Power electronic cooler, power electronic device, and inverter

Abstract

This invention relates to a power electronic cooler (KL), comprising: a substrate (BP) and a cover plate (DP) forming a cooling channel (KN) through which coolant flows, wherein the cover plate (DP) is used for thermal contact with a power electronic device (LV); an insert plate (EP) disposed between the substrate (BP) and the cover plate (DP), dividing the cooling channel (KN) into a supply channel section (ZF) and a return channel section (RF); wherein the insert plate (EP) and the substrate (BP) together form the supply channel section (ZF), and together with the cover plate (DP) form the return channel section (RF); wherein the insert plate (EP) has a bypass opening (UO) between a coolant inlet (EL) and a transfer opening (DO), the bypass opening (UO) being fluidly separated from the return channel section (RF) by a partition wall (TW) surrounding the bypass opening (UO); wherein a bypass channel region (UB) is formed between the bypass opening (UO), the partition wall (TW), and the cover plate (DP). The present invention also relates to power electronic devices with the aforementioned cooler and inverters.

Description

Technical Field

[0001] This invention relates to a power electronics cooler, specifically a cooler for cooling power electronic devices, such as DC-DC converters or inverters, particularly for electric vehicles. Furthermore, the invention relates to a power electronic device incorporating said cooler, and an inverter incorporating said power electronic device. Background Technology

[0002] Power electronics coolers for cooling power electronic devices are known and are used in (power) DC-DC converters or (power) inverters, such as DC-DC converters or inverters in electric vehicles, to cool the power electronic devices or power modules (with multiple power semiconductor switches or similar circuit components with high power loss) of the DC-DC converter or inverter.

[0003] For example, in the so-called EPF2.3 inverters of various electric vehicles, a cooler is provided for cooling the power electronics of the inverter or its power module (with multiple power semiconductor switches).

[0004] For this type of cooler, due to the circuitry of the power unit or its power module, uniform cooling of the power unit or its power module (as well as all power semiconductor switches or similar circuit components with high power loss) is required. Therefore, localized high-temperature spikes on the power unit or its power module should be avoided, as these can lead to performance degradation, even failure of the power unit or inverter, or at least shorten its lifespan.

[0005] Therefore, the objective of this application is to provide a solution for uniformly cooling power electronic devices (such as inverters or DC-DC converters) or their power modules (having multiple power semiconductor switches or similar circuit components with high power loss). Summary of the Invention

[0006] The aforementioned task is addressed by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0007] According to a first aspect of the invention, a power electronics cooler is provided, namely a cooler for cooling power electronic devices (e.g., DC-DC converters or inverters, especially inverters or DC-DC converters for electric vehicles).

[0008] The cooler has a base plate and a cover plate, which together (at least partially) form a cooling channel that extends longitudinally along the cooler and is used to conduct coolant.

[0009] The cover plate also serves to make (direct) thermal contact with the power electronic device. In other words, circuit components of the power electronic device with high power loss or high residual heat, such as power semiconductor switches, are (directly) arranged on the cover plate and make thermal contact with it. Therefore, the cover plate acts as a heat exchanger to transfer the heat of the aforementioned circuit components of the power electronic device to the coolant flowing through the cooling channel. In particular, the cover plate can be configured as a circuit carrier for the power electronic device or its power module, such as a ceramic substrate, on which the aforementioned circuit components are arranged and electrically connected.

[0010] The cooler also has a coolant inlet and a coolant outlet, which are arranged in the longitudinal direction (in particular, side by side with each other and thus one after the other in the transverse direction of the cooler) at the first longitudinal end of the cooling channel.

[0011] The cooler also has an insert plate disposed within a cooling channel between the base plate and the cover plate, dividing the cooling channel into: a supply channel section extending from the coolant inlet to a second longitudinal end of the cooling channel (opposite to the first longitudinal end), and a return channel section extending from the second longitudinal end to the coolant outlet. The insert plate and the base plate (at least partially) form the supply channel section, and together with the cover plate (at least partially), they form the return channel section.

