Inverter with busbar cooling system

Abstract

Inverters, comprehensive: a case; a DC busbar that is located inside the housing and electrically insulated from the housing; a first compressible heating pad arranged on a first flat surface of the DC busbar near a DC input connector; and a second compressible heating pad, which is arranged on a second flat surface of the DC busbar opposite the first flat surface.

Description

TECHNICAL AREA

[0001] Embodiments of the subject matter disclosed herein relate to inverters and, in particular, to a cooling system for a busbar of an inverter. BACKGROUND AND DETOUR

[0002] Inverters are used in many fields to convert direct current (DC) to alternating current (AC). They are used in a wide variety of applications, such as electric vehicles, solar power plants, and industrial equipment. Inverters are power modules that switch at high frequencies to enable the conversion of DC to AC. Inverters have a DC bus input with either a dual or dual single terminal, two bus bars (one positive and one negative), and an electromagnetic interference (EMI) filter. The DC power required by the inverter is supplied via the DC bus input. Because the DC current can be very high, it generates significant amounts of heat.

[0003] To reduce heat generated by line losses in busbars and connectors, these components are typically oversized to decrease electrical resistance and thus reduce heating. However, increasing the size of the busbars and connectors also increases the overall space requirement of the inverter.

[0004] The inventors recognized the aforementioned problems and developed a cooling system for an inverter assembly that at least partially solves them. In one example, the inverter assembly comprises a housing, a DC busbar located inside the housing and electrically insulated from it, a first compressible heat pad positioned on a first flat surface of the DC busbar near a DC input connector, and a second compressible heat pad positioned on a second flat surface of the DC busbar opposite the first flat surface.

[0005] The DC busbar can thus be positioned between and in thermal contact with the first and second heating pads, which in turn can be in thermal contact with the first and second sections of the housing, respectively. The heating pads can therefore electrically insulate the DC busbar from the housing while simultaneously allowing heat exchange with the housing. The DC busbar can be positioned between the two heating pads to increase heat exchange and thus reduce the amount of heat transferred by the DC busbar.

[0006] Furthermore, the first and second compressible heating pads can be made of a compressible material, such as a spongy material. This allows the heating pads to be compressible and to have different thicknesses compared to other components of the Inverter 100. In this way, the required accuracy in shaping the heating pads and other components can be reduced, resulting in a simpler manufacturing process.

[0007] Note that the above brief description is provided to offer a simplified overview of a selection of concepts that are further described in the full description. It is not intended to identify important or essential features of the claimed subject matter, the scope of which is defined solely by the claims following the full description. Furthermore, the claimed subject matter is not limited to implementations that address the disadvantages mentioned above or elsewhere in this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a representation of an inverter and an example operating environment in which it can be used. Fig. Figure 2 shows a cross-section of the inverter. Fig. 1, wherein the cross-section passes through several chambers in the housing. Fig. Figure 3 shows a cross-sectional view of the inverter. Fig. 1, wherein the cross-section passes through a DC arrangement. Fig. Figure 4 shows a detailed perspective view of the DC busbar arrangement in the inverter of Fig. 1. Fig. Figure 5 shows a cross-sectional view of the inverter. Fig. 1, where the section passes through the DC busbar. Fig. Figure 6 shows an exploded view of the DC busbar assembly in the inverter of Fig. 1. Fig. Figure 7 shows a detailed perspective view of the inverter from Fig. 1. Fig. Figure 8 shows another cross-section of the inverter from Fig. 1. DETAILED DESCRIPTION

[0008] The following description relates to systems for a cooling system of an inverter assembly that reduces heat in a DC bus assembly. The inverter assembly described here includes the DC bus, which is electrically insulated from an inverter enclosure. The DC bus is positioned between two compressible heat pads, a first being located on a first flat surface of the DC bus near a DC input connector, and a second being located on an opposite second flat surface of the DC bus. Each of the heat pads is in contact with a heat exchanger, which is in contact with the enclosure, and the heat exchangers are configured to dissipate heat from the heat pads and the DC bus.

