Modular switching cell

Abstract

The present invention relates to a modular switching cell 1 of a high-voltage DC power converter 20, which includes a base module 18 having a first switching unit 2, a second switching unit 3, a first capacitor 4, and a second capacitor 5. In this case, the modular switching cell 1, in which the first switching unit 2, the second switching unit 3, the first capacitor 4, and the second capacitor 5 are installed on a housing 15, is configured to form one of the following bridge circuits: two parallel half-bridge circuits between a first cell terminal 100 and a second cell terminal 200, two series half-bridge circuits between the first cell terminal 100 and the second cell terminal 200, and one full-bridge circuit between the first cell terminal 100 and the second cell terminal 200. The base module 18 is adapted to receive at least three different busbar sets, each including a plurality of busbars 6, 7, 8, 9, 10, 11, 12, 13, and 14 for interconnecting the first switching unit 2, the second switching unit 3, and the capacitor 4 and the second capacitor 5.

Description

Technical Field

[0001] The present invention relates to a modular switching cell. In order to realize various types of cell modules, in particular, the switching cell may include a base module that can be configured by connecting a plurality of terminals of the base module via a plurality of pre-configured busbars. Furthermore, the present invention relates to a system including the modular switching cell and respective busbars. Finally, the present invention relates to a method for manufacturing a modular switching cell.

Background Art

[0002] Modular multilevel converters (MMCs) are known from the prior art. The MMC is a standard approach for realizing a converter for high-voltage direct current power transmission for use in power transmission in the field of power converters. The modular multilevel converter is widely adopted and is also used in medium voltage (MV) drive applications including distribution applications such as self-excited converters.

[0003] An MMC converter is composed of a plurality of cells connected in series to form a phase arm. A common MMC cell is a half-bridge or a full-bridge. A half-bridge cell blocks voltage in one direction, while a full-bridge cell blocks voltage in both directions. MMC cells generally include insulated gate bipolar transistors.

[0004] In the field of converters for manufacturing, the rated current and rated voltage of a converter can cover a wide range to suit a wide range of applications. By installing a number of cells in series to achieve the required rated voltage, various rated voltages can be easily provided. However, generally, the rated current of the converter is within the range of the rated current of a single cell. Therefore, in order to generate the rated current of the converter, various cell configurations with various rated currents are required, or the cell rated current for a low-current converter configuration is not used. As a result, the cost per unit kW increases.

[0005] The configuration of a conventional MMC cell is available as a commercial product. The configurations of many MMC cells are described in the following publications.

Prior Art Documents

Non-Patent Documents

[0006]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem with the above prior art is that the cell configuration is highly optimized for a specific configuration and rated current. The optimization for the specific rated current affects, for example, the selection of the IGBT / diode module and the cell capacitor and bypass switch. In many cases, the rated current is given as an assignment of preset current values. For example, a full-rated cell can conduct all preset currents. A half-rated cell can conduct only half of the preset current. While the dimensions of the half-rated cell are theoretically half, if, for example, an IGBT module is only compatible with the rated current of a full-rated cell, the component cannot be used. Even if the components of the half-rated cell are available, each half-rated cell still requires the same quantity of control components as a full-rated cell, i.e., the same quantity of cell control devices, current / voltage sensors, cell power supplies, etc., and requires a similar cost and volume of mechanical components. The rack support structure for multiple cells can also be different because the dimensions are different. Therefore, the cost and volume of the half-rated cell are much larger than half of the cost and volume of the full-rated cell. Therefore, the actual MMC converter is more expensive (Euro / kW) and its power density is lower (kW / m 3 ). Furthermore, the half-rated cell requires an independent configuration with associated engineering costs.

[0008] If a full-bridge cell is required, the lack of adaptability is also obvious. If the components of the half-rated cell are not available, the half-rated full-bridge cell also requires an independent configuration with associated engineering costs.

[0009] Therefore, an object of the present invention is to provide a switching cell that is inexpensive, has a high power density, and can be used for various configurations and rated currents.

Means for Solving the Problem

[0010] This problem is solved by the features described in the independent claims. The dependent claims include advantageous embodiments of the present invention.

[0011] In particular, the present invention shows a common cell configuration. The cell configuration uses the same basic mechanical configuration for one cell at full rating or two cells in series at half rating. The cost per unit power and per unit power density of the two cells in series at half rating is the same as that of one cell at full rating. These cells can mainly share a common configuration, simplify the configuration, and realize a lower-cost system.

[0012] The present invention is solved in particular by a modular switching cell for high-voltage DC power conversion having a base module. The base module has a first switching unit, a second switching unit, a first capacitor, and a second capacitor. All of these components, namely the first switching unit, the second switching unit, the first capacitor, and the second capacitor, are installed on the housing. Thus, the base module enables different interconnections of these components to reach different configurations. The first switching unit and the second switching unit preferably include IGBTs.

[0013] When the base module is adapted to receive at least three different busbar sets, each busbar set includes a plurality of busbars for interconnecting the first switching unit, the second switching unit, the capacitor, and the second capacitor. Each busbar set enables a different configuration of the base module. In particular, one of these busbar sets enables two parallel half-bridge circuits between the first cell terminal and the second cell terminal. Further, another one of these busbar sets enables two series half-bridge circuits between the first cell terminal and the second cell terminal. Further, another one of these busbar sets enables one full-bridge circuit between the first cell terminal and the second cell terminal. Thus, each busbar set interconnects the components of the base module in various ways. Therefore, the base module can be used for various cell types, particularly for various rated currents and configurations. Therefore, the modular switching cell is inexpensive and enables a high power density.

[0014] Therefore, the present invention provides a common cell configuration. The common cell configuration uses the same basic mechanical structure, i.e., the base module, for one cell of full rating or two cells in series of half rating. The cost per unit power and per unit power density of the two cells in series of half rating is the same as that of one cell of full rating. These cell types can mainly share a common configuration, simplify the configuration, and realize a lower-cost system.