[0012] Viewed along a direction perpendicular to the insert plate or cooler (therefore, perpendicular to the plane containing the longitudinal and transverse directions of the cooler), the cover plate, return channel section, insert plate, supply channel section, and base plate are stacked sequentially. The supply channel section and return channel section are fluidly connected and together form a U-shape that is laterally inclined in the transverse direction of the cooler (i.e., shaped like...). or The cooling channel has two sections where the coolant flows in opposite directions (supply and return) during operation.

[0013] The insert plate has at least one transfer opening (or transfer notch, i.e., a lateral cut in the insert plate) at the second longitudinal end for guiding coolant from the supply channel section to the return channel section. The supply channel section and the return channel section are fluidly connected to each other through this transfer opening.

[0014] In addition, the insert plate has a bypass opening (or bypass notch, i.e., another lateral cut on the insert plate) between the coolant inlet and the transfer opening. This bypass opening is fluidly separated by a partition wall and a return channel section that surrounds (at least partially surrounds) the bypass opening and extends between the insert plate and the cover plate, in particular achieving a fluid seal.

[0015] A bypass passage region is formed between the bypass opening, the partition wall, and the cover plate, extending (from the insert plate or the bypass opening) to the cover plate and laterally (at least partially) defined by the partition wall (and optional sidewalls of the insert plate and / or the cover plate). This bypass passage region is fluidly connected to the supply passage section via the bypass opening, while being fluidly (substantially or approximately) separated by the partition wall from the return passage section, thereby achieving a fluid seal.

[0016] The cover plate, insert plate, and base plate are all basically plate-shaped cooler components with correspondingly shaped side portions. Together, they provide a fluid seal around the cooling channel (except for the coolant inlet and outlet). The insert plate is positioned between the base plate and the cover plate, and can be separated from the base plate and cover plate or removed from the cooling channel without damage when needed. It is also mechanically connected to both.

[0017] The cover plate can be made of a known (especially thermally conductive) cooler material, such as aluminum or aluminum alloy, in order to better absorb residual heat from the power electronic device circuit components arranged on the cover plate and transfer it to the coolant flowing around the cover plate.

[0018] The insert plate and substrate can be made of the same material as the cover plate, or another known, lightweight and inexpensive material (especially one with good thermal conductivity), such as plastic.

[0019] The coolant inlet and coolant outlet can be formed on the substrate as components of the substrate.

[0020] The bypass passage area can be considered as part of the supply passage section, or as a passage that runs parallel to a portion of the supply passage section, extends to the cover plate, and is located between the cover plate and that portion of the supply passage section.

[0021] The partition extends between the insert plate and the cover plate, thus forming a barrier to prevent the coolant from flowing directly from the bypass channel area to the return channel section or vice versa.

[0022] The term "fluidly connected" means that coolant can flow continuously and directly from a first cooling channel segment to another cooling channel segment that is "fluidly connected" to that first channel segment. Similarly, the term "fluidly separated" means that the direct flow of coolant from a first cooling channel segment to a third cooling channel segment that is "fluidly separated" from that first channel segment is permanently blocked.

[0023] The term "(substantially or approximately) partition" means that at most 10%, 5%, or 2% of the total coolant flowing through the bypass channel area can pass directly from the bypass channel area through the partition wall (which is not completely fluid-tight in this case) to the return channel section. Since such a small amount of coolant does not significantly affect the overall cooling effect of the cooler, especially the advantages of the cooler described below, the partition wall typically does not need to be completely fluid-tight. However, the partition wall must ensure that the majority of the coolant, i.e., more than 90%, 95%, or even 98% of the total coolant, returns from the bypass channel area to the supply channel section, and only flows from the supply channel section to the return channel section after passing through it.

[0024] The actual cooling of the power electronic device circuit components (with high power loss or high waste heat, such as power semiconductor switches) arranged on and thermally connected to the cover plate is achieved primarily through the return channel section and the coolant flowing within it. The supply channel section (excluding the bypass channel area) mainly guides the coolant from the coolant inlet to the second longitudinal end of the cooling channel (the end opposite to the coolant inlet), so that the coolant flows from the supply channel section to the return channel section through the transfer opening at the second longitudinal end, and then flows from the second longitudinal end along the entire length of the cooler, i.e., along the entire length of the cover plate (returning), to the coolant outlet located at the first longitudinal end of the cooler. In this process, it absorbs waste heat from the cover plate and cools the circuit components of the power electronic device.

