HK1120614A - Electric switchgear - Google Patents

Description

Electric switch device

Technical Field

The invention relates to an electrical switchgear having a switching pole which is filled with an insulating gas, a monitoring device for the insulating gas of the switching pole, and an inspection connection of an inspection device for inspecting the monitoring device.

Background

Three-pole high-voltage switching devices usually have three switching poles mounted on a frame. These switching poles may be power breaker poles, disconnector poles, earthing switch poles, etc. At the seat of each pole of the switching device there is a housing which accommodates a drive mechanism, one for each pole of the switching device. The three pole housings of the switching device are connected to each other by a further gear mechanism and to the switch actuating mechanism. During the switching process, the switching pole is switched by the switching actuator from the first switching state to the second switching state or vice versa via the gear mechanism.

Due to the switching to the high voltage, the poles of the switchgear and the housing associated therewith are filled with an insulating gas. In order for this insulating gas to perform its insulating function and, above all, the function of extinguishing the arc, it is necessary to keep the insulating gas at a predetermined minimum pressure. This minimum pressure must be maintained in order for the switchgear to operate safely.

It is known how to monitor the pressure acting on the insulating gas. For this purpose, the housings of the three poles of the switching device are connected to a monitoring instrument by means of pipe connections with pressure sensors. When the switching device is in operation, the pressure on the insulating gas is always measured by the pressure sensor and monitored by the monitoring instrument.

The precondition for the monitored pressure of the insulating gas is, of course, that the pressure sensor in the monitoring device must work and display the correct pressure.

It is known how to check the monitoring instrument from time to time. This can be achieved by detaching the pipe connection from the housing and thus from the switching pole. In order for the switching poles to continue to operate in the separated state, a check valve must be provided to prevent the insulating gas from escaping from the switching poles. The operability and the measurement accuracy of the monitoring device, in particular of the pressure sensor therein, can be checked when the switch poles are separated. So that the free end of the pipe connection is provided with a non-return valve or sealed by a venting plug. The inspection scope may then be connected to a monitoring instrument. The pressure sensor of the monitoring instrument is then applied with an inspection pressure by the inspection scope. The pressures indicated by the inspection and monitoring instruments are compared. After inspection, the inspection scope must be removed and the tube connector reconnected to the housing and the switch pole.

Obviously, the above-described process for checking the monitoring instrument is very time consuming. The measures required, namely disconnecting the pipe connection and reconnecting to the switching poles, must be carried out in direct proximity to these poles. Since the switching device is usually working and live during the examination, it is necessary to prevent the examination person from being too close to the live parts, so that the above-described procedure can only be carried out if special measures are taken to protect the examination person.

Disclosure of Invention

The object of the present invention is to provide an electrical switchgear in which monitoring devices for insulating gas can be checked in a time-saving manner.

This object is achieved by an electrical switching device according to the invention.

The electrical switchgear according to the invention has a switching pole which is filled with an insulating gas, a monitoring device for the insulating gas of the switching pole, and an inspection connection of an inspection device for inspecting the monitoring device, wherein a mechanism having an inspection connection is provided, which mechanism is connected to the monitoring device and to the switching pole and has a valve by means of which the switching pole can be separated from the monitoring device.

The valve may simply separate the switching pole from the monitoring instrument. It is therefore not necessary to remove the pipe connection from the switching pole.

The device according to the invention also has an inspection connection to which an inspection device for inspecting the monitoring device can be connected. Here too, the pipe connection does not have to be removed. Alternatively, the inspection scope can simply be connected to the inspection connection and the monitoring instrument inspected.

Another essential advantage of the invention is that the mechanism can be arranged completely independent of the switching poles. This means that the mechanism does not have to be in the area close to the switching pole and therefore no special measures have to be taken to protect the inspection personnel.

Preferably, the mechanism of the present invention may be arranged with the monitoring instrument so that it is remote from the switch pole, if desired. The monitoring instrument and the examination itself can therefore be kept away from the examination instrument and the examination can be carried out completely independently of the switching pole.

In an advantageous embodiment of the invention, a plunger is provided which can switch the valve. The plunger makes it easy for an inspector to separate the switching pole from the monitoring instrument to inspect the monitoring instrument and to reconnect the monitoring instrument to the switching pole.

