JPH04282522A - Buffer type gas breaker with closing resistance - Google Patents

Abstract

PURPOSE:To contrifute to miniaturization of an operating mechanism part while contriving improvement of simplification of structure and reliability by reducing an acting load to ensure a high pole opening speed at the time of breaking action. CONSTITUTION:In an insulation operating rod 6 for driving a movable side electrode 1 in a main contact part, a orthogonal lever 5 to this insulation operating rod 6 is provided, and a making resistance contact movable side electrode 14 is provided in a point end of this lever 5. Further, a damper 23 is provided in a breaking action direction side of the making resistance contact movable side electrode 14.

Description

[Detailed description of the invention]

[Object of the invention]

0002

[Industrial Field of Application] The present invention relates to a puffer type gas circuit breaker with a closing resistor used in substations or switchyards of power systems, and in particular, the present invention relates to a puffer type gas circuit breaker with a closing resistor that is designed to reduce the load applied during the breaking operation. This relates to gas circuit breakers.

0003

2. Description of the Related Art In recent years, as power transmission systems have become larger in capacity, the breaking capacity of circuit breakers used in substations and switchyards has tended to increase. Therefore, circuit breakers are required to have even higher reliability. In order to improve the reliability of circuit breakers, it is important to reduce the number of parts and simplify the structure. In order to simplify this structure, it is desired to reduce the number of interruption points. For example, in a 550 KV system, a two-point puffer type gas circuit breaker with a breaking current of 50 KA has been put into practical use, but there is a demand for a one-point break. Generally, when cutting a large-capacity circuit breaker like this at one point, in order to improve its breaking performance,
The opening speed needs to be much faster than that of a conventional two-point circuit breaker.

By the way, for power transmission voltages of 168 KV or higher, puffer type gas circuit breakers using SF6 gas as the insulating gas are mainly used. This has the advantage that in addition to the fact that SF6 gas has excellent blocking and insulating performance, the structure is simpler than the two-pressure type. Furthermore, in a sealed gas switchgear that insulates the entire substation equipment with SF6 gas, there are even greater benefits in terms of emphasis on insulation from other equipment, equipment placement, etc. For this reason, puffer type gas circuit breakers have become the mainstream of high voltage circuit breakers.

[0005] In addition, such a puffer gas circuit breaker is
When used as a line in a 0KV class large-capacity system, a closing resistance method is adopted to suppress the closing overvoltage at the time of closing. In this system, a closing resistor contact section with a closing resistor is installed in parallel with the main contact section of the puffer type gas circuit breaker.When closing, this closing resistor contact section is closed before the main contact section, and the closing overvoltage is suppressed by the closing resistance. The main contact part is closed in a suppressed state. When opening in this method, it is necessary to first open the closing resistance contact section and then open the main contact section.

An example of such a puffer type gas circuit breaker with a closing resistor is shown in FIG. Note that FIG. 3 shows the cut-off state of a puffer type gas circuit breaker with a closing resistor, and this circuit breaker is housed in a tank (not shown) filled with an insulating gas such as SF6 gas.

In the figure, an insulating cylinder 9 is provided inside a tank (not shown), and a base 8 extending horizontally is fixed to this insulating cylinder 9. A puffer piston 7 is fixed to the tip of the base 8, and a mounting hole is passed through the center of the puffer piston 7, and a horizontally extending puffer cylinder 2 is slidably mounted in this mounting hole. ing. A space surrounded by the puffer cylinder 2 and the puffer piston 7 is a puffer chamber 10.

[0008] Furthermore, at the tip of the puffer cylinder 2,
A movable side voltage 1 for the main contact is provided. An insulating nozzle 3 and a movable current-carrying contact 4 are arranged concentrically around the outer periphery of the main contact movable voltage 1.

