Abstract:
A direct current (DC) link capacitor operable within an electrically drivable vehicle having a high-voltage battery is provided configured to facilitate output of a DC voltage to an inverter configured to process the DC voltage to facilitate powering an electric motor used to drive the vehicle. The DC link capacitor includes a housing enclosing capacitive elements configured to facilitate capacitive processing between an input and an output, at least a first pair of terminals configured to deliver the DC voltage to the input, the capacitive elements processing the DC voltage received at the input into a capacitive DC voltage, and at least a second pair of terminals configured to output the capacitive DC voltage to the inverter, the inverter relying on the capacitive DC voltage to facilitate powering the electric motor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of co-pending U.S. patent application Ser. No. 13/209,552 filed on Aug. 15, 2011, the disclosure of which is incorporated in its entirety by reference herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to power module cooling systems, such as but not limited to cooling systems operable with power modules configured to facilitate driving an electric motor with output from a DC/AC inverter. 
     BACKGROUND 
     Power modules may be used for any number of electronic applications where current and/or voltage manipulation is desired. Power modules, in particularly those operable to support relatively high current and voltage requirements, may generate significant amounts of heat during operation. Because the heat can negatively influence performance, it may be desirable to facilitate cooling of the power module. Accordingly, the present disclosure desires to provide a cooling system operable to facilitate the cooling of power modules. 
     SUMMARY 
     One non-limiting aspect of the present disclosure contemplates a power module cooling system comprising: a first power module having a first plurality of cooling fins; a second power module having a second plurality of cooling fins; a cold plate having a top side shaped to receive the first power module and a bottom side shaped to receive the second power module, the top side and the bottom side being spaced apart to define a fluid passageway into which the first and second plurality of cooling fins extend, the fluid passage extending between first and second apertures included within respective first and second lateral sides of the cold plate, the first aperture directing received fluid through the fluid passageway to the second aperture to facilitate cooling of the first and second plurality of cooling fins. 
     One non-limiting aspect of the present disclosure contemplates a first power module seal around an entire perimeter of a top side of the fluid passageway between the cold plate and the first power module and a second power module seal around an entire perimeter of a bottom side of the fluid passageway between the cold plate and the second power module, the first and second power module seals being operable to prevent fluid from leaking out of the fluid passageway. 
     One non-limiting aspect of the present disclosure contemplates a plurality of fastener apertures within the top side and the bottom side of the cold plate outboard of the fluid passageway and the first and second power module seals, the plurality of fastener apertures aligning with corresponding fastener apertures of the first and second power modules through which fasteners extend to secure the first power module and the second power module to the top side and the bottom side of the cold plate. 
     One non-limiting aspect of the present disclosure contemplates the fasteners apertures are operable with the fasteners to facilitate compressing the first power module against the first power module seal and the second power module against the second power module seal. 
     One non-limiting aspect of the present disclosure contemplates a first cooling manifold operable to exchange fluid with the first aperture and a second cooling manifold operable to exchange fluid with the second aperture. 
     One non-limiting aspect of the present disclosure contemplates a first manifold seal around an entire perimeter of the first aperture between the cold plate and the first manifold and a second manifold seal around an entire perimeter of the second aperture between the cold plate and the second manifold, the first and second manifold seals being operable to prevent fluid from leaking out of the fluid passageway. 
     One non-limiting aspect of the present disclosure contemplates a plurality of fastener apertures within the first and second lateral sides of the cold plate, the plurality of fastener apertures aligning with corresponding fastener apertures of the first and second power manifolds through which fasteners extend to secure the first manifold and the second manifold to the first and second lateral sides of the cold plate. 
     One non-limiting aspect of the present disclosure contemplates a capacitor having a height greater than a combined height of the first and second power modules and a width greater than the first power module, the capacitor having at least a first plurality of capacitor terminals connected to the first power module and a second plurality of capacitor terminals connected to the second power module. 
     One non-limiting aspect of the present disclosure contemplates a clamp bracket used to position the capacitor relative to the first and second power modules being fastened to at least two of the cold plate, the first cooling manifold, and the second coolant manifold, the clamp bracket aligning the first and second capacitor terminals with corresponding terminals of the first and second power modules. 
     One non-limiting aspect of the present disclosure contemplates the clamp bracket is not fastened to the capacitor. 
     One non-limiting aspect of the present disclosure contemplates the clamp bracket fastens to both of the cold plate and the first coolant manifold, wherein the second coolant manifold is shaped differently from the first coolant manifold such that the second manifold cannot be fastened to the clamp bracket. 
     One non-limiting aspect of the present disclosure contemplates outboard ends of the first plurality of fins are position no more than 1 mm from outboard ends of the second plurality of fins. 
