WO2020043449A1 - Medium- or high-voltage switch and use thereof - Google Patents

Abstract

The invention relates to a medium- or high-voltage switch (34), particularly an outdoor medium- or high-voltage switch, with a break distance (36), in which two switching devices (40, 44) are connected in series, comprising a transmission (48), a switching element (46) for controlling the switching devices (38, 42) by means of the transmission (48), and a drive (50) for driving the switching element (46). According to the invention, the transmission (48) is designed such that, when the switching element (46) controls the switching devices (40, 44) for a switching process of the medium- and high-voltage switch (34), it always controls one of the two switching devices (40, 44) for opening and the other one for closing. The invention also relates to a use of said medium- and high-voltage switch (34) and to a direct-current switching device (14) for interrupting an electrical direct current (10) flowing along a medium- or high-voltage current path (12) by means of such a medium- or high-vloltage switch (34).

Description

description

Medium or high voltage switch and its use

The invention relates to a medium or high voltage switch, in particular outdoor medium or high voltage switch, with (i) a switching path in which two Schaltvor directions are connected in series, (ii) a transmission,

(iii) a switching element for controlling the switching devices via the transmission, and (iv) a drive for driving the switching element.

The invention further relates to the use of such a medium or high voltage switch.

A medium or high voltage switch of the type mentioned is known from the document DE 10 2016 202 764 Al be where it is referred to as a circuit breaker. The publication shows an outdoor high-voltage switch with a switching path that connects two in series

Switching chambers each have a switching device, with egg nem gear, with a shift rod as a switching element for controlling the switching devices via the transmission, and with a drive for driving the shift rod. In addition to this switching path, the high-voltage switch discussed in this publication also has a further switching path that is driven in the same way.

In the medium or high voltage range, there are various applications for switching paths with two series-connected switching devices. One of them is a direct current switching device for interrupting an electrical direct current flowing along a medium or high voltage current path. The publication DE 10 2013 213 602 A1 shows such a DC switching device.

It is the object of the invention to provide measures by which new uses for a medium or High-voltage switch, in particular in connection with egg ner DC switching device for interrupting an electrical direct current, result.

The problem is solved by the features of the independent claims. Advantageous refinements are specified in the subclaims.

In the medium or high voltage switch ter according to the invention, in particular outdoor medium or high voltage switch ter, with a switching path in which two switching devices are connected in series, with a transmission, with a

Switching element for controlling the switching devices via the transmission, and with a drive for driving the Schaltele element, it is provided that the transmission is designed such that the switching element when driving the Schaltvorrich lines for a switching process of the medium or high voltage switch always one of the two switching devices for opening and the other for closing.

A possible use for such a medium or high voltage switch is the use in a direct current switching device for interrupting a direct current flowing along a medium or high voltage current path, with a first switching unit that can be connected in this current path, with a Circuit module for forcing a current zero crossing in the first switching unit and with a second switching unit for connecting the direct current switching device or at least the switching module in the medium or high voltage current path, the first switching device of the above medium or high voltage Switch forms the first switching unit and its second switching device forms the second switching unit.

According to a preferred embodiment of the invention, it is provided that the transmission is designed in such a way that the actuation of the switching devices closes the second switching device before the opening of the first of the switching devices. directions. In the context of the application described in the DC switching device, there is a need for this switching sequence.

Alternatively, it is also preferably provided that the gear mechanism is designed in such a way that the control of the

Switching devices closing the second Schaltvorrich device after opening the first of the switching devices be acts. In the context of the described application in the DC switching device, there is also the following need for these switching series.

It is particularly preferably provided that the transmission is designed in such a way that the actuation of the switching devices effects a closing of the second switching device either before or after the opening of the first of the switching devices.

According to a further preferred embodiment of the invention, the first of the switching devices is designed as a commutation switch and the second of the switching devices is designed as an isolating switch. In the context of the application described in the DC switching device, the switching devices generally have exactly this function. For more information, see for example the technical brochure TB 683 2017 A3 / B4-34 "Technical requirements and specifications of state-of-the-art HVDC

Switching equipment "from CIGRE (CIGRE: Conseil International des Grands Reseaux Electriques).

