Modular high voltage supply system

A modular high voltage supply system has a mobile adapter transformer with a high-voltage output side and a low-voltage input side, electrical connecting input-terminals being foreseen at the mobile adapter transformer outer surface, a mobile container with a low voltage supply system, mounted stationarily therein, having a high current busbar and at least one electrical frequency converter connected thereto, electrical connecting output-terminals for the high current busbar being foreseen at an accessible the mobile container edge; and a modular interim busbar system, for temporary electrical connection of input- and output-terminals, having at least one interim busbar with at least one elongated busbar basic module mounted on a frame structure and respective resilient electrical connections on both busbar basic module ends forming an electrical connection to the input- and/or output-terminals and arranged such that a transmission of vibrations from the mobile adapter transformer to the mobile container is suppressed.

FIELD

The invention is related to a modular high voltage supply system.

BACKGROUND

It is known that synchronous generators are used for the conversion of mechanical into electrical energy. Dependent on the frequency of rotation and the excitation of the rotor winding of the synchronous generator a voltage with a corresponding height and frequency will be generated. Such a variable power source might be required as auxiliary power supply in a power plant for example.

The rated power of such variable auxiliary power supplies with rotating generators might be around 12 MVA/4 MW for example wherein the rated output voltage might amount 10 kV. In the case that such a generator is not ready for operation during a certain time, for example due to scheduled maintenance or a breakdown, a prompt replacement is required in order to supply the respective loads with electric energy of the desired voltage and frequency anyhow.

But also for purposes of testing of electrical equipment such as high power transformers, for example with a rated power of 100 MW and above, a variable power source might be required. For the test of such large components it is more common to transport the test equipment to the component to be tested instead of transporting the component to the test equipment.

Disadvantageously within the state of the art is that the transport of a variable power source with rotating generator is rather difficult and time consuming due to its high weight and size. In case of a temporary installation for test purposes it has also to be ensured, that a suitable groundwork is available at the installation site of the generator.

SUMMARY

An aspect of the invention provides a modular high voltage supply system, comprising: a mobile adapter transformer including a high-voltage output side, a low-voltage input side, and electrical connecting input-terminals, configured for the low-voltage input-side, provided at an outer surface of the mobile adapter transformer; a mobile container including a low voltage supply system mounted stationary therein, the low voltage supply system including a high current busbar and an electrical frequency converter connected thereto, electrical connecting output-terminals for the high current busbar being provided at an accessible edge of the mobile container; a modular interim busbar system configured for temporary electrical connection of the input- and output-terminals, wherein the modular interim busbar system includes an interim busbar including an elongated busbar basic module, mounted on a frame structure, and a respective resilient electrical connection on both ends of the busbar basic module which form an electrical connection to the input- and/or output-terminals and which are arranged such that a transmission of vibrations from the mobile adapter transformer to the mobile container is suppressed, wherein the resilient electrical connection includes a first and a second resilient elongated plate-like clamping element, wherein the first and second resilient elongated plate-like clamping elements are arranged opposed to each other in a clamping distance, wherein the first and second resilient elongated plate-like clamping elements are an electrical active part of an interim busbar, and wherein both ends of the opposed clamping elements include a respective electrical contact section, between which a respective further electrical active section of the interim busbar is clamped.

DETAILED DESCRIPTION

An aspect of the invention is related to a modular high voltage supply system, comprising a mobile adapter transformer with a high-voltage output side and a low-voltage input side, wherein electrical connecting input-terminals for the input-side are foreseen at the outer surface of the mobile adapter transformer, further comprising a mobile container with a low voltage supply system mounted stationary therein which comprises a high current busbar and at least one electrical frequency converter connected thereto, wherein electrical connecting output-terminals for the high current busbar are foreseen at an accessible edge of the mobile container and further comprising a modular interim busbar system for the temporary electrical connection of input- and output-terminals

Based on this background it an aspect of the invention to provide a mobile variable power supply within the power range of a few MVA and above which is easy to transport and to mount on site.

An aspect of the invention provides a modular high voltage supply system of the aforementioned kind. This is characterized in that the modular interim busbar system comprises at least one interim busbar with at least one elongated busbar basic module mounted on a frame structure and respective resilient electrical connection means on both ends of the busbar basic module which form an electrical connection to the input- respectively output-terminals and which are arranged in a way, that a transmission of vibrations from the mobile adapter transformer to the mobile container is suppressed.

Basic idea of an aspect of the invention is to replace a rotating generator by a variable power electronic based electrical frequency converter which is arranged with further components such as VAR compensators or the like in a container and which is easy to transport therewith. Since the output voltage of typical frequency converters is in the range of 400V—whereas the required output voltage might amount 10 kV—a mobile adapter transformer is foreseen for adapting the voltage level accordingly. In some cases such adapter transformer might already be available on site without the need for transportation. Dependent on the needs on site it is also possible to provide a mobile adapter transformer with an output voltage of for example 6 kV instead of 10 kV. So the whole modular high voltage supply system comprises two main components which preferably are both mounted in a respective container, for example a standard 6 m or 12 m container, and which are easily to transport on site therewith.

