DE102015112795A1 - Busbar connector and switchgear with conductor rail connector - Google Patents

Abstract

The invention relates to a line rail connector (1a-1h) for connecting at least one switchgear component (20a-20e) with a line rail, comprising a base body (2a, with an inner cavity or a chamber (4a, 4b, 4c), which at least partially and / or at least one evaporator, which is arranged in the cavity or the chamber (4a) and / or is thermally connected to the main body (2a), and basic body and / or evaporators are adapted and designed to evaporate the cooling medium (6a) in the chamber or to transfer into the gas phase, by heat transfer of the base body (2a) to the cooling medium in the chamber, wherein at least one channel (8a) for discharging the vaporized cooling medium (6a) from the chamber and returning the condensed coolant into the chamber (4a) and at least one connection means for connection at least one coolant line is provided for connection to a capacitor. The invention further comprises a switchgear, in particular a low-voltage switchgear, comprising at least one aforementioned conductor rail connector.

Description

The invention relates to a rail connector for connecting at least one switchgear device, in particular a circuit breaker, with the line or conductor rail system of the switchgear. Furthermore, a switchgear, in particular a low-voltage switchgear, is provided, which comprises at least one such conductor rail connector, wherein the conductor or conductor rail is understood as meaning both a busbar and a busbar. The term line rail and conductor rail are used synonymously below and are understood to be synonymous.

In a conventional electrical energy or power distribution system, at least one switchgear is provided, which typically includes and / or provides at least one electrical switch and / or circuit breaker, in particular circuit breaker, which are used or deployed to various electrical equipment and / or control, protect, isolate, and power or shut down equipment or resources.

In the low-voltage sector, switchgear for voltages up to 1 kV and for currents up to a few thousand amperes, in particular 6300 A, are used.

A switchgear or switchgear assembly always requires an incoming feeder and, in many cases, large outgoing feeders and / or branches to distribute power to other parts of the installation. These feeders / branches are connected to a connection on one side (top or bottom) by flat single bent copper connection sets with the main busbar system or the line or conductor rail system of the switchgear. A second set of connectors is used on the other side of the feeder / branch to connect cables or power lines. The connection sets are different based on the rated current and the feeder / branch frame size. Furthermore, the connection blocks on the feeders / branches are different for all frame sizes.

Furthermore, the power of the feed line / branch depends on the IP class of the switchgear and the ambient temperature of the switchgear location. In most cases, a derating factor for the feeder line / branch current must also be used.

In many cases, an even larger or higher-sized feed line / branch must be selected, resulting in a larger amount of material, a more difficult handling and / or processing and higher costs and larger footprint or increased space requirements.

A power or conductor rail of a switchgear is generally formed as a flat strip or rail, in particular of rectangular cross-sectional area, of copper or aluminum, which typically has no supporting function or only a minor function as a structural or supporting member. The maximum amount of electricity that can be safely carried by a busbar is determined by its cross-sectional size or area.

Depending on the particular application and / or size of the switchgear and the individual structure and the respective customer requirements, the respective busbars or conductor rails must be individually pre-processed and individually assembled or installed for each switchgear.

Advantageously, flat strips are relatively easy to assemble or assemble and / or handle, but after preprocessing on-site no short-term change or adjustment of the structure is more possible. Further, the shaping of the flat strip allows heat to be relatively well distributed and / or released to the environment due to its surface area or comparatively large surface area, but due to the dense packing of the bus bars, particularly some layers, within the switch cabinet depending on the applied current the temperature within the housing may nevertheless reach a critical value, so that the current must be reduced and / or other cooling devices must be applied to the switchgear in order to avoid damage to the electrical devices and internals within the switchgear.

Power or busbars are connected to the respective feeders / branches by electrically conductive connectors, hereafter also referred to as busbar connectors, which connectors are usually one of the largest point heat sources in today's switchgear. Conventional rail connectors are generally constructed as flat rails, which are cooled by heat conduction. When the connector is energized, it is heated due to its electrical resistance, in particular electrical resistivity, as well as the AC influences. The heat from the rail connector is generated or generated, is derived mainly by the structure of the switchgear or its structural components, such as frame and housing, which then distribute the heat energy by thermal radiation and / or convection to the environment.

Since the busbar connectors heat up very easily, this can disadvantageously lead to an increased temperature within the switchgear, which affects the reliability and the life of the switchgear itself. If the life of the switchgear is reduced disadvantageously, the intervals for the maintenance of the switchgear must be shortened to ensure a safe operation of the system, which in turn is associated with an increased cost.