It is preferably provided that the switching path has two switching chambers connected in series, in particular vacuum switching chambers, one of the switching devices being arranged in each of the switching chambers. Such a configuration of the switching path has proven itself and is known, for example, from the document DE 10 2016 202 764 A1 mentioned at the beginning. Finally, it is preferably provided that the medium-voltage or high-voltage switch furthermore has an electrical connection for supplying voltage to the switching path between the two switching devices, in particular between the two switching chambers.

The invention further relates to the use of a medium or high voltage switch mentioned above in a direct current switching device for interrupting an electrical direct current flowing along a medium or high voltage current path.

The invention further relates to the use of the above-mentioned medium or high voltage switch in a direct current switching device for interrupting an electrical direct current 10 flowing along a medium or high voltage current path.

Finally, the invention relates to a DC switching device for interrupting a direct current flowing along a medium or high-voltage current path, with

 a first switching unit interconnectable in this current path,

 a circuit module for forcing a current zero crossing in the first switching unit,

 a second switching unit for connecting the direct current switching device or at least the circuit module in the medium or high voltage current path, and

 a medium or high voltage switch mentioned above, the first switching device the first switching unit and the second switching device forms the second switching unit.

Switching units for this medium or high-voltage application can generally be divided into three categories: semiconductor switches (e.g. with GTOs, IGBTs etc.), mechanical switching units and hybrid switching units. Let it go mechanical switching units for higher voltage levels (no rail applications with quenching chamber switches or switches with arcing horns) are divided into switching units with passive or active parallel commutation paths.

In a first switching unit with a high arc burning voltage, a passive resonant circuit can be used because, if the circuit is suitably designed, the current can be increased by the negative voltage-current characteristic curve of an arc. Ideally, there is an artificial current zero in the mechanical switching unit, so that the first switching unit can interrupt the current. With this switching principle, however, the time until the power is interrupted is relatively long.

By using an active parallel commutation path, the switching time can be significantly reduced and the need for a high arc voltage can be prevented. For this purpose, an RLC resonant circuit with a pre-charged capacitor is typically used as a capacitive component.

For this purpose, the capacitor is ideally charged negatively with respect to the current and voltage direction of the first switching unit. In the event of a switch, the first switching unit is opened and a switching arc arises between its contacts. If this has reached a sufficiently large insulation distance to withstand the recurring voltage, the RLC resonant circuit is now closed, so that the capacitor discharges and a zero current pulse is impressed in the mechanical switchgear. If the amplitude of the current zero pulse is now sufficiently high that this leads to a current zero crossing in the mechanical switching device, then the current can be interrupted by the first switching unit.

Accordingly, it is particularly provided that the circuit module to form a resonant circuit together with the first switching unit has at least one inductive component and at least one capacitive component. The Circuit module or its commutation path thus comprises an LC element or an RLC element. Via this resonant circuit, it is then possible to force a current zero crossing in the first switching unit. In other words, the units (resistor R, inductance L, capacitance C) for an RC or RLC resonant circuit are typically connected in such a parallel commutation path.

In a further advantageous embodiment, it is provided that the second switching unit (i) is connected in series with the first switching unit in the medium-voltage or high-voltage current path or (ii) for optionally connecting the switching module to the first switching unit in the switching module, in particular in the commutation path.

The direct current switching device preferably also has a control device for actuating the switching devices. This control device then comprises the transmission

Switching element for controlling the switching devices via the transmission, and the drive for driving the switching element.

According to a preferred embodiment of the DC switching device according to the invention, this has a surge arrester connected in parallel to the first switching unit and to the circuit module.

In the following, exemplary embodiments of the invention are shown schematically in drawings and are described in more detail below. Show:

Fig. 1 is a DC switching device with a tel or high-voltage switch according to a first preferred embodiment of the invention and

Fig. 2 is a DC switching device with a tel or high voltage switch according to a two-th preferred embodiment of the invention. Fig. 1 shows a circuit arrangement 10 with a tel or high-voltage current path 12 and a DC switching device 14 for interrupting a flowing along the medium or high-voltage current path 12 electrical DC current 10. To the course of the medium or To clearly represent high voltage current paths 12 are the starting and end points A, B of the part shown

Current paths 12 marked accordingly.