[0025] The bypass passage area extending to the cover plate allows coolant flowing from the coolant inlet into the supply passage section to flow directly around the cover plate area adjacent to the bypass passage area. Since this area is cooled by the relatively cold coolant that has just flowed into the cooling passage, it is pre-cooled relative to the rest of the cover plate.

[0026] By freely arranging bypass openings between the coolant inlet and the transfer opening, and thus freely arranging the bypass channel area therebetween, the so-called stagnant zone in the return channel section can be selectively avoided or "occupied." Otherwise, due to the asymmetrical arrangement of the coolant outlets in the cooler (lateral direction), and consequently the asymmetrical flow of coolant in the return channel section, this stagnant zone is either obstructed or almost impossible to bypass by the coolant difference in the return channel section; however, by extending the bypass channel area to the cover plate, this stagnant zone is effectively avoided or "occupied." Direct cooling of the cover plate at the stagnant zone "occupied" by the bypass channel area allows the cover plate to achieve relatively uniform cooling without forming temperature hotspots at the cover plate caused by the potential stagnant zone.

[0027] Therefore, a solution is provided that enables uniform cooling of power electronic devices (such as inverters or DC-DC converters) or their power modules (having multiple power semiconductor switches or similar circuit components with high power loss).

[0028] The partition wall may extend from the insert plate toward the cover plate as a protrusion of the insert plate (or as a fixed component of the insert plate). Alternatively or additionally, the partition wall may also extend from the cover plate toward the insert plate as a protrusion of the cover plate (or as a fixed component of the cover plate).

[0029] The bypass opening can be formed at the first longitudinal end of the cooling channel or in the first longitudinal end region, and is located (immediately after) the coolant inlet in the longitudinal direction of the cooler (therefore located at the first longitudinal end of the cooler or cooling channel), so that the coolant or at least a portion thereof flowing into the cooling channel through the coolant inlet can first flow directly through the bypass channel region, thereby directly carrying away the residual heat of the corresponding area of ​​the cover plate.

[0030] By providing a bypass opening and related bypass channel area at the first longitudinal end, any stagnant area formed at the first longitudinal end of the cooling channel can be effectively prevented due to the asymmetrical arrangement of the coolant outlet adjacent to the coolant inlet, and the resulting asymmetrical flow of coolant in the return channel section at the first longitudinal end of the cooling channel.

[0031] The length of the bypass opening in the longitudinal direction of the cooler can be between one-fifth and one-half (1 / 5 to 1 / 2) of the length of the supply channel section, or between three-tenths and two-fifths (3 / 10 to 2 / 5) of the length of the supply channel section, or (approximately) equal to one-third (1 / 3) of the length of the supply channel section.

[0032] The insert plate and / or cover plate may have a flow deflection wall located in or within the bypass opening or bypass passage area, extending at least partially at an angle relative to the longitudinal direction of the cooler, and configured to (targetedly) deflect the coolant flowing in the bypass opening or bypass passage area.

[0033] The flow deflection wall may be part of the partition wall and / or extend from the partition wall into the bypass passage area.

[0034] The insert plate may have a return opening (or return notch, i.e., another lateral cut on the insert plate) at the first longitudinal end of the cooling channel or in the region of the first longitudinal end, and immediately before the coolant outlet, for guiding or returning coolant from the return channel section to the coolant outlet, and is fluidly separated from the supply channel section by a sealing wall surrounding (at least partially surrounding) the return opening, particularly achieving a seal. The return opening allows direct fluid communication between the return channel section and the coolant outlet. The sealing wall fluidly separates or even seals the return channel section from the coolant outlet from the supply channel section and the coolant inlet, effectively preventing coolant from flowing directly from the coolant inlet or supply channel section into the return channel section or coolant outlet.

[0035] The sealing wall may be formed on the insert plate and / or the substrate, and extends vertically from the insert plate toward the substrate, or from the substrate toward the insert plate. The sealing wall may extend from the insert plate toward the substrate as another protrusion of the insert plate (or as another fixed component of the insert plate). Alternatively or additionally, the sealing wall may also extend from the substrate toward the insert plate as a protrusion of the substrate (or as a fixed component of the substrate).