Furthermore, an insulated operating rod 6 extending horizontally is attached to the rear end of the puffer cylinder 2. An operating mechanism (not shown) is connected to the insulated operating rod 6, and the puffer cylinder 2 is configured to reciprocate in the horizontal direction by its driving force. Further, a lever 5 is attached to the insulated operating rod 6 and extends vertically downward with respect to the rod 6.

Further, a current-carrying conductor 12 is arranged opposite to the movable side voltage 1 for the main contact, and this current-carrying conductor 1
A fixed side voltage 11 for the main contact, which can be freely connected to and separated from the movable side voltage 1 for the main contact, is fixed at the center of the main contact 2 . A fixed current-carrying contact 13 that comes into contact with the movable current-carrying contact 4 is provided on the outer periphery of this main contact fixed-side voltage 11 .

The main contact portion of the circuit breaker is constituted by the fixed side voltage 11 for the main contact and the movable side voltage 1 for the main contact.

Incidentally, in a puffer type gas circuit breaker, a closing resistance contact section is electrically connected in parallel with the main contact section in order to suppress overvoltage when the circuit breaker is closed. The main part of this making resistance contact part is the movable side electrode 14 for making resistance contact.
, a fixed side electrode 15 for a closing resistance contact, and a closing resistor 17.

The structure of the closing resistance contact section will be explained in more detail. That is, the movable electrode 14 for the closing resistance contact is attached to the tip of the lever 5 in parallel with the puffer cylinder 2. This movable side electrode 14 for making resistance contact is the electrode 1
It is electrically connected to the movable side voltage 1 for the main contact via a sliding portion 18 that slides on the outer peripheral surface of the main contact.

A spacer 22 is provided at the lower end of the current-carrying conductor 12, and a fixed cylinder 20 is provided horizontally via this spacer 22. The fixed cylinder 20 is connected to the movable electrode 14 for the closing resistance contact.
, and an opening is formed on the side facing the movable contact electrode 14 .

Further, the fixed side electrode 15 for the closing resistance contact is housed in the fixed side cylinder 20 together with a return spring 16. The fixed side electrode 15 for the making resistance contact has its tip protruding from the opening of the fixed side cylinder 20 and is arranged so as to be able to freely come into contact with and separate from the movable side electrode 14 for the making resistance contact.
The return spring 16 always urges the movable electrode 14 side. Further, a space surrounded by the fixed side electrode 15 for the closing resistance contact and the fixed side cylinder 20 is a gas compression chamber 21 . Further, the fixed electrode 15 for the closing resistance contact is provided with a gas vent hole 19 through which the gas in the gas compression chamber 21 escapes.

Furthermore, the closing resistor 17 is connected to the fixed cylinder 2.
The closing resistor contact fixed electrode 15 in the fixed cylinder 20 is electrically connected to the current-carrying conductor 12 via the closing resistor 17 .

The puffer type gas circuit breaker with closing resistor constructed as described above operates as described below. That is, in the cut-off state shown in FIG. 3, when the operating mechanism (not shown) is driven, the insulated operating rod 6 connected to it
moves to the left in the figure, and the movable main contact electrode 1 is inserted into the fixed main contact electrode 11.

Furthermore, as the insulating operation rod 6 moves,
The lever 5 also moves to the left in the drawing, and at the same time, the movable electrode 14 for the making resistance contact also moves to the left in the drawing, and is thrown into the fixed electrode 15 for the making resistance contact. Such a closing operation of the closing resistance contact portion is performed at an earlier timing than the closing operation of the main contact.

Furthermore, since the gas in the gas compression chamber 21 is compressed by the fixed side electrode 15 for the closing resistance contact during the closing operation, the gas compression chamber 21 is compressed by the fixed side electrode 15 for the closing resistance contact.
This acts as a damper for suppressing the chattering of the closing resistance contact.

On the other hand, during the shutoff operation, the puffer cylinder 2 fixed to the insulated operating rod 6 moves rightward in the figure. As a result, the puffer chamber 10 formed by the puffer piston 7 and the puffer cylinder 2 is compressed, so that the arc-extinguishing gas inside the puffer chamber 10 is guided to the insulating nozzle 3, and the movable main contact and the main contact are separated. Fixed electrode 11
The arc is extinguished by being sprayed during this period.

