Power module for operating an electric vehicle drive

Abstract

A power module (10) for operating an electric vehicle drive, comprising a plurality of semiconductor components; a cooling body (16) for conducting away heat generated by the semiconductor components; an intermediate circuit capacitor (18) connected in parallel to the semiconductor components; an intermediate circuit line electrically connecting the intermediate circuit capacitor (18) with the semiconductor components; wherein the intermediate circuit line is at least partially arranged in a recess (17) formed in the cooling body (16).

Description

Technical Field

[0001] This invention relates to the field of electric mobility, and in particular to power modules for electric drives used to operate vehicles. Background Technology

[0002] Power modules, especially integrated power modules, are increasingly used in motor vehicles. These modules are used, for example, in DC / AC inverters, which supply multiphase alternating current to motorized machines such as electric motors. Here, direct current generated by a DC energy source (such as a battery) is converted into multiphase alternating current. Power modules are based on power semiconductors, particularly transistors such as IGBTs, MOSFETs, and HEMTs. Other applications include DC / DC converters, AC / DC rectifiers, and transformers.

[0003] Power switches used in bridge circuits are typically made of power semiconductors. A common example is the so-called half-bridge, which consists of a high-side component and a low-side component. The high-side and low-side components each comprise one or more power switches, i.e., a high-side power switch or a low-side power switch. By selectively switching the high-side and low-side power switches, the direction of the current generated at the output of the power module can be changed between the positive and negative current directions with a very short cycle. This enables so-called pulse-width modulation (PWM) to generate an alternating current based on the DC current fed into the input side of the power module, in the case of a DC / AC inverter. Summary of the Invention

[0004] Therefore, the basic objective of this invention is to realize a power module in which the operating temperature of the power semiconductor is detected with higher accuracy.

[0005] The power modules within the scope of this invention are used to operate electric drives in vehicles, particularly electric and / or hybrid vehicles. The power modules are preferably used in DC / AC inverters. In particular, the power modules are used to power electric machinery (e.g., electric motors and / or generators). DC / AC inverters are used to generate multiphase alternating current from direct current generated by means of a DC voltage from an energy source (e.g., a battery).

[0006] A power module has multiple semiconductor components or chips to generate an output current based on an input current fed in by means of control of the individual semiconductor components. Control of the semiconductor components is achieved by means of control electronics having one or more printed circuit boards on which the multiple electronic components are mounted. The control electronics preferably includes a controller component that generates control signals based on the operating state of the power module and a driver component that controls power switches based on these control signals. Control can be based on so-called pulse width modulation. In the case of an inverter, the input current is direct current (DC), while the output current is alternating current (AC).

[0007] During the operation of a power module, high currents are frequently transmitted through the various semiconductor components. This is especially true for high-voltage applications (such as 400V and 800V applications). Therefore, it is crucial to dissipate the heat generated during power module operation to prevent overheating from affecting the semiconductor components. For this purpose, a cooling element is typically provided, with the semiconductor components thermally coupled to the cooling element.

[0008] Individual semiconductor components are typically combined into what is called a topology switch. Each topology switch has multiple semiconductor components connected in parallel, which preferably form a complete half-bridge with high and low sides within the respective topology switch. As the demand for the amount of vehicle power provided by the electric drive increases, the current to be transmitted by the power module also increases. This necessitates an increase in the number of topology switches, while keeping at least the voltage constant.

[0009] In existing power modules, the increased number of topology switches means that various semiconductor components can only be in limited contact on the DC side, thus keeping leakage inductance due to the impedance of the feed lines low. Furthermore, feed lines of varying lengths are frequently present in these known power modules, resulting in varying leakage inductances. This leakage inductance can couple with rapid switching and cause voltage jumps that, in some cases, exceed the overvoltage of the semiconductor components, thereby affecting them.

[0010] Therefore, the technical task upon which this invention is based is to more effectively combat voltage jumps caused by leakage inductance in power modules.

[0011] The power modules within the scope of this invention are used to operate electric drives in vehicles, particularly electric and / or hybrid vehicles. The power modules are preferably used in DC / AC inverters. In particular, the power modules are used to power electric machinery (e.g., electric motors and / or generators). DC / AC inverters are used to generate multiphase alternating current from direct current generated by means of a DC voltage from an energy source (e.g., a battery).