[0015] Preferably, the first switching unit includes a first AC voltage terminal, a first DC negative terminal, a first DC positive terminal, a first switch between the first AC voltage terminal and the first DC negative terminal, and a second switch between the first AC voltage terminal and the first DC positive terminal. Thus, the first switching unit is preferably configured as a half-bridge module. Further, the second switching unit preferably includes a second AC voltage terminal, a second DC negative terminal, a second DC positive terminal, a third switch between the second AC voltage terminal and the second DC negative terminal, and a fourth switch between the second AC voltage terminal and the second DC positive terminal. Similarly, the second switching unit is preferably configured as a half-bridge module. The base module is adapted to receive each bus set such that the plurality of buses of each bus set interconnect all the terminals of the first switching unit, the second switching unit, the first capacitor, and the second capacitor. Thus, in particular, the first AC voltage terminal, the first DC negative terminal, the first DC positive terminal, the second AC voltage terminal, the second DC negative terminal, the second DC positive terminal, the first capacitor, and the second capacitor are interconnected. These buses are provided such that they form one bridge circuit out of two parallel half-bridge circuits, two series half-bridge circuits, and one full-bridge circuit. Therefore, if different circuits need to be provided, these buses only need to be different. One base module can be used to implement various power converters.

[0016] In a preferred embodiment, at least the first DC negative terminal is electrically connected to the housing. The housing preferably functions as a housing ground. Depending on the cell configuration defined by the plurality of bus sets, the second DC positive terminal or the second DC negative terminal is preferably connected to the housing. In particular, it is preferred that all switching units share the same housing ground such that only one housing ground potential exists within the modular switching cell.

[0017] More preferably, the first switch and the second switch of the first switching unit and the third switch and the fourth switch of the second switching unit are all electronic switches. The electronic switch particularly has an insulated gate bipolar transistor and a diode. These are wired in parallel with each other. Instead of the IGBT, other electronic switches such as an integrated gate commutated thyristor (IGCT), a gate turn-off thyristor (GTO thyristor), a metal oxide semiconductor field effect transistor (MOFET), a high electron mobility transistor (HEMT), or a bipolar junction transistor (BJT) can also be used. In order to realize various modular switching cells, i.e., power converters, all these components can be coupled in various ways, i.e., via various bus sets. 3 switch and the fourth 4 switch all include electronic switches. The electronic switch particularly has an insulated gate bipolar transistor and a diode. These are wired in parallel with each other. Instead of the IGBT, other electronic switches such as an integrated gate commutated thyristor (IGCT), a gate turn-off thyristor (GTO thyristor), a metal oxide semiconductor field effect transistor (MOFET), a high electron mobility transistor (HEMT), or a bipolar junction transistor (BJT) can also be used. In order to realize various modular switching cells, i.e., power converters, all these components can be coupled in various ways, i.e., via various bus sets.

[0018] The modular switching cell preferably includes an individual control device. The control device is adapted to switch the first switch and the second switch of the first switching unit and the third switch and the fourth switch of the second switching unit. Thus, the power input to the modular switching cell can be executed with optimal power conversion. The converted power is output. Therefore, all the controls of all the switches are beneficially controlled by the individual control device.

[0019] More preferably, the first switching unit includes a first sub-switching unit and a second sub-switching unit. In this case, the first switching unit and the second switching unit are not half-bridge modules (for example, half-bridge IGBTs), but individual switch modules (for example, IGBTs). The first sub-switching unit preferably includes the first AC voltage terminal, the first DC negative terminal, and the first switch. The second sub-switching unit preferably includes the first AC voltage terminal, the first DC positive terminal, and the second switch. Therefore, the interconnection of the first switching elements is still possible via a plurality of bus sets. In this case, the two sub-switching units need to be connected separately. Thus, the second switching unit preferably includes a third sub-switching unit and a fourth sub-switching unit. The third sub-switching unit includes the second AC voltage terminal, the second DC negative terminal, and the third switch. The fourth sub-switching unit includes the second AC voltage terminal, the second DC positive terminal, and the fourth switch. Therefore, the second switching unit also includes two sub-switching units that are separately connected via a plurality of bus sets.

[0020] More preferably, a heat sink is provided. The heat sink is provided in particular for dissipating the heat of more than one switching unit. Preferably, a common heat sink is equipped with the first switching unit, the second switching unit, the first capacitor, and the second capacitor. Therefore, the power density of the cell is increased and the cost for providing the cell is reduced.

[0021] The modular switching cell has a bypass switch provided between the first cell terminal and the second cell terminal. The bypass switch is adapted to bypass the switching cell by short - circuiting the first cell terminal and the second cell terminal. When a converter is implemented in the modular switching cell as described above, for example, in case of damage to the switching cell, the bypass switch disables each switching cell. A failure of one switching cell does not lead to a total failure of the converter. In another embodiment, the bypass switch is omitted, and in case of component failure, the components of the switching cell are adapted to short - circuit the first cell terminal and the second cell terminal.

[0022] In another preferred embodiment, all of the first switching unit, the second switching unit, the first capacitor, and the second capacitor can be electrically connected from the same side via the plurality of bus sets. Therefore, the bus sets only need to be arranged on one side of the base module to interconnect all components. Thus, various cell configurations, especially the above - mentioned cell configurations, can be easily provided.

[0023] Furthermore, the present invention relates to a system including the above - mentioned modular switching cell and at least two of the first bus set, the second bus set, and the third bus set. Therefore, the system can be configured to provide various cell configurations. A converter can preferably be implemented from some of these systems. In the system, the first capacitor is provided between a first capacitor terminal and a second capacitor terminal, and the second capacitor is provided between a third capacitor terminal and a fourth capacitor terminal. All of these capacitor terminals can be connected via a plurality of buses of the bus set to connect the plurality of switching units and these capacitors. Various configurations can be provided by the different bus sets. Next, these different bus sets will be described.

