Arrangement for a multi-cell converter, arrangement, and multi-cell converter

Abstract

The invention relates to an arrangement (10) for a multi-cell converter (10) having at least two cells (16), wherein each cell (16) is provided and has at least one storage part (18) for storing electrical energy and a control device (20) for controlling the cell (16), wherein the control device (20) is coupled to an energy receiving coil (24) for wirelessly receiving electrical energy, wherein the control device (20) can be operated by means of the electrical energy. The invention further relates to a multi-cell converter (10).

Description

[0001] Arrangement for a multi-cell inverter, arrangement and multi-cell inverter

[0002] The invention relates to an arrangement for a multi-cell converter. Furthermore, the invention relates to a multi-cell converter.

[0003] In particular, with a so-called multi-cell inverter, the auxiliary voltage must be provided for each cell, whereby this is usually significantly below the operating voltage of the cell, for example 12 volts or 24 volts auxiliary voltage with an 800 volt operating voltage of a cell.

[0004] Typically, in such a multi-cell inverter, each cell draws its own power from its own voltage, for example, in the case of 800 volts, from those 800 volts. However, the control electronics or control unit of a cell only functions once all cells have been charged and the full operating voltage is present. If the multi-cell inverter is operated on a DC bus (for example, 6000 V DC), cell diagnostics can only be performed after this charging process. A self-test of the cells without voltage (e.g., 6000 V DC) on the main bus is therefore not possible and significantly complicates commissioning due to the increased laboratory effort and the associated safety requirements.

[0005] As already mentioned, the prior art includes a direct power supply from the intermediate circuit of each cell. Furthermore, an external power supply via a transformer with a positively and, more importantly, materially bonded primary and secondary windings without air inclusions to ensure partial discharge resistance is also known. However, this approach presents insulation problems with cable routing between the cells and the central power supply.

[0006] In particular, the protective extra-low voltage in the 24-volt circuit is laid in the protection zone of the medium voltage, which necessitates a high wiring effort due to insulation distances as well as more complex maintenance of the overall system.

[0007] The object of the present invention is to create an arrangement and a multi-cell converter by means of which improved operation of a cell of the arrangement or of the multi-cell converter is made possible.

[0008] This problem is solved by an arrangement and a multi-cell inverter according to the independent claims. Advantageous embodiments are specified in the dependent claims. One aspect of the invention relates to an arrangement for a multi-cell inverter with at least two cells, wherein each cell has at least one storage element for storing electrical energy and a control device for controlling the cell.

[0009] It is provided that the control device is coupled with an energy receiving coil for wireless reception of electrical energy, whereby the control device can be operated by means of the electrical energy.

[0010] In particular, the control unit is not powered by the cell's storage component itself, meaning there is no self-sufficiency. Instead, the control unit receives electrical energy via the receiving coil, specifically inductively, and is powered by this received energy. This electrical energy can be provided independently of the cell's energy supply.

[0011] This makes it possible, in particular, to operate the control unit even when the cell's storage portion is sufficiently depleted. Thus, for example, diagnostic functions or other functions can still be performed by the control unit even when the cell's storage portion is sufficiently depleted, as it is independent of the cell's storage capacity.

[0012] In particular, it is thus provided that a cell can be inductively charged using an "open transformer" with primary and secondary coils that are not positively connected. For this purpose, the cell(s) are, for example, pushed with their "back" against a suitable plate. On the opposite side of the plate, an energy-transmitting coil is provided, which then transmits electrical energy through the plate to the energy-receiving coil.

[0013] In particular, this results in a physical separation between the extra-low voltage supply area and the medium voltage area.

[0014] In particular, this allows for a simpler design, as there is no need for cable routing in the medium-voltage protection zone with cables that are difficult to bend, especially due to their high insulation thickness. Furthermore, maintenance of the overall system is simplified because the cell(s) can be removed after disconnecting the load connections without having to unplug any additional connectors. Increased safety is also ensured, particularly through the physical separation of the medium-voltage and extra-low voltage zones, which also facilitates easy maintenance of the extra-low voltage zone. Finally, more cost-effective manufacturing is possible because, for example, as in the prior art, two transformers connected in series are no longer necessary to achieve basic insulation and safe separation.

