Switching assembly, electrical converter unit, traction system and use of thermoelectric unit

Abstract

The present disclosure relates to a switching assembly (20) for an electrical converter cell. The switching assembly (20) comprises at least one transistor unit (22) and at least one thermoelectric unit (36), wherein the at least one transistor unit (22) and the at least one thermoelectric unit (36) are thermally coupled and integrally formed. Furthermore, an electrical converter unit is shown. The electrical converter unit comprises at least one such switching assembly (20). The invention further relates to a traction system for a vehicle. The traction system comprises such an electrical converter unit, an electrical energy storage unit and an electric machine. The electrical energy storage unit and the motor are electrically coupled to the electrical converter unit. Further, a thermoelectric unit (36) of the electrical converter unit is electrically coupled to the electrical energy storage unit and / or the electric machine. In addition, different uses of the thermoelectric unit (36) are presented.

Description

Technical Field

[0001] The present disclosure relates to a switch assembly for an electric converter unit.

[0002] Furthermore, the present disclosure relates to an electrical converter unit comprising at least one switching assembly.

[0003] Furthermore, the present disclosure relates to a traction system for a vehicle, the traction system comprising an electric converter unit.

[0004] The present disclosure also relates to the use of thermoelectric units. Background Art

[0005] In a battery electric vehicle (vehicle) or a hybrid electric vehicle, at least part of the energy required to propel the vehicle is provided by the battery. In addition, due to its controllability and its long service life, AC motors have become standard for the traction systems of such vehicles. This means that each battery electric vehicle or hybrid electric vehicle includes an electric converter unit, which is at least configured to convert the DC power provided by the battery into the AC power required by the motor. Typically, such an electric converter unit is also configured to convert the AC power provided by the motor into DC power for storage in the battery. Thus, the battery can be charged by the AC motor operating as a generator.

[0006] In this context, it has been found that operating an AC motor at a high frequency of the AC power, ie the current alternates at a high frequency, improves the efficiency of the motor and thereby increases the mileage of a vehicle equipped with the motor. Summary of the invention

[0007] It is an object of the present disclosure to further improve the efficiency of battery electric vehicles or hybrid electric vehicles.

[0008] This problem is at least partly solved or alleviated by the subject matter of the independent claims of the present disclosure, wherein further examples are incorporated in the dependent claims.

[0009] According to a first aspect, a switch assembly for an electrical converter unit is provided. The switch assembly comprises at least one transistor unit and at least one thermoelectric unit. The at least one transistor unit and the at least one thermoelectric unit are thermally coupled and integrally formed. In this case, the use of transistor units in the switch assembly of the electrical converter unit is known per se. It has been found that the high switching frequency of such a switch assembly generates high switching losses. Due to the high switching losses, the switch assembly generates heat. However, the high switching frequency is necessary to be able to operate the AC motor at a high switching frequency, which makes the motor efficient, as already explained above. Therefore, the basic idea of ​​the invention is to use thermoelectric units so that the heat generated by the switching losses of the switch assembly can be converted into electrical energy. Thereby, the efficiency is further increased. The generated electrical energy can be fed back into the battery of the electric traction system of the vehicle. This solution is particularly advantageous because the thermoelectric element converts heat into electrical energy at the same location where the heat is generated. In addition, the thermoelectric element is relatively compact and lightweight. This is particularly the case when the thermoelectric element is compared with conventional cooling devices for the switch assembly of the electrical converter unit. In addition, the integral formation of the thermoelectric unit and the transistor unit can be understood as the thermoelectric unit and the transistor unit being formed as a single component. This can be done in a chip manufacturing plant. In other words, the thermoelectric unit and the transistor unit can be formed integrally on chip level. This facilitates production and further enhances the compactness of the switch assembly. If such a switch assembly is used in a battery electric vehicle or a hybrid electric vehicle, this leads to an increase in driving range. Additionally or alternatively, the electrical energy generated by the thermoelectric unit can be fed back into the transistor unit. Thus, the electrical energy is used to switch the transistor unit. This also improves efficiency.

[0010] It should be noted that in the context of the present disclosure, an electrical converter unit may be any one or more of an AC-DC converter unit, a DC-DC converter unit or a DC-AC converter unit.