[0024] The first bus set includes a first bus, a second bus, and a third bus. The first bus electrically connects the first DC negative terminal, the second DC negative terminal, the second capacitor terminal, and the fourth capacitor terminal. The second bus electrically connects the first DC positive terminal, the second DC positive terminal, the first capacitor terminal, and the third capacitor terminal. Finally, the first AC voltage terminal and the second AC voltage terminal are electrically connected via the third bus. In this cell configuration, the first bus is the second cell terminal, and the third bus is the first cell terminal. Therefore, the first bus set preferably defines one half-bridge cell of the full rating. This means that a plurality of switching units are of half rating and are connected in parallel via the first bus set. Therefore, while the cell configuration is a half-bridge, each switching unit preferably conducts a current that is half of the current supplied to each cell.

[0025] In an additional or alternative embodiment, the second bus set includes a fourth bus, a fifth bus, a sixth bus, a seventh bus, and an eighth bus. The fourth bus is electrically connected to the first AC voltage terminal. The fifth bus electrically connects the first DC positive terminal and the first capacitor terminal. The second DC negative terminal and the fourth capacitor terminal are electrically connected via the sixth bus. The seventh bus electrically connects the first DC negative terminal, the second DC positive terminal, the second capacitor terminal, and the third capacitor terminal. Finally, the eighth bus is electrically connected to the second AC voltage terminal. According to this cell configuration, the fourth bus is the first cell terminal, and the eighth bus is the second cell terminal. In this cell configuration, one dual cell of half rating is provided. This means that two switching units are connected in series such that the cell satisfies the functions of two half-rating cells.

[0026] In another additional or alternative embodiment, the third bus set includes the second bus, the fourth bus, the eighth bus, and the ninth bus described above. The ninth bus electrically connects the first DC negative terminal, the second DC negative terminal, the second capacitor terminal, and the fourth capacitor terminal. This cell configuration realizes one full bridge of half rating. Therefore, a plurality of switching units are coupled such that they form one full bridge. In particular, as described above, each switching unit is one half-bridge module. As a result, these half-bridge modules are set to one full bridge by the third bus set.

[0027] Therefore, at least three different cell configurations can be manufactured from the same base module, i.e., the same switching units and capacitors, by simply coupling the base module to one of the first bus set, the second bus set, and the third bus set. This allows for improved adaptability in providing various cell types and / or converters.

[0028] The plurality of buses of each bus set are preferably laminated buses. By providing laminated buses, the space required to interconnect the switching units and capacitors is reduced. Furthermore, the electrical characteristics are improved, for example, the stray inductance is reduced.

[0029] Each bus set includes a plurality of buses that define the first cell terminal and the second cell terminal arranged for electrically connecting the switching cell to other components of the power converter, in particular other switching cells. Therefore, for implementing the converter, each cell is connected via each bus set that constitutes the cell terminal.

[0030] Furthermore, the present invention relates to a high-voltage DC power converter. The converter includes a three-phase voltage input section, and for each phase of the three-phase voltage input section, it includes the above-mentioned plurality of switching cells. The plurality of switching cells are connected in series.

[0031] Therefore, the power converter can be provided with the above-mentioned adaptable and inexpensive switching cells. In this case, the switching cells have a particularly high energy density.

[0032] Finally, the present invention relates to a method for manufacturing a modular switching cell. The method includes the step of providing a base module by attaching a first switching unit, a second switching unit, a first capacitor, and a second capacitor on one side of a housing. This base module is adapted to receive various busbar sets in order to realize various cell configurations. Therefore, at least two different busbar sets are provided. Each busbar set includes a plurality of busbars for interconnecting the first switching unit, the second switching unit, the first capacitor, and the second capacitor. The plurality of busbars of each busbar set are adapted to form one of the following bridge circuits: two parallel half-bridge circuits between a first cell terminal and a second cell terminal, two series half-bridge circuits between the first cell terminal and the second cell terminal, and one full-bridge circuit between the first cell terminal and the second cell terminal. Therefore, each busbar set enables a different cell configuration by variously interconnecting the plurality of components of the base module. As the final step, one of the plurality of busbar sets is attached onto the base element. By attaching each of the busbar sets onto the base element, a switching cell having one of the above-listed plurality of configurations is provided. Since any one of the plurality of busbar sets can be attached onto the base module, the method is a simple and adaptable way to provide different types of switching cells.

[0033] Further embodiments and advantages will become apparent from the following description of the drawings.

Brief Description of the Drawings

[0034]

Figure 1

Figure 2

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Figure 4

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Figure 8

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Figure 10

Figure 11

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Figure 14

Mode for Carrying Out the Invention

[0035] FIG. 1 is a schematic wiring diagram of a high-voltage DC power converter 20 particularly for use in power transmission. The high-voltage DC power converter 20 has a three-phase voltage input section 600 and is adapted to output a DC voltage. A plurality of switching cells 1 are connected in series for each phase of the three-phase voltage input section 600. Thus, as shown in FIG. 2, the output voltage 300 of one phase can be divided into the cell voltages 400 of a plurality of individual switching cells 1. By switching each of these switching cells 1, the phase output voltage 300 can be converted into a DC voltage.

[0036] FIGS. 3 and 4 show switching cells 1 of different cell types. All the switching cells 1 are powered between a first cell terminal 100 and a second cell terminal 200. FIG. 3 shows a half-bridge, while FIG. 4 shows a full-bridge. The half-bridge can block current in only one direction, while the full-bridge can block current in two directions. Thus, the configuration of the half-bridge shown in FIG. 3 is a switching cell 1 that uses only one individual first switching unit 2. On the other hand, the switching cell 1 with the configuration of the full-bridge shown in FIG. 4 has one first switching unit 2 and one second switching unit 3. In this embodiment, the first switching unit 2 and the second switching unit 3 are half-bridge elements. Thus, the two half-bridge elements of the first switching unit 2 and the second switching unit 3 are combined to form one full-bridge in FIG. 4.

[0037] Thus, each of the switching units 2, 3 has two IGBTs 80 and two diodes 90. One IGBT 80 and one diode 90 are connected in parallel, and two sets of parallel IGBTs 80 and diodes 90 are connected in series. In this way, the above half-bridge element is formed.