This is especially true for circuit breakers in central positions, in particular for an input side circuit breaker of a switchgear, in which the heat distribution causes problems, so that the circuit breakers can not normally be used to their electrical power limits, but in this regard, a sufficiently large buffer area is calculated to damage to avoid. Also, the space available is limited, so that neither over-dimensioning of the circuit breaker seems necessary, nor is it possible to provide additional space- or space-consuming cooling devices and / or apply or connect.

In addition to the heat load of a circuit breaker, the thermal conductivity of a busbar is usually not high or large enough to cool the hot areas by the thermal properties / conductivity of the busbar itself.

Within the respective switchgear, the electrical power busbar connector is routed from the respective power or busbars to the circuit breakers. The respective busbar connector in this case has a copper or aluminum body, which usually has no supporting function as a structural member, wherein the maximum amount of current that can be safely carried by a rail connector, determined by its cross-sectional size. The heat, which is generated due to its electrical resistance and the AC influences when current flows through the conductor rail connector, is distributed or discharged through or over its surface area at the respective hot spot.

Therefore, line rail connectors are a common source of danger in today's switchgear. When the busbar is energized, it is heated due to its electrical resistance and AC influences. The heat generated by the busbar is mainly directed to the structure of the substation, which then distributes the heat energy to the environment through convection and / or thermal radiation. Therefore, the bus bar connector is cooled mainly by heat conduction.

The emitted to the environment heat of the rail connector is rather low or low, since the distribution of heat energy and air flow in the switchgear is limited due to the prevailing conditions. Disadvantageously, the busbar connector heats up very rapidly, which leads to an increase in temperature in the switchgear or the switchgear itself, and what the reliability and life of the switchgear itself, and in particular their fixtures, such as circuit breakers, engine control devices, control devices, communication devices and the like, on which ultimately can shorten the life of the switchgear. However, if the life of the switchgear or of switchgear components or fixtures can be shortened, in particular due to the high temperature influence, the maintenance intervals for the switchgear must be shortened to ensure the reliability of the respective switchgear and ensure what increases the maintenance and repair costs. The ventilation and thus the cooling capacity within such a circuit breaker compartment is limited. Also, in addition to the bus bars and the bus bar connector, little or no space is available for additional refrigeration components or is rarely used in the case of forced refrigeration such as a fan. Accordingly, it is an object of the invention to provide a rail connector having improved cooling functionality and improved temperature stability.

This object is achieved according to the present invention by a conductor rail connector comprising the features of claim 1. Further developments and embodiments of the connector and a switchgear comprising at least one such connector are given in further claims and the following description.

Thus, the line rail connector for connecting at least one switchgear component with the main busbar system or busbar system of the switchgear, which comprises a main body with a chamber-like recess which at least partially with a cooling medium can be filled or filled and / or at least one evaporation means is provided, which is arranged in the cavity or the chamber; and / or is thermally connected to the base body and base body and evaporation means are provided and adapted to evaporate the cooling medium in the chamber by absorbing or absorbing the heat energy from the base body, wherein at least one channel and connection means for discharging the evaporated cooling medium and / / or connecting a coolant line to the base body is provided; wherein the evaporated cooling medium by means of the coolant line at least one capacitor is supplied, is condensable therein and as condensate by means of the same refrigerant line again the chamber in the body feed or traceable and is again accumulated in the chamber in the body, so that the main body by dispensing the Heat energy to the cooling medium in the chamber and evaporation of the same is cooled.

The basic idea of the invention is that the conductor rail connector itself comprises a chamber in the manner of a recess or a cavity which is filled with cooling liquid, wherein the cooling liquid through the surrounding body of the connector, which in particular has a double-T-carrier-like geometry , heated and finally evaporated. In order to improve the heat transfer to the cooling medium or coolant, at least one evaporation means or evaporator located or arranged in the chamber can be provided, for example in the manner of a lamellar arrangement for increasing the heat-releasing inner surface of the chamber, which is thermally connected to the main body of the conductor rail connector is, and which is designed and adapted to at least partially absorb the occurring heat energy and / or absorb and deliver to the cooling medium. Accordingly, the bus bar connector is cooled by discharging the generated heat energy to the cooling medium to be evaporated in the chamber. The vaporized cooling medium is condensed in at least one condensing agent or a condenser, which is preferably arranged on at least one line rail and / or a plurality of line rails or covers, and returned to the cavity or the chamber, wherein the heat energy of the cooling medium through a condenser, which in particular has a comparatively large surface, for example due to a lamellar surface, is released to the environment and is returned from the gas phase back into the liquid phase and condensed.

