DE1040648B - High voltage electrical circuit breaker - Google Patents

Description

The invention relates to an electrical high-voltage circuit breaker, which is able to interrupt currents with certainty within a large area.

In the construction of such switches, difficulties arise in particular when the switch to cope with large breaking capacities, z. B. 15 million kVA at 23OkV and 25 million kVA at 33OkV, and also relatively small currents, for example charging currents or small magnetizing currents, should interrupt. In order to break high short circuit one overflow To avoid high pressure inside the switch, exhaust openings can be considerable Provide cross-section. Also, the cross-sections of the bore, within which the arc burns, and the inlet openings for the inflow of the liquid are enlarged towards the arc. If these measures are used, however, there is a risk that the cross-sections of the carrion puff openings and the inlet openings are so large that an effective interruption is relatively small currents is no longer possible.

In addition, switches are already known in which, in addition to the quenching chamber, there is also a chamber is provided, in which an arc is drawn at the beginning of the switch-off process, the one Pressure is generated by which the switching fluid is driven into the arcing chamber. To delete the Achieving an arc when switching off small currents is under the action of springs Piston provided, the cylinder of which is provided with bores through which it connects to the extinguishing chamber communicates. The springs assigned to the piston are dimensioned so that only a piston. Movement occurs when there is a low pressure inside the extinguishing chamber.

It is also known to provide two separate arcing chambers in such switches, one arcing chamber serving to interrupt high currents and the other to interrupt low currents. The arc drawn at the beginning of the disconnection process generates a pressure that drives the switching liquid into the quenching chamber for high currents, while the piston, which is under the action of a spring, has the task of pushing the quenching liquid into the quenching chamber for low currents. The two arcing chambers are arranged next to one another, so that two movable and two fixed contact pieces are required and, in addition, a drive element is required for each movable contact piece. In order to prevent a current flow through the switching point assigned to the quenching chamber for low currents in the case of high currents, electrical
High voltage circuit breaker

Applicant:

Westinghouse Electric Corporation,
East Pittsburgh, Pa. (V. St. A.)

Representative: Dr.-Ing. P. Ohrt, patent attorney,
Erlangen, Werner-von-Siemens-Str. 50

Claimed priority:
V. St. v. America March 24, 1954

Winthxop M. Leeds, Pittsburgh, Pa. (V. St. Α.),
has been named as the inventor

must be provided with this switch means that the circuit in which this switching point is located, interrupt if large currents occur. So that the interruption of the circuit is carried out without current it must be done before opening the switching point that is assigned to the arcing chamber for large currents is. In addition, the opening of the two switching points must be controlled so that when switching off of small currents, the switching point assigned to the arcing chamber for high currents first, namely de-energized, is opened.

The invention also relates to an electrical high-voltage circuit breaker with an arcing chamber for high and a quenching chamber for low currents as well as a chamber in which at the beginning of the Switching off an arc is drawn, which generates a pressure that the switching fluid in the Drives extinguishing chamber for high currents, and which has a piston under the action of a spring, which presses the switching fluid into the arcing chamber for low currents. According to the invention are the two arcing chambers arranged one behind the other

«09 657V331

and penetrated by a common switching pin, which first enters the arc to be interrupted Extinguishing chamber for high currents pulls. The inventive training has compared to the known at the two arcing chambers are arranged side by side, the advantage that only one fixed and a movable contact piece with drive element common to both arcing chambers is required. Aside from that- it is no longer necessary with this switch design to provide means that occur when high currents a current flow via the switching point assigned to the quenching chamber for low currents impede. Due to the design according to the invention, the structure of such switches is considerable simplified.

According to a further embodiment of the invention, the two arcing chambers are through a plate separated from each other, which has bores to which valves are assigned.

Exemplary embodiments of the invention are shown in the drawing.

