CN110313046B

CN110313046B - Electrical switching device

Info

Publication number: CN110313046B
Application number: CN201880012649.1A
Authority: CN
Inventors: T.希拉; S.吉雷; V.莱曼; J.席梅尔芬尼; J.泰克曼
Original assignee: Siemens AG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2017-02-21
Filing date: 2018-01-22
Publication date: 2021-07-23
Anticipated expiration: 2038-01-22
Also published as: BR112019015398A2; EP3559966A1; DE102017202739A1; BR112019015398B1; WO2018153582A1; CN110313046A

Abstract

The electrical switching device has at least one switching point (5, 6). A switching resistor (11a, 11b) is assigned to the switching point (5, 6), said switching resistor being electrically connected in parallel to the switching point (5, 6). The switch resistors (11a, 11b) have a stack of resistor elements.

Description

Electrical switching device

Technical Field

The invention relates to an electrical switching device having at least one switching point and at least one switching resistor, which is electrically connected in parallel with the switching point.

Background

Such an electrical switching device is known, for example, from the publication DE 102006004811 a 1. For potential control, a switching resistor is connected electrically in parallel with the switching point. The electrical switching device is preferably manufactured in a modular construction, so that the assembly can be used several times in different series. Furthermore, the electrical switching device can be easily adapted to changing requirements by means of modular components.

Disclosure of Invention

The object of the invention is therefore to improve a switching device such that it can be designed variably.

According to the invention, the above-mentioned object is achieved for an electrical switching device of the type mentioned at the outset by the switching resistor having a stack of resistor elements.

Electrical switching devices are devices used to interrupt or establish a current path. In this case, the electrical switching device can interrupt the current or switch the current on by interrupting or establishing the current path, respectively. Depending on the design of the electrical switching apparatus, the magnitude of the current to be controlled may vary. For example, the electrical switching device can be designed as a load switching device, i.e. the electrical switching device controls a current which maximally corresponds to its nominal magnitude. However, it can also be provided that the electrical switching device is designed as a so-called disconnector device, i.e. that the electrical switching device is configured not to control the current, except for a negligible charging and discharging current. The electrical switching device can also be designed as a so-called circuit breaker device, i.e. the electrical switching device is also used for controlling currents above its rated current. The circuit breaker device can thus control, for example, a short-circuit current that is a multiple of the rated current. Electrical switching devices can be used at different locations in an electrical energy transmission network depending on their type of construction. The electrical switching device can be used in the low, medium, high and extra-high voltage ranges. Advantageously, the switching point of the switching device is a mechanical switching point. At the mechanical switching point, the impedance of the switching point is changed by the switching contacts which are movable relative to one another. Alternatively, however, the switching point may be constructed, for example, on the basis of a semiconductor, wherein the impedance of the switching point may vary on the basis of external wiring.

Irrespective of the design of the switching point, it can be provided that the switching resistor is arranged in parallel with the switching point. The switching resistance supports the function of the switching point. For example, when interrupting the phase conductor path and possibly the current associated therewith, a reaction may occur to the switching point. For example, in an electrical energy transmission network, energy flow oscillations or oscillations can occur, which lead to voltage overshoots at the switching points. The so-called recovery voltage (wiederkhrspnnung) can be limited by means of the switching resistance, thereby enabling a reliable and fast establishment of the high-impedance state of the switching point. For example, in an ac power supply system, oscillation processes can occur which lead to voltage overshoots at the switching point, which are greater than the rated voltage for which the electrical switching point is designed. However, it is also possible to use electrical switching devices in dc voltage systems, in which case, for interrupting the phase conductor path, it is possible, for example, to force a dc current oscillation through a current zero crossing via an external connection in order to interrupt the phase conductor path in a simplified manner, and thus to interrupt the dc current when necessary.