After placing those components on site—preferably close together in a neighboring position—the container with the low voltage supply system and the adapter transformer have to become electrically connected. The low voltage supply system itself is foreseen to be supplied by an electrical supply on site which can be assumed to be available in a power plant or on a test site. Due to the low output voltage of approximately 400V of the low voltage supply system and due to the high rated power of for example 12 MVA the electrical connection to the adapter transformer has to be foreseen for current levels in the range of 1000 A and above. Furthermore the electrical connection has to be as flexible as possible in order to enable a variable positioning of the container with the LV supply system and the adapter transformer.

According to an aspect of the invention a modular interim busbar system is foreseen for this connection. A busbar can easily be designed for sufficient high currents by increasing its cross section respectively. The base module of the interim busbar is a preferably electric insulating frame structure with an elongated busbar basic module mounted thereon. This might be designed as a massive bar from an electric conducting material. Since the power supply is typically three phased also the modular interim busbar system is preferably three phased and comprises three interim busbars.

A busbar or a busbar module is made for example from copper or aluminum. This are rather stiff materials, so a transmission of vibrations—for example 50/60 Hz respectively 60/120 Hz generated by the adapter transformer—to the container with the LV power supply is afforded therewith in a disadvantageously way. In order to suppress the transmission of vibrations inbetween adapter transformer and container of LV supply system resilient electrical connection means are foreseen on both ends of the busbar basic module. Such resilient electrical connection means have a spring characteristic at least in the direction of one degree of freedom in movement. So, in case that the two resilient electrical connection means on both ends of the busbar basic module are arranged with different orientations respectively perpendicular each to each other, a transmission of vibrations is suppressed in an advantageous way. Dependent on the concrete geometrical arrangement also one single resilient electrical connection means might be sufficient.

The resilient electrical connection means may be connected electrically in series with the base module and further modules of the busbar, so that an electrical connection inbetween the input- and the output-terminals is gained therewith. Preferably a set of modules with different selectable sizes is provided so that variable distances can be bridged therewith by mounting the modules individual according to the requirements on site. The electrical connecting output-terminals for the high current busbar of the container are for example accessible over a closeable opening at the side wall of the container, so that it can be closed during transportation.

According to a further embodiment of the invention a resilient electrical connection means comprises a first and second resilient elongated plate-like clamping element which are arranged opposed each to each other in a clamping distance and which both are electrical active part of an interim busbar. Such an embodiment provides on one side a sufficient high spring characteristic and is on the other side rather easy to mount.

According to a further embodiment of the invention both ends of the opposed clamping elements comprise a respective electrical contact section wherein a respective further electrical active section of the interim busbar is clamped between. Preferably the further electric active section of the busbar has a comparable thickness like the busbar base module, so the clamping is simplified therewith.

According to a preferred embodiment of the invention opposed elongated clamping elements are connected together by means of screws or bolts extending through the respective contact sections and through the respective electrical active section of the interim busbar clamped inbetween, which are provided with respective boreholes accordingly. By screws or bolts a sufficient high pressure can be applied on the components to be connected so that the connection complies with required electrical characteristics. Furthermore such a kind of connection is easily solvable so that a temporary installation of a modular high voltage system can easily dismounted.

According to another variant of the invention elongated clamping elements are made at least predominantly from copper or aluminum. This is suitable conductor material for conducting a high electrical current.

According to a further embodiment of the invention two or more neighbored clamping elements are arranged in parallel in the same plane instead of a single clamping element. This facilitates mounting the resilient electrical connection means in an advantageous way.

According to a further embodiment of the invention the modular interim busbar comprises an electrical active elongated square-shaped hollow busbar section. A weight reduction of the interim busbar is gained therewith in an advantageous way.

According to another variant of the invention the input terminals of the mobile adapter transformer are extending into the elongated square-shaped hollow busbar section in a form-locking manner. By adapting the inner square shape of the hollow busbar to the preferably square shaped outer diameter of the input terminals the electrical connection is facilitated therewith.

According to a further embodiment of the invention resilient electrical connection means are extending into the elongated square-shaped hollow busbar section in a form-locking manner. By adapting the inner square shape of the hollow busbar to the preferably square shaped outer diameter of resilient electrical connection means the electrical connection is facilitated therewith.

According to another embodiment of the invention the input terminals or the resilient electrical connection means extending into the elongated square-shaped hollow busbar section are connected thereto by means of screws or bolts. By screws or bolts a sufficient high pressure can be applied on the components to be connected so that the connection complies with required electrical characteristics. Furthermore such a kind of connection is easily solvable so that a temporary installation of a modular high voltage system can easily dismounted.

According to a further embodiment of the invention the elongated square-shaped hollow busbar section is made at least predominantly from aluminum. A further weight reduction is gained therewith in an advantageous way.

According to a further embodiment of the invention the modular interim busbar system comprises three interim busbars wherein the respective busbar basic modules are arranged within the frame structure in a horizontal and vertical distance each to each other. By arranging the basic modules diagonally the interim busbars can be mounted in an easier way since they are better accessible.