In another embodiment, the body has a double T-structure or a double T-bar structure.

In a further advantageous embodiment, the line rail connector is connected by the at least one channel with at least one switchgear component, wherein the switchgear component, in particular a line rail having at least one condensing agent or the at least one capacitor, which is designed to condense the evaporated cooling medium and / or this condenses by the heat energy is distributed distributed to the environment in the form of heat radiation and / or convection, so that the body is cooled by the discharge of heat energy from the evaporator to the condenser.

The busbar connector and the switchgear component are connected by a respective channel and / or a corresponding coolant line, wherein the channel and / or the line are sealed, so that no steam or liquids are released and a closed cooling circuit and / or a so-called pipe "is formed. The combination of main body, evaporating agent and the condensing agent forms a so-called. Heat-pipe, wherein the at least one evaporation means in the line rail connector or in its chamber is angeordnett and the condensing agent is mounted in the respective switchgear component. Therefore, the busbar connector forms only a part of the heat-pipe, since it comprises only the main body and the at least one evaporation means. The heat-pipe or heat pipe includes the sealed inner cavity or chamber that is integrated with the body of the rail connector, and the cavity includes the cooling medium. The cooling medium and the evaporator are mounted at respective ends of the coolant line, wherein the conduit is advantageously elongated in shape to increase the efficiency of the heat pipe system.

The combination of line rail connector with coolant chamber and possibly evaporation or evaporator and condenser or condensing combined and combines the principles of thermal conductivity and phase transition to distribute heat efficiently and space or space saving from the rail connector and dissipate. The coolant chamber is thermally connected to the hot spot or the hot surface of the busbar connector, wherein the thermal energy of the busbar connector is derived or removed mainly by the evaporation of the cooling medium and the cooling medium itself.

The vapor then rises along the inner cavity and channel and coolant line to the condenser, which includes a cold interface. The vapor is then condensed back into liquid by the condenser and the latent heat is distributed to the environment. The liquid flows back to the vaporizer, either by capillary action or by gravity. The cycle repeats when the cooling medium evaporates again.

The heat-pipe formed by the proposed arrangement has a very high heat transfer coefficient due to the heat transfer by boiling and condensation. When the heat from the condensing agent or condenser to the connected switchgear component is removed by the steam, the heat energy is dissipated more efficiently from the busbar connector as compared with the known busbar connectors.

In a further embodiment, the effective thermal conductivity of the busbar connector varies with the distance between the condensing agent and the base body, in particular with evaporator or evaporation means, which is basically determined by the length of the sealed inner cavity in combination with the length of the coolant line. The thermal conductivity of the line rail connector according to the invention can be up to 80 W / K, for example. Compared with this, the thermal conductivity of the known busbar connectors is about 0.400 W / K. Therefore, the thermal conductivity of the inventive rail connector is significantly increased.

• – wenigstens einen Dampfkanal zum Abgeben des verdampften Kühlmediums
• – wenigstens einen Kondensatormittelkanal zum Rückführen des kondensierten Kühlmediums zum Verdampfungsmittel.

In a further advantageous embodiment, the at least one coolant line is divided into:

• - At least one steam channel for discharging the evaporated cooling medium
• - At least one capacitor means channel for returning the condensed cooling medium to the evaporation means.

Therefore, the refrigerant line has two individual channels, a vapor channel in which the vaporized cooling medium ascends to the condensing agent, and a condensing agent channel in which the condensed cooling medium is returned to the cavity or coolant chamber in the form of liquid. Due to the separation into two channels, the efficiency of the heat pipe or the heat pipe system is advantageously increased because a heat exchange between the rising steam and the condensed cooling medium is prevented or inhibited.

According to another embodiment, the condensed cooling medium is returned to the cavity through at least one wick structure which is at least partially submerged in the cooling medium. Since the wick structure is at least partially immersed in the cooling medium, a capillary force is provided which causes the condensed cooling medium to flow back to the cavity or into the chamber. The amount of cooling medium must be sufficient so that the flow of the cooling medium does not break off by the capillary action, even if the cooling medium evaporates. Finally, to maintain the capillary action, it is necessary for the wick structure to be at least partially submerged in the cooling medium. The wick structure may be, for example, sintered metal powder or a grooved wick having, in particular, a series of grooves parallel to the elongated inner cavity or chamber. The wick structure is typically arranged in the interior of the channel and / or the coolant line or the cavity and / or fills it at least partially.