Fig. 1 shows a side view, partly in section, of a switch in the closed position;

FIG. 2 shows, on an enlarged scale, a section through the left-hand arc extinguishing unit of FIG. 1; included the switch is shown in the half-open position, and the parts of the switch take the position for the interruption of relatively low currents, e.g. B. Charging currents, a;

Fig. 3 corresponds essentially to FIG. 2, the only difference being that it shows the state during the Interruption of relatively large currents, such as B. of fault currents shows;

Fig. 4 is a cross-section on the line IV-IV of Fig. 2, looking in the direction of the arrows;

Figure 5 is a cross-section on line V-V of Figure 2 looking in the direction of the arrows;

FIG. 6 is a cross section according to line VI-VI of FIG. 3.

In the drawing (see FIG. For example, FIG. 1), 1 denotes a boiler, which is up to level 2 with a suitable extinguishing liquid 3, e.g. B. switch oil is filled. Two passages 6 lead through the cover 5 and 7, at the lower ends of which a pair of similar arc extinguishing units 8 are attached. With 9 is denotes a conductive crossbar through which the two arc extinguishing units 8 are electrically connected in series are switched. The cross rod 9 can by an actuating rod 10 made of insulating material in a vertical Direction can be moved up and down. The actuation mechanism for the rod 10 is not shown.

With a contact foot 11 is referred to, which by means of a screw 12 on the lower, provided with thread End of the lead-through bolt of the implementation 6 is attached. The contact foot 11 forms its lower part a chamber 13. Inside this chamber there is a movable contact piece 14, (Jas is rotatable about the axis 15 and forms a fork with two arms 16 outside the chamber. These arms 16 are rotatable with the upper end of an operating rod 18 through a pin 17 Insulating material connected. A spring 19 acts on the actuating rod 18 and tries to follow it up press down.

This compression spring 19 is supported with its lower end on a cap 20, which is at the lower end of the Operating rod 18 is provided. The upper end of the compression spring is supported on a plate 21 made of insulating material which preferably forms part of the arc extinguishing unit 8.

The contact piece 14 cooperates with an intermediate contact piece 23, which consists of a pair of opposing contact parts 24 and 25 is made. These are pressed apart by a compression spring 26 and are electrically connected to one another by flexible conductors 27.

With the lower contact part 25 of the movable contact pin 28 cooperates, on which a Compression spring 29 acts, which tries to push it into the position in which the switch is open. The contact pin can be moved upwards through the outer end 30 of the conductive crossbar 9.

During the switching-off process, the contact piece 14 is moved away from the contact part 24. This creates within the chamber 13 an arc 31 which causes a pressure increase. Moved when switching off further the contact pin 28 down and comes out of contact with the contact part 25, so that how 2 and 3, an arc 32 arises. With a shut-off valve 33 is referred to, the is held in the open position by a compression spring 34. Here, the interior of the chamber 13 is mediated a vent opening 35 vented. As will be described later, the shut-off valve remains open when interrupting relatively low currents, while it is open when interrupting of relatively high currents in which there is a high pressure inside the pressure chamber 13, closes.

Suitably designed plates made of insulating material form the arc extinguishing unit 8. They are through Tie rods 36 made of insulating material with screwed nuts 37 (see. Fig. 1) held.

As can be seen in particular from FIG. 2, an arcing chamber for high currents is just below the Intermediate contact 23 is provided. In series therewith is a quenching chamber 39 for low currents, the is provided below a plate 40. The plate 40 has bores 41 which are controlled by valves 42 are. The valves 42 are by compression springs 43 against the seats 44 in the plate 45 made of insulating material pressed. When a certain pressure is reached in the chamber 13, the valves 42 are opened. the vertical flow channels 46 are formed by openings in the plates of insulating material, which are provided at the upper end of the arc extinction as shown in FIG. You can see that the to be interrupted arc 32 first in the quenching chamber 38 for high currents and then through the Plate 40 is pulled into arcing chamber 39 for low currents.

At the lower end of the arc extinguishing unit there is a piston 47 which is actuated by a compression spring 48 is pressed down. When switching on, the piston is covered by a cap 49, which is on the lower End of the contact pin 28 is attached, taken. The lower end of the is supported on the cap 49 Compression spring 29. The upper ends of the springs 29 and 48 are supported against the plate 50 of insulating material away.