In a first advantageous alternative, a securing cap is provided which is separate from the plunger. The inspection connection of the mechanism can be closed by means of a fixing cap. When the test connection is closed, the valve is switched by the plunger, so that the switching pole and the monitoring device are connected to one another.

When the switching device is working normally, the inspection connector is closed by the fixing cap. Thus, the valve is switched by the plunger to a state in which the monitoring instrument and the switching pole are connected to each other. This means that the pressure acting on the insulating gas can be monitored by the monitoring instrument.

If the monitoring instrument is to be checked for proper functioning, the securing cap is removed from the inspection connection and the inspection instrument is instead connected to the inspection connection. Since the retaining cap has been removed, the valve is no longer held in position connecting the switch pole to the monitoring instrument. Alternatively, the valve switches and separates the switching pole from the monitoring instrument. In this state, the monitoring instrument can be checked by the inspection instrument without affecting the switching poles.

After inspection of the monitoring instrument, the inspection instrument is removed from the inspection sub and the inspection sub is reclosed with the locking cap. Because the plunger is attached to the retaining cap, the valve automatically returns to the position where the switch pole is connected to the monitoring instrument.

The plunger connected to the retaining cap ensures that the switching pole is automatically disconnected from the monitoring instrument when the retaining cap is removed and vice versa, the pole switching pole being automatically reconnected to the monitoring instrument when the retaining cap is in the use position. This makes it possible to prevent a mistake by the inspector.

In a second advantageous alternative, a plunger is provided within the mechanism. The inspection connections of the mechanism can be closed by means of a retaining cap. When the inspection connection is closed, a projection on the locking cap acts on the plunger. The valve is switched by the plunger when the inspection connection is closed, so that the switching pole and the monitoring instrument are connected to each other.

When the switching device is normally operated, the inspection connector is closed by the fixing cap. The valve is thereby opened and the monitoring instrument checks the pressure acting on the insulating gas. When the retaining cap is removed, the valve switches and separates the switch pole from the monitoring instrument. The inspection scope can be used in this state to inspect the monitoring instrument. After inspection of the monitoring instrument, the inspection connection is closed again by means of a fixing cap.

By means of the securing cap acting on the plunger, it is ensured that the switching pole is automatically disconnected from the monitoring instrument when the securing cap is removed, and vice versa, that the switching pole is automatically reconnected to the monitoring instrument when the securing cap is installed. This makes it possible to prevent a mistake by the inspector.

In a further advantageous embodiment of the invention, in the region close to the inspection connection, there is a projection which is assigned to a non-return valve located in the top part of the inspection scope. The inspection sub may be closed by the top piece and the check valve opened by the protrusion if the inspection sub is closed by the top piece. This measure makes it possible to use an inspection instrument with a check valve.

In a further advantageous embodiment of the invention, the valve is designed as a spring-loaded valve which has no further effect when closed and separates the switching pole from the monitoring device. This makes it possible to produce the valve very simply but functionally reliably.

Preferably, the valve is switched by the plunger into the open position against the valve spring force, wherein the switching pole is connected to the monitoring instrument. These measures are simple but ensure a high degree of functional reliability.

Drawings

Other features, applications and advantages of the invention will be found in the following description of an example of an embodiment of the invention as shown in the figures. All features described or illustrated, individually or in combination with each other, are subject matter of the present invention, irrespective of how they are combined together or their relation in the claims, and irrespective of how they are worded or described in the description or the drawings.

Fig. 1 shows a schematic perspective view of a part of an electrical switchgear with a monitoring device for an insulating gas;

FIG. 2 shows a schematic cross-sectional view of a first example of an embodiment of the mechanism of the present invention for inspecting the monitoring instrument of FIG. 1;

FIG. 3a shows a schematic cross-sectional view of a second example of an embodiment of the mechanism of the present invention for inspecting the monitoring instrument of FIG. 1;

FIG. 3b shows a schematic cross-sectional and external view of the plunger of the mechanism of FIG. 3 a; and

fig. 3c shows a schematic cross-sectional view of a locking cap for the mechanism in fig. 3 a.

Detailed Description

Fig. 1 to 3 are examples of a three-pole high-voltage circuit breaker. Instead of breaker poles, it is also possible to provide disconnector poles, earthing switch poles or any other type of poles normally used for switches.

