Power converter, electric drive and method for producing power converter
By adopting the design of multiple functional basic modules and mechanical enclosure units in the power converter, the optimization space of power converters in the prior art in terms of functions and costs is solved, flexible power and current adjustment is achieved, and the flexibility and efficiency of the system are improved.
Patent Information
- Application Number
- CN202380057311.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-07-29
- Filing Date
- 2023-07-27
- Publication Date
- 2025-03-18
AI Technical Summary
There is room for optimization in existing power converters in terms of functionality and cost, especially in electric drive applications in motor vehicles.
A power converter is designed, using multiple functional basic modules, each forming a half-bridge, including semiconductor switches on the positive voltage side and the negative voltage side, and a current connection is achieved through internal and external current connections. These modules are held together by mechanically enclosing units and are connected by current to form a scalable power converter construction concept.
Through this design, the power converter is optimized in terms of function and cost, and can adjust the number and layout of the functional basic modules according to the needs, thereby adapting to different power and current needs, improving the flexibility and efficiency of the system.
Smart Images
Figure CN119654972A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a power converter, such as an inverter or a DC voltage converter, in particular for an electric drive of a motor vehicle, and to an electric drive having such a power converter. The invention also relates to a method for producing a power converter. Background Art
[0002] Power converters for converting an incoming current of one current type (direct current, alternating current) into a current of another current type (alternating current, direct current) or for changing a characteristic parameter of an incoming current (such as voltage) are known and are used in particular in electric drives of motor vehicles.
[0003] As is common in all technical devices, there are general requirements for power converters to be optimized with regard to functionality and costs. Summary of the invention
[0004] The object of the present application is therefore to provide a possibility for optimizing a power converter with regard to functionality and costs.
[0005] This object is achieved by the subject matter of the independent claim. Advantageous embodiments are the subject matter of the dependent claims.
[0006] According to a first aspect of the invention, a power converter, in particular an inverter or a DC voltage converter, in particular for an electric drive of a motor vehicle is provided.
[0007] The power converter has a large number of functional basic modules, each of which forms (only one) half-bridge ("Sub-half-bridge" in English), each half-bridge has (only one) semiconductor switch on the positive voltage side (Highside) and (only one) semiconductor switch on the negative voltage side (Lowside), and each functional basic module correspondingly includes (only one) semiconductor switch on the positive voltage side and (only one) semiconductor switch on the negative voltage side as well as (multiple) internal current connections and multiple external current terminals between the two semiconductor switches for establishing external current connections for the semiconductor switches.
[0008] The power converter has a certain number of power base modules, each power base module includes a plurality (more than one) of the above-mentioned functional base modules and has a mechanical enclosure unit, wherein the enclosure unit of the respective power base module holds the respective corresponding functional base modules together and mechanically connects them to each other, and surrounds the respective corresponding functional base modules, except for their respective external current terminals. Here, the functional base modules of the respective power base modules are (completely) electrically isolated from each other in the respective corresponding enclosure units.
[0009] The power converter has a power converter power module, which comprises a total number of power base modules and has a plurality of current connections, wherein the current connections electrically connect the respective corresponding current terminals of the respective functional base modules of the respective power base modules to one another.
[0010] The power converter described above approximately forms a scalable power converter construction concept with three construction levels: a first construction level, a second construction level and a third construction level.
[0011] The first building level forms functional basic modules, each of which forms (only one) (switchable) half-bridge, each half-bridge having (only one) semiconductor switch on the positive voltage side and (only one) semiconductor switch on the negative voltage side, and each functional basic module correspondingly includes (only one) semiconductor switch on the positive voltage side and (only one) semiconductor switch on the negative voltage side and (multiple) internal current connections between the two semiconductor switches and multiple external current terminals, for example three, namely, a current terminal on the positive voltage side, a current terminal on the negative voltage side and a phase current terminal, for establishing an external current connection for the semiconductor switch (external power interface, for establishing an external current connection for the semiconductor switch).
[0012] The second building level forms power base modules, each of which has a plurality of functional base modules of the first building level and mechanical enclosure units, wherein the enclosure units of the respective power base modules hold the respective corresponding functional base modules together and mechanically connect them to each other and surround the respective corresponding functional base modules, except for their respective current terminals. Here, the functional base modules of the respective power base modules are (completely) electrically isolated from each other within the respective corresponding enclosure units.