[0015] In particular, electrical energy can thus be transferred from the energy-sending coil to the energy-receiving coil. The energy-sending coil is provided with a suitable voltage supply, independent of the multi-cell inverter.

[0016] Furthermore, an air gap is formed between the energy receiving coil and the energy transmitting coil. This prevents the arrangement from reaching the partial discharge limit of the air gap. A specific air gap geometry is provided for this purpose. A minimum air gap is required to achieve the necessary partial discharge resistance. This ensures more reliable operation of the arrangement.

[0017] Furthermore, an insulating layer is provided between the energy receiving coil and the energy transmitting coil. In particular, a suitable separating plate can serve as this insulating layer. Thus, the energy transmitting coil and the energy receiving coil are electrically isolated from each other. This allows for the electrical separation of the low-voltage supply area and the medium-voltage area.

[0018] In particular, it is provided that, for example, in one embodiment both the air gap and the insulation layer are formed.

[0019] According to an advantageous embodiment, the energy receiving coil is designed to receive alternating current. In particular, the energy receiving coil is designed to receive alternating voltage. Electrical energy in the form of alternating current or alternating voltage is thus transferred to the energy receiving coil via an energy transmitting coil. This has the advantage that electrical energy can be transferred reliably with minimal loss.

[0020] Another advantageous embodiment provides that the energy receiving coil is designed to receive alternating current with a transmission frequency from 5 kHz up to and including 1000 kHz. Particularly in the 5 kHz to 1000 kHz range, reliable and essentially lossless transmission of electrical energy via the energy receiving coil can be achieved.

[0021] It is also advantageous if the control device includes a rectifier diode for rectifying the electrical energy. This allows the control device to be powered by current or direct current. The rectifier diode can rectify the electrical energy and thus provide the voltage supply for the control device.

[0022] Furthermore, it has proven advantageous if the insulating layer is a dielectric. In particular, the dielectric has a correspondingly low εr (e r The low εr value results in a low capacitance of the insulation layer. Furthermore, the low εr allows for a low voltage stress in the remaining air gap. Consequently, the insulation layer exhibits a high breakdown voltage.

[0023] In a further advantageous embodiment, the insulating layer is made of polypropylene. Polypropylene is a particularly advantageous insulating layer and simultaneously exhibits a low εr, which allows for improved operation of the arrangement.

[0024] Another advantageous embodiment involves using polyethylene as the insulating layer. Polyethylene also has a low εr and is a very good electrical insulator.

[0025] It has also proven advantageous for the energy receiving coil to touch the insulating layer. In particular, this allows the energy receiving coil to touch the insulating layer, especially when viewed from inside the electrical energy storage device, and thus be in direct contact with it. This provides short distances for energy transfer, enabling the reception of electrical energy with minimal energy loss.

[0026] It may also be provided that an additional air gap is formed between the energy receiving coil and the insulation layer. This additional air gap provides further electrical insulation, thus preventing electrical breakdowns into the medium-voltage range.

[0027] Another aspect of the invention relates to a multi-cell inverter with at least one cell according to the first aspect of the invention or with at least one arrangement according to the second aspect of the invention. In particular, the multi-cell inverter comprises a plurality of electrical cells. The electrical energy storage device can, for example, have a single insulating layer, but a plurality of cells can be connected to this single insulating layer. Furthermore, the multi-cell inverter comprises at least one arrangement, wherein the arrangement in turn comprises a plurality of energy transmitting coils, which correspond to the plurality of energy receiving coils of the plurality of cells. Thus, the multi-cell inverter can be provided with sufficient power to, for example, supply electrical energy to electric motors in ships.

[0028] According to an advantageous embodiment of the multi-cell inverter, at least one cell or at least one arrangement can be located in a cabinet of the multi-cell inverter. The cabinet can thus be used as protection against environmental conditions. In particular, a plurality of cells can be arranged in the cabinet. Furthermore, a plurality of arrangements can also be arranged in the cabinet.

[0029] It is also advantageous if at least one cell can be inserted into a recess in the cabinet. In particular, the cell can also be removed from the cabinet or slid out again without damage. This simplifies maintenance.

[0030] Advantageous cell configurations are to be regarded as advantageous configurations of the arrangement and the multi-cell converter.