     One non-limiting aspect of the present disclosure contemplates outboard ends of the first plurality of fins are positioned no closer than 0.1 mm from outboard ends of the second plurality of fins. 
     One non-limiting aspect of the present disclosure contemplates a cooling system for use with a DC/AC inverter, the DC/AC inverter having a first power module comprised at least of a plurality of first switches controlled with a first driver and a physically separate second power module comprised at least of a plurality of second switches controlled with a second driver, wherein each one of the plurality of first switches is electrically connected in parallel with at least a corresponding one of the plurality of second switches, each of the first and second power modules including a plurality of outwardly extending cooling fins, the cooling system comprising: a cold plate having a fluid passageway through which a cooling fluid flows in a longitudinal direction, the cold plate being configured to position the cooling fins of the first and second power modules in an opposing relationship within the fluid passageway to be cooled by the cooling fluid. 
     One non-limiting aspect of the present disclosure contemplates the opposing relationship is characterized by an outboard end of each cooling fin of the first power module being positioned no more than 1.0 mm from an outboard end of a correspondingly opposed one of the cooling fins of the second power module. 
     One non-limiting aspect of the present disclosure contemplates the cold plate includes opposed top and bottom apertures extending longitudinally across substantially the entire longitudinal direction, the cooling fins of the first and second power modules respectively extending through the opposed top and bottom apertures. 
     One non-limiting aspect of the present disclosure contemplates the cold plate includes opposed left and right apertures at correspondingly opposed longitudinal ends, the left and right apertures being transverse to the top and bottom apertures, the right aperture receiving the cooling fluid and the left aperture expelling the cooling fluid, wherein the left and right apertures are smaller than the top and bottom apertures. 
     One non-limiting aspect of the present disclosure contemplates cooling system further comprising: a left manifold configured to exchange the cooling fluid with the left aperture; a right manifold configured to exchange the cooling fluid with the right aperture; a capacitor having a first set of terminals electrically and mechanically connected to the first power module, a second set of terminals electrically and mechanically connected to the second power module, and a third set at terminals electrically and mechanically connected to an EMI filter; and a clamp bracket configured to secure the capacitor relative to the first and second module and the cold plate, the clamp bracket fastening at one portion to the cold plate and at another portion to the coolant manifold. 
     One non-limiting aspect of the present disclosure contemplates a cooling system wherein a height of the cold plate measured transversely to the longitudinal direction is less than a width of the cold plate measured in the longitudinal direction, and wherein a depth of the cold plate measured laterally to the longitudinal direction is greater than the height and less than the width. 
     One non-limiting aspect of the present disclosure contemplates a three-phase DC/AC inverter comprising: a first power module having a first plurality of switches operable to invert a DC input to a three-phase AC output and a first plurality of cooling fins; a separate second power module having a second plurality of switches matching the first plurality of switches and connected in parallel there with, the second power module including a second plurality of cooling fins; and a cold plate having a fluid passageway through which a cooling fluid flows in a longitudinal direction, the first plurality of cooling fins being positioned by the cold plate in an opposing manner to the second plurality of cooling fins to be cooled by the cooling fluid. 
     One non-limiting aspect of the present disclosure contemplates a direct current (DC) link capacitor operable within an electrically drivable vehicle having a high-voltage battery configured to facilitate output of a DC voltage to an inverter configured to process the DC voltage to facilitate powering an electric motor used to drive the vehicle. The DC link capacitor may comprise a housing enclosing capacitive elements configured to facilitate capacitive processing between an input and an output, at least a first pair of terminals configured to deliver the DC voltage to the input, the capacitive elements processing the DC voltage received at the input into a capacitive DC voltage, and at least a second pair of terminals configured to output the capacitive DC voltage to the inverter, the inverter relying on the capacitive DC voltage to facilitate powering the electric motor. The DC link capacitor may further comprise at least a third pair of terminals configured to deliver the DC voltage to the input. The DC link capacitor may further comprise at least a fourth pair of terminals configured to output the capacitive DC voltage to the inverter. According to one non-limiting aspect of the DC link capacitor, the DC voltage may be received from an electromagnetic interference EMI filter and the inverter may comprise a first power module and a second power module, each of the first and second power modules providing a DC/AC conversion that is combined to facilitate powering the electric motor. The first and third pairs of terminals may be configured to electrically and mechanically connect with the EMI filter, and the second and fourth pairs of terminals may be configured to electrically and mechanically connect with the first and second power modules. The housing may have a height greater than a combined height of the first and second power modules and a width greater than the first power module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is pointed out with particularity in the appended claims. However, other features of the present disclosure will become more apparent and the present disclosure will be best understood by referring to the following detailed description in conjunction with the accompany drawings in which: 
         FIG. 1  schematically illustrates a power module system as contemplated by one non-limiting aspect of the present disclosure; 
         FIG. 2  illustrates a power module cooling system as contemplated by one non-limiting aspect of the present disclosure; 
         FIG. 3  illustrates an assembly view of the power module cooling system as contemplated by one non-limiting aspect of the present disclosure; and 
         FIG. 4  illustrates cooling fins in an opposing relationship as contemplated by one non-limiting aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     As required, detailed embodiments are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale. Some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present disclosure. 
