contact 5. Therefore, the strength of the support for the resistor 33 can be lowered, and deterioration of the mechanical strength of the resistor 33 can be reduced.

〔Effect of the invention〕

As explained above, the present invention has been developed by rationally arranging resistors, against the background that the number of shear breaks is decreasing and the sheath breakers are becoming smaller due to the improvement in the shearing performance of the sheath breakers. It is possible to provide a high-voltage, large-capacity shield breaker that can suppress overvoltage when the shield breaker is turned on to a level below the protection level of the system. Furthermore, since the resistor is arranged horizontally above the axis of the main contact and the resistance contact, the heat dissipation effect is improved and thermal deterioration of the resistor is reduced. Furthermore, since the plurality of resistors are attached to the tank through insulators, they are not directly subjected to vibrations caused by the movement of the movable parts of the main contacts and resistance contacts, and the strength of the support for the resistors can be reduced. This has the effect of reducing mechanical strength deterioration of the resistor.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram showing a conventional breaker,
Figures 2 to 4 show an embodiment of the present invention, where Figure 2 is an internal configuration diagram of the chopper, Figure 3 is a perspective view thereof, and Figure 4 is a vertical cross-section of the chopper. It is a front view. 1... Gas-tight tank, 33... Resistor, 5
...Resistance switching contact, 6...Main contact and disconnection, 7...
…Insulator.

Claims (1)

[Claims] 1. A main contact break section provided in a gas-tight tank, a resistor connected in parallel with the main contact break section to suppress switching overvoltage of the break switch, and a current flowing through this resistor. A resistive switching contact that opens and closes the resistive switching contact, and the resistive switching contact and the main contact slot are arranged almost horizontally, and the resistor is placed along the longitudinal direction of the resistive switching contact and the main contact slot. 1. A shingle breaker characterized in that the resistor is arranged with its central axis deviated upward from the central axis of the gas-tight tank, and the resistor is attached to an upper inner wall of a gas-tight tank via an insulator.