[0009] Fig. Figure 1 shows an inverter 100 that converts direct current (DC) into alternating current (AC). To achieve this functionality, the inverter 100 includes a DC busbar assembly 102 and an AC busbar assembly 104, both of which are electrically connected, either directly or indirectly, to a DC linking capacitor 106. Conductive plates, wiring harnesses, capacitors, cables, combinations thereof, and the like can be used to establish the internal electrical connections in the inverters described here. Likewise, cables, wiring harnesses, combinations thereof, and / or other suitable components can be used to establish electrical connections for electrically coupling the inverter to external components. However, under certain operating conditions, cables can act as antennas that pick up electromagnetic interference (EMI).Therefore, the use of third-party cables within the inverter can be reduced (e.g., avoided) to decrease internal EMI.

[0010] The inverter 100 can be connected to an AC electrical component 108 and a DC electrical component 110 (e.g., a vehicle energy storage system in an electric vehicle (EV) configuration). Cables 109 and 111 and / or other suitable electrically conductive components can be used to electrically couple the AC electrical component 108 and the DC electrical component 110 to the inverter 100. In one example, the inverter 100 can be contained within an EV 112 or another suitable electrical system and can be referred to as the power electronics unit in the EV example. In such an example, the inverter controls the speed of a traction motor in the vehicle. The EV 112 can be a light, medium, or heavy commercial vehicle.In such an example, an AC electrical component 108 could be a traction motor, and the DC electrical component 110 could be a traction battery. Note, however, that the inverter can be found in a number of different environments. For example, the inverter 100 could be found in a solar power plant, an industrial machine, and the like.

[0011] Furthermore, the inverter 100 can include a gate driver circuit board (e.g., a gate driver PCBA) 114 designed to control the power distributed by the inverter 100. In the EV example, the gate driver circuit board 114 controls the power supplied to the traction motor to change the motor's speed. However, as mentioned earlier, the inverter 100 can be used in a variety of operating environments. The gate driver circuit board 114 and the other circuit boards described here can include one or more microprocessors, memory, and similar components to achieve the power matching function. A control board 310 (e.g., the control PCBA), which is located in Fig. As shown in Figure 3, the low-voltage component 116 can receive electrical energy and receive and send signals to it, as indicated by arrows 117. Specifically, electrical connectors 121, which form an external communication interface, serve as a connection between the low-voltage component 116 and a flexible printed circuit board, which is electrically connected to the control board 310 located in Figure 3. Fig. Figure 3 is shown and explained in more detail below. The low-voltage component can include a low-voltage power source and / or a control unit. Therefore, this electrical energy can have a lower voltage than the electrical energy flowing into and out of the inverter via connectors 122 and 125.

[0012] As in Fig. As shown in Figure 1, the intermediate circuit capacitor 106 is electrically coupled to a power module 119 (e.g., a power transistor module) via an electrical interface 118 (e.g., a DC busbar). The electrical interface 120 between the DC busbar assembly 102 and the DC interconnection capacitor 106 is also shown. Furthermore, in Fig. Electrical connectors 122 are shown, which enable efficient electrical coupling between the phase rails in the AC busbar assembly 104 and the AC electrical component 108. DC input connectors 125, which facilitate efficient electrical coupling between DC busbars in the DC busbar assembly 102 and the DC electrical component 110 (e.g., the vehicle's energy storage system, as indicated above), are shown in Fig. Figure 1 is also shown. However, other arrangements of the power module and the DC link capacitor were also considered.

[0013] In the illustrated example, a coolant inlet 128 and a coolant outlet 130 are also included in the inverter 100. A housing 132 (e.g., a casing) can contain coolant lines through which the coolant circulates and which can be hydraulically coupled to the coolant inlet and outlet, such as one or more pumps, a heat exchanger, a filter, and the like. The coolant can include water, glycol, combinations thereof, and the like. In other examples, however, the cooling system may be configured differently or omitted.

[0014] In Fig. 1 is just like in Fig. Figures 2-8 provide a system of axes for reference. In one example, the z-axis can be a vertical axis (e.g., parallel to a gravitational axis), the x-axis can be a lateral axis (e.g., a horizontal axis), and / or the y-axis can be a longitudinal axis. In other examples, however, the axes may have other orientations. The section planes 2-2, 3-3, and 5-5, which define the positions of the elements in the Fig. 2, Fig. 3 and Fig. The 5 cross-sectional views shown are in Fig. 1 is given as a reference.