[0031] A control device can be understood, in particular, as a data processing device containing a processing circuit. The computing unit can therefore process data to perform arithmetic operations. This may also include operations to perform indexed access to a data structure, such as a lookup table (LUT).

[0032] The computing unit may, in particular, contain one or more computers, one or more microcontrollers, and / or one or more integrated circuits, for example, one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), and / or one or more systems on a chip (SoCs). The computing unit may also contain one or more processors, for example, one or more microprocessors, one or more central processing units (CPUs), one or more graphics processing units (GPUs), and / or one or more signal processors, in particular one or more digital signal processors (DSPs). The computing unit may also include a physical or virtual array of computers or other units of the aforementioned type.In various embodiments, the computing unit includes one or more hardware and / or software interfaces and / or one or more storage units.

[0033] A storage unit can be volatile data storage, for example as dynamic random access memory (DRAM) or static random access memory (SRAM), or as non-volatile data storage, for example as read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory or flash EEPROM, ferroelectric random access memory (FRAM), or magnetoresistive random access memory.It can be designed as MRAM (magnetoresistive random access memory) or as phase-change random access memory, PCRAM (phase-change random access memory).

[0034] Further features and combinations of features of the invention will become apparent from the figures and their descriptions, as well as from the claims. In particular, further embodiments of the invention need not necessarily include all features of any one of the claims. Further embodiments of the invention may have features or combinations of features not mentioned in the claims.

[0035] This shows:

[0036] FIG 1 a schematic block diagram according to an embodiment of a multi-cell inverter with an embodiment of at least one cell;

[0037] FIG 2 shows a schematic sectional view of an embodiment of an arrangement; and

[0038] FIG 3 shows another schematic sectional view of an embodiment of an arrangement.

[0039] The invention is explained in more detail below with reference to specific embodiments and associated schematic drawings. In the figures, identical or functionally equivalent elements may be designated with the same reference numerals. The description of identical or functionally equivalent elements is not necessarily repeated with respect to different figures.

[0040] FIG 1 shows a schematic block diagram according to one embodiment of a

[0041] Multi-cell inverter 10. The multi-cell inverter 10 has at least one cabinet 12. Three arrangements 14 are shown in the cabinet 12. Each arrangement has a cell 16. The cell 16 in turn has at least one electrical storage element 18 and a control device 20. A rectifier diode 22 is also shown.

[0042] In particular, FIG. 1 shows at least the cell 16 for the multi-cell inverter 10 with at least the storage unit 18 for storing electrical energy and with the control device 20 for controlling the cell 16. It is specifically provided that the control device 20 is coupled to an energy receiving coil 24 for wirelessly receiving electrical energy, whereby the control device 20 can be operated by means of the electrical energy. In particular, the control device 20 is operated by means of the electrical energy.

[0043] In particular, FIG. 1 further shows that the energy receiving coil 24 is configured to receive alternating current 26. The energy receiving coil 24 can be configured to receive alternating current 26 with a transmission frequency from 5 kHz inclusive up to 1000 kHz inclusive.

[0044] Furthermore, FIG. 1 shows that the arrangement 14 has at least one energy transmitting coil 28. In particular, alternating current 26 can thus be transmitted via the energy transmitting coil 28 to the energy receiving coil 24.

[0045] FIG. 1 further shows that an insulating layer 30 is formed, in particular between the energy transmitting coil 28 and the energy receiving coil 24. In the present embodiment, only a single insulating layer 30 is shown, which, however, can be used jointly for the three arrangements 14.

[0046] In particular, it is thus provided that the cell 16 is inductively charged with an "open transformer" with primary and secondary coils. For this purpose, the cells are pushed with their backs against the insulating layer 30. The insulating layer 30, which can also be designed as an insulating plate, is made, for example, of a standard insulating material such as phenolic resin board, PP, POM, or other options.

[0047] Thus, a structural separation can be achieved between the extra-low voltage supply, which is represented in particular by the alternating current 26, and the medium-voltage range, which is shown in particular by cell 16 or the storage section 18. Furthermore, it is shown that cell 16 can be inserted into a receptacle 36 of the cabinet 12.

