Automotive inverter

Abstract

An automotive inverter including a grounding spring, a thermal boss to measure a coolant temperature, an AC busbar assembly, a DC busbar assembly, a motor harness configured to seal a cable passing into a housing of the automotive inverter, an injection molded plastic double shot and an alignment insulator are provided. The motor cable harness includes a clip that includes two halves, the two halves coming together to surround the cable; an O-ring positioned around the cable and disposed within the two halves surrounding the cable, wherein the two halves encapsulate the O-ring; and a potting material disposed and surrounding the cable.

Description

AUTOMOTIVE INVERTERBACKGROUND

[0001] Automotive inverters are used in electrical vehicle technology to convert DC power to AC power. The converted AC current can then power a traction drive motor in the electric vehicle, for example. Automotive inverters typically employ a relatively large energy storage capacitor as a main DC link to maintain a high voltage across a power bus, for example. The DC link capacitor is interfaced with a high voltage (e.g., 200-1200V) battery for mobile applications.

[0002] Due to an integrated cooling system of the DC link capacitor that is separated by electrical components, there is a need for an electrical connection between the separated cooling system with grounding. A method is desired to measure the temperature of the coolant as it enters and exits the automotive inverter so that the system can take actions if the coolant gets out of its typical range. An interconnection design to interconnect high voltage from the battery pack to the DC link capacitor is desired. An interconnection busbar design to interconnect insulated-gate bipolar transistors (IGBTs) within a sealed unit to an external electrical automotive motor is desired. It is desired to interconnect an external motor sensor to the automotive motor main controller board while also sealing the inside of the inverter from the outside environment. An interconnection including a sealing of upper and lower coolant channels in an automotive inverter is desired. An alignment insulator for separation and alignment of IGBT pins is desired.BRIEF SUMMARY

[0003] An automotive inverter including a grounding spring, a thermal boss to measure a coolant temperature, an AC busbar assembly, a DC busbar assembly, a motor harness configured to seal a cable passing into a housing of the automotive inverter, an injection molded plastic double shot and an alignment insulator are provided.

[0004] A motor cable harness configured to seal a cable passing into a housing of an automotive inverter is provided. The motor cable harness includes a clip that includes two halves, the two halves coming together to surround the cable; an O-ring positioned around the cable and disposed within the two halves surrounding the cable, wherein the two halves encapsulate the O-ring; and a potting material disposed and surrounding the cable.

[0005] A grounding spring configured to be clipped to a middle layer between two conductive layers to enable an electrical grounding connection between the two conductivelayers despite tolerance in height of a component in the middle layer, wherein the grounding spring is formed of an electrically conductive plate bent into a u-shape including inward projections on each side of the u-shape causing ends of the u-shape to be bent outward is provided.

[0006] A thermal boss built into a housing of an automotive inverter with integrated cooling system is provided. The thermal boss positioned on an outer side of a coolant channel and allows measurement of coolant temperature in the cooling channel by a temperature sensor adjacent the coolant channel.

[0007] A DC busbar assembly for an automotive inverter is provided. The DC busbar assembly includes a plurality of DC busbars including copper busbars overmolded with plastic and bent to interconnect an HVDC input connector to a DC link capacitor.

[0008] An AC busbar assembly for an automotive inverter is provided. The AC busbar includes copper busbars overmolded with plastic and bent to interconnect electrical switching components within the automotive inverter with an external electric motor, wherein the overmolding allows for a seal against a housing of the automotive inverter.

[0009] An alignment insulator for an automotive inverter is provided. The alignment insulator includes a middle layer on which electrical switching components can be fixed, wherein the alignment insulator has a molded plastic design for separation and alignment of pins of the electrical switching components.

[0010] An apparatus that includes an injection molded plastic double shot with dual sided face seals for interconnection of an upper coolant channel and a lower coolant channel is provided. The dual sided face seals allow for compression between two plates of the upper coolant channel and the lower coolant channel, respectively.

[0011] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0012] FIG. 1 illustrates a perspective view of an automotive inverter.

[0013] FIG. 2 illustrates a perspective view of a middle layer of the automotive inverter of FIG. 1.

