Electric power converter
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MAHLE INT GMBH
- Filing Date
- 2023-10-25
- Publication Date
- 2026-05-19
AI Technical Summary
Existing electronic power inverters for electrical machines face issues with overheating at the phase terminals, leading to potential damage due to inefficient heat dissipation.
The design incorporates phase terminals with studs extending into recesses in a cast aluminum base plate, which facilitates efficient heat transfer through conduction, and uses a retaining bracket with elastic biasing means to secure power semiconductors against the base plate, enhancing heat dissipation.
This configuration reduces the risk of overheating and minimizes damage by effectively transferring heat away from the connection areas, ensuring reliable operation of the electronic control unit.
Abstract
Description
[Technical field]
[0001] The invention relates to an electronic control unit according to the preamble of independent claim 1.
[0002] Background technology An electronic power inverter for an electric machine is known, for example from EP 3609066. The power inverter has a housing with a semiconductor board, a capacitor board, power terminals and phase terminal studs. The capacitors of the capacitor board are accommodated in recesses in a heat exchanger plate. The phase terminal studs rest on contacts of the semiconductor board and are biased by a pressure plate, via the capacitor board and a damping plate, towards the contacts of the semiconductor board.
[0003] Summary of the Invention The electronic control unit according to the invention as defined in claim 1 has the advantage that the risk of overheating of the phase terminals can be reduced and therefore damage to the electronic control unit can be prevented.
[0004] This is achieved according to a first aspect of the invention by an electronic control unit for an electric machine of an electric drive train, the electronic control unit comprising at least one semiconductor board with a plurality of power semiconductors, a base plate for dissipating heat generated in the electronic control unit, power terminals for supplying power to the electronic control unit, and a plurality of phase terminals for supplying a three-phase current to the electric machine, the phase terminals being connected to terminal contacts in the at least one semiconductor board, at least one of the phase terminals comprising a first stud for electrically connecting to a field winding of the electric machine, the first stud extending away from the base plate, and a second stud for connecting the phase terminal to one of the terminal contacts in the at least one semiconductor board, the first stud and the second stud being electrically connected via a connection, the second stud extending into a recess in the base plate.
[0005] Heat is generated in the connection area between the phase terminals and the semiconductor board, and by providing this connection in the form of a stud extending into a recess in the base plate, heat can be efficiently transferred from the connection area into the base plate.
[0006] The base plate may be a plate of cast aluminum with recesses machined into it. The base plate preferably has heat dissipating fins and / or pins on the side facing away from the semiconductor board.
[0007] The first stud, the second stud and the connection are integrally molded into one metal part, which reduces the number of connection points between the phase connection points on the semiconductor board and the field winding, thereby reducing heat sources.
[0008] The first studs of the multiple phase terminals and the power terminals are preferably arranged linearly adjacent to the semiconductor board when viewed in the stacking direction.
[0009] For the case where each phase terminal is connected to two terminal contacts on the semiconductor board, for example when the phase terminal is connected to two bridge arms of the inverter, the phase terminal may have a third stud for connecting the phase terminal to one of the terminal contacts on the at least one semiconductor board, the second stud and the third stud being electrically connected via a second connection part, and the third stud also extending into a recess in the base plate.
[0010] The recess in the base plate may be a single recess into which the second and third studs extend, or alternatively, a plurality of further recesses may be provided in each one of the second and / or third studs.
[0011] The side walls of each recess are located close to the stud surface without touching it, so that heat can be effectively transferred from the phase terminals to the base plate by conduction. For this purpose, the gap between the stud surface and the base plate in the region of the recesses can be filled with a thermally conductive gap-filling potting material.
[0012] The second stud has a threaded hole and is attached to the face of the at least one semiconductor board facing the base plate via a screw that extends through the semiconductor board into the threaded hole. The third stud also has a threaded hole and is attached to the face of the at least one semiconductor board facing the base plate via a screw that extends through the semiconductor board into the threaded hole. Thus, the phase terminals are securely attached to the electrical contacts in the semiconductor board, minimizing resistance and reducing heat generation.
[0013] The first stud may also be provided with a threaded hole for threaded attachment of the field winding.
[0014] It is also possible that a number of capacitors are connected to the semiconductor board and arranged on the side of the semiconductor board facing the base plate, the capacitors being accommodated in recesses in the base plate. The capacitors can be arranged in the same recess as the second or third phase terminal stud. Alternatively, the capacitors can be arranged in a recess separate from the recesses of the second or third phase terminal stud.
[0015] Furthermore, the electronic control unit may comprise a retaining bracket and a resilient biasing means for biasing the power semiconductor towards the base plate, the retaining bracket having means for mounting the resilient biasing means to the retaining bracket, the retaining bracket being mounted to the base plate. When the retaining bracket is mounted to the base plate, the resilient means is sandwiched between the retaining bracket and the power semiconductor in the stacking direction and biases the power semiconductor towards the base plate to improve heat transfer from the power semiconductor. The resilient biasing means may comprise a plurality of leaf springs.
