JP2677584B2 - High current switch - Google Patents

Description

Description: TECHNICAL FIELD The present invention has at least one first vacuum switching switching chamber, and further comprises at least one current passage for each phase surrounded by a non-magnetic metal capsule. Two current paths having at least one first output current path and a nominal current path connected in parallel to the at least one first output current path, the interrupting of the at least one first output current path upon interruption. A high-current switch whose point opens after switching the current to be interrupted to the at least one first output current path.

Conventional Technology Siemens Publication “The New Generator Switch f
or 8000 A "(new switch for 8000 A generator) (order number: E 139 / 2067-101) is known for this kind of high current switch. A large current switch that is installed in the power transmission connection always flows a relatively large nominal current of 8000 A, so three vacuum switching chambers are connected in parallel per phase. The current load characteristics are limited because the loss of heat is dissipated only through the connections emerging from these vacuum switching chambers.
It can only be quite large and uneconomically costly.

Problem to be Solved by the Invention The problem to be solved by the present invention is not to always supply a current to the vacuum switching chamber, but to supply a short-time current between interruption and closing,
It is to provide a high-current switch having a vacuum switching switch chamber.

According to the present invention, there is provided a high-current switch of the type described at the outset, wherein an axial magnetic field is applied to the interruption 7 of the at least one first output current path 4. And at least one second vacuum switching chamber 6 is provided in at least one second output current passage 4 connected in parallel to the at least one first output current passage, and the at least two output currents are provided. It is solved by that each of the passages 4 has the same impedance value, which mainly has an inductive component.

Other advantageous configurations according to the invention are set out in the dependent claims.

EFFECTS OF THE INVENTION The advantage obtained by the present invention is that the vacuum switching opening / closing chamber is substantially loaded with a uniform load at the time of shutting off, so that it can be better utilized. Even at the time of turning on, the inrush current is evenly distributed in the vacuum switching switching chamber immediately after the preliminary ignition, so that the overload of each vacuum switching switching chamber can be eliminated here as well. Furthermore, the heavy advantage is that a vacuum switching switch room suitable only for a relatively low nominal current can be introduced in the high current switch, neglecting the aforementioned drawbacks,
This is because good opening and closing characteristics can be fully utilized.

Embodiment Hereinafter, the present invention will be described in more detail with reference to the drawings showing only one embodiment.

FIG. 1 shows a principle diagram of the large current switch 1 of the present invention. The large current switch 1 may be configured as a single phase or a multi phase. The current path 2 leads to a high-current switch 1, where it is divided into a nominal current path 3 and an output current path 4 in parallel with this current path 3. The nominal current passage 3 has an auxiliary switching opening / closing point 5, which is bridged by an output current passage 4 in which a vacuum switching opening / closing chamber 6 is equipped with a breaking point 7. Before and after the vacuum switching opening / closing chamber 6, coils 8 and 9 for applying a magnetic field in the axial direction are connected to a breaking point 7. Coil 8,9
Is, as shown in this drawing, the vacuum switching opening / closing chamber 6 spatially.
The vacuum switching opening / closing chamber 6 is concentrically surrounded at a breaking point 7 and is mechanically connected to this breaking point 7 via an insulating holder. The two coils 8, 9 are arranged at the same distance from the open breaking point 7, the longitudinal axis of the coil being equal to the longitudinal axis of the vacuum switching chamber 6. Furthermore, the spacing between the two coils 8, 9 is never greater than the inner diameter of the coil. Both coils 8,9
Have the same number of turns, at least once and at most 5
It is wound twice, mainly twice. The coils 8 and 9 are wound in one layer or multiple layers, and the number of turns need not be an integer. The input terminal 10 is electrically connected to one end of the coil 8, and the other end is connected to the vacuum switching opening / closing chamber 6 via a conductive connecting piece. The vacuum switchgear chamber 6 is connected to one end of the coil 9 and the other end to the output terminal 11 via another connecting piece.