[0038] Each switching cell 1 further has at least one first capacitor 4. The first capacitor 4 is provided in parallel with the switching units 2, 3. Accordingly, a plurality of switching cells 1 divide the phase output voltage 300 between the first cell terminal 100 and the second cell terminal 200 of each switching cell 1 into a plurality of cell voltages. As a result, these switching cells 1 can be used to convert the phase output voltage 300 into a DC voltage.

[0039] A bypass switch 19 may be provided to bypass the energization to the switching cell 1 in the event of a failure of one cell, and thus to keep the converter 20 in an operating state. This bypass switch 19 may be realized by being used in combination with a thyristor, a mechanical contact, or a fast-acting pyrotechnic device. If the semiconductor switch used in the cell also serves as a short-circuit part, for example, if it is a specially designed press-pack IGBT or an integrated gate-commutated thyristor (IGCT), the bypass switch 19 is unnecessary.

[0040] FIG. 5 is a schematic diagram of a switching cell 1 according to an embodiment of the present invention. The switching cell 1 has a first switching unit 2 and a second switching unit 3 as shown in FIGS. 3 and 4, and similarly has a first capacitor 4 and a second capacitor 5. FIG. 5 shows the first switching unit 2, the second switching unit 3, the first capacitor 4, and the second capacitor 5 mounted on a common housing 15. The two switching units 2, 3 also share the same heat sink 17 such that the switching cell 1 has only individual inlets 17a and outlets 17b for cooling the fluid. The switching cell 1 also has a common control device 16 for driving the IGBTs 80 of the switching units 2, 3 in particular. Accordingly, the switching cell 1 has a higher energy density compared to two individual cells each having only one switching unit. Further, since all components are provided on the same housing 15, the housing 15 functions as a common housing ground.

[0041] The switching cell 1 does not have a fixed cell configuration. Rather, the switching cell 1 can be configured to take various cell configurations. As a result, the converter 20 that meets various requirements is provided flexibly. To enable various cell configurations, the switching cell 1 has a base module 18 that includes a first switching unit 2, a second switching unit 3, a first capacitor 4, and a second capacitor 5. The base module 18 is also adapted to accommodate a plurality of different sets of bus bars. Each set of bus bars connects the plurality of components of the base module 18 in various ways to realize various cell configurations.

[0042] Preferably, the plurality of bus bars of the plurality of sets of bus bars contact all the components of the base module 18 from all sides. Therefore, it becomes easy to attach these sets of bus bars and to electrically connect the first switching unit 2, the second switching unit 3, the first capacitor 4, and the second capacitor 5.

[0043] To be electrically connected by a plurality of sets of bus bars, the first switching unit 2 has a first AC voltage terminal 21, a first DC negative terminal 22, and a first DC positive terminal 23. A first switch is provided between the first AC voltage terminal 21 and the first DC negative terminal 22, and a second switch is provided between the first AC voltage terminal 21 and the first DC positive terminal 23. In this case, these two switches are composed of the above-mentioned parallel IGBTs 80 and diodes 90.

[0044] Similarly, the second switching unit 3 has a second AC voltage terminal 31, a second DC negative terminal 32, and a second DC positive terminal 33. A third switch is provided between the second AC voltage terminal 31 and the second DC negative terminal 32, and a fourth switch is provided between the second AC voltage terminal 31 and the second DC positive terminal 33. Similarly, these two switches, that is, the third switch and the fourth switch, are composed of the above-mentioned parallel IGBTs 80 and diodes 90.

[0045] The first capacitor 4 is provided between a first capacitor terminal 41 and a second capacitor terminal 42, and the second capacitor 5 is provided between a third capacitor terminal 51 and a fourth capacitor terminal 52. All the above terminals are preferably on the same side surface of this switching cell 1 so that the switching cell 1 can be electrically connected via a plurality of bus sets from one side.

[0046] Starting from such a basic configuration, the switching cell 1 can be determined to have various cell configurations. In particular, two switching units 2, 3 can be arranged in parallel to increase the rated current or to form a full bridge. These switching units 2, 3 may be arranged in series to form a dual switching cell composed of two conventional switching cells. Three different configurations are shown below. All these configurations are realized by a plurality of different bus sets having the same base module 18.

[0047] Figures 7 and 8 show two parallel half-bridge circuits between a first cell terminal 100 and a second cell terminal 200. Figure 7 schematically shows the configuration of the switching cell 1, while Figure 8 shows a schematic circuit. Figures 9 and 10 show two series half-bridge circuits between a first cell terminal 100 and a second cell terminal 200. Figure 9 shows the configuration of the switching cell 1, while Figure 10 shows a schematic circuit. Finally, a full-bridge circuit between a first cell terminal and a second cell terminal 200 is shown in Figures 11 and 12. Figure 11 schematically shows the configuration of the switching cell 1, while Figure 12 shows a schematic circuit.

[0048] In the configuration according to FIGS. 7 and 8, a first set of busbars including a first busbar 6, a second busbar 7, and a third busbar 8 is used to interconnect the first AC voltage terminal 21, the first DC negative terminal 22, the first DC positive terminal 23, the second AC voltage terminal 31, the second DC negative terminal 32, the second DC positive terminal 33, the first capacitor terminal 41, the second capacitor terminal 42, the third capacitor terminal 51, and the fourth capacitor terminal 52. The first DC negative terminal 22, the second DC negative terminal 32, the second capacitor terminal 42, and the fourth capacitor terminal 52 are electrically connected via the first busbar 6. The first DC positive terminal 23, the second DC positive terminal 33, the first capacitor terminal 41, and the third capacitor terminal 51 are electrically connected via the second busbar 7. The third busbar 8 electrically connects the first AC voltage terminal 21 and the second AC voltage terminal 31. In this configuration, the first busbar 6 is the second cell terminal 200, and the third busbar 8 is the first cell terminal 100.

