Patent Publication Number: US-2022225548-A1

Title: Vehicle Power Module Assembly

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. application Ser. No. 16/018,544 filed Jun. 26, 2018, the disclosure of which is hereby incorporated in its entirety by reference herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to vehicle power module assemblies. 
     BACKGROUND 
     A vehicle power unit may be formed by stacking and connecting a number of power modules based on vehicle power requirements. Pins from the power modules interface with adjacent power electronics. 
     SUMMARY 
     A vehicle power module assembly includes a first power module and a second power module. The first power module includes a first lock feature extending from a lower portion of a first minor side at a first central axis. The second power module includes a second lock feature at an upper portion of a second minor side at a second central axis. The lock features are sized for interlock with one another to secure the power modules to one another. The first lock feature may be a loop element defining a through-hole and the second lock feature may be a wedge. The through-hole may be sized for the wedge to extend therein and to interlock the first power module and the second power module to one another. The first lock feature may be a flexible hook element and the second lock feature may be a slot. The slot may be sized to receive a portion of the hook element to interlock the first power module and the second power module to one another. The first power module may further include a second first lock feature extending from a lower portion of a first major side. The second power module may further include another second lock feature at an upper portion of a second major side. The second first lock feature may be arranged with the another second lock feature such that interlocking of corresponding lock features applies a clamping force sufficient to create a sealed relationship between the first power module and the second power module. The lock features may be arranged upon respective minor sides at respective central axes such that a third power module having a design substantially identical to the first power module or the second power module may be secured in a stack to the first power module or the second power module. The first power module may further include an extension extending about and spaced inward from a perimeter of a lower surface portion of the first power module. The second power module may further include a groove extending about and spaced inward from a perimeter of an upper surface portion of the second power module. The extension and groove may be arranged with one another to align a first coolant channel of the first power module in substantial registration with a second coolant channel of the second power module. The first power module or the second power module may further include two pairs of coolant channels extending therethrough and a coolant cavity connecting two of the two pairs of coolant channels such that coolant flow is directed across a heat generating component disposed within the power module. 
     A vehicle power module assembly includes a first power module and a second power module. The first power module includes a first pair of opposing major sides, each of the first pair of opposing major sides including a flange extending therefrom and each flange including a grasp element. The second power module includes a second pair of opposing major sides and an upper portion spaced from a lower portion to define a pair of grooves therebetween and each located adjacent to one of the second pair of opposing major sides. Each groove extends a length of one of the major sides and each groove is sized to receive one of the grasp elements such that one of the first pair of opposing major sides is substantially flush with one of the second pair of opposing major sides when the first power module and the second power module are secured to one another. The second power module may further include an upper portion having at least one side face defining a first plane offset from a second plane defined by one of the first pair of opposing major sides of the first power module. The flanges of the first power module may be spaced from one another to define a cavity sized to at least partially receive the upper portion of the second power module therebetween. The first power module may include at least a first coolant channel extending therethrough. The second power module may include at least a second coolant channel therethrough. The grooves and grasp elements may be arranged with one another such that the first coolant channel and the second coolant channel are in substantial registration with one another when the first power module and the second power module are secured to one another. The grooves and grasp elements may be arranged with one another such that there are no fasteners projecting externally from the power modules when secured to one another. The first power module or the second power module may further include two pairs of coolant channels extending therethrough and a coolant cavity connecting two of the two pairs of coolant channels such that coolant flow is directed across a heat generating component disposed within the power module. The assembly may further include a third power module. The first power module, the second power module, and the third power module may each include a substantially identical structure such that the third power module may be mounted to the first power module or the second power module. 