When the piston 47 moves downwards under the action of the compression spring 48, the extinguishing liquid, z. B. oil, driven upward through the channels 51 in the direction of the arcing chamber 39, as it is is indicated by the arrows in FIG.

During the switch-on process, the actuating rod 10 is moved upwards, whereby it the conductive crossbar 9 takes with it. Through the ends 30 of the crossbar 9, the caps 49 and thus the two switching pins 28 moved upwards. You grain

Men with the intermediate contacts 23 in contact, while at the same time the pistons 47 through the caps 49, as can be seen from FIG. 2, can be taken along. The crossbar comes towards the end of the switch-on stroke also with the caps 20 attached to the lower end of the actuating rod 18 for engagement, see above that these rods are moved against the compression spring 19 upwards. This will make the contact piece 14 moves downwards and comes into contact with the intermediate contact piece 23. The compression spring 26 generates the required contact pressure between the contact pieces 14 and 28 on the one hand and the contact parts 24 and 25 on the other hand.

During the switch-off process, the actuating rod 10 is driven by a drive (not shown) moved down. During this switch-off movement of the actuating rod, the cross rod 9 will also move moved downwards. The compression spring 19 tries to bring the actuating rod 18 into engagement with the cross rod 9 to hold, whereby the contact piece 14 moves away from the contact part 24 and the pressure generating Arc 31 is generated. Meanwhile, the compression spring 29 holds the cap 49 of the switch-off contact 28 with the end 30 of the crossbar 9 in contact. As a result, there is a separation between the upper one End of the contact pin 28 and the contact part 25, so that between the two to be interrupted Switch-off arc 32 is drawn.

The pressure generated by the arcs 31 drives liquid to the switch-off arc 32 out, whereby this is extinguished during the interruption of a high current, while the piston 27 helps with the interruption of low current values. After extinguishing arcs 3Γ and 32 the transverse rod 9 separates from the caps 49 and reaches the switch-off position 52 (see FIG. 2). Through this two insulating oil sections are inserted between the two arc extinguishing units 8.

The high current arcing chamber 38 will now be described in detail. The two plates 53 and 53 a have an opening 54, the shape of which is shown in FIG. The ends 54 a of the opening 54 are designed kidney-shaped. Through these openings a pair of opposing inlet channels, such as particularly apparent from Fig. 5, created by the vertical flow channels 46 to the lead the upper part of the arc extinguishing chamber 38. There are also two arranged at a certain distance Plates 56 are provided which have openings or bores through which the arc 32 is drawn will.

Between the two plates 56 there is another plate 58 made of insulating material, which is a pair Has vent or exhaust ducts 59, which from the arc duct 60, formed by the bores 57, lead to the space outside the extinguishing unit 8 (cf. in particular FIG. 5). Below the second Plate 56 there is a plate 61 with an opening similar to that indicated by the reference number 54 in FIG. 5 is designated. This opening forms two further inlet channels 55 for the flow of liquid, the comes from the channels 46, as indicated by the arrows 62. The arc quenching chamber formed in this way 64 for high flow is of large cross-section through inlet ports 55 and exhaust ports 59, as in FIG Figs. 2 and 5 shown, marked for the quick and effective interruption of high Streams are suitable. Depending on the level of tension, further plates 61, 56 and 58 can be provided. In the exemplary embodiment there are only two pairs of inlet channels 55 and a single plate 58, in which there are ventilation channels 59.

As can be seen from FIG. 2, the high current arcing chamber 64 is mounted above the plate 40. Underneath the plate 40, plates of suitable design are provided which have a plurality of inlet channels 65, as can be seen from FIG. 2, form. As can be seen in particular from FIG. 6, which shows a cross section through the low current arc chamber 39, the inlet plates 67 here a cutout 68 which forms inlet channels 65 of small cross-section. Furthermore, plates 69 are provided, the bores of smaller cross-section than the bores 57 of the plates 56 of the upper arcing chamber own. Furthermore, there is a plate 71, which consists of two halves 72 laterally moved apart (cf. FIG. 6), the ventilation channels 73 are provided with a smaller cross section than the ventilation channels 59 of the plates 58 of the upper arcing chamber result.