In order to design the switching resistor, it can be advantageously provided that the switching resistor is composed of a plurality of resistor elements, so that the sum of the resistor elements combined with one another reaches the desired resistance value of the switching resistor. For example, the resistive elements may be combined in a stacked manner. The resistance elements may, for example, each have a cylindrical shape, in particular a cylindrical shape with a cylindrical or hollow-cylindrical cross section. The end faces of the plurality of resistance elements may be arranged close to each other and form a stack. In order to improve the electrical contact, it may also be provided that contact elements are arranged between the resistance elements. The stack of resistive elements may be combined into a corner-rigid (winkelstarren) composite. In order to form a composite body which is rigid at the corners and to avoid stacking apart of the resistor elements, the resistor elements can be pressed against one another by applying an external force between them. Alternatively or additionally, the stack of resistor elements may also be surrounded by a housing for guiding the stack of resistor elements in the axial direction. Here, the housing should function in an electrically insulating manner. For example, the stack of resistive elements may be located within a tube made of an electrically insulating material, wherein the tube may be used to apply a compressive force of the resistive stack. Thus, for example, an electrically insulating tube can accommodate the stack of resistance elements, and contact points are arranged on the end side of the insulating tube for electrically connecting the switching resistance in parallel with the switching points. For example, the contact points may also be used to hold and position the switch resistance.

It can advantageously be provided that the ratio of the number of resistive elements forming the stack to the resistance (in ohms) of the stack of resistive elements is less than or equal to 2, in particular less than or equal to 1.5.

In the case where the ratio of the number of stacked resistance elements to the resistance is less than or equal to 2, particularly less than or equal to 1.5, heat from the stack of resistance elements is enabled to be output well. Further, the length of the stack of the resistance elements is limited, so that the electrical parallel connection with the switching point can be easily achieved. By determining the number of resistive elements with respect to the resistance of the stack, a design of the individual resistive elements is defined with respect to the partial resistance which contributes to the total resistance of the stack through the resistive elements. Furthermore, the quality (Masse) of the stack of resistive elements is limited. It has proven to be particularly advantageous if the ratio of the number of resistance elements to the resistance of the stack (in ohms) is shifted from a limit of approximately 0.5, 1, 0.7 to a limit of approximately 1.0, 1, 2. By dimensioning the specification, for example using a sintering method, in particular of ceramic or the like, the resistor element can be manufactured at low cost.

A further advantageous embodiment can provide that the ratio of the length of the switching resistor (in mm) to the resistance of the switching resistor (in ohms) is less than or equal to 8, in particular less than or equal to 6.

By such a ratio of the length of the switch resistance to the resistance in ohms, the possibility is given to form the switch resistance, for example, from one or more stacks of resistive elements. In this case, the load capacity of the switching resistor can be improved by the parallel connection of a plurality of columns. However, it is also possible to provide the switching resistor with only one stack of resistor elements, wherein in this embodiment the on-resistance, in particular the ratio of the length of the stack of resistor elements to the resistance in ohms, also corresponds to the dimensioning specification. In this case, it has proven advantageous to determine the ratio of the length of the switching resistance to the magnitude of the switching resistance in ohms in the range from 3,.., 4 to 6,.., 8.

Advantageously, it can also be provided that the electrical switching device has a multiple-break switching path having a first switching point and a second switching point, which are in electrical contact with one another, wherein a distance in mm is present between the connection points of the multiple-break switching path, which is at most 30 times the magnitude of the switching resistance (in ohms), in particular at most 25 times the magnitude of the switching resistance (in ohms).