[0014] FIG. 3 illustrates a cross sectional view of the middle layer of FIG. 2 with grounding springs.

[0015] FIG. 4 illustrates a perspective view of the grounding spring.

[0016] FIG. 5 illustrates a cross-sectional view of the grounding spring.

[0017] FIG. 6 illustrates a cross-sectional view of coolant channel including a thermal boss.

[0018] FIG. 7 illustrates a top view and a bottom view of the lower coolant channel with thermal bosses located under the inlet and outlet path.

[0019] FIG. 8 illustrates a connection of the thermal bosses from the coolant channel to a temperature sensor on the gate driver board.

[0020] FIG. 9 illustrates a perspective view of a middle layer with alignment features.

[0021] FIG. 10 illustrates a perspective view of a middle layer with retention features.

[0022] FIG. 11 illustrates a top view and a side view of a DC busbar assembly positioned with the automotive inverter.

[0023] FIG. 12 illustrates a perspective top front view of the DC busbar assembly.

[0024] FIG. 13 illustrates a perspective top back view of the DC busbar assembly.

[0025] FIG. 14 illustrates a perspective bottom front view of the DC busbar assembly with Y-capacitors.

[0026] FIG. 15 illustrates a perspective bottom back view of the DC busbar assembly.

[0027] FIG. 16 illustrates a perspective view of the DC busbars.

[0028] FIG. 17 illustrates a perspective view of an AC busbar assembly installed in an automotive inverter.

[0029] FIG. 18 illustrates a perspective view of the AC busbar assembly.

[0030] FIG. 19 illustrates the copper busbars of AC busbar assembly shown in FIG. 18.

[0031] FIG. 20 illustrates a perspective bottom view of the AC busbar assembly.

[0032] FIG. 21 illustrates a perspective view of a motor harness.

[0033] FIG. 22 illustrates a perspective view of the motor harness before the two halves come together.

[0034] FIG. 23 illustrates a cross sectional view of the motor harness surrounding the cable.

[0035] FIG. 24 illustrates views of a clip half.

[0036] FIG. 25A and FIG. 25B illustrate views of an injection molded plastic double shot with dual sided face seals.

[0037] FIG. 26 illustrates the injection molded plastic double shot installed between the two plates.DETAILED DESCRIPTION

[0038] Although an inverter is discussed herein, it should be noted that the system and methods disclosed herein may be applicable to other devices, such as, but not limited to, a converter, a battery, and / or other electrical applications.

[0039] FIG. 1 illustrates a perspective view of an automotive inverter (without its lid), such as for an electric vehicle. The automotive inverter 100 interfaces a high voltage (HV) battery through the DC link capacitor 106. The automotive inverter 100 includes a stacked configuration of components that includes a main controller board 102, an active discharge board 104, the DC link capacitor 106, electrical switching components 112, an upper coolant channel 110, a lower coolant channel 108, a coolant inlet / outlet 116, and a gate driver board 114. The electrical switching components 112 are located between the upper coolant channel 110 and the lower coolant channel 108. In some cases, the main controller board 102, the active discharge board 104, and / or the gate driver board 114 are printed circuit boards.

[0040] FIG. 2 illustrates a perspective view of a middle layer of the automotive inverter of FIG. 1. The middle layer 200 includes a plastic carrier 202. A housing (e.g., 120 of FIG. 1) of the automotive inverter (e.g., automotive inverter 100 of FIG. 1) includes an upper housing portion and a lower housing portion. Carrier 202 is disposed between the upper housing portion and the lower housing portion of the housing. An apparatus including one or more grounding springs 204 can be utilized to aid in the assembly of the stack configuration of components. In some cases, the carrier 202 is a plastic carrier.