The direct current switching device 14 has a switchable in the current path 12 first switching unit 16 and a switching device module 18 for forcing a current zero crossing in the switching unit 16. The switching unit 16 is a mechanical switching device, for example a vacuum interrupter. The circuit module 18 for forcing a current zero crossing in the first switching unit 16 forms, together with this switching unit 16, a resonant circuit 20. For this purpose, the circuit module 18 is designed as a commutation current path, in short: commutation path, which is connected in parallel with the first switching unit 16. A series connection of a resistive element 22, an inductive element 24 and a capacitive element 26 is connected in the circuit module 18 or commutation path. The resonant circuit 20 shown here is thus a series resonant circuit of an RLC resonant circuit. This shown very simple embodiment of the circuit module 18 for forcing a current zero crossing in the first switching unit 16 is only one of several known possibilities for the configuration of such a circuit module 18th

As a further component, the direct current switching device 14 has a second switching unit 28 and an overvoltage path 30 connected in parallel with the first switching unit 16 and the commutation path of the circuit module 18 with an overvoltage arrester 32 connected therein. The result is a parallel connection of the first switching unit 16 with the commutation path of the circuit module 18 and the Overvoltage path 30, which is connected in series with the second switching unit 28 in the medium or high voltage current path 12. The second switching unit 28 is used to connect the remaining part of the DC switching device 14, that is to say the said parallel connection of the first

Switching unit 16 and commutation and overvoltage path 18, 30 in the medium or high-voltage current path 12. As is customary in such DC switching devices 14, the first of the switching units 16 is designed as a commutation switch and the second of the switching units 28 as a disconnector.

The central part of the DC switching device 14, which comprises at least the two switching units 16, 28, is now provided by a medium or high voltage switch 34. In the example, this is formed as an outdoor switch.

Said medium or high-voltage switch 34 comprises a switching path 36 with a first switching chamber 38, which houses a first switching device 40 and with a second switching chamber 42, which houses a second switching device 44. The two switching chambers 38 and 42 are connected in series and by opening or closing the Schaltvorrich lines 40, 44, a current flow through the switching path 36 of the high-voltage switch 34 is prevented or enabled.

The switching path 36 is connected in the medium- or high-voltage current path 12 and the first switching device 40 now forms the first switching unit 16 of the direct current switching device 14 and the second switching device 44 forms the second switching unit 28 of the direct current switching device 14.

Furthermore, the high-voltage switch 34 comprises a Schaltele element 46, a gear 48 and a drive 50. This part of the high-voltage switch 34 serves as a kind of control unit for controlling the switching devices 40, 44 and

Switching chambers 38, 42. The drive 50 drives the switching element 46 and this opens or closes via the gear 48 the switching devices 40, 44 or switching chambers 38, 42. In the example shown, the switching element 46 is designed as a switching rod 52, which is accommodated by a support column 54. The drive 50 is arranged on a stem-shaped base element 56 of the high-voltage switch 34, while a deflection gear 58 is located directly above the drive 50. The support column 54 extends vertically from the drive 50 or the deflection gear 58 to the gear 48, through which the switching path 36 extends transversely to the support column 54 or the shift rod 52 located therein. In other words, the switching path 36 runs horizontally here.

The switching chambers 38, 42 connect on both sides to the Ge gear 48. At the gear 48 there is an electrical connection 60 via which the commutation and overvoltage path 18, 30 in the embodiment of FIG. 1 electrically (not shown) center tap on the switching path 36 between the two switching chambers 38, 42 electrically contacted.

In order to interrupt the electrical direct current 10 flowing along the medium or high voltage current path 12 (via points A and B), the switching units 16, 28 or switching devices 40, 44 must be adapted to the structure of the direct current switching device 14 Open or close switching sequence. This shift range is specified by the gearbox 48. Here, the transmission 48 is designed such that the switching element 46 lines 40, 44 for a switching process of the medium or high voltage switch 34 by means of the switching element 46 at approximately the same time one of the two switching devices 40, 44 for opening and the switching of the switching devices controls each other to close.

To interrupt the electrical direct current 10 flowing along the medium-voltage or high-voltage current path 12, the two switching devices 40, 44 are now controlled such that the second switching device 44 closes before the first of the switching devices 40 opens. In the circuit arrangement 10 shown in FIG. 2 with

Medium or high voltage current path 12 and DC switching device 14 for interrupting one along the

Medium or high voltage current path 12 flowing electrical direct current 10, the direct current switching device 14 essentially corresponds to the direct current switching device 14 shown in FIG. 1, so that only the differences will be discussed below.