At the time of interruption, first, the auxiliary opening / closing position 5 is opened, and the interruption slip current is switched to the output current passage 4. After that, the vacuum switching opening / closing chamber 6 is opened, and the arc burns at the breaking point 7. The current to be interrupted flows through the two coils 8 and 9 of the same size and the same configuration in the same direction, and both coils 8 and 9 are interrupted at the interruption point
And an axial magnetic field acting on the arc generated in the breaking point during breaking. Since the coils 8 and 9 are arranged at the same place at the breaking point 7, this magnetic field is almost uniform and is proportional to the current, and even if the arc has a current value of 50 KA or more, it spreads. Therefore, the contactor at the shutoff point 7 is kept within a limit in which combustion can be suppressed. This kind of current value is
Due to the relatively large number of turns of 24 and 24, it is possible to control and shut off only with a strong axial magnetic field.

Similarly to FIGS. 2 to 5 below, FIG. 1 does not show all mechanical drive members for operating the auxiliary switching opening / closing point 5 and the vacuum switching opening / closing chamber 6 corresponding thereto. Furthermore, the first
The non-magnetic metal capsule surrounding each phase of the large current switch 1 is also not shown in the figure.

FIG. 2 shows another large-current switch 1 in the closed state in the upper half of the drawing and in the closed state in the lower half. The current passage 2 is formed in a tubular shape, and is supported by a metal capsule 16 concentrically arranged with an insulator 15. This metal capsule 16 is also formed in a tubular shape and is made of a non-magnetic metal. The large current switch 1 can be fixed to the foundation by the legs 17 installed on the metal capsule 16. The metal capsule and each front end of the current path 2 have the possibility of connecting a single-phase, metal-sealed generator to a known power transmission connection. The metal capsule has openings for assembling and inspection, and just like the penetrations for mechanical drive members. In the case of the high-output large-current switch 1, the opening and the penetrating portion are normally pressure-sealed. This is because all the transmission connections of the generator are slightly overpressurized in order to reduce the contamination of the insulator 15. In order to improve the loss of heat loss, the power transmission connection of this type of generator is often forced to blow air.

When the large current breaker 1 is turned on to the nominal current passage 3,
There is a gap bridging at the auxiliary opening / closing position 5. The auxiliary opening / closing positions 5 are shown here as finger contacts, but their number can be selected depending on the value of the nominal current. Since a part of this finger contact follows the rest of the contacts during interruption, the switching arc is formed only on this following finger contact. The remaining finger contacts are therefore undamaged and always ensure a reliable introduction of the nominal current. On closing, the finger contacts first close and likewise take on the switching load. The finger contact fits into a holder (not shown) that is moved by the drive. Parallel to the nominal current path 3, only two parallel output current paths 4 are shown here. Each of the output current passages 4 is configured in accordance with the output current passage 4 described in FIG. Two output current paths 4
Are located here inside the hollow nominal current path 3 and are arranged symmetrically about the center. The two output current paths 4 each have an equal impedance value of the main inductive component. Therefore, when a current flows through the output current passages 4, all the output current passages 4 have a uniform current distribution, and none of the vacuum current chambers 6 is overloaded. Therefore, the output opening / closing capacity of each vacuum switching opening / closing chamber 6 can be used completely without any margin of safety.

The operation of the large current switch 1 will be briefly described. When the high-current switch 1 carries the nominal current, the auxiliary switching switch 5 is closed and the entire nominal current flows from the current path 2 to the nominal current path 3. Since the output current path 4 is in the space without the magnetic field inside the nominal current path 3, it does not pass current. In response to a shutoff command for operation switching or short-circuit shutoff, the auxiliary switching opening / closing point 5 is opened first, and the entire current is switched to the output current passage 4 and distributed evenly. After that, the vacuum switching opening / closing chamber 6 is opened, and normally,
The current is cut off at the next current zero point. In the shut-off state, the auxiliary opening / closing position 5 and the vacuum switching opening / closing chamber 6 are open. In closing, first, the vacuum switching opening / closing chamber 6 is closed, and the closing current flows through the output current passage 4 and is uniformly distributed. Immediately after this, the auxiliary switching opening / closing point 5 is also closed, and the current is switched from the output current passage 4 to the nominal current passage 3. In the two switching processes, the electric current flows through the vacuum switching opening / closing chamber 6 only for a very short time each time, so that an excessively large heat load does not occur in the vacuum switching opening / closing chamber. The vacuum switching chamber 6 withstands even short continuous switching cycles without problems.