[0013] The third building level forms a power converter power module, which has all (more than one) power basic modules of the second building level and multiple current connections, wherein these current connections electrically connect the respective corresponding current terminals of the respective functional basic modules of the respective power basic modules to each other.
[0014] The functional basic modules of the first construction level are indivisible basic units (functional basic units) of power basic modules, and therefore also indivisible basic units of power converters, which have a correspondingly minimum power / current carrying capacity that cannot be reduced further. Each functional basic module is (only one) complete half-bridge, which respectively has (only one) semiconductor switch on the positive voltage side and (only one) semiconductor switch on the negative voltage side and its own external current terminal for establishing an external current connection for the semiconductor switch. The functional basic modules can be operated individually, but can also be operated in parallel with other functional basic modules. Here, the functional basic modules can be constructed identically to each other according to requirements, but can also be constructed differently.
[0015] The power base module of the second construction level is a (purely) mechanical and physical complex of a predetermined number of functional base modules, which are surrounded by a common, mechanically stable enclosing unit (except for their respective external current terminals) and are (purely) mechanically and physically integrated into the respective power base module. In this case, the enclosing unit mechanically and physically holds the integrated or enclosed functional base modules together by its own mechanical rigidity and also electrically isolates the functional base modules from each other (within the power base module). The external current terminals that are not surrounded by the enclosing unit enable the subsequent external electrical connection of the power base module in the third construction level.
[0016] Furthermore, the power base module can functionally form only one half-bridge, but the half-bridge can be composed of two, three or more mutually switchable (in parallel) functional base modules or half-bridges (but not yet connected (in parallel) to each other in the second construction level) depending on the power requirements. By varying the number of functional base modules, the performance or power / current carrying capacity of the respective power base module can be scaled. Furthermore, the selection of the module size, i.e. the number of integrated functional base modules, can also be carried out according to application-specific criteria, for example according to the type of power converter (e.g. inverter or DC voltage converter), or according to the available power converter installation space, or according to the number of phases (e.g. in the case of an inverter).
[0017] The functional basic modules in the power basic module can be operated individually or in parallel. The number of functional basic modules in the power basic module determines the power / current carrying capacity or the desired performance required for the power basic module or the half-bridge formed by the power basic module. Thus, the power basic module forms a power basic unit of the power converter.
[0018] The small design of the individual functional base modules and the flexibly definable number of functional base modules in a power base module also enable the integration of the power base modules into power converter power modules having installation spaces with special geometric requirements. The power base modules can thus be mounted in a space-saving manner, for example concentrically on a circular surface, for example an end surface of a stator of an electric machine, or in a space-saving manner, for example radially on the outer circumference of a cylindrical surface of a stator of an electric machine.
[0019] The power converter power module of the third construction level forms the (entire) power electrical part of the power converter, which is controlled by a suitable driver circuit to convert a current of one current type (direct current, alternating current) fed into a current of another current type (alternating current, direct current), or change a characteristic parameter (such as voltage) of the fed current. Typically, the power converter power module includes two, three or more power basic modules, which are electrically connected to each other into a switchable double, triple or more half-bridge (or double, triple or more switch bridge) corresponding to the type and function of the power converter. Here, the electrical connection is carried out by means of the current connection of the power converter power module, which electrically connects the external current terminals of the corresponding functional basic modules of the corresponding power basic modules to each other.
[0020] By selecting the number of functional basic modules in the power basic module and selecting the number of power basic modules in the power converter power module and by correspondingly externally electrically connecting (e.g. connecting in parallel) the external current terminals of the respective corresponding functional basic modules of the corresponding power basic modules, the function of the power converter (inverter or DC converter, or the number of (motor) phases to be supplied with phase current) can be determined and (additionally) the performance or power / current carrying capacity of the power converter can be scaled.
[0021] In the second construction level of the power converter, the functional basic modules in the respective power basic modules or their respective surrounding units are completely electrically isolated from each other. In the third construction level of the power converter or the power converter power module, the functional basic modules are electrically connected to each other via external electrical connections (from the perspective of the functional basic modules or power basic modules) corresponding to the functions and performances of the power converter.
[0022] This provides a possibility to optimize the power converter with regard to functionality and costs.