       FIG. 1  schematically illustrates a power module system  10  having a power module cooling system  12  as contemplated by one non-limiting aspect of the present disclosure. The power module system  10  is shown for exemplary and non-limiting purposes as being configured to facilitate AC powering of an electric motor and/or alternator  14  included within a vehicle (not shown) with DC energy supply from a high voltage (HV) battery  16  also included within the vehicle. The power module system  10  may include a DC connector  20  operable between an open and a closed position to facilitate connecting and disconnecting the HV battery  16  to an electromagnetic interference (EMI) filter  22 . A DC link capacitor  24  may connected to the EMI filter  22  to further filter the DC output from the HV battery  16 . The DC output of the capacitor  24  may be commonly provided to a first power module  30  connected in parallel with a second power module  32 . The first and second power modules  30 ,  32  may be configured to facilitate DC/AC inversion of the DC output into an AC output sufficient for powering the motor/alternator  14 . 
     The power module system  10  may include an AC connector system  34  to facilitate connecting the AC output to the motor/alternator. A current sensing system  36  may be included to facilitate sensing current provided to the motor/alternator  14 , such as to facilitate control of the DC/AC inversion process. A control board  38  may include a signal connector  40  to a vehicle interface  42  of a vehicle bus (not shown). The control board  38  may receive feedback from the current sensors  36  and other devices/systems within the vehicle to facilitate controlling or directing the DC/AC inversion process. The control board  38  may cooperate with a first driver  46  configured to control the first power module  30  and a second driver  48  configured to control the second power module. The first and second drivers  46 ,  48  may be configured to respectively control a plurality of first and second switches included within each module  30 ,  32  such that the opening and closing of the switches  60 ,  62 ,  64 ,  66 ,  68 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  82  can be coordinated to provide the desired AC output to the motor/alternator  14 . 
     The first and second power modules  30 ,  32  are shown to be configured as insulated-gate bipolar transistors (IGBTs) for exemplary non-limiting purposes. The present disclosure, however, is unnecessary limited to this particular configuration or the use of these components. The present disclosure fully contemplates its use and application to virtually any type of power module system, including those in it may not rely upon switches and/or those that may be operable within non-vehicle-based systems. The exemplary description provided herein, however, is believed to be particularly beneficial in that it contemplates a particular configuration for electrically connecting the power modules  30 ,  32  in parallel to facilitate the DC/AC inversion process and cooling the first and second power modules  30 ,  32  with a cold plate  86  such that a packaging size of the power module system  10 , or at least a portion of the power module system components, may be minimized without unduly sacrificing cooling capabilities. 
     The cold plate  86  is shown schematically in  FIG. 1  to be generally positioned between the first and second power modules  30 ,  32 .  FIG. 2  illustrates the cold plate  86  in more detail and as configured as part of the power module cooling system  12  contemplated by one non-limiting aspect of the present disclosure. The cooling system  12  is shown to include a first coolant manifold  88  and a second manifold  90  configured to facilitate a coolant flow through a fluid passageway  92  included within the cold plate  86 .  FIG. 3  illustrates the power module cooling system  12  in more detail, and in particular, the fluid passage  92  through the cold plate  86 , as contemplated by one non-limiting aspect of the present disclosure. A coolant fluid may be received at the first coolant manifold  88  and expelled from the second coolant manifold  90  such that the cooling fluid flows in a longitudinal direction through the cold plate  86  between corresponding first and second apertures  96 ,  98 . The coolant fluid may comprise any suitable liquid, plasma, or gas having characteristic sufficient to facilitate cooling the first and second power modules  30 ,  32 . 
     The first power module  30  may be received within a top side  100  of the cold plate  86  and the second power module  32  may be received within a matching bottom side  102  of the cold plate  86 . The first power module  30  and the second power module  32  may be arranged in an opposing manner such that a bottom side  104 ,  106  of each is directed towards the other. The bottom side  104 ,  106  of each power module  30 ,  32  may include a plurality of cooling fins (only the second power module  32  Figures are shown and generally referred to with reference numeral  110 ). The cooling fins  110  may be metallic or other thermally conducting material. The cooling fins  110  may extend outwardly away from a first printed circuit board (PCB)  112  and second PCB  114  respectively associated with the first and second power modules  30 ,  32 . The cooling fins  110  may be positioned in a diametrically opposed manner through corresponding top and bottom longitudinal openings  118 ,  120  in the cold plate  86 . The cooling fins  110  may be positioned in this opposed manner so that a volume of the fluid flow passageway is minimized while still allowing both power modules  30 ,  32  to be cooled. While the power modules  30 ,  32  are shown to include a relatively large number of discrete cooling fins  110  shaped as blade terminals, the use of the fins  110  may be omitted entirely and/or the fins  110  may be shaped as larger components or in other configurations suitable to facilitate interactions with the coolant flow. 