Fig. 1 relates to a three-pole electrical switching device 10, by means of which high voltages can be switched on and off. Fig. 1 shows three housings 11, on top of which housings 11 breaker poles can be mounted. The drive mechanism for the breaker poles is within the housing 11. Other transmission mechanisms connecting the three housings 11 to each other and to the drivecage are not shown in fig. 1.

All three housings 11 and the breaker poles associated therewith are filled with, for example, sulphur hexafluoride (SF)₆The insulating gas of (1). The housing 11 is provided with a coupling 12 for filling them. Fig. 1 shows three couplings 12 connected hermetically by pipe connections 13 to a monitoring instrument 14. The monitoring device 14 may be arranged in the area close to the switching device 10, but independently of the switching device 10.

When the circuit breaker pole is operating, the insulating gas must be at a predetermined minimum pressure in the pole. In order to monitor this minimum pressure, a pressure sensor, for example a pressure gauge, is provided in the monitoring device 14. The pressure acting on the circuit breaker poles and the insulating gas in the housing 11 is transmitted via the coupling 12 and the pipe connection 13 to the monitoring device 14 and thus to the pressure sensor. The monitoring instrument 14 measures this pressure and compares it to a predetermined minimum pressure. If the measured pressure falls below the minimum pressure, the monitoring instrument 14 triggers an alarm signal.

Fig. 2 shows a mechanism 20 for checking the monitoring device 14 in fig. 1. The means 20 can be formed separately from the monitoring device 14 or can form a common component with the monitoring device 14. The mechanism 20 can be arranged in the area close to the switching device 10, but independent thereof. The arrangement of the monitoring device 14 relative to the mechanism 20 is shown by means of an arrow in fig. 2. The pipe connection 13 is also shown as such.

The mechanism 20 has a connector 21 to which a monitoring instrument can be connected. The mechanism 20 also has a coupling 22 to which the coupling 13 can be connected. The two joints 21, 22 are connected to each other by a pipe in the mechanism 20.

A spring-loaded valve 23 is arranged in the conduit and by means of which the conduit can be closed. For this purpose, the valve 23 has a sliding valve disk 24, the sliding valve disk 24 being assigned to a valve seat 25 in the mechanism 20. The valve disk 24 is loaded by a valve spring 26 such that it rests gas-tightly on a valve seat 25 without further action, thus closing the valve 23. Means for guiding the valve disk 24 and the valve spring 26 are also provided, but are not described in more detail.

The mechanism 20 has an inspection sub 28 connected to the pipe. The connection is arranged on the side of the valve 23 which is assigned to the connection 21 and thus to the monitoring device 14. Thus, regardless of the position of the valve 23, the inspection connection 28 is always connected to the monitoring instrument 14.

The inspection connection 28 can be closed by a retaining cap 29 so that it is airtight. For this purpose, the securing cap 29 can be screwed, for example, onto a corresponding thread on the inspection connection 28. The fixing cap 29 is provided with a plunger 30 on the side facing the mechanism 20, the plunger 30 protruding through the inspection nipple 28 into the inside of the pipe and thus into the inside of the mechanism 20 when screwing. The plunger 30 is not connected to the valve disc 24. The locking cap 29 and the plunger 30 are designed and arranged relative to the valve 23 such that when the locking cap is screwed on, the plunger 30 lifts the valve disc 24 off the valve seat 25 against the force of the valve spring 26. So that the valve 23 can be switched by the plunger 30. The valve 23 is then opened.

The valve 23 is opened by screwing the fixing cap, and the valve 23 is closed when the fixing cap 29 is removed. Fig. 2 shows the valve 23 open.

The junction 21, i.e., the monitoring instrument 14, and the inspection junction 28 form a first gas region G1. The connection 22, i.e. the pipe connection 13, as well as the housing 11 and the breaker pole, form a second gas region G2. This is illustrated by the dashed line in fig. 2.

When the fixing cap 29 is screwed and the valve 23 is opened, the two gas zones G1 and G2 are connected to each other. At the same time, the inspection connection 28 is closed by a fixing cap 29, so that it is airtight. The pressure acting on the housing 11 and the insulating gas 11 in the circuit breaker pole is transmitted by the open valve 23 to the monitoring instrument 14. As previously described, the pressure is monitored at the monitoring instrument 14.

