Patent Publication Number: US-9420724-B2

Title: Power converter assembly

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     This invention was made with government support under Contract No. SPM4A1-09-G-0003/BR03 awarded by the United States Army. The Government has certain rights in this invention. 
    
    
     BACKGROUND OF THE INVENTION 
     Power converters are utilized to convert electrical energy from one form to another, such as converting between AC and DC, or modifying any combination of voltage, current, and/or frequency from an input power to a resulting output power. Higher-power converters may include components capable of dealing with higher temperature operation due to, for example, high voltage and/or high current thermal losses. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one embodiment, a power converter assembly includes a housing, a cold plate located within the housing, a power converter module conductively coupled with the cold plate, receiving a power input, and providing a power output, heat-sensitive circuitry located within the housing and having a predetermined thermal operating limit, and a thermal composite overlying the power converter module and at least partially thermally insulating the power converter module from the heat sensitive circuitry. The power converter module generates heat while converting the power input to the power output, the thermal composite insulates the heat-sensitive circuitry from at least a portion of the generated heat such that the temperature of the heat-sensitive circuitry does not rise above the thermal operating limit, and at least a portion of the generated heat is removed by way of conduction through the cold plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a perspective view of a power converter assembly in accordance with one embodiment of the invention. 
         FIG. 2  is an exploded perspective view of the power converter assembly of  FIG. 1 , showing a heat exchanger assembly, and a thermal composite. 
         FIG. 3  is an exploded perspective view of the thermal composite of  FIG. 2 . 
         FIG. 4  is a top view of the power converter assembly of  FIG. 2 . 
         FIG. 5  is an electrical schematic view of the power converter assembly of  FIGS. 1-4 . 
         FIG. 6  is an exploded perspective view of a power converter module of  FIG. 4 . 
         FIG. 7  is a top view of the power converter with a module potting frame and cover removed for clarity. 
         FIG. 8  is an exploded view of a circuit board for the power converter module of  FIG. 7 . 
         FIG. 9  is an exploded perspective view of the heat exchanger assembly of  FIG. 1 . 
         FIG. 10  is a top view of a partial schematic view of coolant flow paths through a portion of the heat exchanger assembly. 
         FIG. 11  is a top view of internal coolant passageways of the primary cold plate of the heat exchanger assembly of  FIG. 9 . 
         FIG. 12  is a top view of the internal coolant passageways of secondary and tertiary cold plates of the heat exchanger assembly of  FIG. 9 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     Embodiments of the invention may be implemented in any environment utilizing a power converter to convert power from one form to another. Non-limiting examples of power converter utilization may include stepping up or stepping down voltage signals, increasing or decreasing current, converting AC power to DC power, or vice versa. Non-limiting examples of environments utilizing the power converter apparatus may include mobile or fixed structures, mobile vehicles including any land, sea, or air-based vehicles. 
       FIG. 1  illustrates a power converter assembly  10  enclosed within a housing  12  (shown as a dotted box) such that the assembly  10  is included within the cavity  14  defined by the housing  12 . The power converter assembly  10  may include several thermal regulating devices such as primary cold plate  16 , thermal composite  20 , and heat exchanger assembly  22 . The heat exchanger  22  may further include a mounting bracket  23  for, in one example, mounting the heat exchanger  22  with the housing  12 . Any suitable mechanical coupling, such as mechanical fasteners, bolts, nails, pins, etc., as well as non-mechanical fasteners, such as welding or adhesives, may be used to mount the exchanger  22  with the housing  12 . 
     The cold plate  16  may define a portion of the housing  12 , such as a bottom planar wall, and may further include a fluid connection port  24  having an inlet port  26  and an outlet port  28  and extending through the housing  12 , external to the cavity  14 , to provide an external coupling for, respectively, receiving and returning fluid delivered to the cold plate  16 . 
     The power converter assembly  10  may additionally include a coolant reservoir  30 , illustrated as a schematic box having coolant  32  coupled with the fluid connection port  24  and configured to, respectively, deliver coolant  32  to the inlet port  26 , and receive the returned coolant  32  from the outlet port  28 . In one example, the coolant reservoir  30  may be configured having a coolant pump  34  integrated with the reservoir  30  that may be capable of delivering 2.4 to 3.2 gallons per minute (gpm) of coolant to the power converter assembly  10 . One non-limiting example of a suitable coolant may include a glycol fluid mixture. Embodiments of the invention may further include a coolant reservoir  30  configured with integrated or external mechanisms to cool and/or maintain the temperature of the coolant below a predetermined value, which can be a function of the specific environment for the power converter assembly  10  and/or specific characteristics of the power converter assembly  10 . An illustrative predetermined value for a contemplated environment is 71 degrees Celsius, however alternative environmental temperatures, or temperature range for designated operations, may be included. Additionally, while liquid coolant  32  is illustrated, alternative coolant fluids, such as gases, may be included. Particular compositions of coolant  32  fluids are not germane to embodiments of the invention. 
     In the contemplated environment where heat removal is important, the housing  12  may be constructed from a thermally conductive material, such as aluminum, and may include additional housing elements configured for heat management considerations, for example pin fins. The housing  12  may further be exposed to one or more additional cooling mediums, such as ambient air or forced convection air delivered to the outer surface of the housing, if needed for heat management considerations. In one example configuration, the power converter assembly  10  and housing  12  may include a volume defined by 12 inches (width) by 12 inches (length) by 6 inches (height). Additional configurations may be included having alternative measurements and a total volume less than 1000 cubic inches. 
       FIG. 2  illustrates an exploded perspective view of the power converter assembly  10  with the thermal composite  20  and heat exchanger  22  exploded away from the cold plate  16  to better illustrate heat generating components  36 , such as power converter  40 , for example, and heat sensitive circuitry, such a driver circuitry  18 , which may drive the power converter assembly  10 . The thermal composite  20  functions to insulate the heat generating components  36  from the heat sensitive circuitry  18 . As shown, the thermal composite  20  is configured and/or shaped to further the components  36  within a space defined by the composite  20  walls and, for example, the cold plate  16 . Embodiments of the invention may include configurations wherein the components  36  are not completely enclosed within a space defined by the composite  20  walls and the cold plate  16 . For example, as shown, the composite  20  may include one or more access openings  38  to provide for connections to components underneath the thermal composite  20 . 