As can be seen from FIGS. 2 and 3, there are three plates 71 with vent channels and also six pairs of inlet channels 65 provided. If desired, the number of those formed from the plates 71, 69 and 67 can be Parts of the arcing chamber are increased.

If you compare the upper with the lower arcing chamber, you can see that the cross-sections of the holes, the inlet ducts and the vent ducts of the quenching chamber for low flow are smaller than that of the arcing chamber 38 for high current. It can also be seen that the space 75 behind the piston 47 is connected to the space outside the unit 8 through the openings 76 of the piston 47. Consequently the piston 47 will assume its uppermost position at high pressure within the unit 8 and will only move down when the pressure within the unit 8 is released, creating a there is a strong flow of liquid (oil) and thus the unit 8 is cleaned of impurities will.

The effectiveness of the switch is as follows: If a small current is interrupted, the large flow channels 46 and the large ventilation channels 59 only a negligible increase in pressure instead of. Therefore, the spring 34 holds the upper shut-off valve 33 open. As a result, the arc will not interrupted in chamber 38. Only by the pressure of the oil pump 47 is an attempt to be made Interrupt the arc when it is drawn into the lower chamber 39. During this time the valves 42 are closed, so that the oil flow generated by the piston 47 through the three pairs of inlet channels 65 flows to the relatively small openings 70 and in close contact with them the arc stands. From the low current quenching chamber, the liquid flows through the three Pairs of vent channels 42, as shown by arrows 77 in Fig. 6, out. Through the liquid acting on the arc will soon result in an interruption of the arc.

When high currents, e.g. B. short-circuit currents or high load currents, are interrupted by With the high pressure generated in the chamber 13, the upper valve 33 is closed and the valves 42 are closed opened. No oil is pumped through the piston 47, since the piston is driven by the high pressure in the unit 8 is held in its upper position; because the space 75 behind the piston is unimpeded in the Relatively low pressure space outside the unit 8 is vented. The great channels and the Vent openings 59 allow the interruption

Claims (3)

of strong currents without creating a dangerously high pressure within the unit 8. Should the Interruption of the arc will not be completed when the upper part of the contact pin 28 is below reaches the plate 40, the oil flow through the valves 42 now has an additional effect the arc in the arcing chamber for low current. The arc will be extinguished soon. It can be seen from Fig. 2 and 3 that the switch 2 chambers for arc extinguishing for high and for low currents. The upper chamber is especially for the interruption of fault currents and suitable for relatively very high magnetizing currents. Through the large holes and ventilation ducts will avoided the creation of excessively high pressure. The lower arcing chamber for low current with its bores 70 is particularly suitable for the interruption of relatively small currents, which generally will not be interrupted before the arc is drawn under the plate 40 ao will. As already mentioned, the piston 47 is particularly useful when interrupting such low Flows effectively with the valves 42 remaining closed. During the interruption of a high current arc, as mentioned earlier, the Piston 47 held in its uppermost position. However, after the arc is interrupted the pressure in the unit 8 will decrease and consequently an effective flushing action by the piston 47 insert. In all cases, at the end of the switch-off movement, the transverse rod 9 takes the switch-off position so that separating distances are created in the oil and the circuit is kept open. Pate ν ta ν s i> η,: c n 1; ! .Electric high voltage circuit breaker with one quenching chamber for high and one quenching chamber for low currents and one chamber, in which an arc is drawn at the beginning of the switch-off process, which generates pressure, which drives the switching fluid into the arcing chamber for high currents, and one under the action of a spring standing piston, which the switching fluid in the quenching chamber for low currents, characterized in that the two arcing chambers are arranged one behind the other are and are penetrated by a common switching pin, which is to be interrupted Arc first draws in the quenching chamber for high currents. 2. Switch according to claim 1, characterized in that between the two arcing chambers a plate is arranged which has bores to which valves are assigned. 3. Switch according to claim 1, characterized in that the under the action of a spring standing piston has a larger bore than is necessary for the passage of the switch pin. Considered publications:
U.S. Patent Nos. 2,463,029, 2,592,635. 1 sheet of drawings ® 809 657/331 9.58