[0041] FIG. 3 illustrates a cross-sectional view of the middle layer with grounding springs. Referring to FIGs. 1-3, the plastic carrier 202 is disposed between the upper coolant channel 110 and the lower coolant channel 108. The upper coolant channel 110 and the lower coolant channel 108 each include an electrically conductive material. One or more grounding springs 204 can be clipped onto the plastic carrier 202 in multiple areas to aid in the assembly of the stack configuration of components. In order to ground the active discharge board 104, one or more grounding springs 204 are utilized to create a grounding path from the upper coolant channel 110 through the grounding spring 204 down to the lower coolant channel 108. Thus, a grounding spring 204 creates the grounding path despite tolerance in the height of the plasticcarrier 202. The grounding spring 204 attaches on both sides of the plastic carrier 202 to accommodate any tolerance change that may occur in the gap between the upper coolant channel 110 and lower coolant channel 108. As the two halves of the assembly, such as for example, the upper housing portion and the lower housing portion, come together, the two halves compress down and create a spring force on each side of the housing 120 and allow an electrical grounding path through the grounding springs 204 to electrically connect the upper coolant channel 110 and the lower coolant channel 108.

[0042] FIG. 4 illustrates a perspective view of the grounding spring and FIG. 5 illustrates a cross-sectional view of the grounding spring. Grounding spring 204 is formed of an electrically conductive plate that is bent, molded, and / or manufactured into a u-shape. The u- shape of the grounding spring includes an inward projections on each side of the u-shape, causing ends of the u-shape to be bent outward. In some cases, the grounding spring 204 includes copper, beryllium copper, and / or other similarly conductive materials.

[0043] FIG. 6 illustrates a cross-sectional view of coolant channel including a thermal boss. It is desired to measure a temperature of the coolant in the coolant channel as it enters (see arrow on FIG. 6) from the coolant inlet 116. In some cases, it is desired to measure the temperature of the coolant entering and exiting the automotive inverter. Thus, a thermal boss 602 projects from the outer side of the coolant channel. The thermal boss 602 thermally connects the inlet path to the gate driver board. The thermal boss 602 includes a thermal interface material to conduct a temperature of the coolant channel to a chip, e .g . , a temperature sensor adjacent to the coolant channel, on the gate driver board.

[0044] FIG. 7 illustrates a top view and a bottom view of the lower coolant channel with thermal bosses located under the inlet and outlet path. The thermal boss 602 and / or the thermal interface material of the thermal boss 602 can be positioned at an inlet of the cooling channel and / or an outlet of the cooling channel to thermally connect the inlet of the coolant channel and / or the outlet of the coolant channel to a temperature sensor. FIG. 7 illustrates two thermal bosses 602 projecting down in the lower coolant channel (e.g., lower coolant channel 108 of FIG. 1); one at under the inlet path (left side) and one under the outlet path (right side). The thermal bosses 602 can be designed to make contact with the gate driver board (e.g., gate driver board 114 of FIG. 1). FIG. 8 illustrates a connection of the thermal bosses 602 from the lower coolant channel to a corresponding temperature sensor on the gate driver board 114.

[0045] Referring back to FIG. 2, the plastic carrier 202 further includes an alignment insulator for an automotive inverter. The alignment insulator provides a middle layer on which electrical switching components (e.g., electrical switching components 112 of FIG. 1) can befixed. In some cases, the alignment insulator has a molded plastic design for separation and alignment of pins of the electrical switching components. For example, the alignment indicator can include alignment features 206 for the IGBT pins to ensure proper installation into the gate driver board 114.

[0046] FIG. 9 illustrates a perspective view of the middle layer with alignment features 206. FIG. 10 illustrates a perspective view of a middle layer with retention features 1002. The retention features 1002 are included for retention of bidirectional electrical grounding springs.

[0047] FIG. 11 illustrates a top view and a side view of a DC busbar assembly. The DC busbar assembly 1100 includes busbars 1102. The busbars 1102 can be made of, for example, copper overmolded with plastic and bent to interconnect an HVDC input connector 1106 to the DC link capacitor e.g., DC link capacitor 106 of FIG. 1). The DC busbar assembly 1100 also includes a common mode choke (see FIG. 12) glued into a cavity of the DC busbar assembly 1100 for filtering. The common mode choke 1104 surrounds the DC busbars 1102 that extend to the DC link capacitor. The common mode choke 1104 provides electrical filtering of noise in the automotive inverter. DC power comes into the DC busbar assembly 1100 and is filtered by the common mode choke 1104 and Y-capacitors 1108, continues to the DC link capacitor and then goes to the inputs, gets switched and converts to AC power and on to a motor (not shown). The DC busbar assembly 1100 is assembled into the housing of the automotive inverter.