     Additionally, embodiments of the invention may include configurations wherein at least one of the composite  20  wall edges and/or the cold plate  16  may be configured to account for the geometry of specific components  36  positioned directly between the composite  20  and plate  16  such that the composite  20  substantially encloses a majority, but not all, or only a portion of all of the components  36 . Alternatively, embodiments of the invention may include configurations wherein at least one of the composite  20  wall edges and/or the cold plate  16  may be configured and/or keyed to correspond with the opposing composite  20  or cold plate  16  configurations. For example, at least one composite  20  wall edge is illustrated having a cutout  39  configured to match the fluid connection port  24  of the cold plate  16 . Additional configurations and/or cutouts may be included. 
     Embodiments of the invention may include configurations wherein at least one of the plurality of components  36  may include a heat-producing electrical component  40  or circuitry, while one or more other electronics may be considered “heat-sensitive” circuitry. In general, “heat-sensitive” circuitry may operate under limited temperature ratings, and may malfunction or fail if the circuitry temperature or ambient temperature rises above a thermal limit value. In one such example, a thermal limit value of the driving circuitry board may be 105 degrees Celsius. In embodiments of the invention wherein the at least one heat-producing component  40  generates sufficient heat to rise the temperature above the thermal limit value, the thermal composite  38  may be configured to enclose at least a portion of the heat-producing component  40  in order to thermally isolate and/or insulate the heat-producing component  40  from the heat-sensitive board  18 . However, those skilled in the art may understand the viability of heat-sensitive circuitry located proximate to heat-producing components is a relative standard, which may be affected by thermal management concerns, thermal configurations, heat removal capabilities, and the design of the respective heat-sensitive and heat-producing components. The referenced temperature and/or temperature ranges are merely an example of thermal limits. 
     As used herein, any component that is capable of generating an amount of heat that may be detrimental to another component should the heat raise the temperature of the environment or the another component may be considered a heat-producing component. Likewise, any component that may be detrimentally affected by heat introduced into an environment may be considered heat-sensitive circuitry. 
       FIG. 3  illustrates an exploded view of the thermal composite  20 . As shown, the thermal composite  20  may comprise at least a first rigid electrically insulating layer  42 , a second rigid electrically insulating layer  44 , and a third thermally insulating layer  46  positioned between the first and second layers  42 ,  44 , which, when combined, forms a composite structure. In one non-limiting embodiment, at least one of the first and/or second layers  42 ,  44  may comprise Nomex material of 0.25 millimeters thickness, each. One embodiment may also include a third layer  46  comprising a poor thermal conductive material capable of tolerating high temperatures up to, for instance, 650 degrees Celsius, without any effects on the composition of the material. One non-limiting example of a third layer  46  material may include as Pyrogel, or Aerogel, with a thickness of 0.125 millimeters. 
     In the above-described thermal composite  20  example, the third layer  46  material may also include an embedded powder that increases the thermal insulating properties of the layer  46 , such as silica. The assembling of the first, second, and third layers  42 ,  44 ,  46  may act to “sandwich” the third layer  46  having the powder, such that the powder does not readily escape from, or is retained by, the third layer  46  material. As described, the thermal composite  20  may be configured such that the composite  20  provides at least a minimum temperature gradient from the underside of the composite  20  to the topside of the composite  20  of 40 degrees Celsius. Alternative material compositions and/or thicknesses may be included to account for thermal considerations of the power converter assembly  10 . 
     The thermal composite  20  may further comprise at least one thermally resistant fastener, such as thermally resistant tape, thermally resistant thread, or thermally resistant adhesive, which may secure at least two of the first, second, and/or third layers  42 ,  44 ,  46  together to for the unified composite layer  20 . Non-limiting examples of the thermally resistant fastener may further include Kapton tape. 
     Also shown, the composite  20  may additionally comprise a number of subcomponents that may provide for specific structures or specific functionality, while still comprising the same layers  42 ,  44 ,  46  described above. For example, a large access opening  48  is shown as well as a first composite subcomponent  50  having a configuration corresponding to the large access opening  48 , such that when assembled, the first composite subcomponent  50  may be removably coupled with the composite  20  for inspection and/or maintenance of the components  36  enclosed by the composite  20 . Another second composite subcomponent  52  is also shown, which, for example, may be removably coupled with the composite  20  for inspection and/or maintenance of the fluid connection port  24 . Embodiments of the invention may include a similar composite composition of the layers  42 ,  44 ,  46  described above. Each of the composite subcomponents  50 ,  52  may be coupled with the composite  20  by, for example, one or more thermally resistant fasteners, as described above. Alternatively, embodiments of the invention may include one or more configurations of the subcomponents wherein the composite subcomponents comprise dissimilar layers and/or thicknesses, for example, to account for thermal considerations of the whole or a portion of the corresponding power converter assembly  10 . 
     The rigidity of at least one of the first and/or second layers  42 ,  44  may further be configured to define a self-supporting structural and/or geometric shell for the composite  20 . Embodiments of the invention may include thermal composites  20  formed or assembled into particular geometric profiles to address large and/or small surface areas of any desired geometric shape. For example, when formed or assembled using the one or more thermally resistant fasteners, the first, second, or both layers  42 ,  44  may define a structural profile at least partially formed to correspond to the contours of a profile of the components  36 , or the at least one heat-producing component  40 . In another example, the first, second, or both layers  42 ,  44  may define a profile that is intentionally and at least partially spaced from the components  36  or at least one heat-producing component  40   
     When assembled, the composite  20  not only provides for thermal insulation, but also electrical insulation of the at least one heat-producing electrical component  40  from other components outside of the thermal composite  20 , such as the heat-sensitive boards  18 . Embodiments of the invention may further include composite  20  configurations that provide additional functionality, such as hydrophobicity. Additional embodiments of the invention may also include at least one additional electrically insulating layer and at least one additional thermally insulating layer, wherein each of the thermally insulating layers are alternately layered between the respective electrically insulating layers, and may be combined as a single thermal composite  20 , to provide for specific electrical or thermal insulating properties and/or temperature gradients. 