[0016] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]
[0017] [Figure 1] FIG. 2 is a perspective view of an electronic control unit according to the present invention; [Diagram 2] FIG. 2 is an exploded view of the electronic control unit of FIG. 1. [Diagram 3] FIG. 2 is an exploded view of a portion of the electronic control unit of FIG. 1. [Figure 4] FIG. 2 is an exploded assembly view of the electronic control unit shown in FIG. 1 as seen from below. [Diagram 5] FIG. 2 is a cross-sectional view of the electronic control unit of FIG. [Figure 6] FIG. 2 is a perspective view of a phase terminal according to the present invention;
[0018] Detailed Description With reference to the drawings, in Fig. 1 and Fig. 2 an electronic control unit 1 according to the invention is shown. The electronic control unit 1 can be used, for example, as an inverter for an electric machine of an electric drive train. The electronic control unit 1 comprises at least one semiconductor board 2 with a plurality of power semiconductors 3 and a base plate 4 for dissipating heat generated in the electronic control unit 1. The electronic control unit 1 further comprises power terminals 9 for supplying power to the electronic control unit 1 and a plurality of phase terminals 10 for supplying a three-phase current to the electric machine. The phase terminals 10 are connected to terminal contacts 11 in the at least one semiconductor board 2. In Fig. 6 one of the phase terminals 10 is shown. The phase terminal 10 comprises a first stud 12 for electrical connection to a field winding of an electric machine (not shown). As can be seen in Fig. 5 the first stud 12 extends away from the base plate 4 and is arranged above the base plate 4 in a stacking direction 13, which is the direction in which the semiconductor boards 2 are stacked on the base plate 4.
[0019] The first studs 12 of the multiple phase terminals 10 and the power terminals 9 are disposed adjacent to each other in a straight line on the semiconductor board 2 when viewed in the stacking direction 13 .
[0020] The phase terminal 10 has a second stud 14 for connecting the phase terminal 10 to one of the terminal contacts 11 on the semiconductor board 2. The first stud 12 and the second stud 14 are electrically connected via a connection portion 15. The first stud 12, the second stud 14 and the connection portion 15 are integrally molded into a single metal part.
[0021] According to the invention, the second studs 14 extend into the recesses 16 in the base plate 4. Therefore, heat generated in the connection area between the phase terminals 10 and the semiconductor board 2 can be efficiently transferred away from the connection area via conduction from the second studs 14 to the base plate.
[0022] The base plate 4 may be a plate or block of cast aluminium into which a recess 16 is machined. The base plate 4 preferably has heat dissipation fins and / or pins 5 on the side facing away from the semiconductor board 2.
[0023] In the illustrated embodiment, each phase terminal 10 is connected to two terminal contacts 11 on the semiconductor board 2. This is necessary, for example, if the phase terminal 10 is to be connected to two bridge arms of an inverter. In this case, the phase terminal 10 has a third stud 17 for connecting the phase terminal 10 to one of the terminal contacts 11 on the at least one semiconductor board 2. The second stud 14 and the third stud 17 are electrically connected via a second connection 18, the third stud 17 also extending into a recess 16 in the base plate 4.
[0024] In the embodiment shown, the recess 16 in the base plate 4 is a single recess 16 in which the second studs 14 and the third studs 17 extend in the stacking direction 13. Alternatively, a plurality of further recesses 16 may be provided for each one of the second studs 14 and / or the third studs 17, or a plurality of recesses 16 may be provided, each containing a plurality of the second studs 14 and / or the third studs 17, respectively.
[0025] As can be seen in Figure 5, portions of the side walls 19 of each recess 16 are disposed adjacent to the stud surfaces of the second stud 14 and / or the third stud 17 without contacting these stud surfaces. Thus, heat can be effectively transferred from the phase terminals 10 to the base plate 4. To this end, the recesses can be filled with a thermally conductive filler material to facilitate the conduction of heat from the studs 14, 17 to the base plate 4. The second stud 14 and the third stud 17 are generally cylindrical in shape.
[0026] The space between the recess 16 and the second stud 14 and the third stud 17 can be filled with a potting material, for example a silicone gel, to improve heat conduction from the phase terminal 10 .
[0027] The second stud 14 and the third stud 17 are each provided with a threaded hole 20 and are attached to the face of at least one of the semiconductor boards 2 facing the base plate 4 via screws 21 that extend through the semiconductor board 2 and into the threaded holes 20. The phase terminals 10 are thus securely attached to the terminal contacts 11 on the semiconductor board 2, minimizing resistance and reducing heat generation. The heads of the screws 21 may be covered with insulating caps 24, preferably made of plastic, to prevent contact with other parts of the electronic control unit 1, in particular to prevent electrical contact between the heads of the screws 21 and the holding bracket 6, which may be made of aluminum.