     A vehicle power module assembly includes a first power module and a second power module. The first power module includes a lower portion defining a perimeter sidewall, a cavity within the perimeter sidewall, and an inner extension extending about a cavity perimeter spaced inward from the perimeter sidewall. The second power module includes an upper portion spaced from a lower portion to define a groove therebetween extending about a perimeter of the upper portion. The upper portion of the second power module is sized for disposal within the cavity of the lower portion of the first power module such that the inner extension sits within the groove to align the first power module and the second power module for securement to one another. The groove of the second power module may be sized to receive sealant to seal the inner extension therein. The first power module may further include a first coolant channel. The second power module may further include a second coolant channel. The first power module and the second power module may be secured to one another such that the first coolant channel is in fluid communication with the second coolant channel and sealed to prevent leakage of coolant traveling within one of the coolant channels. The inner extension may sit within the groove such that a first side of the first power module is substantially flush with a second side of the second power module. The inner extension may sit within the groove such that no fasteners project externally to the first power module or the second power module. The first power module may include one or more switching units disposed therein. The first power module may further define two pairs of coolant channels and a coolant cavity fluidly connecting two of the two pairs of coolant channels. The coolant cavity may be arranged within the first power module such that coolant disposed therein may travel across the one or more switching units to manage thermal conditions thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic diagram illustrating an example of an electrified vehicle. 
         FIG. 1B  is a circuit diagram illustrating an example of a power supply device coupled to a power source and a load. 
         FIG. 2A  is an exploded perspective view of an example of two power modules. 
         FIG. 2B  is a perspective view of the two power modules of  FIG. 2A  shown mounted to one another. 
         FIG. 2C  is a first perspective view of a portion of one of the two power modules of  FIG. 2A  showing a coolant channel configuration. 
         FIG. 2D  is a second perspective view of the portion of the one of the two power modules of  FIG. 2C . 
         FIG. 3A  is an exploded upper perspective view of an example of two power modules. 
         FIG. 3B  is a perspective view of the two power modules of  FIG. 3A  shown mounted to one another. 
         FIG. 3C  is an exploded lower perspective view of the two power modules of  FIG. 3A   
         FIG. 4A  is an exploded perspective view of an example of two power modules. 
         FIG. 4B  is a perspective view of the two power modules of  FIG. 4A  shown mounted to one another. 
         FIG. 4C  is a top plan view of a portion of one of the power modules of  FIG. 4A . 
         FIG. 4D  is a front view, in cross-section, of  FIG. 4B  showing the two power modules mounted to one another. 
         FIG. 5A  is an exploded perspective view of an example of two power modules. 
         FIG. 5B  is a perspective view of the two power modules of  FIG. 5A  shown mounted to one another. 
         FIG. 5C  is a front view, in cross-section, of  FIG. 5B  showing the power modules of  FIG. 5A  mounted to one another. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could 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. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations. 
       FIG. 1A  illustrates an example of an electrified vehicle, referred to as an electrified vehicle  12  herein. In this example, the electrified vehicle is shown as a plug-in hybrid electric vehicle (PHEV). The electrified vehicle  12  may include one or more electric machines  14  mechanically coupled to a gearbox or hybrid transmission  16 . Each of the electric machines  14  may be capable of operating as a motor and a generator. In addition, the hybrid transmission  16  is mechanically coupled to an engine  18  and the hybrid transmission  16  is mechanically coupled to a drive shaft  20  that is mechanically coupled to a set a set of wheels  22 . The electric machines  14  may provide propulsion and deceleration capability when the engine  18  is turned on or off. The electric machines  14  may also act as generators and provide fuel economy benefits by recovering energy that would normally be lost as heat in a friction braking system. The electric machines  14  may also reduce vehicle emissions by allowing the engine  18  to operate at more efficient speeds and allowing the electrified vehicle  12  to be operated in electric mode with the engine  18  off under certain conditions. The electrified vehicle  12  may also be a battery electric vehicle (BEV), a full hybrid electric vehicle (FHEV), a mild hybrid electric vehicle (MHEV), or other vehicle utilizing an electric drive and/or an electric motor. In a BEV configuration, the engine  18  may not be present. 