As described at the outset, the electrical switching device is used for switching a current path or for switching a current. If a plurality of switching points are now used, which are used together for switching a current path/current, an electrical switching device with a multiple-interrupted switching path is formed. The switching points are preferably connected electrically in series with one another, so that the switching paths have connection points of the electrical switching device at the end points of the switching points connected to one another, between which connection points the phase conductor paths (current paths) or the currents can be switched. For connecting the first and second switching points to one another, for example, contact elements can be used which separate the two switching points from one another. The contact element can preferably be designed to be electrically conductive, so that an electrically conductive connection of the first and second switching point is made via the contact element. As contact element, for example, a gear element, for example a gear head (getriebkopf), can be used, which serves to couple the movement to the first or second switching point. The switching point can project from the contact element. In particular, the switching points may be arranged on opposite sides of the contact element. Advantageously, the switching points may project from the contact element in substantially aligned manner in opposite directions with respect to each other. The connection point of the multiply interrupted switching path can be located at the end of the two switching points remote from the contact element. Thus, for example, an outdoor switchgear with a porcelain-column (live tank) structure can be formed, which can have, for example, a plurality of encapsulation shells which project in a T-shape from an electrically insulating support.

The first switching resistor may be electrically connected in parallel with the first switching point. The second switching resistor may be electrically connected in parallel with the second switching point. In this case, it can be provided that the first and second switching points are each associated with a respective switching resistor. However, it can also be provided that only the first switching point or only the second switching point is associated electrically in parallel with one switching resistor. By electrically connecting the switching resistors in parallel, the switching points electrically connected in parallel with the switching resistors are bridged by the switching resistors. In other words, beside the switching point where the impedance is variable, a parallel current path is built up via the switching resistance. In this case, however, the switch resistance has a large magnitude, so that in the high-impedance state of the switching point only a negligible leakage current can flow through the switch resistance. If necessary, in order to avoid leakage currents, it can additionally be provided that the parallel current path established via the respective switching resistor is temporarily interrupted. Such a disconnection of the parallel current path can preferably take place after the interruption of the phase conductor path and after the intensification of the switching point. In particular in the case of mechanical switching points, it is necessary to strengthen the switching point, for example in order to remove foreign bodies, such as combustion products or other interfering particles, from the switching point in the region of the switching point. Furthermore, by using a plurality of switching points, the following advantages are also given: the voltages to be separated by the switching paths are distributed over a plurality of switching points, so that each switching point only needs to withstand a partial magnitude of the voltage to be controlled between the contact points of the switching paths.

To form the encapsulation housing, a substantially electrically insulating tubular structure can be used, which is provided with fittings at the end-side openings. The fitting can be electrically conductive, wherein the fitting can also be used for electrical contacting of a first or second switching point arranged inside the respective encapsulation housing. Furthermore, the switching resistor can also be connected electrically in parallel to the first or second switching point via an accessory. Furthermore, the fitting can also serve as a holding element for supporting or carrying the switching resistor. This can be advantageous in particular when the switching resistor is arranged outside the encapsulation housing. The switch resistor may also be arranged inside the encapsulation housing.

The preceding description of the arrangement or implementation possibilities of the encapsulation housing and the resulting structure of the electrical switching device can also be applied in a similar manner to the embodiment variants described below, irrespective of the number of switching points, irrespective of the state and position of the switching points and irrespective of the configuration or state of the switching resistors.

A further advantageous embodiment can provide that the first or second switching point is surrounded by a packaging housing, wherein the switching resistor is arranged outside the packaging housing.

The use of the encapsulating housing to surround the switching point has the advantage that the switching point can be protected from external influences. The encapsulation housing can be designed, for example, in the form of an electrically insulating tubular body, in the recess of which the switching point is arranged. Fittings may be provided at the end side of the tubular body to enable electrical contact to be made to switching points located inside the encapsulation housing. In the case of a switching resistor arranged outside such a housing, the cross section of the housing can be designed according to the size of the respective switching point. Then, a switching resistor may be disposed outside the package case as needed. Thereby, a modular construction of the electrical switching device is further supported, wherein the switching resistor is arranged outside the encapsulation housing only when needed, wherein the size of the encapsulation housing itself can be optimized depending on the switching point.

In a further advantageous embodiment, the first and second switching points can each be surrounded by a housing, the switching resistor being arranged outside the housing.