In an advantageous embodiment, the capacitor distributes the heat energy through at least one distribution means, in particular through at least one cooling fin. The distribution means provides an increased surface area, which expands the area to increase the heat transfer rate from the compensator to the environment. The amount of heat distribution from the distribution means is typically determined by its heat conduction, heat convection and heat radiation levels. A preferred solution is to pass the heat through cooling fins, since these are commonly used for heat exchange devices, such as radiators. In another variant, open cavities may be used to increase the heat distribution area.

In a preferred embodiment, the at least one switchgear component is a circuit breaker or busbar or feeder / feeder. Therefore, the condensing means is integrated to condense the cooling medium in the circuit breaker and / or a branch and / or a conductor rail and / or a feed line which is at a lower temperature level than the hot spot or line rail connector. Therefore, no further device in the switchgear for condensing the cooling medium is required.

In an advantageous embodiment, the line rail connector at least two connection or coupling means for thermal and / or mechanical connection, in particular by means of screwing, each with a switchgear component.

In a further variant, the line rail connector is connected by at least one groove to the circuit breaker and / or branch or feed line. Here, a secure connection for force and torque transmission between the rail connector and the circuit breaker and / or the branch or feed line is provided.

Furthermore, a switchgear, in particular a low-voltage switchgear, which comprises at least one line rail connector according to the invention is advantageously proposed.

In another embodiment, the connector is connected to a capacitor which is connected either to the busbar with the same potential, or to a capacitor with cooling fins independent of the busbar location.

Additionally, in another embodiment, the particular rail connector may be connected either directly to the circuit breaker or using the available standard circuit breaker connectors.

With the proposed connector, in principle, the heat flow capacity of the copper (joints and bars) is supported / increased to increase the power density (current capacity) of the circuit breaker, so that no derating is required and the full current capacity of the circuit breaker can be achieved.

In another embodiment, the focus is on the particular integrated evaporator design, but the capacitor system is required to provide full functionality.

These features and other advantageous embodiments are included in the claims and are intended to be exemplified in the figures contained in the drawings accompanying this description.

The enclosed drawings show in

1 : a first exemplary busbar connector,

2 a condensing agent with busbars,

3 a front side of a condensing agent,

4 a back side of a condensing agent,

5 a fourth busbar connector and

1 shows an exemplary rail connector 1a , The rail connector 1a includes a body 2a further comprising a cavity 4a comprising, which with a cooling medium 6a is filled. The cooling medium 6a vaporizes when it is placed under heat energy by an unillustrated evaporation means, the steam then through a channel 8a rises. The rail connector 1a For example, has an anvil shape, so that two respective connecting portions are formed on its front and rear sides. The rail connector 1a has on its front side an exemplary connection area with a circuit breaker and on its rear side an exemplary connection area with a bus bar.

The invention describes the use of a busbar connector for connecting the circuit breaker to the busbar system through a special connector with integrated coolant tank and evaporator. This connector is connected to a capacitor either by the connection to the bus bar with the same potential, wherein the bus bar is used as a cooling medium, or with a condenser with cooling fins regardless of the busbar location.

The special rail connector can either be connected directly to the circuit breaker or using the available standard circuit-breaker connectors. With this type of connection block type of rail connector, the heat flow capacity of the copper joints and rods is basically promoted to increase the power density of the circuit breaker. Therefore, the current carrying capacity is increased. Therefore, no derating is required and the full current capacity of the circuit breaker can be achieved.

2 shows a condensing agent or a capacitor 10b with some busbars 20b . 20c . 20d . 20e that are mounted around this. In this example, the cooling medium is an elongated tube. The condensing agent or the condenser 10b is used to condense the cooling medium from its gaseous state to its liquid state by being cooled, whereby the cooling medium is converted from vapor to liquid.

In this case, the condensing agent is a surface condensing agent, with the steam in the condenser 10b enters, in this case, a rather flat, a plurality of rails comprehensive hollow body, one end of which is closed and the other end has at least one connection means for connecting a coolant line, in the simplest case could serve as a hollow body and a flattened on at least one side tube. The condensation occurs in the hollow body, which transfers the heat to the outside of the hollow body, wherein the latent heat of the evaporated cooling medium is then transferred to the outside of the hollow body. The condensate drips down and collects at the bottom, for example in a kind of trough with drain, which returns the collected cooling medium via a connected coolant line to the cavity or the chamber of the rail connector, so that it can be collected there and re-evaporated. As an example, the outside of the hollow body is cooled by air or cool water flowing around it. The condensing agent or the condenser, in this example the hollow body or a flattened tube which is U-shaped, is provided by busbars 20b . 20c . 20d . 20e guided and includes these at least partially. The busbars with their comparatively low temperature potential serve to distribute the heat energy more efficiently.