     A battery pack or traction battery  24  stores energy that may be used by the electric machines  14 . The traction battery  24  may provide a high voltage direct current (DC) output. A contactor module  42  may include one or more contactors to isolate the traction battery  24  from a high-voltage bus  52  when opened and to connect the traction battery  24  to the high-voltage bus when closed. The high-voltage bus may include power and return conductors for carrying current. The contactor module  42  may be located adjacent to or within the traction battery  24 . One or more power electronics modules  26  (which may also be referred to as an inverter or power module) may be electrically coupled to the high-voltage bus. The power electronics modules  26  are electrically coupled to the electric machines  14  and provide the ability to bi-directionally transfer energy between the traction battery  24  and the electric machines  14 . For example, a traction battery  24  may provide a DC voltage while the electric machines  14  may operate with a three-phase alternating current (AC). The power electronics module  26  may convert the DC voltage to a three-phase AC current to operate the electric machines  14 . In a regenerative mode, the power electronics module  26  may convert the three-phase AC current from the electric machines  14  acting as generators to the DC voltage compatible with the traction battery  24 . 
     In addition to providing energy for propulsion, the traction battery  24  may provide energy for other vehicle electrical systems. The electrified vehicle  12  may include a DC/DC converter module  28  that converts the high voltage DC output from the high-voltage bus to a low-voltage DC level of a low-voltage bus that is compatible with low-voltage loads  45 . An output of the DC/DC converter module  28  may be electrically coupled to an auxiliary battery  30  (e.g., a 12V battery) for charging the auxiliary battery  30 . The low-voltage loads  45  may be electrically coupled to the auxiliary battery  30  via the low-voltage bus. One or more high-voltage electrical loads  46  may be coupled to the high-voltage bus. The high-voltage electrical loads  46  may have an associated controller that operates and controls the high-voltage electrical loads  46  when appropriate. Examples of high-voltage electrical loads  46  may be a fan, an electric heating element and/or an air-conditioning compressor. 
     In a PHEV embodiment, the electrified vehicle  12  may be configured to recharge the traction battery  24  via an external power source  36 . The external power source  36  may include a connection to an electrical outlet. The external power source  36  may be electrically coupled to a charge station or an electric vehicle supply equipment (EVSE)  38 . The external power source  36  may be an electrical power distribution network or grid as provided by an electric utility company. The EVSE  38  may provide circuitry and controls to regulate and manage the transfer of energy between the external power source  36  and the electrified vehicle  12 . The external power source  36  may provide DC or AC electric power to the EVSE  38 . The EVSE  38  may have a charge connector  40  for coupling to a charge port  34  of the vehicle  12 . The charge port  34  may be any type of suitable port configured to transfer power from the EVSE  38  to the vehicle  12 . The charge port  34  may be electrically coupled to an on-board power conversion module  32  which may operate as a charger. The power conversion module  32  may condition the power supplied from the EVSE  38  to provide appropriate voltage and current levels to the traction battery  24  and the high-voltage bus. The power conversion module  32  may interface with the EVSE  38  to coordinate the delivery of power to the electrified vehicle  12 . The EVSE connector  40  may have pins to mate with corresponding recesses of the charge port  34 . 
     One or more wheel brakes  44  may be provided for decelerating the electrified vehicle  12  and preventing motion of the electrified vehicle  12 . The wheel brakes  44  may be hydraulically actuated, electrically actuated, or some combination thereof. The wheel brakes  44  may be a part of a brake system  50 . The brake system  50  may include other components to operate the wheel brakes  44 . 
       FIG. 1B  is a circuit diagram illustrating an example of a power supply device  54  coupled to a power source  56  and a load  58 . The power supply device  54  may convert DC electrical current into AC electrical current. The power supply device  54  may be utilized in an electric drive system of a vehicle, such as the electrified vehicle  12  described above. The power source  56  may be coupled to the power supply device  54  in order to drive the load  58 . The power source  56  may be a battery, such as the traction battery  24  described above, and the load  58  may be an electric machine, such as one of the electric machines  14  described above. The power source  56  may further comprise a high voltage battery that is coupled to a voltage converter (not shown). The power supply device  54  may include a power assembly or power module  60 . The power module  60  may deliver electrical power to the load  58 . The power module  60  may be an inverter or an inverter assembly to convert DC electrical current into AC electrical current. 