[0015] Fig. Figure 2 shows a cross-sectional view of the inverter 100. The inverter 100 in the example shown comprises several chambers within the enclosure 132. These chambers include a phase control chamber 200, a DC chamber 202 (e.g., a separate DC chamber), and / or an external communication chamber 204. By dividing the enclosure into these chambers, EMI can be reduced, allowing the inverter to better meet electromagnetic emission targets. The phase control chamber 200 contains (e.g., completely encloses) the gate driver circuit board 114, which is located in Fig. 1 AC busbar arrangement 104 shown and partially encloses a control board 310, which is in Fig. 3 is shown.

[0016] Furthermore, DC chamber 202 contains the in Fig. Figure 1 shows a DC busbar assembly 102, and the external communication chamber 204 can contain LV communication components (e.g., a communication circuit board 206, connectors 208, and the like) designed as an interface to components outside the inverter. The phase control chamber 200 can exhibit higher noise levels than the DC chamber. Furthermore, the external communication chamber can generate less noise than the DC chamber. In this way, the external communication chamber is designed to shield the LV signals from the noise in the phase control chamber.

[0017] The DC phase control chamber 202 can be arranged transversely between the phase control chamber 200 and the external communication chamber 204 (e.g., low-voltage chamber), and the external communication chamber 204 is located transversely on one side 205 of the inverter 100. By dividing the housing into these chambers, EMI can be reduced and thus the power output of the inverter 100 increased. The phase control chamber 200 contains (e.g., at least partially) the gate driver circuit board 114 and the components in Fig. 1 DC busbar 104 shown, the DC chamber 202 contains the in Fig. The DC busbar assembly 102 is shown, and the external communication chamber 204 can contain external communication components (e.g., the communication circuit board 206, the connectors 208, and the like) that serve as an interface to components outside the inverter. The phase control chamber 200 can exhibit a higher level of EMI than the DC chamber 202. Furthermore, the external communication chamber 204 can exhibit less EMI than the DC chamber 202. The different chambers can be separated by walls of the housing 132.

[0018] Fig. Figure 3 shows a cross-sectional view of the inverter 100, in which internal features of the DC busbar assembly 102 are visible. The AC busbar assembly 104 and the capacitor 106 are also shown. The control board 310 is in Fig. 3 is shown in more detail. The control board 310 is designed to change the amount of electrical energy supplied by the power electronics to the external AC electrical component 108 (e.g. the traction motor).

[0019] The DC busbar assembly 102 comprises an input cavity 300 and an inductor 302. In some examples, the inductor 302 may be a ferrite filter. In other examples, the inductor 302 may be made of a nanocrystalline material or another material, depending on the frequencies to be filtered. The inductor 302 may be composed of several sections in some examples. The construction of the inductor is described here with reference to Fig. 4 explained in more detail.

[0020] The inlet cavity 300 can contain an EMI PCB assembly 303. In the example shown, the EMI PCB assembly 303 comprises EMI filter capacitors 400 and a current sensor 402 (see Fig. 3) and an electrical connector 304, which is used for the electrical connection to the gate driver circuit board 114 (see Fig. 1) is designed. The DC busbar assembly 102 is positioned in the DC chamber 202 of the housing 132, as already discussed. In alternative examples, however, the DC chamber and the external communication chamber can also form a single chamber.

[0021] As already indicated, the DC chamber 202 is separated (e.g. insulated) from the other chambers and provides a cleaner zone (with respect to EMI) that contains EMI noise-sensitive components such as the DC busbar assembly 102, the EMI filter capacitors 400 (described in more detail herein) and an electrical interface 350 with the capacitor 106.

[0022] Fig. Figure 3 also shows one of the DC busbars 404 and connector 330, which electrically connect the control board 310 to the DC link capacitor 106. The connectors 330 and the DC busbars 404 are described in more detail below. Furthermore, the control board 310 is shown arranged in the phase control chamber 200.

[0023] Fig. Figure 4 shows a detailed view of the DC busbar assembly 102 with DC busbars 404 having holes or other suitable features that allow the DC busbars to function as an electrical input interface (e.g., as a screwed electrical input interface) to the DC input connectors 125, as shown in Fig. 1 shown. The DC busbar assembly 102 further comprises output busbars 408 (e.g., a screwed electrical output interface), which in the assembled state are connected to the Fig. The capacitor 106 shown in Figure 1 is coupled. The output busbars 408 include lugs with openings to provide a robust electrical connection. The DC busbars 404 and the other busbars described herein may be constructed of a suitable conductive material such as copper, aluminum, brass, combinations thereof, and the like.