[0011] Furthermore, according to the present disclosure, a thermoelectric unit should be broadly understood as any device configured to convert energy in the form of heat into electrical energy.

[0012] Furthermore, it should be noted that the present invention can be implemented in conjunction with any type of transistor. This includes, for example, MOSFET, non-MOSFET and non-FET solutions. Furthermore, the switching of the insulated gate bipolar transistor results in heating, and this can also be transferred to the thermoelectric unit.

[0013] According to an example, the transistor unit and the thermoelectric unit share a common substrate and / or a common depletion layer and / or a common thermal conductive layer and / or a common die. In short, the transistor unit and the thermoelectric unit are formed as an integral semiconductor component. In other words, the transistor unit and the thermoelectric unit are formed on the same wafer or chip. In this context, a wafer is understood to be a small piece of semiconductor material on which a given functional circuit is manufactured. Therefore, the production of the switch assembly is relatively simple and the switch assembly is compact.

[0014] In an example, the thickness of the substrate is at least 200 micrometers. This facilitates heat conduction within the substrate.

[0015] In an example, the thermoelectric unit is or comprises a thermophotovoltaic cell. A thermophotovoltaic cell is a semiconductor component configured to convert heat into electrical energy. Thermophotovoltaic cells are relatively efficient, i.e. convert heat into electrical energy in a relatively efficient manner. At the same time, thermoelectric cells are very compact.

[0016] Due to the fact that the thermoelectric cell and the transistor cell are formed in one piece, the thermophotovoltaic effect is seamlessly incorporated into the switching assembly, which can be described in simplified terms as a chip. Thus, the heat generated due to switching losses in the infrared spectrum can be used efficiently and electrical energy can be generated in the form of charge flow in the thermophotovoltaic cell. This increases the overall efficiency of the system, offsetting the switching losses encountered in the transistor cell.

[0017] According to an example, the transistor unit comprises at least one field effect transistor. Examples of field effect transistors are MOSFET transistors, nMOSFET transistors, pMOSFET transistors, HEMT transistors, organic field effect transistors and JFET transistors. Such transistors can be switched at high switching frequencies and are relatively efficient.

[0018] According to an example, the transistor cell is a SiC transistor cell. According to another example, the transistor cell is a SiC-MO transistor cell. According to a further example, the transistor cell comprises a dopant such as GaAs, SiGe, carbon graphene or GaN. In addition, such transistors can be switched at high switching frequencies and are relatively efficient. At the same time, they can operate at relatively high temperatures.

[0019] According to another example, the transistor cell may include a wide bandgap transistor. Alternatively, the transistor cell may be designed according to a bipolar architecture. Alternatively, the transistor cell may be designed to accommodate high electron mobility or hole mobility.

[0020] In an example, the thermoelectric unit comprises a heat exchange interface remote from the transistor unit. Using the heat exchange interface, the thermoelectric unit is configured to exchange heat with the environment. In the case where the environment comprises a cooling system, the heat exchange interface provides the possibility of connecting the thermoelectric unit to the cooling system. Thus, heat that is not converted into electrical energy by the thermoelectric unit can be used in such a cooling system. This further improves efficiency.

[0021] According to one example, the heat exchange interface comprises at least one fin. Thus, the geometric surface of the heat exchange interface is increased by the fin. This facilitates heat exchange.

[0022] According to a second aspect, an electric converter unit is provided, comprising at least one switch assembly according to the present disclosure. Thus, the heat generated by the switching losses of the switch assembly of the electric converter can be converted into electrical energy. Thereby, the efficiency is improved. The generated electrical energy can be fed back to the battery of the electric traction system of the vehicle. Alternatively or additionally, the electrical energy can be fed back to the transistor unit of the switch assembly. To this end, the thermoelectric unit can be electrically coupled to the gate driver of the transistor unit. There, the electrical energy can be used to switch the transistor unit. In this case, the electrical energy can be used to modulate the switching waveform and / or change the slew rate, for example to reduce the slew rate. Due to the compactness and efficiency of the switch assembly according to the present disclosure, the electric converter unit is also very compact and can be operated in an efficient manner. If such an electric converter unit is used in a battery electric vehicle or a hybrid electric vehicle, this leads to an increase in mileage.