According to a further embodiment of the invention the mobile container with the low voltage supply system comprises a cooling system. For a rated power of for example 10 MVar installed several frequency converters of a lower rated power are required which are arranged phase wise and also in parallel. To ensure that the heat losses are dissipated from the inner of the container a cooling system, for example with condenser and evaporator, is foreseen.

According to a preferred embodiment of the invention the mobile container is a standard container according to CSC (Container Safety Convention) standard. Several transport systems exist for those kinds of containers, such as trucks, trains and ships so that a transportation of the low voltage supply system in such a container is facilitated therewith.

Further advantageous embodiments of the invention are mentioned in the dependent claims.

FIG. 1shows an exemplary modular high voltage supply system10from a side view. A mobile adapter transformer12with a rated voltage of 400V on its input side and 10 kV on its output side is temporarily arranged on a ground floor40. On the top of the adapter transformer12an oil expansion vessel14, lifting lugs18and three input terminals16for the electrical connection of the input side are foreseen. Respective output terminals22for the 10 kV output side for the supply of electrical loads are indicated with an arrow.

An exemplary vibration source22in the center of the adapter transformer indicates operational vibrations of 50 Hz and an integer multiple therefrom, which are rising during the operation of the adapter transformer.

Neighbored and in parallel to the adapter transformer12a mobile container24with a low voltage supply system is temporarily placed on the ground floor40. The container24comprises three output terminals26for its inner high-current busbar, which are arranged diagonal behind an opening of the outer side wall.

A modular interim busbar system28is foreseen for the temporary electrical connection of the output terminals26of the container24with the input terminals16of the adapter transformer12. The modular interim busbar system28comprises a frame structure30from aluminum bars with three elongated busbar basic modules32mounted thereon in an electrical insulating manner. On one end of the respective busbar basic modules32first resilient electrical connection means34are attached, which form an electrical connection to the output terminals26of the container24. Due to the modular structure of the interim busbars several resilient electrical connection means34with different length are available, so that dependent on the requirements on site resilient electrical connection means34with a respective suitable size are selectable.

On the respective other ends of the busbar basic modules32second resilient electrical connection means36are attached, which are part of an electrical connection to the input terminals16of the adapter transformer12. The other end of the second resilient electrical connection means36is connected to a respective elongated square-shaped hollow busbar section38, which is electrically connected with the input terminals16.

Due to the spring characteristic of the first34and second36resilient electrical connection means of the modular interim busbar system32the transmission of vibrations from the adapter transformer12to the container24is suppressed in an advantageous way.

FIG. 2shows first exemplary resilient electrical connection means50in a cross sectional view. A first52and a second54resilient elongated plate-like clamping element are arranged opposed each to each other in a clamping distance60and are both electrical active part of an interim busbar. At both ends of the opposed clamping elements52,54a respective electrical contact section56,58is foreseen wherein respective further electrical active sections62,64of the interim busbar are clamped between. Screws66are foreseen for connecting the opposed elongated clamping elements52,54together and apply a pressure force thereon. The screws66are extending through holes of the respective contact sections56,58and through the respective electrical further active section62,64of the interim busbar clamped inbetween. The spring characteristic of the resilient electrical connection means is indicated with an arrow68.

FIG. 3shows second exemplary resilient electrical connection means70from a birds view. Two neighbored clamping elements72,74are arranged in parallel in the same plane. At their both axial ends the clamping elements72,74are connected with a first76and a second78further electrical active section of a respective interim busbar. Screws80are foreseen for connecting the opposed elongated clamping elements52,54together and apply a pressure force thereon.

FIG. 4shows an elongated square-shaped hollow busbar section in a three dimensional view.

FIG. 5shows a low voltage supply system in a mobile container102in a sketch100. The low voltage supply system comprises a high current busbar104which is connected to output-terminals106at an opening108at the outer side of the container102. Three electrical frequency converters112,114,116and a VAR compensator are connected to the busbar104. The converters112,114,116are electrically supplied by a busbar for high voltage supply, which can be connected to an external high voltage supply system. A cooling system110is foreseen for to ensure that the heat losses are dissipated from the inner of the container.

FIG. 6shows a mobile container132with a low voltage supply system on a truck134in a sketch130.

FIG. 7shows a mobile adapter transformer142on a truck144in a sketch140.

LIST OF REFERENCE SIGNS

10exemplary modular high voltage supply system

16input terminals for input side of adapter transformer

20output terminals for output side of adapter transformer

26output-terminals for busbar of container

28modular interim busbar system

34first resilient electrical connection means of modular interim busbar system

36second resilient electrical connection means modular interim busbar system

50first exemplary resilient electrical connection means

56electrical contact section of first resilient clamping element

58electrical contact section of second resilient clamping element

62first further electrical active section of interim busbar

64second further electrical active section of interim busbar

68direction of resiliency

70second exemplary resilient electrical connection means

76first further electrical active section of interim busbar

78second further electrical active section of interim busbar

100low voltage supply system in container

106output-terminals for busbar of container

112first electrical frequency converter

114second electrical frequency converter

116third electrical frequency converter

120busbar for high voltage supply

130mobile container on truck

132mobile container with low voltage supply system

140mobile adapter transformer on truck