[0024] In the example shown, the choke 302 is included in the DC busbar assembly 102. The choke 302 is designed to deflect the EMI noise emanating from the inverter in the direction of the Fig. The DC electrical component 110 shown in Figure 1 is reduced. Consequently, the inverter can be placed closer to the DC electrical component if necessary. In the example shown, the choke 302 extends around the body 410 of the assembly at its center. In other examples, however, the choke may have a different contour (e.g., be located on a top or bottom surface of the busbar assembly body) and / or be located at a different point along the busbar assembly. In the example shown, the body 410, the busbars 404, and the busbars 408 form a continuous shape. However, other busbar assembly configurations may be used in other examples.

[0025] The choke 302 can be constructed from various choke sections 409. These sections can, in particular, comprise an upper section and a lower section which, when joined together, surround the body 410 of the DC busbar assembly 102. By constructing the choke in multiple sections, the DC busbar assembly can be designed more efficiently. The choke sections 409 can be C-shaped so that the filter can conform to the housing 410 of the DC busbar, thereby increasing the space efficiency of the DC busbar assembly.

[0026] The choke 302 can, in particular, be a common-mode filter that selectively removes noise in a specific frequency range while allowing signals in another frequency range to pass through, to give an example. In this way, the DC busbar arrangement can precisely filter out unwanted noise.

[0027] The DC busbar assembly 102 also includes a printed circuit board 412 with EMI filtering and current sensing. In the example shown, the printed circuit board 412 with EMI filtering and current sensing includes the EMI filter capacitors 400, the current sensor 402 (e.g., a Hall sensor), and the connector 304 (e.g., the signal wiring harness). The current sensor 402 measures the DC current flowing through the DC busbars 404. The connector 304 sends signals to the control board 310, which is then processed by ... current sensor 402 (e.g., the signal wiring harness). Fig. Figure 3 shows that wires can be used to transmit signals between connector 304 and control board 310. The EMI filter capacitors 400 reduce the amount of EMI noise coming from the inverter towards the external electrical DC component 110 (towards the vehicle's high-voltage power distribution system).

[0028] The EMI filter and current measurement board 412, with its measurement and filter components, can be positioned between the DC busbars 404 and the choke 302, relative to the y-axis. This protects the circuitry on the board from EMI, thereby increasing the inverter's performance compared to inverters without the EMI filtering features described herein.

[0029] The positioning of the circuit board with EMI filtering and current sensing 412 near the DC input connectors 125, as shown in Fig. As shown in Figure 1, this allows the current sensor to be located closer to the DC busbars 404 than at other locations, e.g., near the rear of the DC busbar assembly 102. In this way, the sensor's current measurement can be simplified, so that the signal can be processed with fewer processing resources if desired.

[0030] It is also understood that a field concentrator in the inverter can be omitted if the circuit board with EMI filtering and current sensing 412 is placed near the input connectors 125 (e.g., near the front of the DC busbar assembly 102), as shown in Fig. Figure 1 illustrates this. If the field concentrator is omitted, the DC current sensor signal can be filtered and compensated to remove the DC components from the signal. DC signal processing can include one or more of the following processing strategies: offset calibration, gain calibration, low-pass filtering, and cancellation of external fields (e.g., removing the influence of nearby conductors such as phase busbars).

[0031] Fig. Figure 5 shows a cross-section of the DC busbar assembly 102. As described above, the DC busbar assembly 102 can comprise one or more DC busbars, including the DC busbar 408, as shown in Fig. Figure 5 shows the DC busbar assembly 102 can be cooled via a system of heating pads.

[0032] The DC busbar 408 can be surrounded by a first heating pad 502 and a second heating pad 504, such that the DC busbar 408 is arranged between the first and the second heating pads 502, 504. In some examples, the first heating pad 502 can be in planar contact with a first flat surface 520 of the DC busbar 408. The first flat surface 520 can be located near the DC input connector (e.g., the DC input connector 125 in Fig. 1) are located. In other examples, a first insulating paper 524 can be arranged between the first heating pad 502 and the first flat surface 520 of the DC busbar 408. For example, the first heating pad 502 can be in planar contact with the first insulating paper 524 on a first side 590, and the DC busbar 408 can be in planar contact with the first insulating paper 524 on a second, opposite side 592.