For many applications one vacuum switching switchgear 6 per output current path 4 should ensure sufficient withstand voltage. However, in order to achieve a higher withstand voltage, it is also possible without difficulty to connect two or more vacuum switching switching chambers 6 in series per output current passage 4.

As shown in FIG. 3, the output current path 4 can also be arranged outside the nominal current path 3. This likewise concentric and symmetrical arrangement has the advantage that more output current paths 4 can be arranged evenly around. This large current switch 1
Is suitable for nominal current values greater than the switch of FIG. In the closed state, in the case of the large current switch 1, a small amount of current always flows through the output current path 4 in order to eliminate the current. However, this slight current is limited to an infinite value by the impedance of each output current passage 4, so that the heat load of each vacuum chamber 6 can be ignored.

FIG. 4 shows a combination of devices corresponding to FIGS. 2 and 3 which is particularly suitable for high currents. It should be noted that the large current switch 1 needs to have the same impedance of the output current path 4 inside the nominal current path 3 and the impedance of the output current path 4 outside.

In the case of a space installation condition that is particularly narrow with respect to the large current switch 1, the insulator 15 is formed as a pressure-sealed disk insulator, and the current passages 2 are also formed on both sides of the large current switch 1 inside. It is also possible to shut off in the state of being pressure-sealed. Such spaces are filled with an insulating medium such as compressed air or SF ₆ gas. In this way, it is possible to reduce the insulation distance, and thus the size of the switch, and also to arrange the output current passage 4 and the vacuum switching switch chamber 6 attached thereto closely. FIG. 5 shows another improved embodiment of the high-current switch 1, which is similar to the embodiment corresponding to FIG. However, all this embodiment is equally possible for the remaining embodiments. Each of the output current paths is
Sensor 21 in series with the limiter and I _s limiter 20 is incorporated. The signal detected by the detector 21 is monitored in the evaluation unit 22 and processed. The evaluation unit 22 acts on all I _s limiters 20 simultaneously and activates them simultaneously, as implied by the dotted action line 23. However, it also configured evaluation unit 22 actuates only constant I _s limiter 20. At this time, the output current passage 4 is cut off.
This type of overlapping switching capability enhances the reliability of the large current switch 1 when shutting off. For example, if the vacuum switching opening / closing chamber 6 is not shut off, the sensor 21 in the output current passage 4 that malfunctions displays this. In the evaluation unit 22, still current example in a single output current path 4 of extinguishing the phase at the beginning, that is so to make sure that all the current to be interrupted flows, the evaluation unit 22 is instantaneously all I _s Limiter Activate 20. In high-current switch 1 of a three-phase group, all I _s limiter 20 is operated at all three phases. Since there is no need to investigate the cause for actuating the I _s limiter 20 in total output current path 4 is provided with the output current path 4 may identify devices that sensor 21, and malfunction is operated to the evaluation unit 22. After operation, it is necessary to check the I _s limiter 20 manually. However, this cost is well tolerated given what damage to the generator and other equipment components is prevented.

The above-mentioned malfunction is caused by activating only the I _s limiter 20 of the first extinguished phase, or normally shutting off only the I _s limiter 20 of the malfunctioning output current path 4 and the other two phases of the three phases. It is also possible to do it. However, this switching requires an electronic evaluation unit 22 which operates very fast. If a malfunction occurs the first time the phases were extinguished to a second, actuating only the I _s limiter 20 with a malfunction, or when only actuating I _s limiter 20 the output current path 4 with a malfunction effectively. This is because is because, thereby reducing the cost of time and work to examine the I _s limiter 20. Evaluation unit 22, after actuation of the I _s limiter 20, a large current switch 1
This switch must be inspected each time the switch is turned on and blocked until it is fully operational again. Evaluation unit 22
Needs to be always designed to ensure in each case the optimum use of I _s limiter 20. This includes the
It is necessary to confirm that the operation of the wrong I _s limiter 20 is not performed.