[0036] The cover plate and / or insert plate may have a surface enlargement structure, such as cooler needle fins, that extend into the return channel section.

[0037] The cooler may have a flow guiding structure and / or a flow guiding wall in the supply channel section, configured to guide the coolant from the coolant inlet or from the bypass channel area to the transfer opening. The flow guiding structure or flow guiding wall may extend along the longitudinal direction of the cooling channel.

[0038] The flow guiding structure or flow guiding wall may extend from the insert plate into the flow supply channel section as another protrusion of the insert plate (or as another fixed component of the insert plate). Alternatively or additionally, the flow guiding structure or flow guiding wall may also extend from the substrate into the flow supply channel section as another protrusion of the substrate (or as another fixed component of the substrate).

[0039] The cooler or substrate may have a ramp at the coolant inlet that extends at an angle relative to the bypass opening, which is configured to guide the coolant from the coolant inlet to the bypass opening.

[0040] According to a second aspect of the invention, a power electronic device is provided, for example, as part of a DC-DC converter or inverter.

[0041] The device includes at least two power semiconductors and the aforementioned cooler, wherein the power semiconductors are disposed on a surface of a cover plate opposite to the return channel section and are in thermal contact or thermally connected to the cover plate. Specifically, the first power semiconductor is disposed on a first region of the cover plate surface, which is opposite to the bypass channel region. The second power semiconductor is disposed on a second region of the cover plate surface, which is opposite to a channel region of the return channel section, and this channel region is fluidly separated from the bypass channel region by a partition wall. In particular, this channel region is located between the bypass channel region and the transfer opening.

[0042] The cover plate can be configured as a circuit carrier, such as a DCB substrate or an AMB substrate, or a portion thereof. The power semiconductor can be configured as a SiC semiconductor switch or an IGBT.

[0043] According to a third aspect of the present invention, an inverter is provided, which includes the aforementioned power electronic device and a control circuit (or drive circuit) for controlling (or driving) the power electronic device. The control circuit is electrically (or signalally) connected to the power semiconductor of the power electronic device via a control signal connection. Attached Figure Description

[0044] An exemplary embodiment of the invention will now be described in more detail with reference to the accompanying drawings. The drawings show: Figure 1 shows components of an inverter with a cooler according to an exemplary embodiment of the present invention in a schematic exploded view; Figure 2. In another schematic exploded view, from Figure 1 Components of the cooler; Figure 3. In another schematic exploded view, from Figure 1 Another component of the cooler; and Figure 4. In a schematic cross-sectional view, from Figure 1 Components of an inverter. Detailed Implementation

[0045] Figure 1 An exploded schematic diagram shows components of an inverter according to an exemplary embodiment of the invention, which is used, for example, as a power inverter for an electric vehicle to provide phase current to a drive motor.

[0046] The inverter has a power unit LV and a cooler KL for cooling the power unit LV. The power unit LV is arranged on the cooler KL and is mechanically and thermally connected to it.

[0047] The power unit LV has a circuit carrier, for example made of aluminum alloy or thermally conductive ceramic, which also forms a cover plate DP of the cooler KL.

[0048] On the surface OF of the circuit carrier or cover plate DP facing away from the cooler KL, the power device LV has three (especially identically constructed) power modules LM, arranged one behind the other along the longitudinal direction LR of the cover plate DP (i.e., the longitudinal direction of the cooler KL). The three power modules LM are evenly distributed at the same spacing on the surface OF of the cover plate DP, so that they are located in three approximately equal-sized surface areas of the surface OF (in... Figure 1 The top of each of the three surface regions (left, middle, and right) accounts for approximately one-third of the total surface area of ​​OF.

[0049] Each power module LM has four power semiconductor switches LH1 and LH2, which are arranged in pairs side by side in two rows. Thus, in the longitudinal direction LR, relative to the longitudinal axis LA of the cover plate DP, the two power semiconductor switch pairs LH1 and LH2 of the power module LM are located on the right and left sides of the longitudinal axis LA of the cover plate DP, respectively.