[0033] Similarly, in some examples, the second heating pad 504 can be arranged in planar contact with a second flat surface 522 of the DC busbar 408. The second flat surface 522 can be located opposite the first flat surface 520. In other examples, a second insulating paper 526 can be arranged between the second heating pad 504 and the second flat surface 522 of the DC busbar 408. For example, the second heating pad 504 can be in planar contact with the second insulating paper 526 on its second side 592, and the DC busbar 408 can be in planar contact with the second insulating paper 526 on its first, opposite side 590. Thus, the second heating pad 504 can be positioned towards the first side 590 of the DC busbar 408, and the first heating pad 504 can be positioned towards the second side 592 of the DC busbar 408.The first and second layers of insulating paper can be arranged to protect the components, reducing conductivity and thus increasing durability and reliability.

[0034] The first and second heat pads 502 and 504 can be compressible. For example, the heat pads can be made of a compressible material that is flexible for various end applications, as the heat pads can be compressed and form different thicknesses among other components of the inverter 100. The compressible heat pads can, for example, have a compressibility of 25% to maintain thermal efficiency. In this way, the required accuracy in shaping the heat pads and other components can be reduced, enabling a simpler manufacturing process.

[0035] The first heating pad 502 can also be in planar contact with a first section 512 of the housing 132. In some examples, the first section 512 can be part of the main housing of the inverter. The first section 512 of the housing can serve as a heat exchanger to dissipate the heat generated by the DC busbar 408. The first heating pad 502 can be in contact with the first section 512 on a side of the heating pad opposite the side in contact with the busbar. The first heating pad 502 can be attached to one or both sections, the first section 512 and the DC busbar 408, with an adhesive. For example, the adhesive can be applied to one side of the heating pad, and the position of the heating pad can be maintained by the adhesive and the pressure of components of the arrangement.

[0036] Similarly, the second heating pad 504 can be in planar contact with a second section 514 of the housing 132. The second section 514 of the housing can be a cover used to close the DC chamber. Like the first section 512, the second section 514 can serve as a heat exchanger to dissipate the heat generated by the DC busbar 408. The second section 514 of the housing can be located on the side of the second heating pad 504 opposite the DC busbar 408. Thus, the DC busbar 408 can be surrounded by the first and second heating pads 502 and 504, which in turn can be surrounded by the first and second sections 512 and 514 of the housing. In this way, the DC busbar 408 can be positioned inside the housing and electrically insulated from it by the heating pads.The two heating pads surrounding the DC busbar 408 provide an additional surface area for cooling and heat dissipation, thereby increasing heat exchange between the housing and the busbar. Furthermore, the heating pads can electrically insulate the DC busbar from the housing.

[0037] In some examples, a third compressible heating pad 508 can be installed in the inverter 100. The third heating pad 508 can be located on a side of the first section 512 of the housing 132 opposite the first heating pad 502. For example, the first heating pad 502 can be in thermal contact with the first side 590 of the first section 512, and the third heating pad 508 can be in thermal contact with the second side 592 of the first section 512. The third heating pad 508 is described further below in Fig. 7 described. The third heating pad 508 can be set up to cool the passive discharge of the capacitor, in some examples.

[0038] Fig. Figure 6 shows the inverter 100 with the housing 132 and the DC busbar assembly 102 in a split view. The DC busbar assembly 102 comprises the DC busbars 404, which are formed on a conductive plate, and the choke 302, which can at least partially surround the conductive plate and reduces the amount of EMI noise exiting the DC chamber. In this way, the likelihood of the inverter causing unwanted electromagnetic interference with surrounding components is reduced. The DC input connectors 125, as well as the coolant inlet 128 and the coolant outlet 130, are also shown in Figure 6. Fig. 6 shown.

[0039] The choke 302 can be constructed from several sections 409 (e.g., an upper and a lower section), as shown in the illustrated example. In the assembled state, the sections 409 surround the body 410 of the DC busbars 404 and 408.

[0040] To reduce the transmission of vibrations to the DC busbar assembly 102, a resilient pad 600 and, in some examples, a support structure 602 (e.g., a polymer support) can be used to mount the DC busbar assembly to the housing 132. The resilient pad 600 can be made of polymer foam to dampen vibrations. The resilient pad 600 reduces the movement of the choke 302, thereby reducing the transmission of its vibrations to the busbar body 410. Limiting the movement of the choke 302 reduces the risk of the choke damaging (e.g., puncturing) the electrical insulating materials that may be placed on and around the busbar. Additionally, an adhesive material, such as a glue, can be applied between the choke 302 and the DC busbars 404 to further reduce the movement of the choke 302.