[0048] FIG. 2 shows a schematic sectional view of an embodiment of an arrangement 14. In the following exemplary embodiment, it is shown in particular that an air gap 32 is formed between the insulating layer 30 and the energy transmitting coil 28. The special feature is that the partial discharge limit of the air gap 32 is not reached due to the specific arrangement. This is achieved in particular through the specific combination of the air gap geometry and the insulating layer 30. Specifically, the insulating layer 30 is designed to have a low εr (ec) for low capacitance. Furthermore, a low εr is provided for lower voltage stresses in the remaining air gap 32, so that the required partial discharge withstand capability is maintained. This allows a high breakdown voltage of the insulating layer to be achieved.The transmitter coils, or rather the energy transmitting coils 28, are in turn powered by the power supply located on the insulation layer 30. As already mentioned, the transmission frequency lies primarily in the range between 5 and 1000 kHz. Thanks to the design of the insulation layer 30, the cell 16 can be easily removed for maintenance without having to consider the auxiliary power supply.

[0049] FIG 3 shows a further schematic sectional view of another embodiment of the arrangement 14. In the following exemplary embodiment, it is shown in particular that a further air gap 34 can be provided between the energy receiving coil 24 and the insulating layer 30.

[0050] In other words, FIG 2 shows that the energy transmitting coil 28 touches the insulating layer 30, and FIG 3 shows that the further air gap 34 is formed between the energy receiving coil 24 and the insulating layer 30.

[0051] Furthermore, it is specifically stipulated that the insulating layer 30 is a dielectric. The insulating layer 30 can, for example, be made of polypropylene or polyethylene. Reference numeral list

[0052] 10 multi-cell inverters

[0053] 12 Cabinet 14 Arrangement

[0054] 16 cells

[0055] 18 Memory section

[0056] 20 Control unit

[0057] 22 Rectifier diode 24 Energy receiving coil

[0058] 26 Alternating current

[0059] 28 Energy transmitting coil

[0060] 30 Insulation layer

[0061] 32 air gap 34 further air gap

[0062] 36 recording

Claims

Patent claims 1. Arrangement (14) with at least two cells (16) for a multi-cell inverter (10), wherein the arrangement (16) has an energy transmitting coil (28), wherein each cell (16) has at least one storage element (18) for storing electrical energy and a control device (20) for controlling the cell (16), wherein the control device (20) is coupled to an energy receiving coil (24) for wirelessly receiving electrical energy, wherein the control device (20) can be operated by means of the electrical energy, characterized in that an air gap (32) is formed between the energy receiving coil (24) and the energy transmitting coil (28), wherein an insulating layer (30) is formed between the energy receiving coil (24) and the energy transmitting coil (28), and wherein a single insulating layer (30) is formed for the at least two cells (16).

2. Arrangement (14) according to claim 1 , characterized in that the energy receiving coil (24) is designed to receive alternating current (26).

3. Arrangement (14) according to claim 2, characterized in that the energy receiving coil (24) is designed to receive alternating current (26) with a transmission frequency from 5 kHz inclusive up to 1000 kHz inclusive.

4. Arrangement (14) according to one of the preceding claims, characterized in that the control device (20) has a rectifier diode (22) for rectifying the electrical energy.

5. Arrangement (14) according to one of the preceding claims, characterized in that the insulating layer (30) is a dielectric.

6. Arrangement (14) according to one of the preceding claims, characterized in that the insulating layer (30) is made of polypropylene.

7. Arrangement (14) according to claim 5 or 6, characterized in that the insulating layer (30) is made of polyethylene.

8. Arrangement (14) according to one of the preceding claims, characterized in that the energy receiving coil (24) touches the insulating layer (30).

9. Arrangement (14) according to one of the preceding claims, characterized in that a further air gap (34) is formed between the energy receiving coil (24) and the insulating layer (30).

10. Multicell converter (10) with at least one arrangement (14) according to one of claims 1 to 9.

11. Multicell converter (10) according to claim 10, characterized in that the at least one arrangement (14) is arranged in a cabinet (12) of the multicell converter (10).

12. Multi-cell converter (10) according to claim 11, characterized in that the at least one cell (16) can be inserted into a receptacle (36) of the cabinet (12).

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