[0049] Particularly as shown in FIG. 8, similar to the first capacitor 4 and the second capacitor 5, the first switching unit 2 and the second switching unit 3 are connected in parallel with each other. Therefore, the parallel connection of the plurality of components doubles the current that the switching cell 1 can conduct, so this switching cell 1 is a half-bridge of the full rating. A common case ground is provided to the first DC negative terminal 22 and the second negative terminal 23 via this case 15. These load terminals are the same in this configuration.

[0050] The same base module 18 can be provided using different second sets of busbars shown in FIGS. 9 and 10 to form a half-rated dual cell. The second set of busbars includes a fourth busbar 9, a fifth busbar 10, a sixth busbar 11, a seventh busbar 12, and an eighth busbar 13. These busbars interconnect the first AC voltage terminal 21, the first DC negative terminal 22, the first DC positive terminal 23, the second AC voltage terminal 31, the second DC negative terminal 32, the second DC positive terminal 33, the first capacitor terminal 41, the second capacitor terminal 42, the third capacitor terminal 51, and the fourth capacitor terminal 52.

[0051] The first AC voltage terminal 21 is electrically connected to the fourth bus 9. The first DC positive terminal 23 and the first capacitor terminal 41 are electrically connected via the fifth bus 10. The second DC negative terminal 32 and the fourth capacitor terminal 52 are electrically connected via the sixth bus 11. The seventh bus 12 electrically connects the first DC negative terminal 22, the second DC positive terminal 33, the second capacitor terminal 42, and the third capacitor terminal 51. Finally, the second DC voltage terminal 31 is electrically connected to the eighth bus 13. In the configuration of this cell, the fourth bus 9 is the first cell terminal 100, and the eighth bus 13 is the second cell terminal 200. Therefore, the first switching unit 2 and the first capacitor 4 constitute a half-rated half-bridge. The half-bridge is serially connected to another half-rated half-bridge constituted by the second switching unit 3 and the second capacitor 5. These two half-rated half-bridges are configured to be mirror-symmetric to each other so that they can share the same power supply and control device. A common chassis ground is provided to the first DC negative terminal 22 and the second DC positive terminal by the chassis 15. These terminals are identical in this configuration.

[0052] In the configurations of FIGS. 9 and 10, the cell outputs a cell voltage 500 that is twice as high. This cell voltage 500 is twice the cell voltage 400. Therefore, one full-rated half-bridge or two half-rated half-bridges can be provided using the same components. Thus, the same base module 18 can be provided in different cell forms based on the respective requirements of the converters 20.

[0053] Furthermore, in the configurations of FIGS. 9 and 10, two options are applied to the bypass switch 19. When two bypass switches are connected in series and the center point between these two bypass switches is connected to the center point between these two half-bridges, one bypass switch may be used for each of the two half-bridges, or one bypass switch may be used for the entire switching cell 1. When two bypass switches are used, each bypass switch requires the same rated voltage as the individual switching cell 1, while when using one individual bypass switch for the entire switching cell 1, a double cell voltage 500 which is twice the cell voltage 400 needs to be applied to the bypass switch 19, so a higher rated voltage is required.

[0054] Finally, FIGS. 11 and 12 show the configuration of a half-rated full bridge. In this configuration, two switching units 2, 3 configured as half-bridge modules are combined to form one full bridge. To realize such a configuration, a third bus set includes the above-mentioned second bus 7, the above-mentioned fourth bus 9, the above-mentioned eighth bus 13, and an additional ninth bus 14. The ninth bus 14 electrically connects the first DC negative terminal 22, the second DC negative terminal 32, the second capacitor terminal 42, and the fourth capacitor terminal 52. The housing 15 provides a common housing ground to the first DC negative terminal 22 and the second DC negative terminal 32.

[0055] Preferably, the multiple buses of each bus set are laminated buses. This bus set contributes to reducing the stray inductance, especially between the IGBT 80 and the capacitors 4, 5, to ensure optimal switching of the switching cell 1.

[0056] Therefore, in addition to the full-rated half bridge and the half-rated dual half bridge, another bus set can be provided in the base module 18 to form a half-rated full bridge. Therefore, there are various options for cells that can be provided from just one base module 18.

[0057] FIG. 13 shows the configuration of a cell that is the same as the configuration of the cell shown in FIG. 7. In this case, different first switching unit 2 and second switching unit 3 are used. In the above embodiment, the first switching unit 2 and the second switching unit 3 are shown as half-bridge modules. As shown in FIG. 13, another configuration using individual switching modules may also be adopted.

[0058] Accordingly, the first switching unit 2 includes a first sub-switching unit 2a and a second sub-switching unit 2b. The first sub-switching unit 2a has a first AC voltage terminal 21, a first DC negative terminal 22, and a first switch provided between the first AC voltage terminal 21 and the first DC negative terminal 22. The second sub-switching unit 2b has the first AC voltage terminal 21 and further includes a first DC positive terminal 23 and a second switch provided between the first AC voltage terminal 21 and the first DC positive terminal 23. Similarly, the second switching unit 3 includes a third sub-switching unit 3a and a fourth sub-switching unit 3b. The third sub-switching unit 3a has a second AC voltage terminal 31, a second DC negative terminal 32, and a third switch provided between the second AC voltage terminal 31 and the second DC negative terminal 32. The fourth sub-switching unit 3b has the second AC voltage terminal 31 and a fourth switch provided between the second AC voltage terminal 31 and the second DC positive terminal 33. The sub-switching units 2a, 2b, 3a, 3b need to be separately contacted via the first bus 6, the second bus 7, and the third bus 8. In this case, the configuration of the cell remains the same as the configuration of the cell shown in FIG. 7. The configuration of the switching units 2, 3, that is, the use of the sub-switching units 2a, 2b, 3a, 3b, can be applied to any other cell configuration, particularly the configurations shown in FIGS. 9 and 11.

[0059] Finally, FIG. 14 shows an alternative further configuration of the switching units 2, 3. In this alternative configuration, the switching units 2, 3 are provided as multi-level bridge legs having three levels. To implement such a configuration, additional diodes 90 are included within each of the switching units 2, 3.