[0041] Furthermore, the support structure 602 can be made of a polymer to prevent an undesired electrical connection between the housing 132 and the DC busbar assembly 102. The support structure 602 holds the choke 302 around the busbar body 410. Additionally, the support structure 602 can compress the choke 302 to further reduce the likelihood of choke vibrations. To achieve targeted filter compression of the support structure 602, the thread engagement between the mounting devices and the housing can be adjusted. However, other techniques for improving filter compression have also been considered.

[0042] Furthermore, the support structure 602 can have fastening interfaces 604 designed to accommodate fastening devices (e.g., screws, bolts, combinations thereof, and the like) for attachment to the housing. In the illustrated example, the support structure 602 includes a recess 606 dimensioned to accommodate the flexible cushion 600 and at least part of the choke 302. The recess 606 can have a rectangular cross-section to efficiently connect the support and filter in this example. However, other contours of the support structure recess can be used in alternative examples. The use of a support structure and a flexible support with the above-mentioned features increases the space efficiency of the inverter while providing the desired filter functionality.

[0043] Fig. Figure 6 further shows walls 608 of the housing 132, which can delimit the DC chamber 202. The walls 608 can each extend vertically. In addition, one of the walls can extend longitudinally and another transversely. In this way, the DC chamber can be shaped to enclose the DC busbar assembly in a space-saving manner. However, other contours of the DC chambers were also considered.

[0044] Fig. Figure 7 shows a cross-section through the 100 inverter. The one in Fig. The inverter 100 shown in Figure 7 has a current sensor 700 located on the control board 310, as opposed to the EMI filter and current measurement board. The current sensor 700 measures the current flowing through a current busbar 704, which electrically couples the DC busbars 408 to the capacitor 106. Field concentrators can also be omitted in the inverter 100 to simplify the inverter's design and increase its space utilization.

[0045] By positioning the current sensor 700 on the control board 310, the signal path to the microprocessor (which can also be located on the control board) can be reduced if desired. Positioning the current sensor 700 on the control board 310 also makes it possible to avoid the use of a connection and cable system in the signal path if necessary.

[0046] Fig. Figure 7 also shows discharge resistors 706 connected to the control board 310. In the example shown, the discharge resistors 706 are connected to the control board 310 and the third heat pad 508. The discharge resistor 706 can be in thermal contact with the housing 132 via the third heat pad 508. The discharge resistors 706 can be positioned in recesses of the third heat pad 508 to increase the amount of heat transferred from the resistors to the housing 132. Sections of the third heat pad 508 between the recesses can be in contact with a lower surface 711 of the control board 310. The discharge resistor 706 discharges the DC link capacitor 106 when the inverter assembly is switched off. The discharge function of the resistor 706 can be implemented passively and without control inputs.

[0047] Fig. Figure 7 also shows an electrical spring connector 710, which establishes an electrical connection between the control board 310 and the busbar 704. The electrical spring connector 710 can be used in addition to or as an alternative to the connectors shown in Figure 7. Fig. The 3 connectors shown are used.

[0048] The third heat pad 508 can be connected to the underside 711 of the control board 310 and to the first section 512 of the housing 132, which is connected to the DC busbar assembly 102. In this way, the first section 512 of the housing 132 can form a common cooling surface between the discharge resistor and the DC busbar. By constructing the inverter with the resistors 706 and the third heat pad 508, the area efficiency of the inverter can be increased and, if desired, the number of circuit boards in the inverter can be reduced.

[0049] In Fig. Figure 8 shows the DC busbar assembly 102 again in a cross-sectional view. As described above, the DC busbar assembly 102 comprises the DC busbar 404 and the DC busbar 408. The DC busbar 408 can be cooled via the first and second heat pads 502 and 504. The first section 512 of the housing 132 can be a common cooling surface between the discharge resistor (e.g., the resistors 706) and the DC busbar 408.

[0050] As in Fig. As shown in Figure 8, the first section 512 of the housing 132 can be arranged vertically above the DC busbar 408 and the second section 514 of the housing 132 vertically below the DC busbar 408. In this way, the intervening heat pads (e.g., the first compressible heat pad between the DC busbar 408 and the first section 512 and the second compressible heat pad between the DC busbar 408 and the second section 514) can surround the DC busbar both above and below, thus increasing the surface area for heat exchange with the housing.