[0012] The power module has multiple semiconductor components or chips that generate an output current based on the input current fed in, by means of control of the individual semiconductor components. Control of the topology switch is achieved by means of control electronics, which preferably has one or more printed circuit boards on which the multiple electronic components are mounted. The control electronics preferably includes a controller component that generates control signals based on the operating state of the power module and a driver component that controls the semiconductor components based on the control signals. Control can be based on so-called pulse width modulation. In the case of an inverter, the input current is direct current (DC), and the output current is alternating current (AC).

[0013] Multiple semiconductor components preferably form one or more half-bridges. Each half-bridge can be understood as a topology switch comprising multiple semiconductor components connected in parallel. Each topology switch includes a high side and a low side connected in series with the high side. The semiconductor components include IGBTs, MOSFETs, or HEMTs, respectively. The semiconductor materials on which the respective semiconductor components are based preferably include so-called wide-bandgap semiconductors (semiconductors with large band gaps), such as silicon carbide (SiC) or gallium nitride (GaN), and alternatively or additionally may include crystalline silicon and / or amorphous silicon.

[0014] The power module also includes a cooling element to which the semiconductor component is thermally coupled. The cooling element preferably includes cooling channels for the flow of a cooling medium (e.g., water). Furthermore, the power module includes an intermediate circuit capacitor connected in parallel with the semiconductor component to smooth the input voltage.

[0015] Intermediate circuitry, including multiple buses, is configured to electrically connect intermediate circuit capacitors to semiconductor components. The intermediate circuitry is at least partially arranged within recesses formed in the cooling body.

[0016] This shortens the length of the intermediate circuitry because it does not need to be wound around the coolant to connect to the semiconductor components. According to the invention, the intermediate circuitry can be at least partially guided through a notch formed in the coolant. This reduces the leakage inductance of the power module, thereby decreasing the likelihood of voltage jumps on the semiconductor components (attributed to the coupling between leakage inductance and current changes due to switching of the semiconductor components).

[0017] Furthermore, the structural arrangement according to the invention promotes uniform length of intermediate circuit lines and thus promotes uniform inductance between different semiconductor components. This makes it easy to selectively control the semiconductor components to generate the desired output current. Attached Figure Description

[0018] Embodiments will now be described exemplarily and with reference to the accompanying drawings. In the drawings:

[0019] Figure 1 A schematic diagram of a power module according to one embodiment is shown;

[0020] Figure 2 It shows Figure 1 A schematic diagram of the power module circuit; and

[0021] Figure 3 A schematic diagram of a cooling body according to one embodiment is shown.

[0022] In the accompanying drawings, the same reference numerals refer to the same or similarly functional reference parts. Detailed Implementation

[0023] Figure 1 A schematic cross-sectional view of a power module 10 according to one embodiment is shown. Figure 2 The diagram shows a cross-sectional plane AA. The power module 10 includes multiple topology switches 12, 14, each having multiple semiconductor components connected in parallel. The power module 10 includes an intermediate circuit capacitor 18 for smoothing the input voltage fed into the power module 10 by an energy source (e.g., a battery). A coolant 16 is arranged between the topology switches 12, 14 and the intermediate circuit capacitor 18 to dissipate heat generated by the topology switches 12, 14 during operation and to cool the semiconductor components. The intermediate circuit capacitor 18 is connected in parallel with the topology switches 12, 14. An intermediate circuit line is provided between the intermediate circuit capacitor 18 and the semiconductor components of the topology switches 12, 14. In the embodiment shown here, this intermediate circuit line includes multiple first buses 11A, 11B, 15A, 15B for electrically connecting the semiconductor components to a positive potential and multiple second buses 13A, 13B for electrically connecting the semiconductor components to a negative potential. The coolant 16 has a recess 17 in the middle, which partially accommodates the second buses 13A, 13B. Therefore, the intermediate circuit lines are partially arranged inside the cooling body 16. Buses 11A, 11B, 13A, 13B, 15A, and 15B extend from the intermediate circuit capacitor 18 and extend substantially vertically upward beyond the surface 19 of the cooling body 16 (see [link]). Figure 2 In this intermediate circuit capacitor, buses 11A, 11B, 13A, 13B, 15A, and 15B are connected to their respective potentials. Therefore, notch 17 is designed as a through-hole. This allows easy access to the semiconductor components arranged inside the power module 10, ensuring uniform feed line length.