     The power module  60  may include inverting circuitry and heat generating components such as a plurality of switching units  64 . The power module  60  may be an inverter that includes any number of switching units and is not limited to the number of switching units shown in  FIG. 1A . Each of the switching units  64  may include a transistor  66  arranged antiparallel with a diode  68 . In one example, the transistor  66  may be an insulated gate bipolar transistor (IGBT). The switching units  64  may provide alternating current to the load  58 . The power supply device  54  may include a linking capacitor  72  disposed between the power source  56  and the power module  60 . The linking capacitor  72  may absorb ripple currents generated at the power module  60  or the power source  56 , and stabilize the DC-link voltage, Vo, for power module  60  control. The linking capacitor  72  may be arranged to limit voltage variation at an input of inverting circuitry due to ripple currents generated by the inverting circuitry in the power module  60  or a battery, such as a traction battery, that may comprise the power source  56 . Alternatively, the linking capacitor  72  may be configured to couple one or a plurality of inverters to a power source. 
       FIG. 2A  is a partially exploded perspective view illustrating an example of a portion of a power module assembly, referred to generally as a power module assembly  100  herein. The power module assembly  100  includes a first power module  106  and a second power module  108  shown separated from one another in  FIG. 2A . Each power module may include one or more coolant channels extending through a respective power module. For example, the first power module  106  may include one or more coolant channels  110  and the second power module  108  may include one or more coolant channels  111 . 
     Each of the coolant channels  110  and each of the coolant channels  111  may be oriented within a respective power module at a location adjacent heat generating components to assist in managing thermal conditions thereof. For example, each of the coolant channels  110  and each of the coolant channels  111  may be located adjacent one or more switching units or a power stage. Each of the coolant channels  110  and each of the coolant channels  111  may also assist in orienting the first power module  106  and the second power module  108  for mounting to one another. Each of the coolant channels  110  and each of the coolant channels  111  may be in fluid communication with a thermal management system (not shown) for coolant to be delivered and removed therefrom. 
     While two power modules (the first power module  106  and the second power module  108 ) are shown in  FIGS. 2A and 2B , it is contemplated that the power module assembly  100  may include two or more stacked power modules based on vehicle power requirements. A structural design of each of the first power module  106  and the second power module  108  may be utilized in each of a stack of a plurality of power modules without needing to design additional power module embodiments. 
     Each of the first power module  106  and the second power module  108  may include fastening features or locking features to facilitate securement to and alignment with one another. For example, the first power module  106  may include a pair of first wedge elements  114  and a pair of first loop elements  116 . In  FIGS. 2A and 2B  only one of the pair of first wedge elements  114  and one of the pair of first loop elements  116  is shown due to an orientation of the first power module  106 . 
     The second power module  108  may include a pair of second wedge elements  118  and a pair of second loop elements  120 . In  FIGS. 2A and 2B  only one of the pair of second wedge elements  118  and one of the pair of second loop elements  120  is shown due to an orientation of the second power module  108 . 
     Each of the pair of first wedge elements  114  and each of the pair of first loop elements  116  may be located at a central axis  117  of one of each of a pair of first minor sides  119 . For example, each of the pair of first wedge element  114  and each of the pair of first loop elements  116  may be spaced equidistant from respective corners of the first power module  106 . It is contemplated that each of the pair of first wedge elements  114  and each of the pair of first loop elements  116  may be located on an axis other than the central axis  117 , such as an axis spaced between the central axis  117  and one of the corners of the first power module  106 . A location of each of the pair of first wedge elements  114  and each of the pair of first loop elements  116  may be based on a desired clamping force to promote a sealed relationship between the power modules to facilitate coolant flow between the coolant channels. For example, a particular power module may have optimal operating conditions relating to a coolant flow rate and coolant pressure. The location of the wedges elements and loop elements may be selected to obtain a clamping force between the power modules to maintain the desired coolant flow rate and coolant pressure. 
     In  FIGS. 2A and 2B , only one of the pair of first minor sides  119  is shown due to an orientation of the first power module  106 . Each of the pair of second wedge elements  118  and each of the pair of second loop elements  120  may be located at a central axis  121  of one of each of a pair of second minor sides  123 . For example, each of the pair of second wedge elements  118  and each of the pair of second loop elements  120  may be spaced equidistant from respective corners of the second power module  108 . In  FIGS. 2A and 2B , only one of the pair of second minor sides  123  is shown due to an orientation of the second power module  108 . 