     Turning now to  FIG. 4 , a top perspective view of the power converter assembly  10  is shown with both the thermal composite  20  and heat exchanger  22  removed to better illustrate various components. The assembly  10  may further comprise at least one additional secondary cold plate, or “daughter” cold plate, shown including a secondary cold plate  54  and a tertiary cold plate  56 . Each of the secondary and tertiary cold plates  54 ,  56  may be directly or indirectly fluidly coupled with at least one of the primary cold plate  16  and/or the fluid inlet  26  and fluid outlet  28  of the fluid connection port  24 . For example, as shown, the fluid connection port  24  may be fluidly coupled with the secondary cold plate  54  via a first flexible tubing set  58 , and the secondary cold plate  54  may be further fluidly coupled with the tertiary cold plate  56  via a second flexible tubing set  60 . One example of flexible tubing may include flexible stainless steel tubing. While flexible stainless steel tubing is described, embodiments of the invention may include non-flexible tubing, swage-type fittings, or tubing constructed from material other than stainless steel. 
     The power converter assembly  10  may further comprise at least one inductor  62  underlies the secondary cold plate  54 , and is illustrated as four inductors  62  in dotted line, and at least one transformer  64  underlies the tertiary cold plate  56 , as is illustrated as two transformers  64 , also in dotted line. While the inductors  62  and transformers  64  are illustrated in dotted line, it is understood the dotted lines are merely schematic representations of the aforementioned components, and the dotted lines may not accurately represent the profile, size, shape, and/or configuration of each respective component described. Each of the inductors  62  and transformers  64  may be configured for use in high power applications, and may be collectively referred to as “power magnetics devices.” In one example embodiment, one or more transformers  64  may include a high-frequency switch mode transformer, which for example, may be driven by a respective one or more of the driving circuitry boards  18 . 
     The power converter assembly  10  may also comprise at least one power converter module  66 , illustrated as two power converter modules  66 . Each power converter module  66  includes at least one anode terminal  68  electrically coupled to at least one of the transformers  64  by an anode bus bar  70 , and at least one cathode terminal  72  electrically coupled to at least one inductor  62  by a cathode bus bar  74 . The anode  68  and cathode  72  may be electrically coupled with each respective bus bar  70 ,  74  by at least one of a mechanical or non-mechanical fastener. As shown, the anode  68  and cathode  72  may be fastened using a mechanical fastener, such as a screw  76 . The top perspective view further illustrates a coupling location  77  for the heat exchanger  22   
     An example electrical schematic of the power converter assembly  10  of  FIG. 4  is illustrated in  FIG. 5 . As shown, an external, high voltage and/or high capacity power source  78  such as a battery bank or generator may generate and supply a predetermined power amount, shown as a voltage input  80  to a bank of high-frequency switching circuits, for example high power half-bridge modules  82 , such as MOSFET half-bridge modules. The half-bridge modules  82  may be, for example, driven by the one or more driving circuitry boards  18 . In one example configuration, the power source  78  may provide and/or supply 600 Volts of direct current (VDC) at 27 amperes (amps), or 16.2 Kilowatts (KW). While one non-limiting example of a power supplied by the power source  78  is described, embodiments of the invention may be configured to receive alternative power supply characteristics, for example, at least 550 VDC, or at least 15 KW. 
     In one example embodiment, the half-bridge modules  82 , driven by the driving circuitry boards  18 , may perform high-frequency switching and power conversion functions, and may supply at least one output which is received by the one or more transformers  64 . Each transformer  64  may operate to convert the voltage received from the half-bridge modules  82 , supplied to the primary winding  84 , to a different voltage supplied to the secondary winding  86 . As shown, each secondary winding  86  may have multiple outputs  88 . In one example, each transformer  64  converts a 600 VDC transformer input to a 28 VDC transformer output, at a much higher current, for example, approximately 578 amps, less any losses of the transformer  64 . Each transformer output  88  is supplied to at least one power converter module  66 , which is shown further comprising at least one diode  90  or diode bank corresponding to each output  88 , or two diodes  90  per module  66 . 
     Each power converter module  66  operates to convert the transformer output  88 , or received current and voltage, to a module output  92  current and voltage, via the respective diodes  90 . Each module output  92  if then supplied to the at least one inductor  62 , which may, for example, be configured to reduce any output-voltage ripple generated by the components of the power converter assembly  10 . The power output of the at least one inductor is finally provided as a power converter assembly output, shown as a voltage out  94 , and supplied to at least one electrical load  96 . While an electrical load  96  is described, alternative destinations for the power output  94  may be included, such as a capacitor bank. 
     The power converter assembly  10  may include additional optional components, such as a current sensor  98 , a voltage sensor, one or more output capacitors, capacitor banks, or power bus bars, and may be configured with more or fewer half-bridge modules  82 , transformers  64 , diodes  90 , power converter modules  66 , and/or inductors  62 . Collectively, the power converter assembly  10  may be configured to covert the power supplied by the power source  78  to a power output  94  of at least 15 KW, 28 VDC, and/or 535 amps or ampere loads. This non-limiting example of a power output  94  assumes an estimated 93% power efficiency of the converter assembly  10  as a whole, which may include power losses from at least one of the half-bridge modules  82 , transformer  64 , diodes  90 , power converter modules  66 , and/or inductors  62 , which may include thermal losses from heat generation from one or more of the aforementioned components. Additional configurations of the power converter assembly and/or one or more power converter modules  66  may operate to convert a same or different input power to an output power  94  of at least 10 KW, and/or 500 amps or ampere loads, at a similar or dissimilar power efficiency levels. Furthermore, while a DC power supply  78  is described, embodiments of the invention may be configured such that the power converter modules  66  and/or diodes  90  may be configured to provide for, for example, half-wave or full-wave rectification, and thus provide alternating current (AC) to DC power conversion instead of, or in addition to the aforementioned power conversions. 
       FIG. 6  illustrates one embodiment of a power converter module  66  in further detail. As shown, each power converter module  66  may further include a circuit board  100  having the at least one anode terminal  68  and the at least one cathode terminal  72 , a module potting frame  102  overlying the circuit board  100 , and a module cover  104  which may overlie at least one of the potting frame  102  and circuit board  100 . The circuit board  100  may also include at least one ground connection  105  for grounding the power converter module  66  to a common electrical ground, such as the primary cold plate  16 . 