[0028] The first stud also has a tapped hole 22 for screwing the field winding.
[0029] A number of capacitors 23 are connected to the semiconductor board and arranged on the side of the semiconductor board 2 facing the base plate 4, the capacitors 23 being accommodated in recesses 16 of the base plate 4. The capacitors 23 may be arranged in the same recess as the second phase terminal stud 14 or the third phase terminal stud 17. Alternatively, the capacitors 23 may be arranged in a recess separate from the recess 16 of the second phase terminal stud 14 or the third phase terminal stud 17.
[0030] The electronic control unit 1 comprises a retaining bracket 6, preferably made of aluminium, and resilient biasing means 8 for biasing the power semiconductors 3 towards the base plate 4, the retaining bracket 6 having means for attaching the resilient biasing means 8 to the retaining bracket 6, which is attached to the base plate 4 via screws 7. When the retaining bracket 6 is attached to the base plate 4, the resilient means 8 are sandwiched between the retaining bracket 6 and the power semiconductors 3 in the stacking direction and bias the power semiconductors 3 towards the base plate 4 to improve heat transfer from the power semiconductors 3. The resilient biasing means may comprise a number of leaf springs 8. [Explanation of symbols]
[0031] 1 Electronic Control Unit 2 Semiconductor Board 3. Power Semiconductors 4 Base plate 5 Cooling fins 6 Retaining bracket 7 Screws 8. Leaf Spring 9 Power terminal 10 phase terminal 11 Terminal Contact 12 First Stud 13 Lamination direction 14 Second Stud 15 Connection 16 Recess 17 Third Stud 18 Second connection part 19 Side wall 20 screw holes 21 Screw 22 screw holes 23 Capacitor 24 Insulating cap
Claims
1. An electronic control unit (1) for an electric drive system of an electric machine, the electronic control unit (1) comprises at least one semiconductor board (2) having a plurality of power semiconductors (3), a base plate (4) for dissipating heat generated in the electronic control unit, a power terminal (9) for supplying power to the electronic control unit, and a plurality of phase terminals (10) for supplying three-phase current to the electric machine, wherein the phase terminals (10) are connected to terminal contacts (11) on at least one of the semiconductor boards (2), At least one of the phase terminals (10) is - A first stud (12) for electrically connecting to the field winding of the electric machine, the first stud (12) extending away from the base plate (4), - An electronic control unit (1) having a second stud (14) for connecting the phase terminal (10) to one of the terminal contacts (11) on at least one of the semiconductor boards (2), wherein the first stud (12) and the second stud (14) are electrically connected via a connector (15), and the second stud (14) extends into a recess (16) in the base plate (4).
2. The electronic control unit (1) according to claim 1, wherein the first stud (12), the second stud (14), and the connecting portion (15) are integrally molded into a single metal component.
3. The electronic control unit (1) according to claim 1, wherein the phase terminal (10) further has a third stud (17) for connecting the phase terminal (10) to one of the terminal contacts (11) on at least one semiconductor board (2), the second stud (14) and the third stud (17) are electrically connected via a second connection portion (18), and the third stud extends into a recess (16) in the base plate (4).
4. The electronic control unit (1) according to claim 1 or 2, wherein the second stud (14) and / or the third stud (17) extend within the recess (16), and the side walls (19) of each recess are positioned in close proximity to the stud surface without contacting it.
5. The electronic control unit (1) according to claim 1 or 2, wherein the second stud is provided with a screw hole, and the second stud is attached to at least one surface of the semiconductor board (2) facing the base plate (4) via a screw (7) that penetrates the semiconductor board (2) and extends into the screw hole.
6. The electronic control unit (1) according to claim 1 or 2, wherein a plurality of capacitors are connected to the semiconductor board (2) and arranged on the surface of the semiconductor board (2) facing the base plate (4), and the plurality of capacitors are housed in the recess (16) of the base plate (4).
7. Furthermore, the electronic control unit (1) according to claim 1 or 2 further comprises a retaining bracket (6) and an elastic biasing means (8) for biasing the power semiconductor (3) toward the base plate (4), wherein the retaining bracket (6) has means for attaching the elastic biasing means (8) to the retaining bracket (6), and the retaining bracket (6) is attached to the base plate (4).
8. The electronic control unit (1) according to claim 7, wherein the elastic biasing means (8) has a plurality of leaf springs (8).
9. The electronic control unit (1) according to claim 1 or 2, wherein the base plate (4) has heat dissipation fins and / or pins (5) on the side facing away from the semiconductor board (2).