In the case of a first and a second switching point equipped with an encapsulating housing, the possibility is given to install each switching point in a protected space, wherein the switching resistance can be assigned not only to two switching points but also to only one switching point. The arrangement of the switch resistor outside the encapsulation housing enables the encapsulation housing and the switch resistor to be aligned substantially parallel with respect to each other. For example, the switching resistors can be electrically connected in parallel by conductors (fittings) which are located on the end side of the package housing and which contact the first and second switching points, respectively. The switching resistor can be supported on the respective encapsulation housing.

A further advantageous embodiment can provide that the first or second switching point is surrounded by a packaging housing, wherein the switching resistor is arranged within the packaging housing.

The arrangement inside the encapsulation housing surrounding the first or second switching point has the following advantages: the switch resistor can benefit from the mechanical protection of the package housing and does not require a separate housing per se. This allows the switching resistor to be electrically contacted in a simple manner to the respective switching point.

In a further advantageous embodiment, the first and second switching points can each be surrounded by a housing, the switching resistor being arranged within the housing.

The provision of a respective encapsulation of the first and second switching point makes it possible to provide the first or second switching point, or both switching points, with a respective switching resistor, wherein the switching resistor is arranged in the respective encapsulation of the respective switching point. The protective effect of the corresponding encapsulation can also be extended to the switching resistor.

An advantageous embodiment can provide that the encapsulation housing is a pressure vessel.

It can be advantageously provided that the encapsulation housing is filled with an electrically insulating fluid.

The encapsulation housing is designed as a pressure vessel, so that the interior of the encapsulation housing can be filled with an electrically insulating fluid and the electrically insulating fluid is put under pressure so that the interior of the encapsulation housing has a different pressure with respect to the environment of the encapsulation housing. Here, the pressure vessel is designed such that it can withstand differential pressure. This enables a suitable fluid to be enclosed inside the encapsulating housing. For example, the package housing may be filled with an electrically insulating oil or an electrically insulating gas. In particular, gases or liquids having a fluorine component have proven to be advantageous, which have a large electrical insulation effect on the one hand and a good arc extinguishing effect on the other hand. Thus, for example, sulfur hexafluoride (Schwefel hexafluoride), fluoroketone (fluoroketone), fluoronitrile (fluoronitrile) may be used. In addition, however, other electrically insulating fluids may be used, such as nitrogen, oxygen, and the like.

Drawings

Embodiments of the present invention are schematically illustrated in the drawings and described in detail later. In this case, the amount of the solvent to be used,

fig. 1 shows a side view of an electrical switching apparatus.

Detailed Description

The electrical switching device according to fig. 1 is designed as an outdoor circuit breaker with a porcelain-type (live tank) structure in the high-voltage range, in particular for voltages above 800000 volts. Such an electrical switching apparatus has a support base 1, the support base 1 being typically formed of an electrically conductive material and conducting an electrical ground potential. The drive means 2 are located on the support base 1. The drive means 2 are normally likewise arranged at ground potential. By means of the drive device 2, the electrical switching device is enabled to be operated, i.e. to open or establish a current path. The drive 2 supplies the energy required for this purpose, in this case the required movement energy. The electrically insulating sections of the support columns 3 are arranged on the support base 1. The support column 3 is composed of a first and a second electrically insulating section, wherein the electrically insulating sections are substantially tubular and are closed at the ends by fittings (Armaturen). The mutually facing sides of the electrically insulating sections of the support columns 3 are bolted to each other, so that an elongated tubular support column 3 is formed. The end faces of the support columns 3 are located on the support base 1. The electrically insulating section of the support column 3 is hollow and is provided with ribs (verripsung) on the outer surface side. By means of the ribs, the creepage path through the surface of the support column 3 is lengthened and a drip edge is formed on the support column 3, giving improved open-air strength (freilftfestigkeit). A gear head 4 is arranged on the end of the support column 3 facing away from the support base 1. The gear head 4 closes the support column 3 and is connected to the support column 3 in a angularly rigid manner (winkelstarr). A first switching point 5 and a second switching point 6 are placed on the gear head 4 in a transverse direction with respect to the axial extension of the support column 3. For this purpose, the first and second switching points are enclosed by a first encapsulation housing 7 and a second encapsulation housing 8. The two encapsulation shells 7, 8 are constructed analogously to the electrically insulating sections of the support columns 3. That is, the two package housings 7, 8 are formed to have a substantially hollow cylindrical, electrically insulating tubular shape, wherein fittings for closing the package housings 7, 8 are arranged on end sides of the package housings 7, 8, respectively. The two packing cases 7, 8 are arranged on opposite sides of the gear head 4 with respect to the gear head 4, and protrude from the gear head 4 in opposite directions. The ends of the two encapsulating shells 7, 8 facing the gear head 4 are mechanically connected to the gear head 4 by the fittings of the encapsulating shells 7, 8 there, so that the encapsulating shells 7, 8 are supported by the gear head 4 on the support column 3. The housing of the gear head 4 is made of an electrically conductive material, wherein the electrical contact of the fitting connected to the gear head 4 is provided via the gear head 4.

