ELECTRICAL DEVICE WITH A SEMICONDUCTOR CIRCUIT

Description

[0001] The invention relates to a converter having an electrical device with a semiconductor circuit between an AC voltage connection and a DC voltage connection, which is designed for a high voltage and arranged in a housing.

[0002] Such a converter is known from the prior art, particularly from high-voltage technology. For example, converters for converting alternating current to direct current or vice versa have converter valves that comprise a plurality of power semiconductors. The power semiconductors are semiconductor switches designed for high voltage, i.e., for voltage differences above 1 kV. The power semiconductors are typically housed in one or more housings.

[0003] EP 0 299 275 B1, for example, discloses a power converter whose converter valves comprise thyristors arranged in housings in the form of modules. The modules are combined to form valve towers mounted in a valve hall. The valve hall is at ground potential. During operation of the power converter, the thyristors of the semiconductor circuit, in contrast, are at different high-voltage potentials, so that the semiconductor circuit or its components must be electrically insulated from the housing or the housing wall of the module. This is usually achieved by providing sufficient distance between the semiconductor circuit or its components and the housing wall. With high voltages applied to the semiconductor circuit, this necessarily results in large housing dimensions. The width and length of the housing are usually up to several meters.This makes access to the semiconductor circuit much more difficult for installation and maintenance work.

[0004] A converter is known from DE 198 41 134 A1.

[0005] The converter comprises an electrical device with a semiconductor circuit between an AC voltage connection and a DC voltage connection, which is designed for a high voltage and arranged in a housing, wherein the semiconductor circuit has a series connection of power semiconductors, wherein the housing is a module frame on which the semiconductor circuit is mounted, and comprises a plurality of housing parts which are frame segments, wherein different electrical potentials can be assigned to the frame segments.

[0006] The object of the invention is to propose a converter of this type which enables maintenance to be as simple as possible.

[0007] The problem is solved by a converter having the features of patent claim 1.

[0008] During operation of the electrical device according to the invention, different housing parts can each be brought to a different, previously predetermined electrical potential. The respective electrical potential of a housing part can be adapted to the electrical potential of the components of the semiconductor circuit that are closest in spatial arrangement.

[0009] In this way, advantageously flexible voltage differences can be achieved between the semiconductor circuit and the housing. In particular, for example, a component of the semiconductor circuit or a semiconductor circuit part located at the highest voltage level no longer needs to be insulated from an entire housing located at ground potential or at the lowest potential of the semiconductor circuit part, but rather from a housing part located at a predetermined, higher (partial) potential.

[0010] The insulating air gaps between the semiconductor circuit and the housing can be advantageously reduced. This significantly reduces maintenance effort by improving access to the semiconductor circuit.

[0011] According to the invention, at least one housing part is at a high-voltage potential during operation. This allows the insulation distances to be kept particularly small in a semiconductor circuit to which a high voltage is applied during operation. For example, if the semiconductor circuit consists of several components, one of which is at a high-voltage potential, the housing part that is spatially closest to this component is assigned to this high-voltage potential.

[0012] For semiconductor circuits that have particularly high voltage differences at their terminals, for example, more than 10 kV, it is considered advantageous if adjacent housing components each have a potential difference of between 1 kV and 200 kV or even more during operation. In this way, the voltage levels of the housing components can be graduated, allowing adaptation to the voltage applied to the semiconductor circuit. By appropriately assigning the potentials to the housing components according to their spatial arrangement relative to the semiconductor circuit or its components, a particularly compact housing design can be achieved.

[0013] According to the invention, the housing is a module frame on which the semiconductor circuit is mounted. Accordingly, the housing does not necessarily have a design that completely encloses the semiconductor circuit. Rather, it can be advantageous for the housing to be designed as a module frame. The module frame surrounds the semiconductor circuit and provides a suitable suspension device to which the semiconductor circuit can be attached. The module frame surrounds the semiconductor circuit laterally, but it does not have to completely cover the semiconductor circuit from above and / or below. The arrangement of the semiconductor circuit ensures both good cooling and particularly good accessibility to the semiconductor circuit.