     As shown, each of the anode and cathode terminals  68 ,  72  may be elongated along a length of the circuit board  100  and may extend normally upwards, away from the board  100 . The illustrated embodiment shows one example configuration wherein there are two anode terminals  68  spaced from each other by a cathode terminal  72  common to each anode terminal  68 , although alternatively configured embodiments, such as a one-to-one ratio, or a multi-to-one ratio of anode terminals  68  to cathode terminals  72 , may be include. Additionally, while the height of the cathode terminal  72  extending normally away from the circuit board  100  is shown greater than the height of the anode terminal  68 , the relative heights are not critical and alternative configurations may be included. As shown, each of the anode terminals  68  and cathode terminals may further include fastener openings  106  configured to correspond with the fasteners or screws  76  coupling the bus bars  70 ,  74  to the respective anode and cathode terminals  68 ,  74 . 
     The circuit board  100  may further include a number of diodes  108  electrically arranged in parallel and provided in a gap between an anode terminal  68  and cathode terminal  72 , and configured to provide a forward bias from the anode  68  to cathode  72 . In the configuration illustrated, a single power converter module  66  may include a first plurality of diodes  110  and second plurality of diodes  112  electrically arranged, respectively, in parallel between a first anode  68  and common cathode  72 , and a second anode  68  and common cathode  72 . In this sense, the common cathode  72  may provide a common output from the power supplied to each of the anodes  68  and delivered via each of the pluralities of diodes  110 ,  112 . Utilizing this configuration, a single power converter module  66  may be capable of full-wave rectification of a varying power signal, such as a first AC power signal and a second AC power signal out of phase from the first, delivered to the respective anode terminals  68 . In the non-limiting illustrated example, the power converter module may fit in a volume defined by 4.05 inches long (e.g. along the elongated terminal  68 ,  72  direction), 2.7 inches wide, and 0.61 inches tall (e.g. from the bottom of the circuit board  100  to the tallest terminal  68 ,  72 ). 
     In another embodiment, the illustrated power converter module  66  may provide half-wave rectification of a common varying power signal delivered to each anode terminal  68 . Additionally, while the illustrated example embodiment is shown having two anode terminals  68  and a common cathode terminal  72 , embodiments of the invention may include a single anode terminal  68  electrically coupled with a single cathode terminal  72  via a single plurality of diodes  110 , to effect, for example, half-wave rectification. This alternative embodiment described may, for instance, have a smaller footprint and/or volume than the embodiment illustrated, such as 4.05 inches long, by 1.60 inches wide, by 0.61 inches tall. 
     In one embodiment, the circuit board  100  may include silicon carbide (SiC) diodes  108 , wherein each SiC diode  108  is configured with an open chip mount or configuration (i.e. without additional chip packaging) and capable of operating under at least 40 amp loads each without component failure, for example, due to thermal generation during operation. SiC diodes are merely provided as one example diode composition because of their ability to handle high voltage (e.g. 600V to 1200 V) and high current power (50 A to 1500 A, collectively) while avoiding detrimental peak transients and/or thermal failure due to transients and/or parasitics from the high frequency switching operations. 
     For example, using the example power characteristics described above, performing a 15 KW power conversion spread over two power converter modules, a plurality of fifteen diodes  108  distributed between a single anode terminal  68  and cathode terminal  72  may collectively generate at least 440 thermal Watts of heat, wherein a thermal Watt is defined as 3.413 British thermal units (BTU) per hour. Due to this heating constraint, each SiC diode  108  is spaced relative to each other on the circuit board such that the spacing prevents thermal failure of one or more diodes  108 , and/or the power converter module  66  as a whole. In the illustrated example configuration, each SiC diode  108  may be spaced at least 3 millimeters apart from each other. In another embodiment of the invention, the spacing for thermal management concerns may include consideration of additional thermal management mitigation components, such as those that are included below. 
     The module potting frame  102  may include a number of openings corresponding to components of the circuit board  100 . For example, a first and second opening  114 ,  116  may align with, correspond to, and/or be configured to allow the anode terminals  68  to extend through the respective opening  114 ,  116  when the module  66  is assembled. In another example, a third opening  117  may align with, correspond to, and/or be configured to allow only the cathode terminal  72  to extend though the opening  117  when the module is assembled. Alternative configurations for providing access to the anode and/or cathode terminals  68 ,  72  may be included. The potting frame  102  and circuit board  100  may each further include correspondingly aligned openings  118  for receiving a fastener, such as a screw  76 . Alternative fasteners and corresponding fastener openings  118 , or alternative methods of fastening may be included. 
     As shown, the first and/or second openings  114 ,  116  may further align with, correspond to, and/or be configured to provide access to a respective plurality of diodes  110 ,  112  when the potting frame  102  is coupled with the circuit board  100 . In this sense, when the potting frame  102  is coupled with the circuit board, the potting frame  102  may define sidewalls  120  about at least a portion of the plurality of diodes  110 ,  112 . The sidewalls  120  abutting the circuit board  100 , when coupled, may further allow for inclusion of, for example, a dielectric layer, such as an epoxy, to be formed, spread, and/or otherwise fixed, such that the dielectric layer overlies the SiC diodes  108  and/or at least a portion of the circuit board, to reduce the chance and/or risk of electrical short between aforementioned components. 
     The module cover  104  may include openings  122  corresponding with each of the potting frame openings  114 ,  116 ,  117 , and/or just provide an opening  122  configured to allow the respective anode and/or cathode terminals  68 ,  72  to extend through when the module  66  is assembled. The cover  104  may also include indicia  123  such as a ground symbol near a ground connection  105  or a diode symbol indicating the forward bias between the respective anode and cathode terminal  68 ,  72 , in order to improve the ease of assembly and/or maintenance of the power converter module  66 . 
     Each of the module cover  104  and the potting frame  102  may also include correspondingly aligned fastener openings  118  for receiving a fastener, such as a screw  76 , for coupling the potting frame  102  with the cover  104 . Alternative embodiments of the invention may include, for example, a common fastener opening between each of the cover  104 , potting frame  102 , and circuit board  100 , such that a single fastener, such as a non-conductive screw  76  may secure and/or couple the power converter module  66  together. At least one of the cover  104 , potting frame  102 , and circuit board  100  may further include an additional fastener opening, illustrated as correspondingly aligned openings  124  in each of the potting frame  102  and circuit board  100 , for receiving a fastener that may couple and/or secure the power converter module to the primary cold plate  16 . 