3 shows a front side of a condensing agent or capacitor 10c wherein the condensing agent typically comprises fastening means, in particular recesses and screws and / or clamps, for attaching the condensing agent to at least one switchgear component and / or line rail. In the example shown here holes for fastening by means of screwing.

4 shows a back of a condensing agent or capacitor 10d , The condensing agent 10d includes distribution means 22 , For example, cooling fins on its surface. The cooling fins increase the heat conduction, convection and / or radiation of the condensing agent 10d , In this exemplary embodiment, the cooling fins operate as radiators to distribute the heat energy.

5 shows another exemplary rail connector 1d , The rail connector 1d includes a groove 24 for connecting a switchgear device or component, for example a circuit breaker or a switchgear. The groove provides, for example, an anti-twist connection. The groove 24 is typically vertically aligned.

LIST OF REFERENCE NUMBERS

1a

 Line rail connector

1d

 Line rail connector

1f

 Line rail connector

1g

 Line rail connector

1h

 Line rail connector

2a

body

4a

cavity

6a

cooling medium

8a

channel

10b

 condensing agent

10c

 condensing agent

10d

 condensing agent

20b

 conductor rail

20c

conductor rail

20d

 conductor rail

20e

 conductor rail

22

distribution means

24

ril

Claims (8)

Conductor rail connector ( 1a , d, f, g, h) for connecting at least one switchgear component ( 20a - 20e ) comprising a conduit, comprising: - a body ( 2a ) with an inner cavity or a chamber ( 4a ), which at least partially with a cooling medium ( 6a . 6b ) is filled or filled; - and / or at least one evaporator, which - in the cavity or the chamber ( 4a ) is arranged; and / or - thermally with the main body ( 2a ) connected is; and base body and / or evaporator are adapted and designed for the cooling medium ( 6a ) to evaporate in the chamber or to transfer into the gas phase, by heat transfer of the body ( 2a ) to the cooling medium in the chamber; where at least one channel ( 8a ) for discharging the evaporated cooling medium ( 6a . 6b ) from the chamber and; and returning the condensed refrigerant to the chamber ( 4a ) and at least one connection means for connecting at least one coolant line for connection to a capacitor is provided. Conductor rail connector ( 1a - 1h ) according to claim 1, characterized in that the conductor rail connector ( 1a , d, f, g, h) through the at least one channel ( 8a ) with connecting means with at least one condensing agent ( 10 ) or condenser is fluidly connected, such that, the evaporated cooling medium ( 6a ) by dispensing and distributing the absorbed heat energy to the environment and in particular to a standing with the capacitor in thermal communication switchgear component, for example one or more bus bars or feeders / branches, re-condensed and returned to the chamber, whereby heat energy from the body and thus the line rail connector is derived and cooled. Conductor rail connector ( 1a , d, f, g, h) according to claim 2, characterized in that the at least one channel ( 8a ) and / or the foreseeable coolant line is divided into: - at least one steam channel for discharging the evaporated cooling medium ( 6a ), and - at least one condenser channel for returning the condensed cooling medium to the chamber. Conductor rail connector ( 1a , d, f, g, h) according to any one of the preceding claims, characterized in that the condensed cooling medium ( 6a ) to the cavity or to the chamber ( 4a ) is returned by at least one wick structure which at least partially in the cooling medium ( 6a ) is immersed. Conductor rail connector ( 1a , d, f, g, h) according to any one of the preceding claims, characterized in that the condensing agent or the condenser ( 10 ) or the capacitor, the heat energy through at least one distribution means ( 22 ), in particular by at least one cooling fin, distributed and / or releases to the environment. Conductor rail connector ( 1a , d, f, g, h) according to any one of the preceding claims, characterized in that the at least one power or line rail ( 20a - 20e ) is a circuit breaker or a branch. Conductor rail connector ( 1a , D, f, g, h) according to claim 6, characterized in that the guidance rail connectors ( 1a , d, f, g, h) by at least one groove ( 24 ) is connected to the circuit breaker and / or branch and / or line rail and / or feed line.  Switchgear, in particular a low-voltage switchgear, comprising at least one line rail connector according to one of the preceding Claims 1 to 7.

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