[0014] According to the invention, the module frame comprises several frame segments separated from one another by insulator components. The housing parts in the form of frame segments can, for example, be plate-shaped. To insulate the frame segments from one another, insulator components are provided between two frame segments to which different potentials are to be assigned. The insulator components are mounted on the frame segments and include electrically insulating spacers. This enables a particularly simple and effective distribution of the potentials on the housing.

[0015] According to an advantageous embodiment of the invention, the module frame has a C-shape. Accordingly, the module frame is configured at least in one spatial plane such that it resembles the letter C. For this purpose, the module frame has a one-sided indentation in this plane that is at least partially bounded on three sides. A particular advantage of this embodiment arises, for example, when two of the electrical devices are arranged opposite one another, with the indentations of the C-shaped module frames of the two devices facing one another. This creates a free space between the two devices. This free space can advantageously be used to enable additional access for maintenance work on the semiconductor circuits. For example, a lifting platform can be provided, which is arranged in the free space and serves to provide appropriate accessibility for maintenance work.

[0016] According to the invention, the semiconductor circuit comprises a series connection of power semiconductors. Such a series connection usually results in a voltage difference being present between the connection terminals of the series connection during operation of the electrical device. In high-voltage applications, this voltage difference can be in the range of over 10 kV or even over 200 kV. This means that a first power semiconductor in the series connection can be at a low potential, for example, at ground potential, whereas a last power semiconductor in the series connection can be at a high-voltage potential, for example, well over 100 kV. In this case, the distribution of the potentials at the housing is particularly effective. The housing components can be assigned graduated voltage or potential levels, allowing compact dimensions for the individual housing components.The power semiconductor at the highest potential then does not need to be insulated from a housing at ground potential for the entire potential difference between ground potential and high-voltage potential.

[0017] A particularly advantageous application of the invention arises when the semiconductor circuit comprises thyristors. For example, at least one of the power semiconductors in the series circuit can be a thyristor. Thyristors are often used in high-voltage converters because these semiconductor switches can have a particularly high blocking capability. The blocking capability of the thyristors or the other power semiconductors in an advantageous application of the invention can, for example, be between 1 kV and 8 kV or more.

[0018] Advantageously, each thyristor in the series circuit is assigned an RC circuit and / or a valve choke. The RC circuit comprises a resistance element and a capacitor, which are suitably arranged in parallel with the thyristor. The RC circuit is arranged with each thyristor in the housing.

[0019] For example, a series connection of power semiconductors can be at least partially accommodated in a module housing that comprises several housing parts that are at different electrical potentials during operation of the converter.

[0020] The advantages of the converter according to the invention result from the previously described advantages of the electrical device according to the invention.

[0021] All previously described variants and embodiments of the electrical device according to the invention can of course be used alone or in combination with one another in the converter according to the invention.

[0022] The invention is described below with reference to Figure 1 and 2 illustrated embodiments of the electrical device according to the invention and the converter according to the invention. Figure 1 shows an embodiment of a converter according to the invention in a schematic representation; Figure 2 shows an embodiment of an electrical device according to the invention in a schematic plan view.

[0023] In detail, Figure 1a converter 1 is shown. The converter 1 has an AC voltage side with an AC voltage connection 2 for connection to a three-phase AC voltage network. The converter 1 also has a DC voltage side with a DC voltage connection 3 for connection to a DC voltage line. The converter 1 comprises three phase branches, which are also referred to as valve branches 41-46. Each of the valve branches 41-46 has a series connection of thyristor modules 6. A broken line 17 in each valve branch 41-46 illustrates that, in general, more than the three explicitly shown thyristor modules can be arranged there.

[0024] Each thyristor module 6 is an electrical device with a series connection of several thyristors, which are arranged in a housing together with an associated thyristor circuit and valve chokes.