     Each of the pair of first loop elements  116  may be sized to receive one of the pair of second wedge elements  118  to align and secure the first power module  106  to the second power module  108  as shown in  FIG. 2B . Each of the wedge elements and each of the loop elements may be arranged with wedge elements and loop elements of the other of the power modules to secure the power modules to one another to facilitate a sealed relationship between the first power module  106  and the second power module  108  and to prevent coolant leakage. 
     The first power module  106  and the second power module  108  may include additional features to assist in aligning respective coolant channels with one another and to assist in aligning respective fastening features with one another. For example, the first power module  106  may include a first groove  124  at an upper portion and the second power module  108  may include a second groove  126  at an upper portion. The first power module  106  may include a first extension  128  at a lower surface and the second power module  108  may include a second extension  130  at a lower portion. Each extension may be sized to sit within a respective groove. Each of the grooves may be arranged with a respective extension to assist in aligning the coolant channels  110  of the first power module  106  in substantial registration with the coolant channels  111  of the second power module  108 . 
     It is contemplated that a third power module (not shown) may include a structural design substantially identical to one of the first power module  106  or the second power module  108  for securement to the first power module  106  or the second power module  108  in a stack. For example, the third power module may include fastening features for alignment with corresponding fastening features of the first power module  106  or the second power module  108 . The structural design of the first power module  106  and the second power module  108  provides flexibility to utilize various numbers of power modules in a stack based on vehicle power requirements, e.g. higher power requirements may use two or more power modules. 
       FIGS. 2C and 2D  illustrate an example of an internal structure of the first power module  106  relating to the coolant channels  110 . In  FIGS. 2C and 2D  a first pair of the coolant channels  110  is referred to as a first pair of coolant channels  110 ′ and a second pair of the coolant channels  110  is referred to as a second pair of coolant channels  110 ″ for clarity. The first power module  106  may include a frame  129  for retaining electrical components, such as a power stage  132 . The power stage  132  may include one or more switching units that generate heat during operation. The frame  129  may define a coolant cavity  136  on each side. Each of the coolant cavities  136  fluidly connects one or the first pair of coolant channels  110 ′ or the second pair of coolant channels  110 ″. For example, each of the coolant cavities  136  may be arranged with respective coolant channels such that coolant flows across the power stage  132  as represented by arrows  138 . It is contemplated that each of the coolant cavities  136  may have various shapes to promote desired coolant flow across or adjacent the power stage  132 . 
       FIGS. 3A through 3C  show another example of a power module assembly, referred to generally as a power module assembly  150  herein. The power module assembly  150  may include a first power module  152  and a second power module  154 . Each of the first power module  152  and the second power module  154  include fastening features, locking features, and/or alignment features to assist in mounting the power modules to one another, to assist in positioning one or more coolant channels of each power module in substantial registration with coolant channels of the other of the power modules, and to facilitate a sealed relationship between the power modules. The first power module  152  may include one or more coolant channels  153  and the second power module  154  may include one or more coolant channels  155 . 
     Each of the one or more coolant channels  153  and each of the one or more coolant channels  155  may be oriented within a respective power module at a location adjacent heat generating components to assist in managing thermal conditions thereof. For example, each of the one or more coolant channels  153  and each of the one or more coolant channels  155  may be located adjacent one or more switching units or a power stage. In another example, a coolant cavity may be defined between respective pairs of coolant channels to direct coolant across the heat generating component as described in relation to  FIGS. 2C and 2D . 
     In one example of fastening features, the first power module  152  may include one or more first slots  162  located on one or both of a pair of power module minor sides  164  and one or both of a pair of power module major sides  166 . Each of the one or more first slots  162  may be located at a central axis  170  of a respective power module minor side  164  or a central axis  171  of a respective power module major side  166 . In  FIGS. 3A and 3B , only two of the first slots  162 , one of each of the pair of power module minor sides  164 , and one of each of the pair of the power module major sides  166  are shown due to an orientation of the first power module  152 . 