[0050] Therefore, a total of twelve power semiconductor switches LH1 and LH2 from the three power modules LM (each power module LM has four power semiconductor switches LH1 and LH2) are arranged in pairs on six partial surface areas (of the surface OF) of the cover plate DP. These six partial surface areas are respectively distributed on the left and right sides of the longitudinal axis LA of the cover plate DP, and are located in the aforementioned three surface areas (in Figure 1 The middle area is one of the three surface regions (left, center, and right). For ease of description, the first partial surface region located in the upper left of surface OF in the figure will be referred to below—it is (in Figure 1 Part of the left surface area (in the middle), while (in Figure 1 The first part of the surface area (B1) is located above the longitudinal axis LA of the cover plate DP – indicated by reference numeral B1, while the other five part surface areas are indicated by reference numeral B2, so as to more easily and clearly show the special features of the first part surface area B1 relative to the remaining part surface areas B2 and the technical role of the cooler KL.

[0051] In this embodiment, the four power semiconductor switches LH1 and LH2 of each power module LM constitute the two positive voltage side and two negative voltage side power semiconductor switches in the two sets of parallel half-bridges of the bridge circuit. In this embodiment, all power semiconductor switches LH1 and LH2 are, for example, SiC semiconductor switches.

[0052] Located in the first part of the surface region B1 (in Figure 1 The two power semiconductor switches of the power module LM on the left (in the middle) are hereinafter referred to as reference numeral LH1, while the other two power semiconductor switches of the same power module LM and the power semiconductor switches of the other two power modules LM are hereinafter referred to as reference numeral LH2.

[0053] The inverter also has a set of control circuits, including a drive circuit (not shown in the figure) for controlling the power electronic device LV or driving the power semiconductor switches LH1 and LH2 mentioned above. The control circuit is electrically connected to the power semiconductor switches LH1 and LH2 of the power electronic device LV or their control terminals via a control signal connection (not shown in the figure).

[0054] In addition to the cover plate DP, the cooler KL also has a base plate BP. The base plate BP and the cover plate DP form a cooling channel KN for conducting liquid coolant (e.g., cooling water). This channel extends along the longitudinal direction LR of the cooler KL.

[0055] The cooler KL also has a coolant inlet EL and a coolant outlet AL, which are formed on the substrate BP and are arranged side by side with each other in the longitudinal direction LR at the first longitudinal end E1 of the substrate BP or the cooling channel KN, so that they are arranged back and forth with each other in the transverse direction QR of the cooler KL.

[0056] The cooler KL also has an insert plate EP arranged in the cooling channel KN between the substrate BP and the cover plate DP, dividing the cooling channel KN into: a supply channel section ZF extending longitudinally from the coolant inlet EL, i.e., from the first longitudinal end E1 of the cooling channel KN along the longitudinal direction LR to the second longitudinal end E2 of the cooling channel KN (away from the first longitudinal end E1); and a return channel section RF extending longitudinally from the second longitudinal end E2 to the coolant outlet AL, i.e., back to the first longitudinal end E1. The insert plate EP and the substrate BP (at least partially or substantially completely) form the supply channel section ZF, and together with the cover plate DP (at least partially or substantially completely), they form the return channel section RF.

[0057] The insert plate EP has two transfer openings DO at the second longitudinal end E2, which are arranged side by side along the longitudinal direction LR to guide the coolant from the supply channel section ZF to the return channel section RF.

[0058] The insert plate EP is located at the first longitudinal end E1 of the cooling channel KN and is located (immediately) after the coolant inlet EL in the longitudinal direction LR. It has a bypass opening UO that runs through the insert plate EP (i.e., through the cooler KL) in the vertical direction SR, and a partition wall TW that (at least partially) surrounds the bypass opening UO.

[0059] The partition wall TW extends outward from the insert plate EP along the vertical direction SR to the cover plate DP, thereby forming a cavity-shaped bypass channel region UB. This region extends along the vertical direction SR from the bypass opening UO to the cover plate DP and is laterally defined by the partition wall TW (and optional sidewalls of the insert plate EP and / or the cover plate DP). Viewed along the longitudinal direction LR of the cooler KL, the bypass channel region UB extends from the coolant inlet EL (or its end facing the cooling channel) to a position at the same height as the first partial surface region B1 of the aforementioned cover plate DP in the longitudinal direction LR. Along the transverse direction QR, the width of the bypass channel region UB is also consistent with the width of the first partial surface region B1. Therefore, viewed along the vertical direction SR, the area of ​​the bypass channel region UB is substantially the same as the area of ​​the first partial surface region B1. Along the longitudinal direction LR, the length of the bypass opening UO or the bypass channel region UB is approximately one-third of the total length of the insert plate EP or the return channel section RF. Along the lateral direction QR, the width of the bypass opening UO or bypass channel area UB is approximately equal to half the total width of the insert plate EP or return channel section RF.