[0025] The structure of the thyristor module 6 is described in the following Figure 2 discussed in more detail.

[0026] Figure 2 shows an electrical device in the form of a thyristor module 6. The thyristor module 6 comprises a semiconductor circuit 7, which includes a first thyristor module 71, a second thyristor module 74, and an upper and a lower valve choke 72 and 73, respectively. The first and second thyristor modules 71 and 74 each comprise a series circuit of thyristors and an associated thyristor circuit.

[0027] The semiconductor circuit 7 is arranged in a housing in the form of a module frame 8. The module frame 8 has a plurality of frame segments 81-86. The frame segments 81-86 are arranged around the semiconductor circuit 7 in such a way that they form a C-shape with a recess 9 in the plane of the drawing of the Figure 2 form. In the Figure 2In the illustrated embodiment, the module frame 8 comprises six frame segments 81-86. In general, their number and size can vary as desired and be adapted to the respective application and the design of the semiconductor circuit 7.

[0028] The frame segments 81-86 are electrically insulated from each other by insulating components in the form of insulating spacers 10-15. Due to the insulation, different electrical potentials can be assigned to the frame segments 81-86. Thus, each frame segment 81-86 can have its own, predefined potential level during operation of the thyristor module 6.

[0029] For example, if the valve choke 73 is connected to a pole at a negative potential and the valve choke 72 is connected to a pole at a more positive potential, the frame segment 81 can be assigned a higher potential than the frame segment 85. In this way, the insulation distances between the upper valve choke 72 or at least a portion of the first thyristor module 71 and the frame segment 81 can be selected to be relatively small. Likewise, the insulation distances between the lower valve choke 73 or at least a portion of the second thyristor module 74 and the frame segment 85 can be selected to be relatively small.

[0030] In the Figure 2In the embodiment shown, a further thyristor module 61 is arranged opposite the thyristor module 6. The thyristor module 6 and the further thyristor module 61 are constructed in the same way, so that the construction of the further thyristor module 61 need not be discussed in detail. The indentation 9 of the thyristor module 6 and an indentation 91 of the further thyristor module 61 face each other. A lifting platform 16 is arranged in the free space formed by the two indentations 9, 91. The lifting platform 16 can be positioned perpendicular to the plane of the drawing. Figure 2 be moved. Thus, both the thyristor modules 6 and 61, as well as the thyristor modules arranged above them (not shown graphically), can be reached by means of the lifting platform 16. Accessibility to the thyristor modules and semiconductor circuits for installation and maintenance purposes is thus greatly improved.

Claims

1. Converter (1) having an electrical device (6) with a semiconductor circuit (7) between an AC voltage supply (2) and a DC voltage supply (3), which is designed for a high voltage and is arranged in a housing (8), wherein the semiconductor circuit (7) has a series connection (71, 74) of power semiconductors, wherein the housing (8) is a module frame on which the semiconductor circuit (7) is mounted, and comprises a plurality of housing parts (81-86) which are frame segments (81-86) which are separated from one another by means of insulator components (10-15) and are thus electrically insulated from one another, wherein the insulator components (10-15) are mounted on the frame segments and comprise electrically insulating spacers, wherein different electrical potentials can be assigned to the frame segments (81-86).

2. Converter (1) according to claim 1, wherein at least one frame segment (81-86) is intended to be at a high voltage potential during operation.

3. Converter (1) according to any one of claims 1 or 2, wherein adjacent frame segments (81-86) are provided to each have a potential difference between 1 kV and 200 kV in operation.

4. Converter (1) according to one of the preceding claims, wherein the module frame (8) has a C-shape.

5. Converter (1) according to claim 1, wherein at least one of the power semiconductors is a thyristor.

6. Converter (1) according to any one of claims 4 or 5, wherein each of the power semiconductors has an electrical blocking capability of at least 1kV.

7. Converter (1) according to any one of claims 5 or 6, wherein each thyristor is assigned an RC circuit and / or a valve choke.