[0060] In summary, while the above-described switching cell 1 can be used for various purposes, all the switching cells 1 share the same base components. Therefore, always the same hardware can be employed to provide the various switching cells 1 for the converter 20. Since only a single set of control components, for example the control device 16 and the heat sink 17, need to be provided, the switching cell 1 is low-cost. In the switching cell 1, maximum component reuse and configuration reuse are possible. Further, especially in the case of two half-bridges at half rating, a compact cell configuration is provided. The number of components, the amount of coolant, and the electrical connections are reduced, improving reliability. Note that although this application relates to the invention described in the claims, other aspects may include the following configurations. 1. · A first switching unit (2), · A second switching unit (3), · A first capacitor (4), · A second capacitor (5), A modular switching cell (1) of a high-voltage DC power converter (20) comprising a base module (18) having In the modular switching cell (1) in which the first switching unit (2), the second switching unit (3), the first capacitor (4), and the second capacitor (5) are installed on the housing (15), · Two parallel half-bridge circuits between a first cell terminal (100) and a second cell terminal (200), · Two series half-bridge circuits between the first cell terminal (100) and the second cell terminal (200), · One full-bridge circuit between the first cell terminal (100) and the second cell terminal (200), To form one of the bridge circuits among them, the base module (18) is adapted to receive at least three different bus sets, and each bus set includes a plurality of buses (6, 7, 8, 9, 10, 11, 12, 13, 14) for interconnecting the first switching unit (2), the second switching unit (3), the first capacitor (4), and the second capacitor (5) in the modular switching cell (1). 2. · The first switching unit (2) has a first AC voltage terminal (21), a first DC negative terminal (22), a first DC positive terminal (23), a first switch between the first AC voltage terminal (21) and the first DC negative terminal (22), and a second switch between the first AC voltage terminal (21) and the first DC positive terminal (23), · The second switching unit (3) has a second AC voltage terminal (31), a second DC negative terminal (32), a second DC positive terminal (33), a third switch between the second AC voltage terminal (31) and the second DC negative terminal (32), and a fourth switch between the second AC voltage terminal (31) and the second DC positive terminal (33), · To form one of the bridge circuits among the two parallel half-bridge circuits, the two series half-bridge circuits, and the one full-bridge circuit, the plurality of buses (6, 7, 8, 9, 10, 11, 12, 13, 14) of each bus set are adapted to interconnect the first AC voltage terminal (21), the first DC negative terminal (22), the first DC positive terminal (23), the second AC voltage terminal (31), the second DC negative terminal (32), the second DC positive terminal (33), the first capacitor (4), and the second capacitor (5). The base module (18) of the modular switching cell (1) according to item 1 above is adapted to receive each bus set. 3. At least the first DC negative terminal (22) is electrically connected to the housing (15), The housing (15) of the modular switching cell (1) according to item 2 above functions as a housing ground. 4. All of the first switch and the second switch of the first switching unit (2) and the third switch and the fourth switch of the second switching unit (3) are electronic switches wired in parallel with each other, particularly including an insulated gate bipolar transistor (80) and a diode (90). The modular switching cell (1) according to item 2 or 3 above. 5. The modular switching cell (1) according to any one of items 2 to 4 above, characterized by an individual control device (16) adapted to switch the first switch and the second switch of the first switching unit (2) and the third switch and the fourth switch of the second switching unit (3). 6. · The first switching unit (2) includes a first sub-switching unit (2a) and a second sub-switching unit (2b), The first sub-switching unit (2a) includes the first AC voltage terminal (21), the first DC negative terminal (22), and the first switch, The second sub-switching unit (2b) includes the first AC voltage terminal (21), the first DC positive terminal (23), and the second switch, · The second switching unit (3) includes a third sub-switching unit (3a) and a fourth sub-switching unit (3b), The third sub-switching unit (3a) includes the second AC voltage terminal (31), the second DC negative terminal (32), and the third switch. The fourth sub-switching unit (3b) is the modular switching cell (1) according to any one of 2 to 5 above, which includes the second AC voltage terminal (31), the second DC positive terminal (33), and the fourth switch. 7. The modular switching cell (1) according to any one of 2 to 6 above, in which a common heat sink (17) is provided for the first switching unit (2), the second switching unit (3), the first capacitor (4), and the second capacitor (5). 8. A bypass switch (19) is provided between the first cell terminal (100) and the second cell terminal (200). The bypass switch (19) is the modular switching cell (1) according to any one of 2 to 7 above, which is adapted to bypass the modular switching cell (1). 9. The modular switching cell (1) according to any one of 2 to 8 above, in which all of the first switching unit (2), the second switching unit (3), the first capacitor (4), and the second capacitor (5) can be electrically connected from the same side through the plurality of bus sets. 10. In a system including the modular switching cell (1) according to any one of claims 2 to 9 and at least two bus sets of a first bus set, a second bus set, and a third bus set. The first capacitor (4) is provided between a first capacitor terminal (41) and a second capacitor terminal, and the second capacitor (5) is provided between a third capacitor terminal (51) and a fourth capacitor terminal (52). · The first bus set includes a first bus (6), a second bus (7), and a third bus (8), and the first DC negative terminal (22), the second DC negative terminal (32), the second capacitor terminal (42), and the fourth capacitor terminal (52) are electrically connected through the first bus (6). The first DC positive terminal (23), the second DC positive terminal (33), the first capacitor terminal (41), and the third capacitor terminal (51) are electrically connected through the second bus (7). The first AC voltage terminal (21) and the second AC voltage terminal (31) are electrically connected via the third bus bar (8). The first bus bar (6) is the second cell terminal (200), and the third bus bar (8) is the first cell terminal (100), and / or · The second bus bar set includes a fourth bus bar (9), a fifth bus bar (10), a sixth bus bar (11), a seventh bus bar (12), and an eighth bus bar (13). The first AC voltage terminal (21) is electrically connected to the fourth bus bar (9). The first DC positive terminal (23) and the first capacitor terminal (41) are electrically connected via the fifth bus bar (10). The second DC negative terminal (32) and the fourth capacitor terminal (52) are electrically connected via the sixth bus bar (11). The first DC negative terminal (22), the second DC positive terminal (33), the second capacitor terminal (42), and the third capacitor terminal (51) are electrically connected via the seventh bus bar (12). The second AC voltage terminal (31) is electrically connected via the eighth bus bar (13). The fourth bus bar (9) is the first cell terminal (100), and the eighth bus bar (13) is the second cell terminal (200), and / or · The third bus bar set includes the second bus bar (7), the fourth bus bar (9), the eighth bus bar (13), and a ninth bus bar (14). The system in which the first DC negative terminal (22), the second DC negative terminal (32), the second capacitor terminal (42), and the fourth capacitor terminal (52) are electrically connected via the ninth bus bar (14). 11. The system according to 10 above, wherein the plurality of bus bars (6, 7, 8, 9, 10, 11, 12, 13, 14) of each bus bar set are laminated bus bars. 12. The system according to 10 or 11 above, wherein each bus bar set includes a plurality of bus bars (6, 7, 8, 9, 10, 11, 12, 13, 14) that define the first cell terminal (100) and the second cell terminal (200) arranged to electrically connect the modular switching cell (1) to other components of the high-voltage DC power converter (20), particularly to other modular switching cells (1). 13. A high-voltage DC power converter (20) including a three-phase voltage input section (600), and including a plurality of modular switching cells (1) according to any one of claims 1 to 9 for each phase of the three-phase voltage input section (600), The high-voltage DC power converter (20) in which the plurality of modular switching cells (1) are connected in series. 14. · A step of providing a base module (18) by mounting a first switching unit (2), a second switching unit (3), a first capacitor (4), and a second capacitor (5) on a housing (15), · A step of providing at least two different bus sets each including a plurality of buses (6, 7, 8, 9, 10, 11, 12, 13, 14) for interconnecting the first switching unit (2), the second switching unit (3), the first capacitor (4), and the second capacitor (5), wherein the plurality of buses (6, 7, 8, 9, 10, 11, 12, 13, 14) of each bus set are Two parallel half-bridge circuits between a first cell terminal (100) and a second cell terminal (200), Two series half-bridge circuits between the first cell terminal (100) and the second cell terminal (200), One full-bridge circuit between the first cell terminal (100) and the second cell terminal (200), A step of being adapted to constitute one of the bridge circuits, · A method of manufacturing a modular switching cell (1), characterized by including a step of mounting one of the plurality of bus sets on a base module (18).