When the securing cap 29 is unscrewed and the valve 23 is closed, the two gas zones G1 and G2 are separated from each other and are gas-tight. The housing 11 and the circuit breaker pole are thus separated from the monitoring apparatus 14, so that they are airtight. The check connection 28 is open.

An inspection scope, not shown, for inspecting the monitoring instrument 14 can be connected to the inspection connection 28. By means of which a varying examination pressure can be generated and displayed by means of a gas. Preferably the check pressure can be generated by the same insulating gas as is charged in the circuit breaker poles.

This test pressure acts via the test connection 28 on the monitoring device 14, in particular on a pressure sensor in the monitoring device 14. The examination pressure displayed by the examination apparatus may be compared with the pressure measured by the monitoring apparatus 14. In this way, the operability and the measurement accuracy of the monitoring device 14, in particular of the pressure sensor of the monitoring device 14, can be checked.

Because valve 23 is closed, the entire inspection of the monitoring instrument 14 described above is performed in the first gas region G1 and has no effect on the insulating gas in the second gas region G2. The valve spring 26 is dimensioned such that the valve 23 remains safely closed when subjected to the inspection pressure generated by the inspection scope.

After inspection of the monitoring instrument 14, the inspection scope is removed again and the securing cap 29 is screwed back so that the valve 23 is opened. The insulating gas diffuses within the two gases G1 and G2 and the monitoring instrument 14 re-monitors the pressure on the insulating gas.

Fig. 3a to 3c show a mechanism 40 for checking the monitoring device 14 in fig. 1. The mechanism 40 in fig. 3a to 3c is substantially the same as the mechanism 20 in fig. 2. Accordingly, corresponding parts are denoted by the same reference numerals. Please refer to the description of these components in conjunction with fig. 2. Only the differences and differences of the mechanism 40 of fig. 3a to 3c are mainly explained below.

Unlike the mechanism 20 of fig. 2, the mechanism 40 of fig. 3a to 3c is adapted to have an inspection scope with a check valve attached.

Fig. 3a shows the mechanism 40 together with a top part 41, wherein the top part 41 belongs to the examination apparatus and comprises a non-return valve 42. The check valve 42 has a valve disk 43, a valve seat 44, and a valve spring 45. The valve disc 43 is arranged to be slidable and the valve seat 44 is placed inside the top piece 41. Valve disk 43 is loaded by valve spring 45 so that valve disk 43 rests on valve seat 44 and is airtight without other effects. In this state the check valve 42 is closed. This state is not shown in fig. 3 a.

On the side facing away from the valve seat 44, the valve disk 43 is provided with a plunger 46. Means for retaining and guiding the valve disc 43 and the valve spring 45 are also provided, but are not described in detail.

Independently of the mechanism 40, i.e. upon removal, the check valve 42 in the top part 41 of the examination apparatus closes. As previously mentioned, this state is not shown in fig. 3 a.

Alternatively, fig. 3a shows a state where the top piece 41 is screwed to the inspection joint 28 of the mechanism 40. Within the mechanism 40, there is a protrusion 48 in the area proximate the inspection tab 28. The boss 48 and plunger 46 are designed and cooperate so that when the top piece 41 is screwed on, the valve disc 43 lifts off the valve seat 44. The check valve 42 then opens. As described above, this open state of the check valve 42 is shown in fig. 3 a.

On the mechanism 40 in fig. 3a there is a plunger 50, which plunger 50 differs from the plunger 30 in the mechanism 20 in fig. 2 in that it is tubular in design and has a slot 51 at its free end. The plunger 50 is not connected to the valve disk 24 nor to the retaining cap, but rather is designed as a separate component.

The plunger 50 is shown in detail in figure 3 b.

According to fig. 3a, the protrusion 48 passes through an elongated slot 51 of the plunger 50. The elongated slot 51 is designed to allow the plunger 50 to move freely without being constrained by the boss 48. Due to the tubular design of the plunger 50, it is also able to move freely relative to the plunger 46 of the check valve 42. The movement of the plunger 50 of the valve 23 and the plunger 46 of the check valve are therefore independent of each other.