[0051] The DC busbar 408 can have one or more through-openings 802 through which a fastening element 804 can be passed. The fastening element 804 can be guided through the through-openings 802 in the direction of the heat-conducting material (e.g., the heat-conducting pad).

[0052] Fig. Figure 8 also shows a sealing cover 806 of the housing 132. The sealing cover 806 can be formed as part of the first section 512 of the housing 132 or otherwise connected to it. The sealing cover 806 can extend around and under the choke 302 and also under the DC busbar 408. With this arrangement, the DC busbar assembly 102 can exhibit lower EMI.

[0053] The disclosure also provides a mounting for an inverter, comprising: a housing, a DC busbar arranged within and electrically insulated from the housing, a first compressible heating pad arranged on a first flat surface of the DC busbar near a DC input connector, and a second compressible heating pad arranged on a second flat surface of the DC busbar opposite the first flat surface. In a first example of the system, the first compressible heating pad is in thermal contact with a first section of the housing. In a second example of the system, which optionally includes the first example, the first section of the housing is configured as a heat exchanger.In a third example of the system, optionally comprising one or both of the first and second examples, the first section of the enclosure is configured as a common cooling surface between a discharge resistor and the DC busbar. In a fourth example of the system, optionally comprising one or more or each of the first through third examples, the system further comprises: a third compressible heat pad arranged in thermal contact with the first section of the enclosure and the discharge resistor, wherein the first compressible heat pad is arranged on a first side of the first section of the enclosure and the third compressible heat pad is arranged on a second side of the first section of the enclosure.In a fifth example of the system, optionally comprising one or more or each of the first four examples, the system further comprises: a first insulating paper arranged between the first compressible heating pad and the first flat surface of the DC busbar. In a sixth example of the system, optionally comprising one or more or each of the first five examples, the system further comprises: a second insulating paper arranged between the second compressible heating pad and the second flat surface of the DC busbar. In a seventh example of the system, optionally comprising one or more or each of the first six examples, the second compressible heating pad is in thermal contact with a second section of the housing.In an eighth example of the system, which optionally includes one or more or each of the first to seventh examples, the first and second compressible heat pads are arranged for heat exchange from the DC busbar to the enclosure.

[0054] The disclosure also provides support for a cooling system for a DC busbar of an inverter, comprising: a first heating pad arranged on a first side of the DC busbar, and a second heating pad arranged on a second, opposite side of the DC busbar, wherein the first and second heating pads are in thermal contact with the DC busbar and with an enclosure of the inverter. In a first example of the system, the first and second heating pads are made of a compressible material. In a second example of the system, which optionally includes the first example, the first heating pad is in thermal contact with a first section of the enclosure, wherein the first section of the enclosure is arranged vertically above the DC busbar.In a third example of the system, optionally comprising one or both of the first and second examples, the system further comprises: a third heat pad in thermal contact with the inverter housing, the third heat pad comprising recesses configured to contact a discharge resistor. In a fourth example of the system, optionally comprising one or more or each of the first through third examples, the first section of the housing is configured as a heat exchanger between the third heat pad and the first heat pad. In a fifth example of the system, optionally comprising one or more or each of the first through fourth examples, the first section of the housing is configured as a common cooling surface between the discharge resistor and the DC busbar.In a sixth example of the system, which optionally includes one or more or each of the first five examples, the second heating pad is in thermal contact with a second section of the housing, the second section of the housing being arranged vertically below the DC busbar. In a seventh example of the system, which optionally includes one or more or each of the first six examples, a first insulating paper is arranged between the first heating pad and the DC busbar, and a second insulating paper is arranged between the second heating pad and the DC busbar.

[0055] The disclosure also provides a mounting for a power electronics unit for a traction motor, comprising: a DC chamber, which includes: a DC busbar assembly comprising at least one DC busbar, wherein the DC busbar is positioned between and in thermal contact with a first compressible heating pad and a second compressible heating pad. In a first example of the system, the DC busbar assembly is electrically isolated from a housing of the power electronics unit via the first and second compressible heating pads.In a second example of the system, which optionally includes the first example, the first compressible heating pad is in thermal contact with a first section of the housing, which is arranged vertically above the DC busbar, and the second compressible heating pad is in thermal contact with a second section of the housing, which is arranged vertically below the DC busbar.