[0048] FIG. 12 illustrates a perspective top front view of a DC busbar assembly. FIG. 13 illustrates a perspective top back view of the DC busbar assembly. Referring to FIGs. 11-13, the DC busbar assembly 1100 further includes Y-capacitors 1108. The Y-capacitors 1108 are attached to the DC busbars 1102 and also provide filtering purposes. The DC busbar assembly 1100 includes DC busbars 1102, for example, overmolded in plastic, filtering with Y- capacitors 1108 and a common mode choke 1104.

[0049] FIG. 14 illustrates a perspective bottom front view of the DC busbar assembly with Y-capacitors. FIG. 15 illustrates a perspective bottom back view of the DC busbar assembly with Y-capacitors. FIG. 16 illustrates a perspective view of the DC busbars. Referring to FIGs. 14-16, the Y-capacitors 1108 are crimped to the DC busbars 1102, which eliminates the need for a separate printed circuit board.

[0050] FIG. 17 illustrates a perspective view of an AC busbar assembly installed in an automotive inverter. FIG. 18 illustrates a perspective view of the AC busbar assembly. Referring to FIGs. 17 and 18, an AC busbar assembly 1700 for an automotive inverter includes copper busbars 1702 overmolded with plastic and bent to interconnect to electricalswitching components within the automotive inverter with an external electric motor. The overmolding allows for a seal against the housing of the automotive inverter. The AC busbar assembly 1700 includes copper busbars 1702 that are bent and shaped into a position to electrically connect between tabs of the IGBTs on the gate driver board. Three copper projections 1704 of the busbars 1702 come up through the gate driver board and attach with a screw connection to connect the terminals directly to the copper projections 1704. On the other end of the AC busbar assembly 1700, each copper projection 1704 has a corresponding terminal on the other side of the assembly.

[0051] FIG. 19 illustrates the copper busbars 1702 of AC busbar assembly 1700 shown in FIG. 18. The AC busbar assembly 1700 includes flexible braided copper busbars 1702 braised to rigid busbars 1706 to provide flexibility for customer installation.

[0052] FIG. 20 illustrates a perspective bottom view of the AC busbar assembly. Referring to FIG 20, the AC busbars 1702 are overmolded in plastic to create a custom seal which includes a pass through for a harness. A sealant is applied around the busbars 1702 and motor harness 2100 (see FIG. 21) to prevent ingress into the automotive inverter from a motor cavity. The AC busbar assembly 1700 includes multiple mounting points to allow for mounting to the housing and seal against the housing (e.g., housing 120 of FIG. 1). The AC busbar assembly 1700 can withstand high temperatures of up to 175 °C and seal against a cast aluminum housing.

[0053] FIG. 21 illustrates a motor harness surrounding a cable. Referring to FIG. 21, the cable 2102 passes through the motor harness 2100 from a sealed automotive inverter to an electric motor. The motor harness 2100 is configured to seal the cable 2102 passing into the housing of an automotive inverter. The motor harness 2100 includes a clip 2104 that includes two halves, the two halves coming together to surround the cable 2102. When the two halves come together, they seal against one another. The two halves are embedded with rubber seal wraps 2106 around the motor harness 2100 and encapsulate the O-ring 2108 to provide a leakproof joint. The O-ring 2108 is positioned within the two halves surrounding the cable 2102.

[0054] FIG. 22 illustrates a perspective view of the motor harness before the two halves come together. FIG. 23 illustrates views of a clip half. Referring to FIG.22 and FIG. 23, each half of the clip 2104 includes long strain arms 2112 to support the cable 2102 so that when the cable 2102 is manipulated from the outside, the cable 2102 does not move or shift within the motor harness 2100 and / or break the seal of a sealant applied around the cable 2102.

[0055] FIG. 24 illustrates a cross sectional view of the motor harness surrounding the cable. Referring to FIG. 24, the two halves of the clip 2104 (one shown) are embedded with rubber seal wraps 2106 around the cable 2102 and encapsulate the O-ring 2108 to provide a leakproof joint. Motor harness 2100 also includes a sealant 2110 disposed with the two halves of the clip 2104 and surrounding the cable 2102. The clip 2104 is designed to allow the sealant 2110 to extend up around the motor harness 2100 to the O-ring 2108 to provide sealing on the cable 2102 and between the two halves of the clip 2104. In some cases, the sealant 2110 is a potting material.