[0024] Figure 2A top view of the power module 10 is shown. In this exemplary embodiment, the power module 10 has six topology switches 12, 14, which are assigned to three current phases, thereby providing two topology switches 12, 14 for each current phase (in... Figure 2 (Left column topology switch, middle column topology switch, or right column topology switch). First buses 11A, 11B, 15A, 15B are arranged on the side of the cooling body 16 and extend along the edge of the cooling body 16. Second buses 13A, 13B are arranged between the upper topology switch 12 and the lower topology switch 14. Therefore, the different sections of the intermediate circuit lines assigned to the current phases for all three current phases are concentrated on the surface 19 where the topology switches 12, 14 of the cooling body 16 are placed. Alternatively, these different sections of the intermediate circuit lines can be arranged inside the cooling body 16 and / or inside the intermediate circuit capacitor 18.

[0025] Figure 3 A schematic diagram of the cooling body 16 is shown. The cooling body 16 is visible here in a horizontal cross-sectional view. The cooling body 16 includes a cooling medium inlet 22, a cooling medium outlet 24, and an intermediate space arranged therebetween for the flow of the cooling medium 30. The intermediate space is divided into two cooling channels 26 and 28 by a recess 17 and a wall 32 surrounding the recess. The first cooling channel 26 is primarily designed to cool the upper topology switch 12, while the second cooling channel 28 is primarily designed to cool the lower topology switch 14. The number of topology switches is... Figure 2 In many cases where the exemplary embodiments shown herein exist, additional cooling channels can be achieved through additional notches and walls. List of reference numerals in the attached diagram: 10 Power Modules Busbar 11A, 11B, 15A, 15B Busbars 13A and 13B 12, 14 Topology switches 16 cooling body 17 Notch 18. Intermediate circuit capacitor 19 Surface 22 Cooling medium inlet 24 Cooling medium outlet 26 First Cooling Channel 28 Second Cooling Channel 30 Cooling medium 32 walls.

Claims

1. A power module (10) for operating an electric vehicle drive, comprising: Multiple semiconductor components; Cooling element (16), the cooling element being used to dissipate heat generated by the semiconductor component; Intermediate circuit capacitor (18), the intermediate circuit capacitor being connected in parallel with the semiconductor component; Intermediate circuit line, the intermediate circuit line electrically connects the intermediate circuit capacitor (18) to the semiconductor component; The intermediate circuit lines are at least partially arranged in a notch (17) formed in the cooling body (16). The notch (17) is designed as a through section, through which the intermediate circuit line is guided from the intermediate circuit capacitor (18) through the through section to the semiconductor component, wherein the intermediate circuit line includes a plurality of first buses (11A, 11B, 15A, 15B) and a plurality of second buses (13A, 13B). The plurality of semiconductor components constitute at least two topology switches (12, 14), each topology switch comprising a plurality of semiconductor components connected in parallel, wherein the first bus (11A, 11B, 15A, 15B) is arranged on the side of the cooling body (16) and extends along the edge of the cooling body (16), while the second bus (13A, 13B) is arranged in a notch located between the two topology switches (12, 14) in the middle region of the cooling body (16).

2. The power module (10) according to claim 1, wherein the intermediate circuit capacitor (18) is arranged on the side of the cooling body (16) away from the semiconductor component.

3. The power module (10) according to claim 1 or 2, wherein the semiconductor components are assigned to a plurality of current phases, wherein the intermediate circuitry has a plurality of segments, each segment being assigned to one of the current phases.

4. The power module (10) according to claim 3, wherein the segments of the intermediate circuit lines are electrically concentrated on the surface (19) of the cooling body (16) opposite to the intermediate circuit capacitor (18).

5. The power module (10) according to claim 3, wherein the section of the intermediate circuit line is electrically concentrated in the cooling body (16).

6. The power module (10) according to claim 3, wherein the section of the intermediate circuit line is electrically concentrated in the intermediate circuit capacitor (18).

7. The power module (10) according to claim 1 or 2, wherein the notch in the cooling body (16) extends in the direction between the inlet (22) and the outlet (24) of the cooling body (16), wherein the internal space of the cooling body (16) through which the cooling medium (30) flows is divided by the notch into two sub-channels (26, 28).

8. The power module (10) according to claim 3, wherein the semiconductor components are assigned to three, six, nine or twelve current phases.

9. A cooling body (16) for a power module (10) according to any one of claims 1 to 8, wherein the cooling body (16) is used to dissipate heat generated by a semiconductor component, wherein the cooling body (16) has an internal recess (17) for at least partially accommodating intermediate circuit lines of the power module (10).

10. An inverter comprising a power module (10) according to any one of claims 1 to 8 and / or a cooling element (16) according to claim 9.

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