       FIG. 7  illustrates a top view of the circuit board  100  of  FIG. 6 , showing a detailed view of the layout of the terminals  68 ,  72  and SiC diodes  108  arranged in parallel between each anode and cathode terminal  68 ,  72 , as well as the spacing of the diodes  108 . While the illustrated embodiment is shown having fifteen SiC diodes  108  for each anode-cathode connection, additional configurations may be included having more or fewer diodes  108 , and/or alternative spacing of the diodes  108 , to account for at least one of power requirements of the module  66  and/or thermal considerations of the components. The circuit board  100  may further include a plurality of conductive regions  126  corresponding with each SiC diode  108  and electrical coupled with each respective anode terminal  68 , and wire bonding  128  electrically coupling the conductive region  126  to the respective SiC diode  108 . 
     Turning now to  FIG. 8 , an exploded perspective view illustrates the multiple layers of the circuit board  100 , wherein the diodes  108  have been removed for clarity. In addition to the previously described terminals  68 ,  72 , the circuit board  100  may include a circuit mask layer  130  for positioning electrical components such as the diodes  108 , terminals  68 ,  72 , and exposing portions of the conductive regions  126 , an electrically conductive layer  132  having at least an anode conductive portion  134  and an electrically isolated cathode conductive portion  136 , a dielectric layer  138  such as a dielectric film, and a thermally conductive substrate layer  140  isolated from the electrically conductive layer  132  by the dielectric layer  138 . The thermally conductive substrate layer  140  may comprise any high thermal conduction material, such as copper. Additional conductive substrate layers may be included. 
     As illustrated by dotted outline, the anode conductive portion  134  aligns with both the anode position  142  and the conductive region  126  defined by the circuit mask  130 , such that the anode conductive portion  134  is electrically coupled with each of the conductive regions  126 , and anode terminal  68 . Additionally illustrated by dotted outline, the cathode conductive portion  136  aligns with the cathode position  144  and diode positions  146  defined by the circuit mask  130 , such that the cathode conductive portion  136  is electrically coupled with each of the cathode terminal  72  and diodes  108 . 
     When assembled and operating, each power converter module  66  provides a high current (e.g. greater than 50 amp) power converter. During high current operation, each of the SiC diodes  108  may experience power loses through thermal heating, as described above. The thermally conductive substrate layer  140  of the circuit board  100  provides a thermally conductive pathway for conductive heat transfer down and away from at least a portion of the diodes, where the heat may be further removed from the conductive substrate  140  via, for example a thermally conductive relationship with the primary cold plate  16 , as described herein. Embodiments of the invention may include configurations wherein only a portion of the heat generated by the diodes  108  may be removed by way of the conductive substrate  140 , while the remaining heat may be removed through a combination of convection and radiation. In one example, wherein a plurality of diodes  110 ,  112  collectively generates at least 440 thermal Watts of heat, 343 thermal Watts of heat may be removed via the cold plate  16  and/or conductive substrate layer  140 . 
       FIG. 9  illustrates a portion of the power converter assembly  10  including only the components utilized for heat removal, cooling, and/or heat exchanging. As shown, a heat exchanger assembly  148  includes the heat exchanger  22 , the primary cold plate  16 , the secondary cold plate  54 , and the tertiary cold plate  56 . Each of the cold plates  16 ,  54 ,  56  may be formed, molded, or machined from a highly thermally conductive material suitable for transference of heat via direct or indirect conduction with at least one heat-generating component. One example of a cold plate  16 ,  54 ,  56  composition may include copper, but alternative compositions may be included. Each of the secondary and tertiary cold plates  54 ,  56  may be supported by and coupled with the primary cold plate  16  via one or more fasteners, such as screws  152 . 
     As previously described, the secondary cold plate  54  may be fluidly coupled with at least one of the primary cold plate  16  and/or the fluid connection port  24  such that coolant  32  pumped from the coolant reserve  30  may be delivered to a coolant passage of the secondary plate  54  via at least one of the fluid connection port  24 , a coolant passage of the primary cold plate  16 , and/or the first tubing set  58 . Similarly, the tertiary cold plate  56  may be fluidly coupled with the secondary cold plate  54  such that coolant  32  pumped from the coolant reserve  30  may be delivered to a coolant passage of the tertiary plate  56  via, for example, the second tubing set  60 . While the terminology of a “passage” may be used herein, each “passage” of embodiments of the invention may include multiple passages or passageways, for example, an input and output passage, or a delivery and return passage, even though terminology may imply only a single passage or passageway. 
     While the illustrated embodiment describes at least a portion of a cooling circuit wherein coolant  32  may be delivered serially to the primary cold plate  16 , followed by the secondary cold plate  54 , followed by the tertiary cold plate  56 , alternative configurations may be included, wherein, for example, coolant  32  is pumped in parallel to two or more components, such as the secondary and tertiary plates  54 ,  56  simultaneously. Additional coolant circuit configurations may include any combination of the aforementioned descriptions including any or all of the cold plates  16 ,  54 ,  56 . 
     At least one of the cold plates  16 ,  54 ,  56  may further define at least one component seat  150  for receiving a heat-producing component. For example, as illustrated, the primary cold plate  16  includes a number of recessed component seats  150  for receiving heat-producing components including the power magnetic devices (e.g. the inductors  62  and transformers  64 ). Each component seat  150  may, for instance, provide a planar face  154  for thermally coupling the respective cold plate  16 ,  54 ,  56  to one or more respective heat-producing components. Additionally, embodiments of the invention may include an additional thermally conductive layer between one or more cold plate  16 ,  54 ,  56  and one or more heat-producing components, such as a thermal epoxy or thermally conductive film, for example, to increase the surface area of the thermal conduction, to increase conduction efficiency, or to maintain the thermal coupling. 
     The primary cold plate  16  may further include one or more component seats  150  for receiving each of the power converter modules  66 . Embodiments of the invention may further include component seats  150  on at least one of the secondary or tertiary cold plates  54 ,  56 , for example, corresponding with component seats  150  of the primary cold plate  16 . In this sense, a corresponding pair of recessed component seats  150  between the primary and secondary cold plates  16 ,  54  may be utilized to receive, for example, a transformer  64 , and secure the transformer  64  within the pair of component seats  150  when the tertiary cold plate  56  is fastened with the primary cold plate  16  via the screws  152 . In this example, the screws may provide a compressive configuration to physically bias any two cold plates  16 ,  54 ,  56  towards each other about the heat-producing component, such that the physical biasing may further maintain the thermal coupling between the plates  16 ,  54 ,  56  and the heat-producing component. 