[0023] For example, each functional basic module also has a plurality of signal terminals. Here, the enclosing unit of the respective power basic module also encloses the respective corresponding functional basic module, in addition to its respective signal terminals. The power converter also has one or more driver circuits, each driver circuit being connected to the signal terminals of the respective corresponding functional basic module in a signal technology manner and controlling the respective corresponding functional basic module in accordance with the function of the power converter.
[0024] Since each functional basic module is formed with (only one) semiconductor switch on the positive voltage side and (only one) semiconductor switch on the negative voltage side, and these semiconductor switches are only electrically connected to the respective corresponding driver circuit via their signal terminals in the third construction level, the semiconductor switches can be controlled and monitored separately. This makes it possible to locate defects in the individual semiconductor switches in a simple manner. In addition, the separate control of the individual functional basic modules makes it possible to apply static and dynamic measures to symmetrize the load currents on the different functional basic modules or semiconductor switches in different functional basic modules.
[0025] The surrounding unit of the respective power basic module has, for example, a surface with recesses, wherein signal terminals of the respective functional basic module of the respective corresponding power basic module are exposed via the recesses for establishing electrical contact, in particular in the form of contact surfaces exposed via the recesses.
[0026] For example, each functional basic module also has a cooling surface for cooling the respective functional basic module. Here, the surrounding unit of the respective power basic module also surrounds the respective corresponding functional basic module in addition to its respective cooling surface. The power converter power module also has a cooling body for cooling the functional basic module, wherein the functional basic module is placed on the cooling body via its respective cooling surface and is physically and thermally connected to the cooling body.
[0027] In this case, the cooling surface of the respective functional base module of the respective power base module and the surface of the surrounding unit of the respective corresponding power base module that has the recess can face away from one another.
[0028] The external current terminals of the respective functional basic modules of the respective power basic modules can extend out of the surrounding unit of the respective corresponding power basic modules in the extension direction of the surface with the groove of the surrounding unit of the respective corresponding power basic modules. In particular, the external current terminals can extend parallel to the surface.
[0029] For example, the surrounding unit of the respective power basic module hermetically surrounds the semiconductor switch on the positive voltage side and the semiconductor switch on the negative voltage side of the respective functional basic module integrated in the respective corresponding power basic module.
[0030] For example, the surrounding unit has a molding compound, which is injection molded or overmolded around the functional basic module of the respective power basic module. The functional basic module is embedded in the respective molding compound and is mechanically and physically held together by the molding compound. Alternatively or in addition to the molding compound, the surrounding unit also has a supporting frame, which holds the functional basic modules (additionally) of the respective power basic module together and mechanically and physically connects them to each other.
[0031] For example, the current connection is formed as a current connection busbar ("Busbars" in English), which is formed, for example, from a metal sheet (for example a copper sheet) by, for example, stamping. Each current connection busbar can be welded, soldered, sintered or glued, screwed or riveted to the respective current terminal of the respective corresponding functional basic module of the respective power basic module. With these current connection busbars, the external power interface of the power converter can be realized in a cost-effective and functionally unrestricted manner.
[0032] For example, the functional basic modules are constructed identically to one another in terms of their shape and function, in particular have identical switching characteristics. In this case, in the production of the power basic modules, identical functional basic modules are integrated into the respective power basic modules in the same number. Alternatively, the functional basic modules can be formed differently in groups in terms of their shape and function. In this case, the power basic modules composed of respective groups of functional basic modules of the same shape and function can each have the same number of functional basic modules (of the same shape and function). However, the power basic modules are constructed identically to one another here.
[0033] This identical design of the functional base module or power base module simplifies or enables good current symmetry even without additional symmetrization measures, for example by individual actuation of the semiconductor switches by means of driver circuits additionally adapted for this purpose.
[0034] For example, the semiconductor switch on the positive voltage side and the semiconductor switch on the negative voltage side are formed based on silicon carbide or as silicon carbide transistor switches. In particular, the two semiconductor switches can be formed as SiC-MOSFET ("Silicon-Carbide Metal Oxide Field-Effect Transistor" in English) or SiC-IGBT ("Silicon-Carbide Insulated Gate Bipolar Transistor" in English). Alternatively, the two semiconductor switches can also be formed based on gallium nitride, for example, as GaN-MOSFET ("Gallium-Nitrid Metal Oxide Field-Effect Transistor" in English) or GaN-IGBT ("Gallium-Nitrid Insulated Gate Bipolar Transistor" in English).