[0060] The partition wall TW fluidly separates the bypass passage area UB from the return passage section RF, or fluidly seals the bypass passage area UB from the return passage section RF, thereby preventing coolant from flowing directly from the bypass passage area UB through the partition wall TW to the return passage section RF, or flowing in the reverse direction.

[0061] The insert plate EP also has a flow deflection wall UW, which, like the partition wall TW, extends from the insert plate EP in the vertical direction SR towards the cover plate DP. The flow deflection wall UW is either part of the partition wall TW or a wall segment extending from the partition wall TW into the bypass channel region UB, this segment extending obliquely relative to both the longitudinal direction LR and the transverse direction QR. The flow deflection wall UW deflects the coolant flowing into the bypass channel region UB from the coolant inlet EL, allowing the coolant to flow uniformly around the bypass channel region UB, thereby uniformly cooling the first part of the surface region B1 of the cover plate DP.

[0062] The coolant inlet EL has a ramp RP at the transition area leading to the cooling channel KN and the bypass opening UO. The ramp extends at an angle relative to the bypass opening UO and is configured to guide the coolant from the coolant inlet EL to the bypass opening UO, thereby providing better flow around the bypass channel area UB.

[0063] The insert plate EP is located at the first longitudinal end E1 of the cooling channel KN, and is located in the longitudinal direction LR (immediately before) the coolant outlet AL, and in the transverse direction QR in front of the bypass opening UO (which can also be understood as behind depending on the perspective). It has a return opening RO (or return notch) that runs through the insert plate EP in the vertical direction SR, which connects the return channel section RF and the coolant outlet AL in fluid, and is thus configured to guide the coolant from the return channel section RF to the coolant outlet AL when the cooler KL is running.

[0064] The insert plate EP and the substrate BP each have a (at least partially) sealing wall AW surrounding the return opening RO (see also...) Figure 2 and Figure 3 Both extend vertically from the insert plate EP to the substrate BP, or from the substrate BP to the insert plate EP, respectively, and are located within the supply channel section ZF. The sealing walls AW of the two plates EP and BP are closely adjacent to each other and connected by a shape fit described below (see [link to relevant documentation]). Figure 3 This allows for a fluid-sealed separation between the return opening RO (and the coolant outlet AL) and the supply channel section ZF or bypass channel area UB.

[0065] Figure 2 Another schematic exploded view shows the cover plate DP and the insert plate EP, with the cover plate DP facing away from the aforementioned surface OF, i.e., the lower side facing the return channel section RF, and the insert plate EP facing away from the cover plate DP, i.e., the lower side facing the supply channel section ZF.

[0066] The cover plate DP has an enlarged surface structure on the underside facing the return channel section RF, with cooler pin fins PF distributed in the underside surface region adjacent to the return channel section RF and extending outward from the cover plate DP into the return channel section RF, thereby extending in the direction toward the insert plate EP.

[0067] The insert plate EP has a flow guiding structure on its underside facing the supply channel section ZF. This structure has two flow guiding walls LW extending longitudinally LR and extending outward from the insert plate EP into the supply channel section ZF. The flow guiding walls LW are configured to guide the coolant flowing into the supply channel section ZF from the coolant inlet EL or from the bypass channel area UB to the two transfer openings DO.

[0068] Figure 3 Another schematic exploded view shows the insert plate EP and the substrate BP, showing the sides of the two plates EP and BP facing the supply channel section ZF, respectively.

[0069] The substrate BP has a groove-shaped structure RN that surrounds the entire substrate. Correspondingly, the insert plate EP has a wall structure WS that at least partially surrounds the entire substrate and corresponds to the groove structure RN, extending into the groove structure RN, thereby establishing a fluid-tight connection between the insert plate EP and the substrate BP, and thereby achieving a fluid seal in the supply channel section ZF.

