DE212011100212U1 - Frame for a modular voltage-driven converter and insulation device - Google Patents

Abstract

Frame (13) for a modular live converter (11), comprising one or more converter modules (121, ..., 12n), the frame (13) comprising: - a housing (15) for receiving the one or more converter modules (121, ..., 12n), and - an insulation device (10), comprising: - a first electrically conductive layer (16), comprising a first connection means (19) for connection to a housing (14) which forms the frame (13), - a second electrically conductive layer (17), comprising a second connecting means (20) for connecting to a converter module (121) of the one or more converter modules (121, ..., 12n), and - an insulation layer (18), which separates the first electrically conductive layer (16) and the second electrically conductive layer (17).

Description

Field of the invention

The invention relates generally to the field of voltage-driven converters, and more particularly to transducer frames, isolation and protection therefor.

Background of the invention

Voltage Source Converters (VSCs), also referred to as STATCOMs, are now a valuable solution for increasing the power quality of an electric power grid and ensuring grid code compliance in the case of stochastic generation integration (ie, wind power, solar power) The need to reduce system costs leads the technology towards standard solutions, and with reference to 1 become multilevel converters 1 often through a serial / parallel connection of standard converter modules 2 ₁ , ..., 2 _n , (also referred to as converter cells, transducer links or valves) built. These standard converter modules 2 ₁ , ..., 2 _n be in mechanical framework 3 stacked. The multilevel converter 1 is typically connected to a medium / high voltage, and the converter phase must be sufficient from a housing 4 be isolated, for example, a container in which the multilevel converter 1 is placed. Such insulation is achieved by insulators and a suitable air clearance to walls, floor and ceiling of the housing, as indicated in the figures by the double arrows.

Sufficient air gaps between the frame and the housing must thus be ensured for the electrical insulation, which limits the compactness of the solution and greatly affects the system cost when the voltage-controlled converter 1 is directly connected to distribution and transmission voltage levels. The air isolation distances limit the size and number of frames that can be installed in standard containers, resulting in an increased number of required containers for accommodating the voltage-driven transducers.

US 3,805,140 discloses a solution where an isolation barrier is attached to the inner wall of a metal container housing of an AC-DC converter. Placing such an isolation barrier on the container walls can be cumbersome, and making such an isolation barrier for an entire container is both expensive and difficult.

In addition to the above solutions of sizing the housing to provide sufficient air gaps and lining the housing with insulation material, solutions using insulation oil or vacuum insulation are known.

The above-mentioned known solutions have one or more disadvantages, such as high material, production and installation costs, and the requirement of a large footprint, which is a danger to the environment. Furthermore, the maintenance costs are high, especially for oil or gas insulated structures, and mechanical costs for ensuring the seals of all parts are very high.

Summary of the invention

In view of the above, it is an object of the invention to provide cost effective and compact isolation means for transducer module assemblies.

The object is achieved according to a first aspect of the invention by a frame for a modular voltage-driven converter comprising one or more converter modules. The frame includes a housing for receiving the one or more transducer modules; and an insulation device comprising: a first electrically conductive layer comprising a first connection means for connection to a housing which houses the frame, a second electrically conductive layer comprising a second connection means for connection to a transducer module of the one or more transducer modules, and an insulating layer separating the first electrically conductive layer and the second electrically conductive layer.

The invention provides a compact isolation solution for modular transducer systems, which allows the reduction of the size and number of housings for accommodating the transducer modules. The invention thus also enables a reduction of system costs. The reduced size requirement of the enclosures may instead be exploited by introducing additional transducer modules for applications where such a need exists.

Furthermore, the solution of the invention can be standardized and suitable for mass production, which in turn allows a compact system with low cost. The small footprint that is required in the frame and the insulation device according to the invention makes them particularly suitable for example for offshore wind power platforms.

The object is achieved according to a second aspect of the invention by a frame isolation device comprising a modular voltage-driven converter having one or more Transducer modules receives, solved. The isolation device comprises a first electrically conductive layer comprising a first connection means for connection to an enclosure which receives the frame. The isolation device further comprises a second electrically conductive layer comprising a second connection means for connecting to a transducer module of the one or more transducer modules. The insulation device further comprises an insulation layer separating the first electrically conductive layer and the second electrically conductive layer. The above-mentioned properties are also achieved for this aspect of the invention.

Other features and advantages of the invention will become apparent upon reading the following descriptions and accompanying drawings.

Brief description of the drawings

1 shows a transducer frame according to the prior art.

2 shows a converter frame and an isolation device according to the invention.

3 shows a detail of 2 ,

4 shows the invention for a delta-connected voltage-controlled converter.

5 shows an advantage achieved by the invention.