[0035] According to a second aspect of the present invention, an electric drive device is provided. The device has an electric machine and a power converter as described above, wherein the power converter is formed as an inverter. In this case, a power converter power module of the power converter is electrically connected to the electric machine via a phase current connection.
[0036] According to a third aspect of the invention, a method is provided for producing a power converter, in particular an inverter or a DC voltage converter, which is used in particular for an electric drive of a motor vehicle.
[0037] According to the method, a large number of functional basic modules are provided, each functional basic module forming (only one) half-bridge, each half-bridge having (only one) semiconductor switch on the positive voltage side and (only one) semiconductor switch on the negative voltage side and multiple current terminals, and each functional basic module correspondingly has (only one) semiconductor switch on the positive voltage side and (only one) semiconductor switch on the negative voltage side and (multiple) internal current connections between the two semiconductor switches and multiple external current terminals for establishing external current connections for the semiconductor switch (external power interface for establishing external current connections for the semiconductor switch).
[0038] Then, a certain number of power base modules are formed, each of which has a mechanical enclosure unit and a plurality of (e.g., two or three) functional base modules. Here, the enclosure unit of each power base module surrounds the respective corresponding functional base module, except for its respective current terminals, and mechanically and physically connects the respective corresponding functional base modules to each other. At the same time, the enclosure unit of each power base module electrically isolates the respective corresponding functional base modules in the respective enclosure unit from each other.
[0039] Subsequently, a power converter power module is formed, which has a power base module and a plurality of current connections, wherein the current connections electrically connect the respective corresponding current terminals of the respective corresponding functional base modules of the corresponding power base modules to one another.
[0040] The advantageous embodiments of the power converter described above can also be regarded as advantageous embodiments of the method, insofar as they can also be applied to the method described above. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] Hereinafter, exemplary embodiments of the present invention will be explained in detail with reference to the accompanying drawings.
[0042] Figure 1A , Figure 1B A functional basic module according to an exemplary embodiment of the present invention is shown in a schematic top view and a schematic cross-sectional view, respectively;
[0043] Figure 2A , Figure 2B The schematic top view shows Figure 1A or Figure 1B A power basic module according to an exemplary embodiment of the present invention of a functional basic module in;
[0044] Figure 3 A schematic cross-sectional view shows Figure 2A or Figure 2B The power base module in
[0045] Figure 4 The schematic diagram shows a Figure 2B The inverter in the power base module is an electric drive. DETAILED DESCRIPTION
[0046] Figure 1A , Figure 1B The schematic top view ( Figure 1A ) and schematic cross-sectional view ( Figure 1B ) shows a functional basic module FB of an inverter IV according to an exemplary embodiment of the present invention. In this case, the inverter IV is part of an electric drive EA of an electric vehicle for operating an electric motor EM (see Figure 4 ).
[0047] The functional basic module FB forms only one half-bridge of the power module LM of the inverter IV and thus forms an indivisible basic functional unit of the power module LM of the inverter IV as the first building stage of the power module LM of the inverter IV. Correspondingly, the functional basic module FB has a single semiconductor switch T1 on the positive voltage side and a single semiconductor switch T2 on the negative voltage side. In addition, the functional basic module FB has a single current terminal on the positive voltage side, a current terminal on the negative voltage side and a single phase current terminal, via which the functional basic module FB establishes an external current connection between the semiconductor switches T1 and T2 inside the module on the one hand and a DC power supply ("DC-Link" in English) and the phase line of the motor EM outside the module on the other hand.
[0048] The two semiconductor switches T1 and T2 are formed as silicon carbide transistors. The current terminal on the positive voltage side, the current terminal on the negative voltage side and the phase current terminal are respectively formed as a current connection busbar H+ on the positive voltage side, a current connection busbar H- on the negative voltage side and a phase current connection busbar P, which are stamped and formed from copper plates.
[0049] The functional base module FB has an AMB substrate (AMB: Active Metal Brazing) as a circuit carrier ST of the half bridge, which has a layer / plate-shaped electrical insulator, which is composed of aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4) or a similar ceramic substrate material and has a copper layer on each of the two flat upper sides of the insulator.
[0050] The first copper layer on the first upper side of the insulating body forms a conductor track for establishing a current connection between the semiconductor switches T1, T2 on the one hand and the positive voltage-side current connection busbar H+ or the phase current connection busbar P on the other hand. Correspondingly, the first copper layer is structured on the first upper side corresponding to the function of the functional basic module FB (as a half bridge). The two semiconductor switches T1, T2 are each surface-mounted on a respective conductor track LB.