The first and second switching points 5, 6 are arranged inside the encapsulating housing 7, 8. The first and second switching points 5, 6 each have a switching contact which can be moved relative to one another. The relatively movable switching contacts are designed such that they can be brought into contact with one another or can be separated from one another. In order to change the state of the first and second switching point 5, 6, a kinematic chain, for example in the form of an axially displaceable switching rod, is arranged inside the bearing column 3, which kinematic chain preferably acts as an electrical insulator. The movement of the drive 2 output on the support base 1 can thus be transmitted to the gear head 4 within the support column 3. In the gear head 4, this movement can be distributed to the two encapsulation shells 7, 8, so that the switch contacts of the first and second switch points 5, 6 can perform a relative movement. The switching points 5, 6 are arranged in such a way that they make electrical contact with corresponding fittings of the encapsulation housing 7, 8, which fittings touch the gear head 4. Thus, the switching points are electrically connected in series with each other through the gear head 4 by means of the fitting connected to the gear head 4, thereby forming a multiple-interrupted switching path. The two switching points 5, 6 are electrically conductively connected via their respective other side to a fitting which closes the respective encapsulation housing 7, 8 at the free end of the respective encapsulation housing 7, 8. The fittings located there form the connection points 9, 10 of the multiple (double) interruption switching paths of the electrical switching device. Thus, a distance D extends between the connection points 9, 10, which distance D comprises the length of the electrically insulating sections of the encapsulation housing 7, 8 and the length of the electrically conductive contact elements for contacting the two switching points 5, 6.

The first switching point 5 and the second switching point 6 are assigned a

respective switching resistor

11a, 11 b. Two switching

resistors

11a, 11b are electrically connected in parallel with the first switching point 5 and the second switching point 6, respectively. For this purpose, the switching

resistors

11a, 11b are each electrically conductively connected to a fitting at the boundary of the encapsulation housing 7, 8, at the end of which the respective switching point 5, 6 is formed. In addition to the electrical contact of the switching

resistors

11a, 11b via the fittings of the encapsulation housing 7, 8, mechanical support or support is provided for the switching

resistors

11a, 11b via said fittings and thus via the encapsulation housing 7, 8. The switching

resistors

11a, 11b are each identically constructed. The switching

resistors

11a and 11b each have a stack of n resistor elements. The resistance elements are each arranged in a tubular, electrically insulating cylinder which forms a mechanical protection for the respective stack of resistance elements. On the other hand, the cylinder also serves to apply a force to a resistive element located inside the switch resistor. The number of switch resistors may vary depending on the size of the respective package housing 7, 8 or gear head 4. Thus, the stack of resistive elements has n resistive elements.