Detailed description of embodiments

In the following description, for purposes of explanation and not limitation, specific details, such as particular architectures, interfaces, techniques, etc., are set forth in order to provide further understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be embodied in other embodiments that depart from these specific details. In other instances, detailed descriptions of known devices, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail. The same reference numerals in the description refer to similar elements.

Referring to 2 is a mechanical frame 13 Also referred to as a converter frame, shown according to an embodiment of the invention. The frame 13 is for a modular voltage-driven converter 11 and could include a standardized mechanical transducer frame with the adjustments described. The modular voltage-controlled converter 11 includes one or more transducer modules 12 ₁ , ..., 12 _n (therefore modular).

For example, the voltage-driven converter could 11 be designed for use at a connection voltage of 33 kV, and the voltage-controlled converter 11 could then include, for example, 80 converter modules. Each phase of the voltage-controlled converter 11 can thus a variety of frames 13 to accommodate the transducer modules needed for this specific voltage level (see also 4 ).

The frame 13 includes a housing 15 for receiving the one or more transducer modules 12 ₁ , ..., 12 _n . The housing 15 can be made of metal or plastic, for example. The housing 15 includes means for receiving the transducer modules, such as terminals or fasteners, through which a transducer module inserted into the frame housing 15 is inserted, attached to it. The transducer modules are then cabled together to collectively provide the desired voltage level.

The frame 13 further comprises an isolation device 10 which is a first electrically conductive layer 16 and a second electrically conductive layer 17 includes. The electrically conductive layers 16 . 17 are through an electrical insulation layer 18 separated. The isolation device 10 is in 3 shown in more detail.

The first electrically conductive layer 16 comprises a first connection means 19 that for a connection, for example, with an enclosure 14 that the frame 13 absorbs, is suitable. Typically, the frame 13 (or a number of frames) in a standard size container, and the enclosure 14 may include such a container. In another example, the enclosure 14 a concrete enclosure with internal metal structures (ie for limiting electromagnetic emission). The first electrically conductive layer 16 should be a lanyard 19 include, which is connectable to such a housing, the housing is typically grounded. Alternatively, the first electrically conductive layer 16 be connectable to another ground potential. The first connection means 19 may comprise welded joints, ie the first conductive layer 16 is by welding with the enclosure 14 connected. Another example includes removable electrical connections created by mechanical pressure and through which the first connection means 19 with the enclosure 14 is connected. Still other examples include bolts and / or screws.

The second electrically conductive layer 17 comprises a second connecting means 20 for connection to a converter module 12 _{1 of} the one or more converter modules 12 ₁ , ..., 12 _n . The second connection means 20 is typically connected to an active part having the highest electrical potential (relative to ground potential, for example) in the direction of the insulation distance to be reduced, that is, in the case shown, vertically toward the ceiling of the enclosure 14 , and vertically towards the floor of the enclosure 14 , The second connection means 20 could be identical to the first connection means, and include, for example, an electrical connection, welded connections, bolts or screws.

The insulation layer 18 is between the first and second electrically conductive layers 16 . 17 arranged and thus separates the first electrically conductive layer 16 from the second electrically conductive layer 17 , The insulation layer 18 may comprise a solid insulating material, preferably with a high dielectric constant, such as plastic or rubber.

In one embodiment, the insulating layer is 18 dimensioned to the isolation device 10 with a capacity to protect the modular voltage-driven converter 11 to provide for fast incoming peak currents. That is, the insulation layer 18 can be dimensioned to the isolation device 10 with a capacity suitable for their intended use. The isolation device 10 then serves as a distributed extra shunt capacitance along the voltage-driven converter 11 , The material of the insulation layer 18 may additionally or alternatively be selected to the isolation device 10 with the desired capacity to protect the modular voltage-driven converter 11 to provide for such fast incoming peak currents.

When laying out and making the insulation device 10 It should be ensured that the first electrically conductive layer 16 , the second electrically conductive layer 17 and the insulation layer 18 be made and connected to eliminate any air between them. This prevents partial discharges. Next, it should be ensured that each of the first electrically conductive layer 16 , the second conductive layer 17 and the insulation layer 18 is free from air.

Another design aspect with respect to such partial discharges is the shape of the first electrically conductive layer 16 , the second electrically conductive layer 17 and the insulation layer 18 , In particular, they should be designed to evenly distribute an electric field, for example by providing the layers with smoothed (rounded) edges.

The isolation device 10 can be at an upper part 21 of the housing 15 and / or a lower part 22 of the housing 15 be arranged. The first electrically conductive layers 16 each isolation device are with the enclosure 14 connected, and thus typically with the ground potential, since the housing is typically grounded. The second electrically conductive layers 17 are connected to the terminals of the adjacent converter modules. In the case shown, these would accordingly be the topmost converter module of a stack of converter modules and the converter module of the stack of modules placed at the bottom. The second electrically conductive layers 17 thus assume the same potential as these converter modules.