     The above-described embodiments may provide for a heat exchanger assembly  148  and/or cooling structure that includes at least two cold plate planar faces  154  configured to thermally couple with at least two corresponding planar faces of a heat-producing component, such as one or more power magnetics devices. In this sense, a first face of, for example, a transformer  64  may conductively couple with a planar face  154  of the primary cold plate  16  such that at least a portion of heat generated by the transformer  64  is removed by way of thermal conduction to the primary cold plate  16 . Likewise, a second face of, for example, a transformer  64  may conductively couple with a planar face  154  of the tertiary cold plate  56  such that at least a different portion of heat generated by the transformer  64  is removed by way of thermal conduction to the tertiary cold plate  56 . Each of the respective planar faces  154  of, for instance, the primary and secondary cold plates  16 ,  54  may remove heat from one or more inductors  62  via thermal conduction in a similar fashion. Furthermore, the thermal coupling of the power converter module  66  with the primary cold plate  16  may also remove heat from the module  66  and/or diodes  108  via thermal conduction. 
     While the cold plate faces  154  and the heat-producing components may be described having planar faces, embodiments of the invention may include heat-producing components having faces that are not planar, and wherein the corresponding cold plate faces  154  define a geometric profile to match the non-planar faces of the heat-producing components. Furthermore, while the corresponding faces  154  of the cold plates  16 ,  54 ,  56  may be applied to opposing faces of the heat-producing component, alternative embodiments of the invention may include applying cold plate faces  154  to non-opposing faces of the heat-producing components, wherein heat is removed via conduction from the non-opposing faces. 
     The heat exchanger  22  is shown further comprising a mounting bracket  156 , a coolant passage of the heat exchanger  22  (schematically illustrated as dotted lines  160 ), and a plurality of thermally conductive fins  162 . The mounting bracket  156  may further include at least one coolant passage  158  and may be configured to physically and fluidly couple the exchanger coolant passage  160  with a coolant passage  164  of the primary cold plate  16 . The mounting component may also include a number of, for example, O-rings  166  to ensure a fluid-tight coupling. The heat exchanger  22  and/or mounting bracket  156  may be coupled together, or with the primary cold plate  16 , by any of the aforementioned fastener means, such as screws  76 . 
     The plurality of thermally conductive fins  162  may be thermally conductively coupled with the heat exchanger passageway  160  such that coolant delivered from the primary cold plate  16  (via the passage  164 ), through the mounting passage  158 , and into the exchanger passage  160  may conductively remove heat from the fins  162 . The plurality of fins  162  may be configured to align in parallel over an elongated length of the heat exchanger  22  and define a plurality of spaces (respectively between fins) such that air may fluidly pass from one end of the heat exchanger  22  (illustrated as an air input  168 ) to the opposing end of the length of the heat exchanger  22  (illustrated as an air output  170 ). 
     The heat exchanger assembly  148  may further include a fan  172  configured to mount to the heat exchanger  22  at the air input  168 , and configured to effect a movement of ambient air into the air input  168 , past the plurality of fins  162 , and out of the air output  170 . In this sense, the movement of air past the fins  162  conductively couple with the coolant passage  160  cools the air by forced convection, and thus, may remove at least a portion of heat from the moving air. Additionally, embodiments of the invention may include at least one fin (illustrated as two fins  174 ) shaped and/or physically oriented to direct, or redirect, at least a portion of air at the output  170  of the heat exchanger  22  toward different directions. For example, when assembled, the fins  174  may direct at least a portion of the cooled air towards or away from at least one of a heat-generating or heat-producing component, or heat-sensitive circuitry, as previously described. In this sense, the fins  174  may be utilized to provide targeted cooling for specific heat management needs or concerns. 
       FIG. 10  illustrates a top schematic view of one embodiment of the heat exchanger assembly  148  coolant flow, with the direction of coolant flow generally indicated by arrows. Coolant may be delivered to the fluid connection port  24  via the inlet port  26 . From the inlet port  26 , the coolant may be delivered sequentially or in parallel to a number of cooling components including the primary cold plate  16  to at least partially remove heat from, for example, the inductors  62  (position illustrated by dotted outline), transformers  64  (position illustrated by dotted outline), and power converter modules  66  (position illustrated by dotted outline), the secondary cold plate  54  to at least partially remove heat from one or more inductors  62 , the tertiary cold plate  56  to at least partially remove heat from one or more transformers  64 , and the heat exchanger  22  (position illustrated by dotted outline) to at least partially remove heat from the ambient air, as described herein. Embodiments of the invention may further include delivering coolant to additional cooling plates and/or passageways  176  that may, for example, provide conductive cooling to heat-sensitive circuitry, such as the driving circuitry boards  18  (position illustrated by dotted outline). 
       FIG. 11  illustrates one exemplary embodiment of the internal coolant passageways of the primary cold plate  16  illustrating at least a portion of different coolant flow paths, coolant circuits, and/or coolant loops. For example, a first coolant loop  178  may be defined by at least one passageway configured to deliver coolant proximate to one or more inductors  62 , followed by a first power converter module  66 , at least one transformer  64 , and a second power converter module  66  before returning the coolant to the outlet port  26 . A second coolant loop  180  may be defined by at least one passageway configured to deliver coolant proximate to one or more inductors  62  and followed by the heat exchanger  22  before returning the coolant to the outlet port  26 . Additionally, a third coolant loop  182  may be defined by at least one passageway configured to deliver coolant proximate to one or more inductors  62  and followed by any additional cooling components  176  before returning the coolant to the outlet port  26 . While three coolant loops  178 ,  180 ,  182  of the primary cold plate  16  are illustrated, any number of coolant loop variations may be formed and/or machined as part of the cold plate  16  to effect a cooling of one or more thermally conductive relationships with one or more heat-producing components including, but not limited to, power converter modules  66 , inductors  62 , transformers  64 , and with one or more heat-sensitive circuitry components, for example, the driving circuitry boards  18 . The coolant loops  178 ,  180 ,  182  described are configured to maintain and/or exceed one or more temperature and/or thermal management considerations, as defined herein. 