Furthermore, the movable electrode 14 for the closing resistance contact also performs a separating operation from the fixed electrode 15 for the closing resistance contact, but due to the response delay of the return spring 16, the moment the movable electrode 14 for the closing resistance contact begins to move. Both electrodes 14 and 15 are separated,
This timing is earlier than the opening operation of the main contact with wipe.

[0022] According to the puffer type gas circuit breaker with closing resistor as described above, the structure is simple, and at the same time, the overvoltage at the time of closing is suppressed by the closing resistor contact part, so that it can be used even when interrupting a large current. Demonstrates excellent reliability.

[0023]

[Problem to be Solved by the Invention] However, when attempting to reduce the number of breaking points for the above-mentioned puffer type gas circuit breaker with closing resistor for the purpose of simplifying the structure, the following problems occurred. . In other words, in order to ensure excellent interrupting performance while reducing the number of interrupting points as described above,
It is necessary to significantly increase the opening speed of the main contact. Such an increase in the opening speed of the main contact portion causes an increase in the inertial force that acts during the breaking operation, and therefore, the stress that acts on each member increases.

In particular, in the conventional puffer type gas circuit breaker with closing resistor shown in FIG. This caused a large moment of force to be generated due to the influence of inertial force during the shutoff operation.

FIG. 4 shows an example of the theoretical value of the moment T0 of the force acting on the lever 5 in the direction of the arrow in FIG. 3 during the shutoff operation. As shown in the figure, near the end of the breaking operation, a large inertial force acts on the movable side electrode 14 for the closing resistance contact, etc., so the moment T0 of the force also becomes very large. Therefore, since a large moment of force is applied to the lever 5, a large load is applied to the insulated operating rod 6, the puffer cylinder 2, the supporting member of the puffer cylinder 2, the parts on which the puffer cylinder 2 slides, etc., which may cause damage. was.

In order to eliminate such drawbacks, there is an increasing need to increase the mechanical strength of the constituent members, and measures such as increasing the wall thickness of the members may be considered. However, since this leads to an increase in the weight of the movable parts of both contact portions, the opening speed slows down, making it impossible to obtain the required opening speed.

[0027] Therefore, in order to obtain the necessary opening speed, it is conceivable to increase the driving force to the movable parts of both contact portions. However, in order to increase the driving force, it is necessary to increase the size of the operating mechanism. As a result, there are problems in that the overall size of the device increases and the structure tends to become complicated.

The present invention was proposed to solve the problems of the prior art, and its purpose is to:
We provide a puffer-type gas circuit breaker with closing resistance that reduces the load applied during breaking operation, ensures high opening speed, simplifies the structure and improves reliability, and contributes to the miniaturization of the operating mechanism. It's about doing.

[Configuration of the invention]

[0030]

[Means for Solving the Problems] In order to achieve the above object, the puffer type gas circuit breaker with closing resistor of the present invention is provided with a movable side electrode of the main contact portion that is movable to drive in the closing operation direction and the disconnection operation direction. An insulated operating rod is provided with a lever that extends in a direction perpendicular to the moving direction of the insulated operating rod, and a movable electrode for the closing resistance contact is provided at the tip of the lever, and a lever that extends in the direction of the breaking operation of the movable electrode for the closing resistance contact is provided at the tip of the lever. It is characterized in that a damper is provided on the side of the movable side electrode for the making resistance contact.