     Each of the central axes  170  may be located at a region substantially equidistant from each of two adjacent corners of the respective power module. The first power module  152  may further include a first hook element  172  located on one or both of the power module minor sides  164  and one or both of the power module major sides  166 . Each of the first hook elements  172  may be flexible and include a hook  173  sized for inserting within a slot of a power module located below and as further described herein. Each of the first hook elements  172  may be located at a respective central axis  170  aligned with a respective one of the one or more first slots  162 . 
     The second power module  154  may include one or more second slots  176  located on one or both of two power module minor sides  178  and one or both of two power module major sides  180 . Each of the one or more second slots  176  may be located at a respective central axis  179  or a central axis  181  and each may be sized to receive one of the hooks  173  to secure the first power module  152  to the second power module  154 . The second power module  154  may further include a second hook element  182  located on one or both of the two power module minor sides  178  and one or both of the two power module major sides  180 . Each of the second hook elements  182  may be flexible and include a hook  183  sized for inserting within a slot of a power module located below the second power module  154 . Alternatively, each hook  183  may be sized for grasping a portion of a supporting surface, such as a tray or support structure (not shown). Each of the second hook elements  182  may be located at a respective central axis  179  or central axis  181  aligned with a respective one of the one or more second slots  176 . 
     It is contemplated that each of the slots and hook elements may be located on an axis other than the central axis  170  or the central axis  171 , such as an axis spaced between a respective central axis and the respective power module corners. A location of each of the slots and hook elements may be based on a desired clamping force to promote a sealed relationship between the power modules to facilitate coolant flow between the coolant channels. For example, a particular power module may have optimal operating conditions relating to a coolant flow rate and coolant pressure. The location of the slots and hook elements may be selected to obtain a clamping force between the power modules to maintain the desired coolant flow rate and coolant pressure. 
     In one example of alignment features, an upper portion of the first power module  152  may include a first groove  184  and an upper portion of the second power module  154  may include a second groove  186 . Each of the grooves may extend about and may be spaced inward from a perimeter of the upper portion of a respective power module. A lower portion of the first power module  152  may include a first extension  188  and a lower portion of the second power module  154  may include a second extension  190 . Each of the extensions of the first power module  152  and the second power module  154  may extend about and may be spaced inward from a perimeter of the lower portion of a respective power module. 
     Each of the grooves and extensions may be located upon a respective power module to assist in aligning fastening features of the respective power modules for securement to one another and to assist in aligning corresponding coolant channels for fluid communication therebetween. For example, the second groove  186  and the first extension  188  may be arranged with one another such that the first extension  188  rests within the second groove  186  when the first power module  152  and the second power module  154  are secured to one another. The arrangement between the first extension  188  and the second groove  186  may also assist in aligning central axes  170  and central axes  171  of the first power module  152  with corresponding central axes  179  and central axes  181  of the second power module  154 . Alignment of the central axes further assists in aligning respective hook elements for insertion within respective slots to secure the first power module  152  and the second power module  154  with one another. Each of the grooves may be sized to receive a sealant material to assist in securing a respective extension within a respective groove. 
     It is contemplated that a third power module (not shown) may include a structural design substantially identical to one of the first power module  152  or the second power module  154  for securement to the first power module  152  or the second power module  154  in a stack. For example, the third power module may include fastening features for alignment with corresponding fastening features of the first power module  152  or the second power module  154 . The structural design of the power modules provides flexibility to utilize a number of power modules in a stack based on vehicle power requirements, e.g. higher power requirements may use two or more power modules. 
       FIGS. 4A and 4B  show another example of a power module assembly, referred to generally as a power module assembly  200  herein. The power module assembly  200  may include a first power module  202  and a second power module  204  each having fastening features and alignment features. The first power module  202  may include a pair of first minor sides  208  and a pair of first major sides  210 . The second power module  204  may include a pair of second minor sides  212  and a pair of second major sides  214 . The first power module  202  may include a pair of first side grooves  218  extending a length of one of the pair of first major sides  210 . The second power module  204  may include a pair of second side grooves  220  extending a length of one of the pair of second major sides  214 . 