Description of Symbols

[0061] 1 Switching Cell 2 First Switching Unit 21 First AC Voltage Terminal 22 First DC Negative Terminal 23 First DC Positive Terminal 3 Second Switching Unit 31 Second AC Voltage Terminal 32 Second DC Negative Terminal 33 Second DC Positive Terminal 4 First Capacitor 41 First Capacitor Terminal 42 Second Capacitor Terminal 5 Second Capacitor 51 Third Capacitor Terminal 52 Fourth Capacitor Terminal 6 First Bus 7 Second Bus 8 Third Bus 9 Fourth Bus 10 Fifth Bus 11 Sixth Bus 12 Seventh Bus 13 Eighth Bus 14 Ninth Bus 15 Housing 16 Control Device 17 Heat Sink 17a Inlet 17b Outlet 18 Base Module 19 Bypass Switch 20 Converter 80 IGBT 90 Diode 100 First Cell Terminal 200 Second Cell Terminal 300 Phase Output Voltage 400 Cell Voltage 500 Double Cell Voltage 600 Three-Phase Voltage Input Section

Claims

1. - A first switching unit (2), - A second switching unit (3), - A first capacitor (4), - A second capacitor (5), A modular switching cell (1) of a high-voltage DC power converter (20) comprising a base module (18) having, In the modular switching cell (1) in which the first switching unit (2), the second switching unit (3), the first capacitor (4), and the second capacitor (5) are installed on a housing (15), - Two parallel half-bridge circuits between a first cell terminal (100) and a second cell terminal (200), - Two series half-bridge circuits between the first cell terminal (100) and the second cell terminal (200), - One full-bridge circuit between the first cell terminal (100) and the second cell terminal (200), For forming one of the bridge circuits, the same base module (18) is adapted to receive at least three different bus sets, and each bus set includes a plurality of buses (6, 7, 8, 9, 10, 11, 12, 13, 14) for interconnecting the first switching unit (2), the second switching unit (3), the first capacitor (4), and the second capacitor (5), A modular switching cell (1), characterized in that at least three different cell configurations are formed by connecting the same base module to a plurality of said bus sets.

2. - The first switching unit (2) has a first AC voltage terminal (21), a first DC negative terminal (22), a first DC positive terminal (23), a first switch between the first AC voltage terminal (21) and the first DC negative terminal (22), and a second switch between the first AC voltage terminal (21) and the first DC positive terminal (23). - The second switching unit (3) has a second AC voltage terminal (31), a second DC negative terminal (32), a second DC positive terminal (33), a third switch between the second AC voltage terminal (31) and the second DC negative terminal (32), and a fourth switch between the second AC voltage terminal (31) and the second DC positive terminal (33). ・To form one of the bridge circuits among the two parallel half-bridge circuits, the two series half-bridge circuits, and the one full-bridge circuit, the plurality of buses (6, 7, 8, 9, 10, 11, 12, 13, 14) of each bus set are connected to the first AC voltage terminal (21), the first DC negative terminal (22), the first DC positive terminal (23), the second AC voltage terminal (31), the second DC negative terminal (32), the second DC positive terminal (33), the first capacitor (4), and the second capacitor (5). The same base module (18) is adapted to receive each bus set. The modular switching cell (1) according to claim 1 is characterized in that.