[0056] FIG. 25A and FIG. 25B illustrate views of an injection molded plastic double shot with dual sided face seals. In order to cool the IGBTs on the gate driver board (e.g., driver board 114 of FIG. 1), the coolant channels need to be clamped around the IGBTs within a certain clamping pressure. Due to component tolerances, a rigid coolant interconnect between the upper coolant channel (e.g., upper coolant channel 110 of FIG. 1) and the lower coolant channel (e.g., lower coolant channel 108 of FIG. 1) has a risk of creating a low clamping pressure condition on the IGBTs. A double shot with dual sided face seals 2500 is able to bridge the gap between the upper coolant channel and lower coolant channel while taking into account the tolerances of the surrounding components by allowing for compression between two plates, such as for example, a first plate of the upper coolant channel, and a second plate of the lower coolant channel. Referring to FIG. 25A and FIG. 25B, the double shot with dual sided face seals 2500 includes an injection molded plastic with EPDM (ethylene propylene diene monomer), such as for example, synthetic rubber, material molded into the proper shape to create a seal. The seal is molded on both sides to allow for compression between two plates, (e.g., a first plate of the upper coolant channel, and a second plate of the lower coolant channel).

[0057] FIG. 26 illustrates the injection molded double shot with dual sided face seals 2500 of FIG. 25B installed between the two plates (e.g., a first plate of the upper coolant channel, and a second plate of the lower coolant channel). The seal design accommodates various tolerances of the surrounding components.

[0058] Clause 1. A motor cable harness configured to seal a cable passing into a housing of an automotive inverter, the motor harness comprising: a clip comprising two halves, the two halves coming together to surround the cable; an O-ring positioned around the cable and disposed within the two halves surrounding the cable, wherein the two halves encapsulate the O-ring; and a potting material disposed and surrounding the cable.

[0059] Clause 2. The motor cable harness of clause 1, wherein a rubber material is embedded into each half of the two halves of the clip to create a seal between the two halves when the two halves come together.

[0060] Clause 3. An apparatus comprising: a grounding spring configured to be clipped to a middle layer between two conductive layers to enable an electrical grounding connection between the two conductive layers despite tolerance in height of a component in the middle layer, wherein the grounding spring is formed of an electrically conductive plate bent into a u-shape including inward projections on each side of the u-shape causing ends of the u-shape to be bent outward.

[0061] Clause 4. The grounding spring of clause 3, wherein the electrically conductive plate comprises beryllium copper.

[0062] Clause 5. An apparatus comprising: an injection molded plastic double shot with dual sided face seals for interconnection of an upper coolant channel and a lower coolant channel, the dual sided face seals allowing for compression between a first plate of the upper coolant channel and a second plate of the lower coolant channel, respectively.

[0063] Clause 6. The apparatus of clause 6, wherein the injection molded double shot with dual sided face seals provides a predefined minimum clamping pressure.

[0064] Clause 7. A DC busbar assembly for an automotive inverter comprising: a plurality of DC busbars comprising copper overmolded with plastic and bent to interconnect an HVDC input connector to a DC link capacitor.

[0065] Clause 8. The DC busbar assembly of clause 7, further comprising Y capacitors attached with the plastic molding of the DC busbar assembly.

[0066] Clause 9. The DC busbar assembly of clause 7 or 8, further comprising a common choke surrounding the DC busbars and extending to an end connecting to the DC link capacitor.

[0067] Clause 10. An AC busbar assembly for an automotive inverter, comprising: copper busbars overmolded with plastic and bent to interconnect electrical switching components within the automotive inverter with an external electric motor, wherein the overmolding allows for a seal against a housing of the automotive inverter.

[0068] Clause 11. An alignment insulator for an automotive inverter, the alignment insulator comprising: a middle layer on which electrical switching components are fixed, wherein the alignment insulator has a molded plastic design for separation and alignment of pins of the electrical switching components.