       FIG. 12  illustrates exemplary embodiments of the internal coolant passageways of the secondary and tertiary cold plates  54 ,  56 . As shown, the secondary cold plate  54  includes at least one coolant passage  184 , such that coolant may be delivered to the secondary cold plate  54  to effect a conductive cooling of at least a portion of the secondary cold plate  54 . Similarly, the tertiary cold plate  56  includes at least one coolant passage  188  such that coolant may be delivered to the tertiary cold plate  56  to effect a conductive cooling of at least a portion of the tertiary cold plate  56 . 
     As illustrated the secondary cold plate  54  may include a first coolant passage  184  and a second coolant passage  186 , wherein the first and second passages  184 ,  186  are interrupted by delivering coolant to the tertiary cold plate  56 . In this configuration, coolant delivered to the secondary cold plate  54  may initially cool a first portion of the secondary cold plate  54  proximate to the first coolant passage  184 , upstream from the serial fluid coupling with the tertiary cold plate  56 , followed by cooling a different second portion of the secondary cold plate  54  proximate to the second coolant passage  186 , downstream from the serial fluid coupling with the tertiary cold plate  56 . Alternative coolant passage  184 ,  186 ,  188  may be included in embodiments of the invention. 
     The above-described embodiments provide for a power converter assembly  10  capable of high voltage and high current power conversion in a small, included structure. The above-described embodiments further provide for cooling the various heat-producing components of the power converter assembly  10  in accordance with heat management considerations. The cooling of the assembly  10  may be concerned with two particular “thermal zones” of the assembly: a first zone defined by the volume enclosed by the thermal composite  20  and the primary cold plate  16 , and including heat-generating components such as the power converter modules  66 , the inductors  62 , the transformers  64 , and heat-removing components including at least a portion of the primary cold plate  16 , the secondary cold plate  54 , the tertiary cold plate  56 , and the first and second tubing sets  58 ,  60 ; and a second zone defined by the housing  12  and including all components not enclosed in the first zone, including heat-sensitive components such as the driving circuitry boards  18  and heat-removing components including at least another portion of the primary cold plate  16 , the heat exchanger  22 , and fan  172 . 
     The heat exchanger assembly  148 , in combination with the coolant reservoir  30  and coolant pump  34 , operate to remove heat generated by the heat-producing components by removing heat via conduction with the cold plates  16 ,  54 ,  56  and via forced air convection of the ambient air with the heat exchanger  22  and fan  172 . By removing the heat generated by the heat-producing components, the heat exchanger assembly  148  prevents the heat-sensitive circuity from damage and/or thermal failure by preventing the temperature of the heat-sensitive circuitry from rising above the thermal limit value of the circuitry. In this sense, the heat exchanger assembly  148  operates to control the temperature of the one or more heat-producing components, heat-sensitive components, and ambient air within the housing  12 . 
     For example, a heat-producing component, such as a power converter module  66  will generate a large amount of heat, as measured in thermal Watts, during the high current power conversion described herein. In one example configuration, each power module may generate at least 440 collective thermal Watts via at least conduction (e.g. into the circuit board  100 ) and convection (e.g. into the first zone included by the primary cold plate  16  and thermal composite  20 ). The heat generated by the power converter module  66  may be further transferred into the second zone through conduction and/or radiation of heat through the thermal composite  20 , or through any access openings or imperfect seems of the composite  20 . In this embodiment, the majority of heat generated by a power converter module may be removed via a conduction path defined from, for example, the diodes  108 , through to circuit board  100 , through the conductive substrate layer  140 , through a thermal coupling with the primary cold plate  16 , and into a coolant passage of the primary cold plate  16 , wherein, for instance, coolant  32  traversing the first coolant loop  178  will absorb the heat and carry it away to a location external to the power converter assembly  10 , such as the coolant reservoir  30 . In this example, the heat exchanger assembly  148  may be configured to remove at least 300 thermal Watts of heat from each power converter module  66  via conduction. While 300 thermal Watts is described, alternate amounts of heat removal may be included. 
     In another example, a heat-producing component, such as an inductor  62  during power conversion operation of the assembly  10 , which may be generated via at least conduction (e.g. into at least one of primary cold plate  16  or the secondary cold plate  54 , each of which are conductively coupled with each inductor  62 ), and again, convection (e.g. into the first zone). Again, some heat may be further transferred into the second zone through conduction and/or radiation of heat through the thermal composite  20 , or through any access openings or imperfect seems of the composite  20 . In this embodiment, the majority of heat generated by the inductor  62  may be removed via another conduction path defined from, for example, at least one face of the inductor  62 , through a corresponding component seat  150  of at least one of the primary or secondary cold plates  16 ,  54 , wherein, for instance, coolant  32  traversing the first, second, and/or third coolant loops  178 ,  180 ,  182  will absorb the heat and carry it away to a location external to the power converter assembly  10 , such as the coolant reservoir  30 . In this example, the heat exchanger assembly  148  may be configured to remove at least 15 thermal Watts of heat from each inductor  62  via conduction (e.g. 7.5 thermal Watts of heat into each plate  16 ,  54 ). Embodiments of the invention may be configured to remove at least a portion of heat generated by the inductor  62  through each of the cold plates  16 ,  54 , although the distribution of heat removal does not need to be equally shared between the plates  16 ,  54 . 
     In another example, a heat-producing component, such as an transformer  64  during power conversion operation of the assembly  10 , which may be generated via at least conduction (e.g. into at least one of primary cold plate  16  or the tertiary cold plate  56 , each of which are conductively coupled with each transformer  64 ), and again, convection (e.g. into the first zone). Again, some heat may be further transferred into the second zone through conduction and/or radiation of heat through the thermal composite  20 , or through any access openings or imperfect seems of the composite  20 . In this embodiment, the majority of heat generated by the transformer  64  may be removed via another conduction path defined from, for example, at least one face of the transformer  64 , through a corresponding component seat  150  of at least one of the primary or tertiary cold plates  16 ,  56 , wherein, for instance, coolant  32  traversing the first coolant loop  178  will absorb the heat and carry it away to a location external to the power converter assembly  10 , such as the coolant reservoir  30 . In this example, the heat exchanger assembly  148  may be configured to remove at least 100 thermal Watts of heat from each transformer  64  via conduction (e.g. 50 thermal Watts of heat into each plate  16 ,  56 ). Embodiments of the invention may be configured to remove at least a portion of heat generated by the transformer  64  through each of the cold plates  16 ,  56 , although the distribution of heat removal does not need to be equally shared between the plates  16 ,  56 . 