     The first power module  202  may include one or more coolant channels  221  and the second power module  204  may include one or more coolant channels  222 . Each of the coolant channels may be located adjacent heat generating components (not shown) included within a respective power module. For example, each of the one or more coolant channels  221  and each of the one or more coolant channels  222  may be located adjacent one or more switching units or a power stage. In another example, a coolant cavity may be defined between respective pairs of coolant channels to direct coolant across the heat generating component as described in relation to  FIGS. 2C and 2D . 
     The first power module  202  may include a pair of first flanges  224  each extending from one of the first major sides  210  and defining a cavity  225  therebetween. Each of the pair of first flanges  224  may be flexible and include a first grasp element  226 . The first power module  202  may include a first upper portion  228  offset from a first lower portion  229  to define each of the pair of first side grooves  218  therebetween. For example, a pair of side faces  227  of the first upper portion  228  may each define a first upper plane offset from a first lower plane defined by a respective one the pair of first major sides  210  as further illustrated in  FIG. 4C . A cross-sectional area of an upper surface of the first upper portion  228  may be less than a cross-sectional area of the first lower portion  229  to assist in facilitating securement to another power module, such as the second power module  204 . 
     The second power module  204  may include a pair of second flanges  230  each extending from one of the second major sides  214  and defining a cavity  231  therebetween. Each of the pair of second flanges  230  may be flexible and include a second grasp element  232 . The second power module  204  may include a side face of a second upper portion  234  offset from a side face of one of the second flanges  230 . For example, each of two side faces of the second upper portion  234  may define a second upper plane offset from a second lower plane defined by respective first major sides  210  and first flanges  224 . 
       FIG. 4D  illustrates detail of an example of the fastening features and the alignment features of the power module assembly  200 . As mentioned above, each of the first flanges  224  may be of a flexible material such that each of the first flanges  224  may spread outward of the second upper portion  234  to position each of the first grasp elements  226  for interlock within a respective second side groove  220  to secure the first power module  202  to the second power module  204 . In this example, the grooves and grasp elements are arranged with one another such that there are no fasteners projecting externally from the power modules when secured to one another. Each of the first grasp elements  226  may be sized to rest within the respective second side groove  220  such that the second upper portion  234  is at least partially disposed within the cavity  225 . 
     It is contemplated that a third power module (not shown) may include a structural design substantially identical to one of the first power module  202  or the second power module  204  for securement to the first power module  202  or the second power module  204  in a stack. For example, the third power module may include fastening features for alignment with corresponding fastening features of the first power module  202  or the second power module  204 . The structural design of the power modules provides flexibility to utilize a number of power modules in a stack based on vehicle power requirements, e.g. higher power requirements may use two or more power modules. 
       FIGS. 5A and 5B  show another example of a power module assembly, referred to generally as a power module assembly  250  herein. The power module assembly  250  may include a first power module  252  and a second power module  254 . Each of the first power module  252  and the second power module  254  may include fastening features and alignment features to assist in securing the first power module  252  to the second power module  254 . The first power module  252  may include a pair of first minor sides  258  and a pair of first major sides  260 . In  FIGS. 5A and 5B  only one of the pair of first minor sides  258  and one of the pair of first major sides  260  is visible due to an orientation of the first power module  252 . 
     The first power module  252  may include one or more first coolant channels  261  and the second power module  254  may include one or more second coolant channels  262 . Each of the coolant channels may be located adjacent heat generating components (not shown) included within a respective power module. Examples of the heat generating components include switching units or a power stage. For example, each of the one or more first coolant channels  261  and each of the one or more second coolant channels  262  may be located adjacent one or more switching units or a power stage. In another example, a coolant cavity may be defined between respective pairs of coolant channels to direct coolant across the heat generating component as described in relation to  FIGS. 2C and 2D . 