The encapsulating housings 7, 8, the support column 3 and the gear head 4 are each embodied as a pressure vessel, so that the interior of the encapsulating housings 7, 8, the support column 3 and the gear head 4 can be filled with an electrically insulating fluid, which is encapsulated. In this case, an electrically insulating fluid is advantageous, in particular, which increases the insulation strength inside the support column 3 or inside the encapsulation 7, 8. Preferably, the electrically insulating fluid inside the encapsulation 7, 8 can be placed under overpressure

This makes it possible to subject differential pressure to the encapsulation housings 7, 8 or also to the support column 3 or the gear head 4. In this case, the encapsulation housing 7, 8 can be embodied as a pressure vessel.

Claims

1. Electrical switching device having at least one switching point (5, 6) and at least one switching resistance (11a, 11b) which is electrically connected in parallel with the switching point and has a stack of resistive elements (n),

it is characterized in that the preparation method is characterized in that,

the ratio of the number of resistive elements (n) forming the stack to the resistance of the stack of resistive elements (n) in ohms is less than or equal to 2.

2. The electrical switching apparatus of claim 1,

characterized in that said ratio is less than or equal to 1.5.

3. The electrical switching apparatus of claim 1,

it is characterized in that the preparation method is characterized in that,

the ratio of the length of the switch resistance (11a, 11b) in mm to the resistance of the switch resistance (11a, 11b) in ohms is less than or equal to 8.

4. The electrical switching apparatus of claim 1,

it is characterized in that the preparation method is characterized in that,

the ratio of the length of the switch resistance (11a, 11b) in mm to the resistance of the switch resistance (11a, 11b) in ohms is less than or equal to 6.

5. Electrical switching apparatus according to any one of claims 1 to 4,

it is characterized in that the preparation method is characterized in that,

the electrical switching device has a multiple-interruption switching path with a first switching point (5) and a second switching point (6), which are in electrical contact with each other, wherein a distance (D) in mm is present between the connection points (9, 10) of the multiple-interruption switching path, which is at most 30 times the magnitude of the switching resistance (11a, 11b) in ohms.

6. Electrical switching device according to claim 5, characterized in that the distance (D) is at most 25 times the magnitude of the switching resistance (11a, 11b) in ohms.

7. An electrical switching apparatus according to claim 5,

it is characterized in that the preparation method is characterized in that,

the first switching resistor (11 a) is electrically connected in parallel with the first switching point (5) and/or the second switching resistor (11 b) is electrically connected in parallel with the second switching point (6).

8. An electrical switching apparatus according to claim 5,

it is characterized in that the preparation method is characterized in that,

the first or second switching point (5, 6) is surrounded by a packaging housing, wherein the switching resistor is arranged outside the packaging housing.

9. An electrical switching apparatus according to claim 5,

it is characterized in that the preparation method is characterized in that,

the first and second switching points (5, 6) are each surrounded by a housing (7, 8), wherein the switching resistors (11a, 11b) are arranged outside the housing.

10. An electrical switching apparatus according to claim 5,

it is characterized in that the preparation method is characterized in that,

the first or second switching point (5, 6) is surrounded by a packaging housing (7, 8), wherein the switching resistor (11a, 11b) is arranged within the packaging housing (7, 8).

11. An electrical switching apparatus according to claim 5,

it is characterized in that the preparation method is characterized in that,

the first and second switching points (5, 6) are each surrounded by a packaging housing (7, 8), wherein the switching resistors (11a, 11b) are arranged within the packaging housings (7, 8).

12. Electrical switching apparatus according to any one of claims 8 to 11,

it is characterized in that the preparation method is characterized in that,

the encapsulation housing (7, 8) is a pressure vessel.

13. Electrical switching apparatus according to any one of claims 8 to 11,

it is characterized in that the preparation method is characterized in that,

the encapsulation housing (7, 8) is filled with an electrically insulating fluid.