3. At least the first DC negative terminal (22) is electrically connected to the housing (15), The housing (15) functions as a housing ground. The modular switching cell (1) according to claim 2 is characterized in that.

4. All of the first switch and the second switch of the first switching unit (2) and the third switch and the fourth switch of the second switching unit (3) are electronic switches wired in parallel with each other, particularly including an insulated gate bipolar transistor (80) and a diode (90). The modular switching cell (1) according to claim 2 or 3 is characterized in that.

5. An individual control device (16) adapted to switch the first switch and the second switch of the first switching unit (2) and the third switch and the fourth switch of the second switching unit (3). The modular switching cell (1) according to any one of claims 2 to 4 is characterized in that.

6. ・The first switching unit (2) includes a first sub-switching unit (2a) and a second sub-switching unit (2b), The first sub-switching unit (2a) includes the first AC voltage terminal (21), the first DC negative terminal (22), and the first switch, The second sub-switching unit (2b) includes the first AC voltage terminal (21), the first DC positive terminal (23), and the second switch, - The second switching unit (3) includes a third sub-switching unit (3a) and a fourth sub-switching unit (3b), - The third sub-switching unit (3a) includes the second AC voltage terminal (31), the second DC negative terminal (32), and the third switch, - The fourth sub-switching unit (3b) includes the second AC voltage terminal (31), the second DC positive terminal (33), and the fourth switch, and the modular switching cell (1) according to any one of claims 2 to 5, characterized in that.

7. - The modular switching cell (1) according to any one of claims 2 to 6, characterized in that a common heat sink (17) is provided for the first switching unit (2), the second switching unit (3), the first capacitor (4), and the second capacitor (5).

8. - A bypass switch (19) is provided between the first cell terminal (100) and the second cell terminal (200), - The modular switching cell (1) according to any one of claims 2 to 7, characterized in that the bypass switch (19) is adapted to bypass the modular switching cell (1).

9. - The modular switching cell (1) according to any one of claims 2 to 8, characterized in that all of the first switching unit (2), the second switching unit (3), the first capacitor (4), and the second capacitor (5) can be electrically connected from the same side via a plurality of the bus sets.

10. - In a system including the modular switching cell (1) according to any one of claims 2 to 9 and at least two of the first bus set, the second bus set, and the third bus set, - The first capacitor (4) is provided between a first capacitor terminal (41) and a second capacitor terminal, and the second capacitor (5) is provided between a third capacitor terminal (51) and a fourth capacitor terminal (52), - The first bus set includes a first bus (6), a second bus (7), and a third bus (8), and the first DC negative terminal (22), the second DC negative terminal (32), the second capacitor terminal (42), and the fourth capacitor terminal (52) are electrically connected via the first bus (6). The first DC positive terminal (23), the second DC positive terminal (33), the first capacitor terminal (41), and the third capacitor terminal (51) are electrically connected via the second bus bar (7), The first AC voltage terminal (21) and the second AC voltage terminal (31) are electrically connected via the third bus bar (8), The first bus bar (6) is the second cell terminal (200), the third bus bar (8) is the first cell terminal (100), and / or - The second bus bar set includes a fourth bus bar (9), a fifth bus bar (10), a sixth bus bar (11), a seventh bus bar (12), and an eighth bus bar (13), The first AC voltage terminal (21) is electrically connected to the fourth bus bar (9), The first DC positive terminal (23) and the first capacitor terminal (41) are electrically connected via the fifth bus bar (10), The second DC negative terminal (32) and the fourth capacitor terminal (52) are electrically connected via the sixth bus bar (11), The first DC negative terminal (22), the second DC positive terminal (33), the second capacitor terminal (42), and the third capacitor terminal (51) are electrically connected via the seventh bus bar (12), The second AC voltage terminal (31) is electrically connected via the eighth bus bar (13), The fourth bus bar (9) is the first cell terminal (100), the eighth bus bar (13) is the second cell terminal (200), and / or - The third bus bar set includes the second bus bar (7), the fourth bus bar (9), the eighth bus bar (13), and a ninth bus bar (14), The system in which the first DC negative terminal (22), the second DC negative terminal (32), the second capacitor terminal (42), and the fourth capacitor terminal (52) are electrically connected via the ninth bus bar (14).

11. The system according to claim 10, characterized in that the plurality of bus bars (6, 7, 8, 9, 10, 11, 12, 13, 14) of each bus bar set are laminated bus bars.

12. Each busbar set includes a plurality of busbars (6, 7, 8, 9, 10, 11, 12, 13, 14) that define the first cell terminal (100) and the second cell terminal (200) arranged to electrically connect the modular switching cell (1) to other components of the high-voltage DC power converter (20), in particular to other modular switching cells (1). The system according to claim 10 or 11, characterized in that.

13. A high-voltage DC power converter (20) including a three-phase voltage input section (600), and for each phase of the three-phase voltage input section (600), including a plurality of modular switching cells (1) according to any one of claims 1 to 9, The plurality of modular switching cells (1) are connected in series to the high-voltage DC power converter (20).

14. - Providing a base module (18) by mounting a first switching unit (2), a second switching unit (3), a first capacitor (4), and a second capacitor (5) on a housing (15); - Providing at least two different busbar sets each including a plurality of busbars (6, 7, 8, 9, 10, 11, 12, 13, 14) for interconnecting the first switching unit (2), the second switching unit (3), the first capacitor (4), and the second capacitor (5), wherein the plurality of busbars (6, 7, 8, 9, 10, 11, 12, 13, 14) of each busbar set are Two parallel half-bridge circuits between the first cell terminal (100) and the second cell terminal (200); Two series half-bridge circuits between the first cell terminal (100) and the second cell terminal (200); One full-bridge circuit between the first cell terminal (100) and the second cell terminal (200); Adapting to form one of the bridge circuits; - Mounting one of the busbar sets of the plurality of busbar sets on the same base module (18), A method of manufacturing a modular switching cell (1), characterized in that at least three different cell configurations are formed by coupling the same base module to a plurality of the busbar sets.

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