[0031]

[Operation] In the present invention having the above configuration,
Near the end of the breaking operation, a large inertial force acts on the movable electrode for the closing resistance contact, and a large moment of force is applied to the lever. However, near the end of the breaking operation, the movable electrode for the closing resistance contact comes into contact with the damper. Thereby, the force acting on the lever is reduced by the reaction force acting from the damper on the movable side electrode for the closing resistance contact. Therefore, the maximum value of the moment of force acting on the lever can be made extremely small.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a puffer type gas circuit breaker with a closing resistor according to the present invention will be described in detail below with reference to FIGS. 1 and 2. Note that the same members as those in the conventional example shown in FIG. 3 are designated by the same reference numerals, and explanations thereof will be omitted. FIG. 1 shows the closed state, and FIG. 2 shows the closed state.

As shown in FIGS. 1 and 2, a movable cylinder 27 is provided in the horizontal direction on the base 8 at a position facing the movable electrode 14 for the closing resistance contact. In other words, the movable cylinder 27, the movable electrode 14 for the making resistance contact, the fixed electrode 15 for the making resistance contact, and the fixed cylinder 27 are arranged on the same straight line.

Further, a damper 23 that slides within the cylinder and a return spring 26 that urges the damper 23 toward the movable electrode 14 for the closing resistance contact are housed in the movable cylinder 27.

The tip of the damper 23 is provided to protrude from the movable cylinder 27 so as to come into contact with the end of the movable electrode 14 for the closing resistance contact, and the base of the damper 23 is always disposed within the movable cylinder 27. A gas vent hole 24 is opened in the. In addition, the movable cylinder 27 and the damper 2
The space surrounded by 3 is a gas compression chamber 25.

The operation of this embodiment having such a configuration is as follows. Note that the closing operation of this embodiment is the same as the closing operation of the conventional example shown in FIG. 3, so a description thereof will be omitted. Furthermore, in the breaking operation of this embodiment, the arc-extinguishing operation and the opening operation are also the same as the closing operation of the conventional example shown in FIG. 3, so their explanations will be omitted.

That is, in conjunction with the breaking operation of this embodiment, the movable side electrode 14 for the making resistance contact and the fixed side electrode 15 for the making resistance contact are opened and separated. At this time, the movable electrode 14 for the closing resistance contact moves rightward in the drawing, and the end of the movable electrode 14 for the closing resistance contact contacts the damper 23 near the end of this opening operation. As the opening operation progresses, the closing resistance contact movable electrode 14 moves rightward in the figure, and its end presses the damper 23 into the movable cylinder 27 against the biasing force of the return spring 26. Thereby, the damper 23 compresses the gas in the gas compression chamber 25.

FIG. 5 shows the theoretical value P of the pressure change inside the gas compression chamber 25 during the shutoff operation in this embodiment. The moment TD of the force acting on the lever 5 from the damper 23 due to the rise in pressure within the gas compression chamber 25 is expressed by the following equation (1).

[0039]

[Math 1]

Here, P is the pressure inside the gas compression chamber 25, P
φ is the filling pressure of gas in a container (not shown), Sc is the cross-sectional area on the inner diameter side of the cylinder 27, and L is the length of the lever 5.

In this embodiment, the total moment T of the force acting on the lever 5 is the movable side electrode 1 for the making resistance contact described above.
It is the sum of the moment T0 of the force due to the inertial force acting on the damper, and the moment TD of the force acting on the damper, and the following (2
) is expressed by the formula.

T=T0 +TD (2) Also, FIG. 6 shows the moment of force T0 due to inertial force, the moment of force TD acting from the damper, and the sum of the moments of force T
shows the theoretical value of As is clear from this figure, the moment T0 of force due to inertia force is reduced by the moment TD of force acting from the damper 23, so the maximum value TMAX of the total moment T of force is lower than that of the conventional method shown in FIG. It is much smaller than the maximum value T0MAX of T0, which is the sum of the moments of force.

According to this embodiment as described above, the moment of the force acting from the damper 23 is obtained by utilizing the pressure increase in the gas compression chamber 25 in the movable cylinder 27,
Due to the action of this moment of force, the moment of force acting on the lever 5 due to the inertial force during the shutoff operation can be reduced. Therefore, it is possible to reduce the load acting on the insulating operation rod 6, the puffer cylinder 2, the support member of the puffer cylinder 2, or the sliding portion thereof. As a result, the opening speed of the main contact can be reliably increased,
It becomes possible to reduce the number of interrupting points while ensuring excellent interrupting performance. Therefore, the structure can be simplified and reliability can be improved.