[0051] The second copper layer on the second upper side of the insulating body facing away from the first upper side forms a cooling surface KF of the functional base module FB, via which waste heat of the functional base module FB or the two semiconductor switches T1, T2 is discharged during operation of the inverter IV. Accordingly, the second copper layer (in particular in one piece) extends over the entire surface of almost the entire surface of the second upper side.
[0052] The current connecting busbars H+, H- on the positive voltage side and the negative voltage side and the phase current connecting busbar P are electrically connected to the respective semiconductor switches T1, T2 directly or via printed conductors on the circuit carrier ST, or, if necessary, via other connecting elements (such as bonding wires, bonding strips or metal stamped connectors) corresponding to the function of the functional basic module FB (as a half bridge).
[0053] The functional base module FB also has one or more carrier frames TR made of electrically insulating material, for example in the form of a molding compound, which carry the current connecting busbars H+, H-, P, physically connect them to one another and to the circuit carrier ST and at the same time electrically isolate them from one another. On the circuit carrier ST and therefore on the upper side facing away from its cooling surface KF, the carrier frame TR has signal terminals SA made of copper sheets, which are embedded in the carrier frame TR except for their respective exposed contact surfaces. The functional base module FB also has internal signal connections IS, which are in the form of bonded connections and electrically connect the respective signal terminals SA to the respective control terminals or signal terminals of the respective corresponding semiconductor switches T1, T2, corresponding to the function of the functional base module FB (as a half bridge).
[0054] Figure 2A , Figure 2B A power base module LB2 ( Figure 2A )、LB3( Figure 2B ), the power base module has two or three Figure 1A and Figure 1B Functional basic module FB.
[0055] Figure 2A The power base module LB2 in the embodiment has two functional base modules FB which are constructed identically to one another, except for the exposed terminal parts of the respective external current connection busbars H+, H-, P, the respective signal terminals SA and the respective cooling surfaces KF (see Figure 3 ), the functional basic modules are completely enclosed in a common mechanically stable enclosing unit MM in the form of a molding compound and are thus (purely) mechanically and physically integrated into the respective power basic module. In this case, the molding compound MM has a recess AS, through which the signal terminals SA and the cooling surface KF are exposed for external electrical or thermal contact. In this case, the recess AS for the signal terminals SA is formed on the surface of the molding compound MM facing away from the cooling surface KF. The current connecting busbars H+, H-, P extend from the molding compound MM in the direction of extension of the above-mentioned surface of the molding compound MM, in particular parallel to the plane of the surface.
[0056] Similarly, Figure 2BThe power base module LB3 in the embodiment has three functional base modules FB constructed identically to one another, except for the exposed terminal parts of the respective external current connection busbars H+, H-, P, the respective signal terminals SA and the respective cooling surfaces KF (see Figure 3 ), the functional basic modules are completely enclosed in a common mechanically stable enclosing unit MM in the form of a molding compound and are thus (purely) mechanically and physically integrated into the respective power basic module. In this case, the molding compound MM has a recess AS, through which the signal terminals SA and the cooling surface KF are exposed for external electrical or thermal contact. In this case, the recess AS for the signal terminals SA is formed on the surface of the molding compound MM facing away from the cooling surface KF. The current connecting busbars H+, H-, P extend out of the molding compound MM in the direction of extension of the above-mentioned surface of the molding compound MM or in a plane parallel to the surface.
[0057] The power base modules LB2 and LB3 as the second construction level of the power module LM of the inverter IV respectively form a (pure) mechanical and physical complex of a predetermined number (two or three in this embodiment) of functional base modules FB, each of which is completely surrounded by a common mechanically stable molding compound MM (except for its respective external current and signal terminals H+, H-, P and SA and its respective cooling surface KF) and is purely mechanically and physically integrated into the respective power base modules LB2 and LB3. Here, the molding compound MM mechanically and physically holds the integrated or surrounded functional base modules FB together through its own mechanical rigidity, and also electrically isolates the functional base modules FB from each other inside the power base module. The external current and signal terminals H+, H-, P and SA that are not surrounded by the molding compound MM enable the functional base modules FB to be externally electrically wired in the third construction level to be described later.