The isolation device 10 Can frame in different ways 13 be attached. A first example involves the use of electrically insulating fasteners, such as cooperating engagement members, such as male and female fasteners. That is, the frame housing 15 may be provided with female connecting means, in the male connecting means connected to the isolation device 10 are introduced.

If the frame housing 15 is made of an electrically conductive material, such as metal, and the housing 15 connected to the top converter module (converter module 12 ₁ in the case shown), then the housing would be 15 at the same potential as the second electrically conductive layer 17 , The isolation device 10 and in particular the second electrically conductive layer 17 The same could then simply by metal screws or the like on the frame 13 be attached.

The invention also includes the isolation device 10 for a frame 13 as described above. That is, a frame 13 , which is a modular voltage-driven converter 11 receives one or more converter modules 12 ₁ , ..., 12 _n includes. The isolation device 10 is designed taking into account the aspects already described above. The isolation device 10 comprises a first electrically conductive layer 16 , a second electrically conductive layer 17 and an insulation layer 18 that separates them.

In one embodiment, the first electrically conductive layer 16 , the second electrically conductive layer 17 and the insulation layer 18 connected to eliminate any air between them. Preferably, it is also ensured that each layer 16 . 17 . 18 is free from air.

In one embodiment, the first electrically conductive layer 16 , the second electrically conductive layer 17 and the insulation layer 18 shaped so as to include smoothed corners, whereby an electric field is evenly distributed.

In one embodiment, the insulating layer comprises 18 a solid insulating material with a high dielectric constant, such as plastic or rubber.

In one embodiment, the insulating layer is 18 dimensioned so that they are the isolation device 10 with a capacity to protect the modular voltage-driven converter 11 provides for fast incoming peak currents.

In one embodiment, a material is the insulating layer 18 selected to the isolation device 10 with a capacity to protect the modular voltage-driven converter 11 to provide for fast incoming peak currents.

In an embodiment, the first connection means comprises 19 and the second connection means 20 welded connections or removable electrical connections.

In one embodiment, the first connection means 19 connected to ground potential, and the second connection means 20 is with an active part of the modular voltage-driven converter 11 connected to the highest electrical potential.

Although some special embodiments of the isolation device above 10 described, the isolation device 10 be provided with any combination of features already in the explanation of the frame 10 have been described.

4 shows a delta-connected voltage-controlled converter 11 which thus has three phase phases L1, L2, L3. As previously mentioned, the frame is 13 (or a number of frames) housed in a standard size container, with the enclosure 14 includes such a container. This is useful for a number of reasons; For example, much of the wiring can be done on the same site for all transducers. The containers are then shipped to their intended location of operation, with shipping being simplified by the standard size containers.

It is noted that the delta connection of the voltage-driven converter is given by way of example only and other types of connections may also benefit from the teachings of the invention, such as star-connected voltage-controlled converters or single-phase converters.

5 shows the briefly mentioned aspect of providing a distributed extra shunt capacitance along the voltage-driven converter 11 , This is a natural protection against fast incoming peak currents, which can be caused, for example, by lightning phenomena (as shown by the arrow at the far left). Such flash phenomena may possibly damage the converter modules. As mentioned, the capacitance value of the isolation device 10 by varying the insulating material (with different dielectric constants) and / or by adjusting the insulation thickness. The isolation device (s) 10 thus provides distributed peak capacities that protect the transducer modules.

By the invention, the through the insulation device 10 provided electrical insulation with a limited distance, resulting in a much more compact transducer system compared to the prior art. The isolation device 10 can with the mechanical frame 13 , which holds the converter modules, be integrated. Production costs are reduced, even minimized, thanks to a solution that uses standardized inserts.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 3805140 [0004]

Claims (21)