[0070] The sealing wall AW of the insert plate EP is configured as a double-wall structure, thus forming a slot between the sealing wall AW or its two walls. The sealing wall AW of the substrate BP is inserted into this slot and together with the sealing wall AW of the insert plate EP, forms a fluid seal between the return opening RO and the supply channel section ZF or the bypass channel area UB.

[0071] The following reference Figure 4 A more detailed description of how the cooler KL works: Figure 4 A schematic cross-sectional view shows the source... Figure 1 The diagram illustrates components of an inverter or power unit LV and its cooler KL, showing a simplified view of the power unit LV from the coolant inlet EL and bypass channel area UB, representing schematic cooling operation of the cooler KL. The flow of coolant during cooling operation is illustrated by arrows in the diagram.

[0072] Coolant, as an inlet flow ES, flows into cooling channel KN through coolant inlet EL. At the end of coolant inlet EL, it is (at least) partially guided into bypass channel region UB by a ramp RP extending at an incline relative to bypass opening UO. There, coolant flows around cooler fins PF on region B1 of cover plate DP, forming numerous small vortices or flow around fins PF, while simultaneously cooling region B1 and the two power semiconductor switches LH1 located in region B1, such that these two switches LH1 are cooled before the remaining power semiconductor switches LH2 located in the remaining region B2.

[0073] Subsequently, the coolant flows from the bypass channel area UB (return) to the supply channel section ZF, and within the area of ​​the (remaining) supply channel section ZF, it mixes with the portion of coolant that enters directly from the coolant inlet EL (without bypassing the bypass channel area UB) or flows through the supply channel section ZF, so that the coolant is fully mixed before reaching the transfer opening DO at the end of the supply channel section ZF, and forms a supply flow ZS with a basically uniform coolant temperature.

[0074] The mixed coolant or supply flow ZS then flows as a through-flow DS through two transfer openings DO, entering the return channel section RF and forming a return flow RS therein. This return flow RS then flows around the cooler pin fins PF on the remaining area B2 of the cover plate DP, and similarly to the situation in the bypass channel area UB, again forming numerous small vortices or flows around the cooler pin fins PF, while simultaneously cooling the entire remaining area B2 of the cover plate DP and the remaining ten power semiconductor switches LH2 located in this area B2. The coolant then flows through the return opening RO to the coolant outlet AL, and from there out of the cooler KL.

[0075] Because region B1 of the cover plate DP and the two power semiconductor switches LH1 located within it are cooled via the bypass channel region UB before the remaining region B2 is cooled, and region B1 would otherwise be cooled due to the lateral arrangement of the coolant outlet AL or return opening RO in the transverse direction QR of the cooler KL, i.e., in the transverse direction QR of the cooling channel KN, and the much larger extension of the cooling channel KN or return channel section RF in the transverse direction QR relative to the return opening RO or coolant outlet AL (as a so-called stagnation zone), the coolant return RS in the return channel section RF is poor or almost impossible to bypass, thus ensuring that region (B1) is also adequately cooled. Therefore, overall uniform cooling of the entire cover plate DP, and consequently of all three power modules LM or all twelve power semiconductor switches LH1, LH2, can be ensured.