[0069] Clause 12. A thermal boss comprising: a thermal interface material that conducts a temperature of a coolant channel to a temperature sensor adjacent to the coolant channel; and the temperature sensor adjacent to the coolant channel, wherein the thermal boss is built into a housing of an automotive inverter with integrated cooling system, the thermal boss positioned on an outer side of the coolant channel and allowing measurement of coolant temperature in the cooling channel by the temperature sensor.

[0070] Clause 13. The thermal boss of clause 12, wherein the thermal interface material of the thermal boss is positioned at an inlet of the coolant channel or an outlet of the coolant channel to thermally connect the inlet of the coolant channel or the outlet of the coolant channel to the temperature sensor.

[0071] Clause 14. The thermal boss of clause 12 or 13, wherein the thermal boss projects from the outer side of the coolant channel.

[0072] Clause 15. The thermal boss of any clause 12-14, wherein the temperature sensor is connected to a gate driver board of the automotive inverter.

[0073] Although the subject matter has been described in language specific to structural features and / or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts that would be recognized by one skilled in the art are intended to be within the scope of the claims.

Claims

CLAIMSWhat is claimed is:

1. A motor cable harness configured to seal a cable passing into a housing of an automotive inverter, the motor cable harness comprising: a clip comprising two halves, the two halves coming together to surround the cable; an O-ring positioned around the cable and disposed within the two halves surrounding the cable, wherein the two halves encapsulate the O-ring; and a potting material disposed and surrounding the cable.

2. The motor cable harness of claim 1, wherein a rubber material is embedded into each half of the two halves of the clip to create a seal between the two halves when the two halves come together.

3. An apparatus comprising: a grounding spring configured to be clipped to a middle layer between two conductive layers to enable an electrical grounding connection between the two conductive layers despite tolerance in height of a component in the middle layer, wherein the grounding spring is formed of an electrically conductive plate bent into a u-shape including inward projections on each side of the u-shape causing ends of the u-shape to be bent outward.

4. The apparatus of claim 3, wherein the electrically conductive plate comprises beryllium copper.

5. An apparatus comprising: an injection molded plastic double shot with dual sided face seals for interconnection of an upper coolant channel and a lower coolant channel, the dual sided face seals allowing for compression between a first plate of the upper coolant channel and a second plate of the lower coolant channel, respectively.

6. The apparatus of claim 5, wherein the injection molded plastic double shot with dual sided face seals provides a predefined minimum clamping pressure.

7. A DC busbar assembly for an automotive inverter comprising:a plurality of DC busbars comprising copper overmolded with plastic and bent to interconnect an HVDC input connector to a DC link capacitor.

8. The DC busbar assembly of claim 7, further comprising Y capacitors attached with the plastic of the DC busbar assembly.

9. The DC busbar assembly of claim 7, further comprising a common choke surrounding the DC busbars and extending to an end connecting to the DC link capacitor.

10. An AC busbar assembly for an automotive inverter, comprising: copper busbars overmolded with plastic and bent to interconnect electrical switching components within the automotive inverter with an external electric motor, wherein the overmolding allows for a seal against a housing of the automotive inverter.

11. An alignment insulator for an automotive inverter, the alignment insulator comprising: a middle layer on which electrical switching components are fixed, wherein the alignment insulator has a molded plastic design for separation and alignment of pins of the electrical switching components.

12. A thermal boss comprising: a thermal interface material that conducts a temperature of a coolant channel to a temperature sensor adjacent to the coolant channel; and the temperature sensor adjacent to the coolant channel, wherein the thermal boss is built into a housing of an automotive inverter with integrated cooling system, the thermal boss positioned on an outer side of the coolant channel and allowing measurement of coolant temperature in the coolant channel by the temperature sensor.

13. The thermal boss of claim 12, wherein the thermal interface material of the thermal boss is positioned at an inlet of the coolant channel or an outlet of the coolant channel to thermally connect the inlet of the coolant channel or the outlet of the coolant channel to the temperature sensor.

14. The thermal boss of claim 12, wherein the thermal boss projects from the outer side of the coolant channel.

15. The thermal boss of claim 12, wherein the temperature sensor is connected to a gate driver board of the automotive inverter.

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