     The first power module  252  may further include a first upper portion  264  arranged with a first lower portion  265  to define a first groove  266  therebetween and extending about a perimeter of the first power module  252 . The first upper portion  264  may define a first upper surface groove  271  spaced inward from the pair of second minor sides  272  and the pair of second major sides  274 . While not visible in  FIGS. 5A and 5B  due to an orientation of the second power module  254 , the second groove  278  is shown in  FIG. 5C  and is shaped and oriented similar to the first groove  124  of  FIG. 2A . The first lower portion  265  may include a first sidewall  269  extending about the perimeter and defining a first cavity  267 . The first upper portion  264  may define a first side face  268  extending about a perimeter of the first upper portion  264 . The first side face  268  may be spaced inward from planes defined by each of the pair of first minor sides  258  and the pair of first major sides  260 . The first power module  252  may include a first extension  270  spaced inward from the first sidewall  269  and within the first cavity  267  as illustrated in  FIG. 5C . 
     As mentioned above, the second power module  254  may also include fastening and alignment features to assist in securing the first power module  252  to the second power module  254 . The second power module  254  may include a pair of second minor sides  272  and a pair of second major sides  274 . In  FIGS. 5A and 5B  only one of the pair of second minor sides  272  and one of the pair of second major sides  274  is visible due to an orientation of the second power module  254 . 
     The second power module  254  may further include a second upper portion  276  arranged with a second lower portion  277  to define a second groove  278  therebetween and extending about a perimeter of the second power module  254 . The second upper portion  276  may define a second upper surface groove  275  spaced inward from the pair of second minor sides  272  and the pair of second major sides  274 . While not visible in  FIGS. 5A and 5B  due to an orientation of the second power module  254 , the second groove  278  is shown in  FIG. 5C  and is shaped and oriented similar to the first groove  124  of  FIG. 2A . 
     The second lower portion  277  may include a second sidewall  281  extending about the perimeter and defining a second cavity  279 . The second upper portion  276  may define a second side face  280  extending about a perimeter of the second upper portion  276 . The second side face  280  may be spaced inward from planes defined by each of the pair of second minor sides  272  and the pair of second major sides  274 . The second power module  254  may include a second extension  282  extending about an inner perimeter of the second lower portion  277  within the second cavity  279 . 
       FIG. 5C  is a front view, in cross-section, illustrating an example of the fastening features securing the first power module  252  to the second power module  254 . In this example, the second upper portion  276  of the second power module  254  is disposed within the first cavity  267  of the first power module  252  such that the first extension  270  of the first power module  252  sits within the second upper surface groove  275  of the second power module  254  to secure the first power module  252  to the second power module  254 . Portions of the first sidewall  269  of the first lower portion  265  are aligned for a flush relationship with portions of the pair of second minor sides  272  and portions of the pair of second major sides  274 . 
     The grooves and extensions may be arranged with one another such that one of the one or more first coolant channels  261  and one of the one or more second coolant channels  262  are in substantial registration with one another when the first power module  252  and the second power module  254  are secured to one another. The grooves and extensions may also be arranged with one another to create a sealed relationship between the first power module  252  and the second power module  254  such that coolant may flow between the one or more first coolant channels  261  and the one or more second coolant channels  262  without leaking. For example, each of the first upper surface groove  271  and the second upper surface groove  275  may be sized to receive a seal material therein. The seal material may secure a respective extension within a respective groove to assist in preventing leakage of coolant flowing within the coolant channels. Additionally, the grooves and extensions of each power module may be arranged with one another such that there are no fasteners projecting externally from either power module. It is also contemplated that the sidewalls may be of a flexible material to facilitate a snap fit between the first power module  252  and the second power module  254 . 
     It is contemplated that a third power module (not shown) may include a structural design substantially identical to one of the first power module  252  or the second power module  254  for securement to the first power module  252  or the second power module  254  in a stack. For example, the third power module may include fastening features for alignment with corresponding fastening features of the first power module  252  or the second power module  254 . The structural design of the power modules provides flexibility to utilize a number of power modules in a stack based on vehicle power requirements, e.g. higher power requirements may use more than two power modules while lower power requirements may use only two power modules. 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the disclosure that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and can be desirable for particular applications.