[0023] The electrical converter unit may be any one or more of an AC-DC converter unit, a DC-DC converter unit or a DC-AC converter unit. In this case, the electrical converter unit may be referred to as a power inverter unit.

[0024] According to a third aspect, a traction system for a vehicle is provided. The traction system comprises an electric converter unit, an electric energy storage unit and an electric motor according to the present disclosure. The electric energy storage unit and the electric motor are electrically coupled to the electric converter unit. The thermoelectric unit of the electric converter unit is electrically coupled to the electric energy storage unit and / or the electric motor. Such a traction system is efficient because the heat generated due to switching losses in the electric converter unit can be converted into electric energy, which can be fed into the electric energy storage unit or can be used in the electric motor. Alternatively or additionally, the electric energy can be fed back into the transistor unit of the switching assembly. To this end, the thermoelectric unit can be electrically coupled to the gate driver of the transistor unit. There, the electric energy can be used to switch the transistor unit. In this case, the electric energy can be used to modulate the switching waveform and / or change the slew rate, for example to reduce the slew rate. As a result, the mileage of a vehicle using the traction system is increased.

[0025] According to a fourth aspect, there is provided a use of a thermoelectric unit, in particular a thermophotovoltaic cell, for cooling a transistor unit. As described above, using a thermoelectric unit, in particular a thermophotovoltaic cell, heat can be converted into electrical energy. In other words, the thermoelectric unit can be used to extract heat from the transistor unit to generate electrical energy. In other words, the thermoelectric unit can be used to cool the transistor unit.

[0026] According to a fifth aspect, there is provided a use of a thermoelectric unit, in particular a thermophotovoltaic cell, for reducing the switching losses of a transistor unit. As described above, the thermoelectric unit can extract heat from the transistor unit and can convert the heat into electrical energy. The electrical energy can be used within a system of which the thermoelectric unit and the transistor unit form a part. Thus, the switching losses are reduced. At the same time, such a cooling effect reduces the switching losses.

[0027] According to a sixth aspect, there is provided a use of a thermoelectric unit, in particular a thermophotovoltaic cell, for attenuating electromagnetic interference of a transistor unit. In this case, the thermoelectric unit can be positioned so that it shields electromagnetic interference originating from the transistor unit. Alternatively or additionally, the thermoelectric unit can generate a waveform so that it is modulated on a common mode / differential mode signal to ensure that electromagnetic interference originating from the transistor unit is suppressed.

[0028] It should be noted that the above-mentioned examples can be combined with each other regardless of the aspects involved.

[0029] These and other aspects of the disclosure will be apparent from and elucidated with reference to the examples described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Examples of the present disclosure will be described below with reference to the following drawings.

[0031] Figure 1 A battery electric vehicle comprising a traction system according to the present disclosure having an electric converter unit according to the present disclosure and several switch assemblies according to the present disclosure is shown,

[0032] Figure 2 Shown in more detail Figure 1 one of the switch assemblies, and

[0033] Figure 3 With Figure 2 The views corresponding to the views show a switch assembly according to another example. DETAILED DESCRIPTION

[0034] The drawings are merely schematic representations and serve merely to illustrate examples of the present disclosure. Identical or equivalent elements are in principle provided with the same reference numerals.

[0035] Figure 1A vehicle 10 is shown, which in this example is a battery electric vehicle.

[0036] Thus, the vehicle 10 includes a traction system 12 having an electrical energy storage unit 14 (which may also be referred to as a battery), an electric machine 16 , and an electrical converter unit 18 .

[0037] The electrical energy storage unit 14 and the electric machine 16 are both electrically coupled to an electrical converter unit 18 .

[0038] In this example, the motor 16 is a three-phase AC motor.

[0039] Thus, the electrical converter unit 18 is configured to convert the DC power provided by the electrical energy storage unit 14 into 3-phase AC power for the electric machine 16 .

[0040] Furthermore, the electric converter unit 18 is configured to convert the three-phase AC power generated by the electric machine 16 into DC power to be fed into the electric energy storage unit 14 in the case where the electric machine 16 operates as a generator.