High-current switch 1 of this kind having a vacuum switching switch chamber 6
Since the inspection of the vacuum switching opening / closing chamber 6 is extremely small, is particularly suitable for a pump supply power plant in which it is necessary to design a switch of a generator with a large number of switching times.

For example, as in the case of a large current switch, a large current switch 1 which has less demands on the breaking capability does not use the coils 8 and 9 in only one output current passage 4 and at least one vacuum switching switch chamber 6 It is enough to provide. In order to interrupt the load current, this breaking capacity is sufficient with the breaking capacity of at least one vacuum switching switching chamber 6 in which the contacts are arranged to generate a relatively weak axial magnetic field.

[Brief description of the drawings]

1, a principle diagram of a large current switch according to the present invention, FIG. 2, a first embodiment of a large current switch according to the present invention, FIG. 3, a second embodiment of a large current switch according to the present invention, 4 is a third embodiment of the large current switch according to the present invention, FIG. 5 is a fourth embodiment of the large current switch according to the present invention. Reference symbols in the figure: 1 …… Large current switch 2 …… Current passage 3 …… Nominal current passage 4 …… Output current passage 5 …… Auxiliary switching opening / closing location 6 …… Vacuum switching opening / closing chamber 7 …… Breaking location 8, 9 …… coil 10 …… input terminal 11 …… output terminal 15 …… insulator 16 …… metal capsule 17 …… foot 20 …… _Is1 limiter 21 …… sensor 22 …… evaluation device 23 …… operating conductor

Claims (7)

(57) [Claims] 1. At least one first vacuum switching chamber (6) and at least one current passage (2) for each phase surrounded by a non-magnetic metal capsule (16). One current path (2) has at least one first output current path (4) and a nominal current path (3) connected in parallel to this at least one first output current path, and when shut off, said A high current switch (1), which is opened after the interruption point (7) of the at least one first output current path (4) switches the current to be interrupted to the at least one first output current path (4), An axial magnetic field is applied to the interruption point (7) of the at least one first output current passage (4), and at least one second vacuum switching switching chamber (6) is connected to the at least one first output. Parallel to current path Is provided in at least one second output current path (4) connected to, and each of the at least two output current paths (4) has the same impedance value mainly having an inductive component. Current switch. 2. The at least one nominal current passage (3) is hollow and the at least two output current passages (4) are arranged in the at least one nominal current passage (3). The large current switch according to claim 1, wherein the large current switch is provided. 3. The at least one nominal current passage (3) is hollow and the at least one first output current passage (4) is in the at least one nominal current passage (3). High current according to claim 1, characterized in that the at least one second output current path (4) is arranged outside the at least one nominal current path (3). Switch. 4. At least two vacuum switching opening / closing chambers (6) each having at least two coils (8, 9) of the same size and flowing in the same direction, and one vacuum switching opening / closing switch before and after each coil. High current switch according to claim 1, characterized in that the chamber (6) is connected. 5. Both coils (8,9) concentrically surround each vacuum switching chamber (6) at the point of interruption, each coil (8,9) being at the same distance from the open point of interruption. And each of the coils (8, 9) has at least one, or at most five,
5. A large current switch according to claim 4, characterized in that it mainly has two windings, and that both coils (8, 9) are not always installed at intervals wider than the inner diameter of the coil. . 6. Each of the at least two output current path (4), one of I _s limiter (20) and a sensor (21) is provided with entirely one evaluation unit of the sensor (21) Claim 22, characterized in that it is connected to (22) and that this evaluation unit (22) acts on the entire I _s limiter (20) at the same time or selectively on a given I _s limiter (20). The high current switch according to any one of 1 to 3. 7. The high-current switching device according to claim 6, wherein the evaluation unit (22) is provided with a device for identifying the sensor (21) chamber (6) for generating a signal. vessel.