     The cooling of the power modules  30 ,  32  through the cooling fins  110  may be maximized by maximizing the amount of fluid flowing contacting the cooling fins  110 . This may be achieved by maximizing interference between the cooling fins  110  in the coolant flow. Optionally, the cooling fins  110  of the first power module  30  may be positioned at a distance X of no more than 1.0 mm from the cooling fins of the second power module, to maximize interference with the coolant flow as shown in  FIG. 4 . More preferably, to ensure the cooling fins  110  provide maximum interference with the coolant flow, the cooling fins of the first power module  30  may be positioned within 0.5 mm of the cooling fins  110  of the second power module  32 . It may be desirable to maintain at least a 0.1 mm distance X between the opposed cooling fins  110  in order to ensure at least some coolant fluid is able to pass from the first coolant manifold  88  to the second coolant manifold  90  to a desired velocity, i.e., the velocity of coolant flow may be proportional to the distance X between the opposed cooling fins. 
     A volume of the coolant passageway  92  may be approximately equal to a width of the cold plate  86  measured in the longitudinal direction between the first and second aperture  96 ,  98  multiplied by a depth of the cold plate  86  measured in the lateral direction between ends of the first aperture  96  multiplied by a height of the cold plate  86  measured in the transverse direction corresponding with a thickness of the cold plate  86  equal to a separation between the top and bottom sides. The height of the coolant passageway  92  may optionally be less than a height of the first power module  30  such that the volume of the coolant passageway  92  is less than a volume comprising one of the first and second power modules  30 ,  32 . In this manner, a coolant passage  92  having a volume somewhat less than the volume of one of the first and second power modules  30 ,  32  may be sufficient to facilitate simultaneously cooling both of first and second power modules  30 ,  32 . The ability to cool multiple power modules  30 ,  32  with a fluid passageway  92  of minimal size may be beneficial in limiting the size and packaging requirements for the power module cooling system  12 , which can be particularly beneficial when used within a vehicle. 
     The cold plate  86  may include a top seal  122  and a matching bottom seal (not shown) positioned around an entire outer perimeter of the respective top and bottom, longitudinal apertures  118 ,  120 . The seals  122  may cooperate with the PCBs  112 ,  114  of the first and second power modules  30 ,  32  to facilitate sealing the coolant passageway  92 . The cold plate may include apertures  130  (only one labeled) outboard of the seals  122  that align with apertures  132  (only one labeled) of the first and second power modules  30 ,  32 . Fasteners (not shown) may be inserted through the apertures  130 ,  132  to press the first and second power module  30 ,  32  against the cold plate  86 , and thereby, the top and bottom seals  122  to facilitate the sealing effects. Additional seals  136  (only left shown) may be included around the entire outer perimeter of the first and second apertures  96 ,  98  to facilitate a sealing arrangement with the respective first and second coolant manifolds  88 ,  90 . Additional apertures  138  (only one shown) may be included to facilitate fastening the coolant manifolds to the cold plate to establish the sealing arrangement around the first and second apertures. 
     The capacitor  24  may be positioned relative to a back side of the cold plate  86  with a clamp bracket  140 . The capacitor  24  may include a first row  142  and a second row  144  of a plurality of terminals for establishing the electrical connections with the corresponding first and second power modules  30 ,  32 , such as to provide the electrical connections shown in shown in  FIG. 1 . The capacitor  24  may include a third row  146  of a plurality of terminals for establishing electrical connections with the EMI filter  22  (the top two terminals may establish the positive connection to the EMI filter  22  and the bottom two terminals may establish the negative connection to the EMI filter  22 ). The clamp bracket  140  may be configured to facilitate positioning the capacitor  24  relative to the power modules  30 ,  32  and the cold plate  86  such that the capacitor  24  is not directly fastened to either one of the power modules  30 ,  32  or the cold plate  86 , other than by soldering or other electrical plus mechanical means used to connect to reporter terminals  142 ,  144 . This arrangement may be beneficial in permitting the use of an off-the-shelf capacitor or without having to include recesses or other fastening points within the capacitor. 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the disclosure. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the disclosure.