[0058] Furthermore, the two power base modules LB2 , LB3 each functionally form only one half-bridge, wherein the functional base modules FB in the respective power base modules LB2 , LB3 can be connected in parallel with one another. The two power base modules LB2 , LB3 differ only in terms of performance or power / current carrying capacity.
[0059] Depending on the power requirements, a power basic module consisting of four or more functional basic modules or half-bridges can also be formed. By varying the number of functional basic modules, the performance or power / current carrying capacity of the power basic module can be scaled. In addition, the selection of the module size (i.e. the number of integrated functional basic modules) can also be carried out according to application-specific criteria, for example according to the type of power converter (e.g. inverter or DC voltage converter) or according to the power converter installation space or according to the number of phases (e.g. in the case of an inverter).
[0060] The functional basic modules in the power basic module can be operated individually or in parallel according to their subsequent wiring in the third construction level to be described below. The number of functional basic modules in the power basic module and their subsequent wiring determine the power / current carrying capacity or performance of the power basic module. Thus, the power basic module forms a power basic unit.
[0061] Figure 3 A schematic cross-sectional view shows Figure 2A Power Base Module LB2 or Figure 2B Since the two power basic modules LB2 and LB3 differ from each other only in the number of integrated functional basic modules FB, the two power integrated modules LB2 and LB3 have the same cross-sectional view.
[0062] The power base modules LB2 and LB3 each have a molding compound MM as a common mechanically stable enclosing unit, which completely fills the respective functional base module FB except for its respective signal terminals SA, its respective cooling surface KF and the exposed terminal parts of the respective external current connection busbars H+, H-, P, thereby protecting the functional base module FB from environmental influences. In addition, the molding compound MM also serves as a carrier for the functional base module FB or the power base module LB2 and LB3 embedded therein through its own mechanical rigidity, and gives the functional base module FB or the power base module LB2 and LB3 mechanical stability.
[0063] Optionally, the power base modules LB2 , LB3 each have a cooler KL of known type, on which the functional base module FB of the respective power base module LB2 , LB3 rests via its respective flat cooling surface KF and is physically and thermally connected to the cooler.
[0064] In the second construction level of the power module LM of the inverter IV, the functional base modules FB of the respective power base modules LB2, LB3 are only purely mechanically connected via the respective molding compound MM. In particular, the functional base modules FB of the respective power base modules LB2, LB3 are completely electrically isolated from each other via the respective molding compound MM. In the third construction level of the power module LM of the inverter IV, which will be described below, the functional base modules FB of the respective power base modules LB2, LB3 are electrically connected to each other via electrical connections that are external from the functional base modules FB or the power base modules LB2, LB3, corresponding to the functions and performances of the inverter IV.
[0065] Thus, the power base modules LB2 and LB3 of the second construction level each form a purely mechanical and physical complex of a predetermined number (two or three) of functional base modules FB, which are mechanically and physically integrated into the respective power base modules LB2 and LB3 by a common mechanically stable molding compound MM. Here, the molding compound MM mechanically and physically holds the integrated or surrounded functional base modules FB together by its own mechanical rigidity, and also electrically isolates the functional base modules FB from each other inside the power base module. The external current / signal terminals H+, H-, P and SA that are not surrounded by the molding compound MM enable the functional base modules FB to be externally electrically wired later in the third construction level.
[0066] Figure 4 The schematic diagram shows an electric drive EA having an electric machine EM and an inverter IV for operating the electric machine EM. The inverter IV has a power module LM, which has three Figure 2B The power basic module LB3, the driver circuit GD and the control circuit CB for operating the power module LM.
[0067] The power module LM forms the third construction level of the power modules LM of the inverter IV or the (entire) electrical power part of the inverter IV. The three power basic modules LB3 each form one of the three half-bridges with the corresponding power / current carrying capacity of the inverter IV.
[0068] The driver EA also has a DC connection GV, via which the current connection busbars H+, H- on the positive voltage side or the negative voltage side of the functional basic module FB of the respective power basic module LB3 are electrically connected to the intermediate circuit of the driver EA not shown in the figure.
[0069] The drive EA also has three phase current connections PV, via which the three power basic modules LB3 are each electrically connected to one of the three windings of the electric machine EM.
[0070] The driver EA also has a plurality of signal connections SV (only some of which are schematically drawn in the figure for the sake of a better overview) via which the driver circuit GD or the control circuit CB is electrically connected to the respective functional basic module FB or the respective signal terminals.