[0041] To this end, the electrical converter unit 18 comprises a total of six switch assemblies 20 , wherein a pair of switch assemblies of the six switch assemblies 20 is associated with each of the three phases of the electrical machine 16 .

[0042] exist Figure 2 1. One switch assembly 20 is shown in more detail in FIG. 1. It should be noted that in this example, all six switch assemblies 20 are identical.

[0043] The switch assembly 20 includes a transistor unit 22 .

[0044] In this example, the transistor unit 22 includes a field effect transistor 24. Note that the field effect transistor is only an example. This example can also be combined with other types of transistors.

[0045] The field effect transistor 24 is constructed on a substrate 26 .

[0046] Furthermore, it has a gate 28 , a source 30 and a drain 32 .

[0047] The depletion layer 34 is provided on the substrate 26 .

[0048] The field effect transistor 24 can operate in the same manner as known field effect transistors. Therefore, no further details are provided thereon.

[0049] The switch assembly 20 further comprises a thermoelectric unit 36 ​​.

[0050] In the present example, thermoelectric unit 36 ​​includes thermophotovoltaic cells 38 .

[0051] It should be noted that, due to the fact that all switch assemblies 20 are identical, in this example, all switch assemblies 20 include a thermoelectric unit 36. In other examples, only a portion of the switch assemblies 20 may be equipped with a thermoelectric unit 36.

[0052] In this example, transistor cell 22 and thermoelectric cell 36 share a common substrate, which is substrate 26 .

[0053] More generally, transistor cell 22 and thermoelectric cell 36 are integrally formed, such as simultaneously formed in the same chip manufacturing facility.

[0054] Note that in other examples, transistor cell 22 and thermoelectric cell 36 may alternatively or additionally share one or more of a depletion layer, a thermally conductive layer, or a wafer.

[0055] In addition, due to the fact that the transistor unit 22 and the thermoelectric unit 36 ​​are integrally formed, the transistor unit 22 and the thermoelectric unit 36 ​​are thermally coupled.

[0056] Therefore, the heat generated due to the switching losses of the field effect transistor 24 can be transferred to the thermophotovoltaic cell 38. Figure 2 This is indicated by arrow 40 .

[0057] Thermophotovoltaic cells 38 are configured to convert this heat into electrical energy.

[0058] Thermophotovoltaic cell 38 is electrically coupled to electrical energy storage unit 14 .

[0059] Thus, the electrical energy generated by the thermophotovoltaic cell 38 can be fed into the electrical energy storage unit 14. Thus, the heat generated due to the heat loss of the field effect transistor 24 is not lost but reused in the form of electrical energy.

[0060] In other words, the thermoelectric unit 36 ​​, more precisely the thermophotovoltaic cell 38 , is used to cool the transistor unit 22 .

[0061] Furthermore, at the level of the electrical converter unit 18 and at the level of the traction system 12 , thermoelectric units 36 , more precisely thermophotovoltaic cells 38 , are used to reduce the switching losses of the transistor unit 22 .

[0062] Furthermore, due to the arrangement of the thermoelectric unit 36 ​​, the thermoelectric unit 36 ​​, more precisely the thermophotovoltaic cell 38 , serves to attenuate electromagnetic interference of the transistor unit 22 .

[0063] Figure 3 A switch assembly 20 according to another example is shown. In the following, only the switch assembly 20 according to another example will be explained. Figure 2 of the examples.

[0064] exist Figure 3In the switch assembly 20 , the thermoelectric unit 36 ​​further includes a heat exchange interface 42 away from the transistor unit 22 .

[0065] exist Figure 3 In the example shown, the heat exchange interface 42 and the transistor unit 22 are arranged on opposite sides of the thermoelectric unit 36 ​​.

[0066] Furthermore, fins 44 are provided on the exchange interface 42 .

[0067] Therefore, in Figure 3 In the example of FIG. 4 , the heat represented by arrow 40 may not be fully converted into electrical energy under certain conditions.

[0068] In this case, excess heat, represented by arrow 46 , may be provided to the environment of the switch assembly 20 or to a cooling system of the traction system 12 .