     Any heat that enters the second zone may also be removed from the power converter assembly  10  by way of conduction into the housing  12 , and radiation of that heat to the external environment, for example, via the pin fins, or it may be removed by way of forced convection by the movement of ambient air of the second zone through the heat exchanger  22 . In this embodiment, the plurality of fins  162  of the heat exchanger  22  remove heat by way of forced convection when the fan effects a movement of the warm or hot ambient air past the fins  162 , which are thermally coupled with the coolant passage  160  of the heat exchanger  22 . The heat from the ambient air is transferred into the coolant passage, wherein, for instance, coolant  32  traversing the second coolant loop  180  will absorb the heat and carry it away to a location external to the power converter assembly  10 , such as the coolant reservoir  30 . In this example, the heat exchanger  22  may be configured to remove at least 70 thermal Watts of heat from the ambient air of the second zone by forced convection. In addition to cooling the ambient air by forced convection, the shaped fins  174  of the heat exchanger  22  may further direct the cooled air exiting the exchanger  22  toward, for example, at least one of a heat-producing component, one or more access openings  38 , or a heat-sensitive circuitry such as the driving circuit boards  18  to further distribute and/or manage the thermal concerns of the power converter assembly  10 , as needed. 
     The combined efforts of the heat exchanger assembly  148  may operate to keep all components of the power converter assembly  10 , the first zone, the second zone, or the cavity  14  of the housing  12 , at or below a maximum thermal limit value that, when exceeded, may cause thermal damage or failure to one or more components, such as the heat-sensitive circuitry. In one example, power converter assembly  10  may remain at or below 85 degrees Celsius during continual operation, when supplied with, for example, coolant at 71 degrees Celsius and ambient air (internal or external to the housing  12 ) at 71 degree Celsius. Embodiments of the invention may include an expected operating temperature range for the power converter assembly  10 , such as between 85 and 105 degrees Celsius, wherein the thermal limit value may include a time component (e.g. thermal limit value is above 90 degrees Celsius for more than 3 minutes, etc.). 
     Additionally, embodiments of the invention may include different thermal limit values for different components. For example, it is known that power magnetics devices, such as inductors  62  and transformers  64  lose efficiency as thermal loses build during operation. At a high enough temperature, known as the Curie temperature, a power magnetics device may lose the material&#39;s permanent magnetism, drastically reducing operating efficiency. In this embodiment, the heat exchanger assembly  148  may be configured to remove heat from the assembly  10  such that the temperature of one or more power magnetics device is maintained at, below, or within a predetermined amount of the Curie temperature of the device. For example, the heat exchanger assembly  148  may be configured to keep a transformer  64  operating at a rate of at least an 50% efficiency, or at least below 70% of the transformer&#39;s Curie temperature 
     Many other possible embodiments and configurations in addition to that shown in the above figures are contemplated by the present disclosure. For example, one embodiment of the invention contemplates accounting for additional heat-producing components such as filter cans, switching devices, and bus bars variously located within at least one of the first and/or second zones. Additionally, the design and placement of the various components may be rearranged such that a number of different in-line configurations could be realized. 
     The embodiments disclosed herein provide a power converter assembly capable of converting large amounts of power, yet may be included in a relatively small volume. One advantage that may be realized in the above embodiments is that the thermal composite of the above described embodiments may act as a thermal and electrical shield preventing high temperatures generated in the first zone from easily escaping into the second zone, which may have heat-sensitive circuitry. The thermal composite additionally forces a higher thermal environment to be maintained in the first zone, which forces more generated heat to be absorbed by the coolant-cooled portions of the assembly, which are generally more effective at removing heat. Furthermore, the thermal composite includes a high thermal gradient from the bottom surface to the top surface, and thus drastically reduces and/or minimizes any thermal radiated emissions from the first zone. This may lead to a reduction in costs associated with the assembly by using lower temperature components in the second zone of the assembly, or in reducing development costs of high temperature devices that do not currently exist or do not operate in such high temperature environments. Another advantage of the above-described embodiments is that electrical components in the second zone may have an improved component reliability and lifespan due to lower operating temperature. 
     Another advantage of the above-described embodiments is that the heat exchanger assembly provides a high level of heat removal from the heat-producing components to prevent the components from experiencing thermally-related efficiency losses, thermal runaway, and/or catastrophic thermal failure. The high level of heat removal further provide for an assembly embodiment to be included in a relatively small volume, and thus, increases the portability and/or availability of the assembly to be installed in environments where space is a concern. 
     Yet another advantage of the above-described embodiments is that the heat exchanger assembly effectively cools the power magnetics devices, which may dramatically lower the thermal resistance of such ferrite materials, as well as prevent saturation of the devices due to exceeding the Curie temperature rating for each respective device. 
     Even yet another advantage of the above-described embodiments is that the power converter module is capable of removing large amounts of heat via the conductive substrate, allowing the diodes to operate at a higher power level without thermal effects and/or failure. Additionally the use of SiC diodes without chip packaging allows for higher power level operation with fewer parasitics, transients, and voltage spikes at a reduced circuit board surface area. Furthermore, the design allows for a plurality of configurations including AC to DC power conversion, DC to DC power conversion, half-wave rectification and/or full-wave rectification, at power levels high enough to provide for, for example, a 15 KW power output. The combination of increased cooling mechanisms and smaller power converter modules may aid in collectively reducing the volume of the power converter assembly by 60%, and reduce the weight of the assembly by 50%, when compared to preexisting units that only operated at 8 KW power output. 
     To the extent not already described, the different features and structures of the various embodiments may be used in combination with each other as desired. That one feature may not be illustrated in all of the embodiments is not meant to be construed that it may not be, but is done for brevity of description. Thus, the various features of the different embodiments may be mixed and matched as desired to form new embodiments, whether or not the new embodiments are expressly described. All combinations or permutations of features described herein are covered by this disclosure. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.