[0071] In the third construction level of the power modules LM of the inverter IV, the functional base modules FB are electrically connected to one another externally and partly internally.
[0072] The inverter IV or its power modules LM are therefore divided into three building levels with a building concept which is freely scalable according to performance requirements, having a first, second and third building level:
[0073] The first construction level forms a functional basic module FB, which, as an indivisible functional basic unit of a power basic module LB3 or a power module LM, respectively has (only one) (switchable) half-bridge, which has (only one) semiconductor switch on the positive voltage side and (only one) semiconductor switch T1, T2 on the negative voltage side, and external current terminals H+, H- and P for establishing an external current connection for the semiconductor switches T1, T2 (i.e., an external power interface for establishing an external current connection for the semiconductor switches).
[0074] The second building level forms a power base module LB3, which has a plurality of functional base modules FB and a molding compound MM of the first building level as mechanical enclosing units, wherein the molding compound MM of each power base module LB3 holds the respective corresponding functional base modules FB together and mechanically connects them to each other, and (completely) surrounds these functional base modules except for their respective current / signal terminals H+, H- and P and SA. Here, the functional base modules FB of the respective power base modules LB3 are electrically isolated from each other in the respective corresponding molding compounds MM. If necessary, the thermal interface (i.e., the cooling surface KF and / or the cooler KL) of the functional base module FB or the power base module LB3 can also be at least partially molded around the molding compound MM.
[0075] The third building level forms the power module LM as the (entire) electrical power part of the inverter IV, which has all the power basic modules LB3 of the second building level and all the necessary current connections GV, PV and signal connections SV, wherein the current and signal connections GV, PV, SV electrically connect the respective corresponding current / signal terminals H+, H- and P and SA of the functional basic modules FB of the respective power basic modules LB3 to each other.
[0076] By selecting the number of functional basic modules FB in the power basic module LB3 and the number of power basic modules LB3 in the power module LM, the functionality and performance or the power / current carrying capacity of the inverter IV can be scaled.
[0077] The small structural shape of the individual function base modules FB and the flexibly determinable number of function base modules FB in the power base module LB3 also enable the power base module LB3 to be flexibly integrated in a power module LM with special geometric requirements. The power base module LB3 can thus be mounted in a space-saving manner, for example concentrically on a circular surface of the end face of the stator of the electric machine EM or radially on the outer circumference of a cylindrical surface of the stator of the electric machine EM.
[0078] The external electrical connection of the functional base module FB in the third construction level increases the flexibility of the inverter design. In addition, this facilitates symmetrical current distribution in the design of the power module LM and facilitates subsequent design adaptation. This in turn enables high switching speeds in the semiconductor switches T1, T2 used, thereby enabling the use of fast-switching, low-loss SiC semiconductor switches and extremely low parasitic inductances in the load and control circuits of the semiconductor switches T1, T2.
[0079] Thus, the inverter IV can be manufactured in a functionally and cost-optimized manner.
Claims
1. A power converter (IV) having: a plurality of functional basic modules (FB), each of which forms a half bridge with a semiconductor switch on the positive voltage side (T1) and a semiconductor switch on the negative voltage side (T2) and has a plurality of external current terminals (H+, H-, P); - a certain number of power base modules (LB2, LB3), each power base module having a plurality of functional base modules and a surrounding unit (MM) in the functional base module (FB), wherein the surrounding unit (MM) of the respective power base module (LB2, LB3) mechanically connects the respective corresponding functional base modules (FB) to each other and surrounds the respective corresponding functional base module except for its respective current terminals (H+, H-, P), wherein the functional base modules (FB) of the respective power base modules (LB2, LB3) are electrically isolated from each other in the respective corresponding surrounding unit (MM); - A power converter power module (LM), comprising the power base module (LB2, LB3) and a plurality of current connections (GV, PV), wherein the current connections (GV, PV) electrically connect the respective corresponding current terminals (H+, H-, P) of the respective functional base modules (FB) of the respective power base modules (LB2, LB3) to each other.
2. The power converter (IV) according to claim 1, - wherein each functional base module (FB) also has a plurality of signal terminals (SA); - wherein the enclosing unit (MM) of the respective power base module (LB2, LB3) also encloses the respective corresponding functional base module (FB), in addition to its respective signal terminals (SA); - wherein the power converter (IV) further comprises a driver circuit (GD) which is respectively connected in a signal-related manner to a signal terminal (SA) of the respective corresponding functional basic module (FB).