[0044] Furthermore, the mechanical strength of these members can be improved, and moreover, it can contribute to downsizing of the operating mechanism and simplifying the structure.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and for example, the damper is not limited to a gas damper that utilizes gas pressure as in this embodiment, but an oil damper or the like may also be used. effect can be obtained. Also,
By changing the size of the gas vent hole, it can be freely set according to the specifications of the circuit breaker.

[0046]

As described above, according to the present invention, the insulated operating rod that drives the movable side electrode of the main contact portion is provided with a lever orthogonal to the insulated operating rod, and the closing resistor is attached to the tip of the lever. By providing a movable side electrode for the contact and further providing a damper on the side of the movable side electrode for the closing resistance contact in the breaking operation direction, the load applied during the breaking operation can be reduced, so the opening speed of the main contact section can be ensured. It is possible to reduce the number of interruption points by increasing the number of interruption points. Therefore, the structure can be simplified and reliability can be increased. Further, since the load applied during the shutoff operation can be reduced, it is possible to contribute to downsizing of the operating mechanism section.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an embodiment of a puffer type gas circuit breaker with closing resistance according to the present invention, showing the closing state.

FIG. 2 is a side cross-sectional view showing one embodiment of the puffer type gas circuit breaker with closing resistance according to the present invention, showing the shut-off state.

FIG. 3 is a side sectional view showing an embodiment of a conventional puffer type gas circuit breaker with a closing resistor, showing the shutoff state.

FIG. 4 is a characteristic diagram showing the moment of force acting on the lever in a conventional puffer type gas circuit breaker with closing resistance.

FIG. 5 is a characteristic diagram showing pressure changes in the movable gas compression chamber in the embodiment shown in FIG. 1;

6 is a characteristic diagram showing the moment of force acting on the lever in the embodiment shown in FIG. 1. FIG.

[Explanation of symbols]

1 Movable side electrode for main contact 2
Puffer cylinder 5 Lever 6 Insulated operating rod 7 Puffer piston 10 Puffer chamber 11 Fixed electrode for main contact 12 Current-carrying conductor 14 Movable electrode for closing resistance contact 15
Fixed side electrode for closing resistance contact 23 Damper 25 Gas compression chamber 27 Movable side cylinder

Claims (1)

[Claims] Claim 1: A main contact section is housed in a tank filled with an insulating gas, and includes a fixed side electrode fixed in the tank, and a movable side electrode that can be freely connected to and separated from the fixed side electrode. An insulated operating rod that drives the movable electrode in the closing operation direction and the disconnection operation direction with respect to the fixed electrode is movably installed, and a closing resistor contact portion that suppresses overvoltage at the time of closing is connected to the main electrode. In a puffer type gas circuit breaker with a closing resistor electrically connected in parallel with a contact portion, the closing resistor contact portion is connected in series with a fixed side electrode for the closing resistor contact and the fixed side electrode for the closing resistor contact. It consists of a closing resistor and a movable electrode for the closing resistance contact that can be freely connected to and separated from the fixed side electrode for the closing resistance contact, and the fixed side for the closing resistance contact of the closing resistance contact section is connected to the fixed side electrode of the main contact section. An electrode and a closing resistor are provided, and the insulated operating rod is provided with a lever extending in a direction perpendicular to the direction of movement of the insulated operating rod, and a movable side for the closing resistor contact of the closing resistor contact portion is provided at the tip of the lever. A puffer type gas circuit breaker with a closing resistor, characterized in that a damper is provided on the breaking operation direction side of the movable electrode for the closing resistor contact, and the movable side electrode for the closing resistor contact comes into contact with the damper. .