In the example shown in FIG. 2, the medium or high-voltage current path 12 runs “only” between the connection 60 connected to the center tap in the transmission 48 as point A and the point B lying on the opposite side of the first switching chamber 38 first

Switching unit 16 or the first switching device 40 directly connected in this current path. The second switching unit 28 or the second switching device 44 is parallel to the first switching unit 16 or the parallel path of the commutation and the overvoltage path 18, 30

first switching device 40 switched so that this parallel connection of the two paths 18, 30 via the second switching unit or second switching device can be switched on. With regard to the complete switching path 36 of the medium or high voltage switch 34 (with both switching chambers 38, 42), the circuit module 18 providing the commutation path and the overvoltage current path 30 are connected in parallel.

In order to interrupt the electrical direct current 10 flowing along the medium or high voltage current path 12 (via points A and B), the switching units 16, 28 or switching devices 40, 44 must be adapted to the structure of the direct current switching device 14 Open or close switching sequence. This shift sequence is also specified by the transmission 48 in this exemplary embodiment.

To interrupt the direct current 10 flowing along a medium or high voltage current path 12, the two switching devices 40, 44 are now activated in this way. It occurs that the second switching device 44 closes after the opening of the first of the switching devices 40.

_Z reference oaks:

10 circuit arrangement

 12 medium or high voltage current path

14 DC switching device

 16 switching unit, first

 18 circuit module

 20 resonant circuit

 22 component, resistive

 24 components, inductive

 26 component, capacitive

 28 switching unit, second

 30 surge current path

 32 surge arresters

 34 medium or high voltage switches

36 switching distance

 38 first switching chamber

 40 first switching device

 42 second switching chamber

 44 second switching device

 46 switching element

 48 gears

 50 drive

 52 shift rod

 54 support column

 56 stem-shaped base element

 58 reversing gear

 60 connection

 10 direct current

 A point

 B point

Claims

Claims 1. Medium or high voltage switch (34), in particular outdoor medium or high voltage switch, with  a switching path (36) in which two switching devices (40, 44) are connected in series,  a gear (48),  a switching element (46) for driving the Schaltvor directions (38, 42) via the transmission (48), and  a drive (50) for driving the switching element (46), characterized in that the gearbox (48) is designed such that the switching element (46) when actuating the switching devices (40, 44) for a switching process of the medium or high voltage switch (34) always one of the two switching devices (40, 44) for opening and the other is controlled to close. 2. Medium or high voltage switch according to claim 1, characterized in that the transmission (48) is designed such that the actuation of the switching devices (40, 44) causes the second switching device (44) to close before the opening of the first of the switching devices (40). 3. Medium or high voltage switch according to claim 1, characterized in that the transmission (48) is designed such that the actuation of the switching devices (40, 44) causes the second switching device (44) to close after the first of the switching devices (40) has opened. 4. Medium or high voltage switch according to one of claims 1 to 3, characterized in that the first of the switching devices (40) is designed as a commutation switch and the second of the switching devices (44) is designed as an isolating switch. 5. Medium or high voltage switch according to one of claims 1 to 4, characterized in that the switching path (34) has two series-connected switching chambers (38, 42), one of the switching devices (40, 44) being arranged in each of the switching chambers (38, 42). 6. Medium or high voltage switch according to one of claims 1 to 5, characterized in that the switching element (46) is designed as a switching rod (52). 7. Medium or high voltage switch according to one of claims 1 to 6, marked by a connection (60) for a voltage supply to the switching path (36) between the two switching devices (40, 44), in particular between the two interrupters (38, 42). 8. Use of a medium or high voltage switch (34) according to one of claims 1 to 7 in a direct current switching device (14) for interrupting a along a medium or high voltage current path (12) flowing electrical direct current (10). 9. DC switching device (14) for interrupting a along a medium or high voltage current path (12) flowing electrical direct current (10) with  a first switching unit (16) which can be connected in this current path (12),  a circuit module (18) for forcing a current zero crossing in the first switching unit (16), and a second switching unit (28) for switching on the DC switching device (14) or at least a part (18) the direct current switching device (14) in the medium or high-voltage current path (12), marked by a medium or high voltage switch (34) according to any one of claims 1 to 7, the first switching device (40) the first switching unit (16) and the second switching device (44) forms the second switching unit (28). 10. DC switching device according to claim 9, marked by a surge arrester (32) connected in parallel to the first switching unit (16) and to the circuit module (18).