As described above, when the top piece 41 is screwed, the check valve 42 is opened. As also described in connection with fig. 2, the valve 23 is closed as a result of the removal of the retaining cap. This state is shown in fig. 3 a. Inspection gas can now flow in through the free inlet of the top part 41 and inspect the monitoring instrument 14, as described above.

After inspection, the inspection scope with top piece 41 is removed again and check valve 42 is closed. The valve 23 of the mechanism 40 is not affected by unscrewing of the top part 41 and remains closed.

Then, instead of the top piece 41, a fixing cap 53 is screwed to the inspection joint 28. Unlike the securing cap 29 in the mechanism 20 of fig. 2, this securing cap 53 does not have a plunger, but rather has a tubular projection 54, the tubular projection 54 projecting through the inspection connector 28 into the space within the mechanism 40 when the securing cap 53 is threaded.

Fig. 3c shows the retaining cap 53 with the tubular projection 54 in detail.

When the fixing cap 53 is screwed, the tubular projection 54 moves to the free end of the plunger 50, and moves the plunger 50 toward the valve 23. Thereby, the valve disc 24 of the valve 23 rises and leaves the valve seat 25 and the valve 23 opens.

The inspection connector 28 is thus closed hermetically by the fixing cap 53 and the monitoring instrument 14 is connected to the circuit breaker pole by the tubular connector 13. As described above, the monitoring instrument 14 monitors the pressure acting on the insulating gas.

Claims (10)

1. An electrical switchgear (10) having a switching pole which is filled with an insulating gas, a monitoring device (14) for the insulating gas of the switching pole, and an inspection connection (28) of an inspection device for inspecting the monitoring device (14), characterized in that means (20, 40) having an inspection connection (28) are provided, the means (20, 40) being connected to the monitoring device (14) and the switching pole, and the means (20, 40) having a valve by means of which the switching pole can be separated from the monitoring device (14).

2. The switching device (10) as claimed in claim 1, wherein an inspection scope can be connected to the inspection connector (28) when the switching pole is separated from the monitoring instrument (14).

3. The switching device (10) as claimed in one of the preceding claims, wherein a plunger (30, 50) is provided, by means of which plunger (30, 50) the valve (23) is closed and opened.

4. The switching device (10) as claimed in claim 3, wherein a securing cap (29) is provided which is separate from the plunger (30), the inspection connection (28) of the mechanism (20) being closable by the securing cap (29), and the valve (23) being switched by the plunger (30) when the inspection connection (28) is closed, so that the switching pole and the monitoring apparatus (14) are connected to one another.

5. The switching device (10) as claimed in claim 3, wherein the plunger (50) is located in the mechanism (40), the inspection connection (28) of the mechanism (40) being closable by a retaining cap (53), the projection (54) of the retaining cap (53) acting on the plunger (50) when the inspection connection (28) is closed, and the valve (23) being switched by the plunger (50) when the inspection connection (28) is closed, so that the switching pole and the monitoring apparatus (14) are connected to one another.

6. Switching device (10) according to claim 5, wherein in the region close to the inspection connection (28) a protrusion (48) is provided, which is assigned to a non-return valve (42) in a top part (41) of an inspection scope, wherein the inspection connection (28) can be closed by the top part (41), and wherein the non-return valve (42) is opened by means of the protrusion (48) when the inspection connection (28) is closed by the top part (41).

7. The switching device (10) as claimed in one of the preceding claims, wherein the valve (23) is designed as a spring-loaded valve which, when closed, has no further effect and separates the switching pole from the monitoring apparatus (14).

8. The switching device (10) as claimed in claim 7 and any one of claims 3 to 6, wherein the valve (23) is switched by the plunger (30, 50) against the force of a valve spring (26) into the open position in which the switch pole is connected to the monitoring apparatus (14).

9. The switching device (10) as claimed in one of the preceding claims, wherein the monitoring apparatus (14) is provided with a pressure sensor and the operational capability of the pressure sensor is checked when the switching pole is separated from the monitoring apparatus (14) and when the inspection scope is connected to the inspection connection (28).

10. The switching device (10) according to any one of the preceding claims, wherein the pressure acting on the insulating gas in the switching pole is monitored by the monitoring instrument (14) when the switching pole is connected to the monitoring instrument.