Frame ( 13 ) for a modular voltage-controlled converter ( 11 ) comprising one or more transducer modules ( 12 ₁ , ..., 12 _n ), the frame ( 13 ) comprises: - a housing ( 15 ) for receiving the one or more transducer modules ( 12 ₁ , ..., 12 _n ), and - an isolation device ( 10 ), comprising: - a first electrically conductive layer ( 16 ), comprising a first connecting means ( 19 ) for a connection to an enclosure ( 14 ), the frame ( 13 ), - a second electrically conductive layer ( 17 ), comprising a second connecting means ( 20 ) for connection to a converter module ( 12 ₁ ) of the one or more converter modules ( 12 ₁ , ..., 12 _n ), and - an isolation layer ( 18 ), which is the first electrically conductive layer ( 16 ) and the second electrically conductive layer ( 17 ) separates. Frame ( 13 ) according to claim 1, wherein the first electrically conductive layer ( 16 ), the second electrically conductive layer ( 17 ) and the insulating layer are connected to each other to eliminate any air between them. Frame according to claim 1 or 2, wherein each of the first electrically conductive layer ( 16 ), the second conductive layer ( 17 ) and the insulation layer ( 18 ) is free from air. Frame ( 13 ) according to one of the preceding claims, wherein the first electrically conductive layer ( 16 ), the second electrically conductive layer ( 17 ) and the insulation layer ( 18 ) are shaped so as to evenly distribute an electric field. Frame ( 13 ) according to claim 4, wherein the second electrically conductive layer ( 17 ) and the insulation layer ( 18 ) comprise smooth edges. Frame ( 13 ) according to any one of the preceding claims, wherein the insulating layer ( 18 ) comprises a solid insulation material having a high dielectric constant, such as plastic or rubber. Frame ( 13 ) according to any one of the preceding claims, wherein the insulating layer ( 18 ) is dimensioned to the isolation device ( 10 ) with a capacity to protect the modular voltage-driven converter ( 11 ) to provide fast incoming peak currents. Frame ( 13 ) according to one of the preceding claims, wherein a material of the insulating layer ( 18 ) is selected to the isolation device ( 10 ) with a capacity to protect the modular voltage-driven converter ( 11 ) to provide fast incoming peak currents. Frame ( 13 ) according to one of the preceding claims, wherein the first connection means ( 19 ) and the second connecting means ( 20 ) welded connections or removable connections. Frame ( 13 ) according to one of the preceding claims, wherein the first connection means ( 19 ) is connected to a ground potential, and the second connection means ( 20 ) with an active part of the modular voltage-driven converter ( 11 ) is connected to the highest electrical potential. Frame ( 13 ) according to one of the preceding claims, wherein the isolation device ( 10 ) at an upper part ( 21 ) of the housing ( 15 ) and / or at a lower part ( 22 ) of the housing ( 15 ) is arranged. Frame ( 13 ) according to one of the preceding claims, wherein the isolation device ( 10 ) by electrically insulating fasteners on the frame ( 13 ) is attached. Isolation device ( 10 ) for a frame ( 13 ), a modular voltage-driven converter ( 11 ) receiving one or more converter modules ( 12 ₁ , ..., 12 _n ), wherein the isolation device ( 10 ) comprises: - a first electrically conductive layer ( 16 ), comprising a first connecting means ( 19 ) for connecting to an enclosure ( 14 ), the frame ( 13 ), - a second electrically conductive layer ( 17 ), comprising a second connecting means ( 20 ) for connection to a converter module ( 12 ₁ ) of the one or more converter modules ( 12 ₁ , ..., 12 _n ), and - an isolation layer ( 18 ), which is the first electrically conductive layer ( 16 ) and the second electrically conductive layer ( 17 ) separates. Isolation device ( 10 ) according to claim 13, wherein the first electrically conductive layer ( 16 ), the second electrically conductive layer ( 17 ) and the insulating layer are connected to each other to eliminate any air between them. Isolation device ( 10 ) according to claim 12 or 13, wherein each of the first electrically conductive layer ( 16 ), the second conductive layer ( 17 ) and the insulation layer ( 18 ) is free from air. Isolation device ( 10 ) according to one of claims 13 to 15, wherein the first electrically conductive layer ( 16 ), the second electrically conductive layer ( 17 ) and the insulation layer ( 18 ) are shaped that they include smooth edges, whereby an electric field is evenly distributed. Isolation device ( 10 ) according to one of claims 13 to 16, wherein the insulating layer ( 18 ) comprises a solid insulation material having a high dielectric constant, such as plastic or rubber. Isolation device ( 10 ) according to one of claims 13 to 17, wherein the insulating layer ( 18 ) is dimensioned to the isolation device ( 10 ) with a capacity to protect the modular voltage-driven converter ( 11 ) to provide fast incoming peak currents. Isolation device ( 10 ) according to one of claims 13 to 18, wherein a material of the insulating layer ( 18 ) is selected to the isolation device ( 10 ) with a capacity to protect the modular voltage-driven converter ( 11 ) to provide fast incoming peak currents. Isolation device ( 10 ) according to one of claims 13 to 19, wherein the first connecting means ( 19 ) and the second connecting means ( 20 ) welded connections or removable connections. Isolation device ( 10 ) according to one of claims 13 to 20, wherein the first connecting means ( 19 ) is connected to a ground potential, and the second connection means ( 20 ) with an active part of the modular voltage-driven converter ( 11 ) is connected to the highest electrical potential.

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