3. A power converter (IV) according to claim 2, wherein the surrounding unit (MM) of the respective power base module (LB2, LB3) has a surface with a groove (AS), whereby the signal terminal (SA) of the respective functional base module (FB) of the respective corresponding power base module (LB2, LB3) is exposed for electrical contact.
4. A power converter (IV) according to any one of the preceding claims, - wherein each functional base module (FB) also has a cooling surface (KF) for cooling the respective functional base module (FB); - wherein the surrounding unit (MM) of the respective power base module (LB2, LB3) also surrounds the respective corresponding functional base module (FB), in addition to its respective cooling surface (KF); - wherein the power converter power module (LM) also has a cooling body (KL) for cooling the functional base module (FB), wherein the functional base module (FB) is placed on the cooling body (KL) via its respective cooling surface (KF) and is thermally connected to the cooling body (KL).
5. A power converter (IV) according to claims 3 and 4, wherein the cooling surface (KF) of the respective functional basic module (FB) of the respective power basic module (LB2, LB3) and the surface having the groove (AS) of the surrounding unit (MM) of the respective corresponding power basic module (LB2, LB3) face away from each other.
6. A power converter (IV) according to claim 3 or 5, wherein the external current terminals (H+, H-, P) of the respective functional basic modules (FB) of the respective power basic modules (LB2, LB3) extend from the surrounding units (MM) of the corresponding power basic modules (LB2, LB3) along the extension direction of the surface of the surrounding units (MM) of the respective corresponding power basic modules (LB2, LB3) having the groove (AS).
7. A power converter (IV) according to any one of the preceding claims, wherein the enclosing unit (MM) of the respective power basic module (LB2, LB3) airtightly encloses the semiconductor switch (T1) on the positive voltage side and the semiconductor switch (T2) on the negative voltage side of the respective corresponding functional basic module (FB).
8. The power converter (IV) according to any one of the preceding claims, wherein the surrounding unit (MM) comprises a molding compound which is injection-molded around a functional basic module (FB) of the respective power basic module (LB2, LB3).
9. A power converter (IV) according to any one of the preceding claims, wherein the surrounding unit (MM) has a supporting frame, which holds the functional basic modules (FB) of the respective power basic modules (LB2, LB3) and mechanically connects the functional basic modules (FB) to each other.
10. A power converter (IV) according to any one of the preceding claims, wherein the current connection is formed as a current connection busbar.
11. The power converter (IV) according to any one of the preceding claims, wherein the functional basic modules (FB) are constructed identically to one another and / or each power basic module (LB2, LB3) has an identical number of respectively identical functional basic modules (FB).
12. The power converter (IV) according to any one of the preceding claims, wherein the semiconductor switch (T1) on the positive voltage side and the semiconductor switch (T2) on the negative voltage side are formed based on silicon carbide.
13. An electric drive device (EA) having: -Electrical machines (EM); - A power converter (IV) according to any one of the preceding claims, formed as an inverter; - wherein a power converter power module (LM) of the power converter (SR) is electrically connected to the electric machine (EM) via a phase current connection (PV).
14. A method for manufacturing a power converter (IV), comprising the following method steps: - providing a plurality of functional basic modules (FB), each power basic module forming a half bridge having a semiconductor switch (T1) on the positive voltage side and a semiconductor switch (T2) on the negative voltage side and a plurality of current terminals (H+, H-, P); - forming a certain number of power base modules (LB2, LB3), each power base module having a plurality of functional base modules (FB) and a surrounding unit (MM), wherein the surrounding unit (MM) of the respective power base module (LB2, LB3) surrounds the respective corresponding functional base module (FB) except for its respective current terminals (H+, H-, P) and mechanically connects the respective corresponding functional base modules (FB) to each other, wherein the functional base modules (FB) of the respective power base modules (LB2, LB3) are electrically isolated from each other in the respective corresponding surrounding unit (MM); -Forming a power converter power module (LM), which has a power base module (LB2, LB3) and a plurality of current connections (GV, PV), wherein the current connections electrically connect the respective corresponding current terminals (H+, H-, P) of the respective functional base modules (FB) of the respective power base modules (LB2, LB3) to each other.