[0056] Fig.Figures 1-8 show example configurations with the relative arrangement of the various components. If these elements are in direct contact with each other or directly coupled, they can be described as being in direct contact or directly coupled, respectively, in at least one example. Similarly, elements shown side by side or adjacent to each other can be described as being adjacent to each other or adjacent to each other, respectively, in at least one example. For instance, components that are in planar contact with each other can be described as being in planar contact. As another example, elements that are separated from each other, with only a gap between them and that have no other components, can be described as such in at least one case.In yet another example, elements that are displayed above / below each other, on opposite sides, or to the left / right of each other can be described as such, relative to one another. Furthermore, in at least one example, as shown in the figures, a topmost element or the highest point of an element can be referred to as the "top" of the component, and a bottommost element or the lowest point of the element can be referred to as the "bottom" of the component. The terms top / bottom, upper / lower, and above / below used here can refer to a vertical axis of the figures and be used to describe the positioning of elements within the figures relative to each other. Thus, in one example, elements displayed above other elements are arranged vertically above the other elements.As a further example, the shapes of the elements depicted in the figures can be described as such (e.g., circular, straight, flat, curved, rounded, beveled, angled, etc.). Furthermore, the depicted elements that intersect each other can be described as intersecting elements or as mutually intersecting elements in at least one example. Additionally, for example, an element shown inside or outside another element can be described as such.

[0057] The following claims highlight in particular certain combinations and subcombinations that are considered novel and not obvious. These claims may refer to "one" element or "a first" element, or the equivalent thereof. Such claims are to be understood as including one or more such elements, with two or more such elements neither required nor excluded. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application. Such claims, whether they have a broader, narrower, the same, or different scope than the original claims, are also considered to be included in the subject matter of the present disclosure.

Claims

[1] Inverters, including: a case; a DC busbar that is located inside the housing and electrically insulated from the housing; a first compressible heating pad arranged on a first flat surface of the DC busbar near a DC input connector; and a second compressible heating pad, which is arranged on a second flat surface of the DC busbar opposite the first flat surface. [2] Inverter according to claim 1, wherein the first compressible heat pad is in thermal contact with a first section of the housing. [3] Inverter according to claim 2, wherein the first section of the housing is designed as a heat exchanger. [4] Inverter according to claim 2, wherein the first section of the housing is configured as a common cooling surface between a discharge resistor and the DC busbar. [5] Inverter according to claim 4, further comprising a third compressible heat pad arranged in thermal contact with the first section of the housing and the discharge resistor, wherein the first compressible heat pad is arranged on a first side of the first section of the housing and the third compressible heat pad is arranged on a second side of the first section of the housing. [6] Inverter according to one of the preceding claims, further comprising a first insulating paper arranged between the first compressible heat pad and the first flat surface of the DC busbar. [7] Inverter according to one of the preceding claims, further comprising a second insulating paper arranged between the second compressible heat pad and the second flat surface of the DC busbar. [8] Inverter according to one of the preceding claims, wherein the second compressible heat pad is in thermal contact with a second section of the housing or wherein the first and the second compressible heat pads are arranged for the thermal exchange of heat from the DC busbar to the housing. [9] Cooling system for a DC busbar of an inverter, comprising: a first heating pad arranged on a first side of the DC busbar; and a second heating pad located on a second, opposite side of the DC busbar, wherein the first and second heating pads are in thermal contact with the DC busbar and with an inverter housing. [10] Cooling system according to claim 9, wherein the first and second heat pads are formed from a compressible material. [11] Cooling system according to claim 9 or 10, wherein the first heat pad is in thermal contact with a first section of the housing, the first section of the housing being arranged vertically above the DC busbar. [12] Cooling system according to claim 11, further comprising a third heat pad in thermal contact with the housing of the inverter, wherein the third heat pad comprises recesses configured to contact a discharge resistor, wherein the first section of the housing is configured as a heat exchanger between the third heat pad and the first heat pad. [13] Cooling system according to claim 12, wherein the first section of the housing is configured as a common cooling surface between the discharge resistor and the DC busbar. [14] Cooling system according to one of claims 9 to 13, wherein the second heat pad is in thermal contact with a second section of the housing, wherein the second section of the housing is arranged vertically below the DC busbar, and / or wherein a first insulating paper is arranged between the first heat pad and the DC busbar and a second insulating paper is arranged between the second heat pad and the DC busbar.

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