[0069] In addition, reference Figure 2 An explanation is provided by an example.

[0070] As used herein, the phrase "at least one" with respect to a list of one or more entities should be understood to mean at least one entity selected from any one or more entities in the list of entities, but does not necessarily include at least one of each entity specifically listed within the list of entities, and does not exclude any combination of entities in the list of entities. This definition also allows that entities other than the entities specifically identified within the list of entities to which the phrase "at least one" refers may optionally be present, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or equivalently, "at least one of A or B", or equivalently, "at least one of A and / or B") may refer to at least one A, optionally including more than one A, with no B (and optionally including entities other than B) in one example; to at least one B, optionally including more than one B, with no A (and optionally including entities other than A) in another example; and to at least one (optionally including more than one) A and at least one (optionally including more than one) B (and optionally including other entities) in yet another example. In other words, the phrases "at least one," "one or more," and "and / or" are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions "at least one of A, B, and C," "at least one of A, B, or C," "one or more of A, B, and C," "one or more of A, B, or C," and "A, B, and / or C" may represent A alone, B alone, C alone, A and B together, A and C together, B and C together, A, B, and C together, and optionally any of the foregoing in combination with at least one other entity.

[0071] Other variations of the disclosed examples may be understood and effected by those skilled in the art in practicing the claimed disclosure, by studying the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope of the claims.

[0072] Reference numerals list

[0073] 10 Vehicles

[0074] 12 Traction system

[0075] 14Electric Energy Storage Unit

[0076] 16 Motor

[0077] 18 Electric converter units

[0078] 20 switch assembly

[0079] 22 transistor unit

[0080] 24 Field Effect Transistors

[0081] 26 substrates

[0082] 28 grid

[0083] 30 Source

[0084] 32 Drain

[0085] 34 Depletion layer

[0086] 36 Thermoelectric units

[0087] 38 Thermophotovoltaic cells

[0088] 40 Arrows

[0089] 42 hot swap interface

[0090] 44 fins

[0091] 46 Arrows

Claims

1. A switch assembly (20) for an electric converter unit (18), comprising at least one transistor unit (22) and at least one thermoelectric unit (36), wherein the at least one transistor unit (22) and the at least one thermoelectric unit (36) are thermally coupled and integrally formed.

2. The switch assembly (20) according to claim 1, wherein: The transistor unit (22) and the thermoelectric unit (36) share a common substrate (26) and / or a common depletion layer and / or a common heat conducting layer and / or a common wafer.

3. The switch assembly (20) according to any one of the preceding claims, wherein: The thermoelectric unit (36) is a thermophotovoltaic cell (38) or comprises a thermophotovoltaic cell (38).

4. The switch assembly (20) according to claim 1, wherein: The transistor unit (22) includes at least one field effect transistor (24).

5. The switch assembly (20) according to claim 1, wherein: The thermoelectric unit (36) includes a heat exchange interface (42) remote from the transistor unit (22).

6. The switch assembly (20) according to claim 5, wherein: The heat exchange interface (42) includes at least one fin (44).

7. An electrical converter unit (18) comprising at least one switch assembly (20) according to any one of the preceding claims.

8. A traction system (12) for a vehicle (10), comprising an electric converter unit (18) according to claim 7, an electric energy storage unit (14) and an electric machine (16), wherein: The electrical energy storage unit (14) and the electric machine (16) are electrically coupled to the electrical converter unit (18), and wherein a thermoelectric unit (36) of the electrical converter unit (18) is electrically coupled to the electrical energy storage unit (14) and / or the electric machine (16).

9. Use of a thermoelectric cell (36) for cooling a transistor cell (22).

10. The use according to claim 9, wherein The thermoelectric unit (36) is a thermophotovoltaic cell (38).

11. Use of a thermoelectric unit (36) for reducing switching losses of a transistor unit (22).

12. The use according to claim 11, wherein The thermoelectric unit (36) is a thermophotovoltaic cell (38).

13. Use of a thermoelectric unit (36) for attenuating electromagnetic interference of a transistor unit (22).

14. The use according to claim 13, wherein The thermoelectric unit (36) is a thermophotovoltaic cell (38).

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