Claims

1. A cooler (KL) for cooling power electronic devices (LV), characterized in that, include: - The substrate (BP) and the cover plate (DP) together form a cooling channel (KN) extending along the longitudinal direction (LR) of the cooler (KL) for guiding the coolant, wherein the cover plate (DP) is used for thermal contact with the power electronic device (LV); - A coolant inlet (EL) and a coolant outlet (AL) are provided at the first longitudinal end (E1) of the cooling channel (KN) along the longitudinal direction (LR); - An insert plate (EP) is disposed within the cooling channel (KN), located between the base plate (BP) and the cover plate (DP), and divides the cooling channel (KN) into a supply channel section (ZF) extending from the coolant inlet (EL) to the second longitudinal end (E2) of the cooling channel (KN), and a return channel section (RF) extending from the second longitudinal end (E2) to the coolant outlet (AL); - Wherein, the insertion plate (EP) and the substrate (BP) together form the supply channel section (ZF), and together with the cover plate (DP) together form the return channel section (RF). - Wherein, the insertion plate (EP) is provided with a transfer opening (DO) at the second longitudinal end (E2) for guiding coolant from the supply channel section (ZF) to the return channel section (RF). - Wherein, the insert plate (EP) has a bypass opening (UO) between the coolant inlet (EL) and the transfer opening (DO), the bypass opening (UO) being fluidly separated by the surrounding partition wall (TW) and the return channel section (RF); - Wherein, a bypass channel region (UB) is formed between the bypass opening (UO), the partition wall (TW) and the cover plate (DP), the bypass channel region (UB) extends to the cover plate (DP) and is in fluid communication with the supply channel section (ZF) through the bypass opening (UO), and is fluidly separated by the partition wall (TW) and the return channel section (RF).

2. The cooler (KL) according to claim 1, characterized in that, The bypass opening (UO) is formed at the first longitudinal end (E1) of the cooling channel (KN) and is located downstream of the coolant inlet (EL) in the longitudinal direction (LR).

3. The cooler (KL) according to any one of the preceding claims, characterized in that, The length of the bypass opening (UO) in the longitudinal direction (LR) is between one-fifth and one-half of the length of the supply channel section (ZF), or between three-tenths and two-fifths of the length of the supply channel section (ZF), or equivalent to one-third of the length of the supply channel section (ZF).

4. The cooler (KL) according to any one of the preceding claims, characterized in that, The insert plate (EP) and / or the cover plate (DP) have a flow deflection wall (UW) disposed in or at the bypass opening (UO) or in the bypass channel region (UB), extending at least partially at an angle relative to the longitudinal direction (LR), and configured to deflect coolant flowing in the bypass opening (UO) or the bypass channel region (UB).

5. The cooler (KL) according to claim 4, characterized in that, The flow deflection wall (UW) is a portion of the partition wall (TW) and / or extends from the partition wall (TW) into the bypass channel area (UB).

6. The cooler (KL) according to any one of the preceding claims, characterized in that: - The insertion plate (EP) has a return opening (RO) at the first longitudinal end (E1) and upstream of the coolant outlet (AL) for guiding coolant from the return channel section (RF) to the coolant outlet (AL). - Wherein, the return opening (RO) is fluidly separated from the supply channel section (ZF) by a sealing wall (AW) surrounding the return opening (RO).

7. The cooler (KL) according to any one of the preceding claims, characterized in that, The cover plate (DP) and / or the insert plate (EP) have surface enlargement structures and / or cooler needle fins (PF) that extend into the return channel section (RF).

8. The cooler (KL) according to any one of the preceding claims, characterized in that, A flow guiding structure and / or flow guiding wall (LW) is provided in the supply channel section (ZF), which is configured to guide coolant from the coolant inlet (EL) and / or from the bypass channel area (UB) to the transfer opening (DO).

9. The cooler (KL) according to any one of the preceding claims, characterized in that, A ramp riser (RP) is provided at the coolant inlet (EL), which extends at an incline toward the bypass opening (UO) and is configured to guide coolant from the coolant inlet (EL) to the bypass opening (UO).

10. A power electronic device (LV), comprising: - At least two power semiconductors (LH1, LH2); - The cooler (KL) according to any of the preceding claims; - Wherein, the power semiconductors (LH1, LH2) are disposed on the surface (OF) of the cover plate (DP) opposite to the return channel section (RF) and are in thermal contact with the cover plate (DP); - Wherein, the first power semiconductor (LH1) of the two power semiconductors is disposed on a first portion of the surface region (B1) of the surface (OF) away from the bypass channel region (UB), and the second power semiconductor (LH2) of the two power semiconductors is disposed on a second portion of the surface region (B2) of the channel region (KB) of the surface (OF) away from the return channel segment (RF), wherein the channel region (KB) is fluidly separated from the bypass channel region (UB) by the partition wall (TW).

11. An inverter, comprising: - The power electronic device (LV) according to claim 10; - A control circuit for controlling the power electronic device (LV), which is electrically connected to the power semiconductor (LH) via a control signal connection.

Images