Abstract:
A controller according to an exemplary aspect of the present disclosure includes, among other things, a cold plate and at least one electronic component mounted to the cold plate by an intermediate thermoelectric cooler.

Description:
BACKGROUND 
     Modern electromechanical systems include various components that generate heat. Aircrafts include multiple of these types of systems. One such system is a starter/generator for use with a gas turbine engine. Starter/generators are mechanically coupled to a shaft of the gas turbine engine. In order to start the engine, the starter/generator operates in a “starter” mode and begins to rotate the shaft of the gas turbine engine. When the gas turbine engine is operating, the starter/generator operates in a “generator” mode, and generates power for distribution throughout the aircraft. 
     Controllers for starter/generators typically include multiple types of electronic components, each of which generates significant heat. This heat must be managed to prevent damage to the electronic components. Some known controllers include electronic components mounted to a cold plate. 
     Controllers for starter/generators for gas turbine engines are known to use a cold plate, which is cooled by fuel, to manage the temperature of the electronic components. As the fuel absorbs heat from the electronic components, the temperature of the fuel increases, which increases the efficiency of combustion in the engine. 
     Controllers outside of the context of starter/generators also face similar design challenges. 
     SUMMARY 
     A controller according to an exemplary aspect of the present disclosure includes, among other things, a cold plate and at least one electronic component mounted to the cold plate by an intermediate thermoelectric cooler. 
     The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings can be briefly described as follows: 
         FIG. 1  is a schematic view of a cooling system for a controller. 
         FIG. 2  is a top, schematic view of the arrangement of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  schematically illustrates a cooling system  20  associated with a controller  22 . In this example, the controller  22  is in electrical communication with a starter/generator  24 , which is mechanically coupled to a gas turbine engine  26 . To start the gas turbine engine  26 , power from the controller  22  is directed to the starter/generator  24 . The starter/generator is mechanically coupled to a shaft of the gas turbine engine  26 , and is configured to rotate the shaft to begin operation the gas turbine engine  26 . 
     After operation begins, the starter/generator  24  acts as a generator, and directs power to the motor controller  22  for distribution throughout an aircraft, for example. While a particular system  20  is illustrated and discussed herein, this disclosure extends to other types of controllers  22 . In particular, this application extends to controllers that are not used with starter/generators. 
     The controller  22  includes a variety of different electronic components. The various electronic components each have different maximum operating temperatures, which are predetermined (often by the manufacturer of the particular component) and known. If operating above the maximum operating temperate, the components may fail. At a minimum, performance may suffer. 
     In order to cool the electronic components in the controller  22 , the components are mounted, either directly or indirectly, to a cold plate  28 . The cold plate  28  includes at least one cooling passageway  30  therein. The passageway  30  includes an inlet  32  in fluid communication with a source  33  of cooling fluid F. In this example, the cooling fluid F is fuel that will ultimately be combusted in the gas turbine engine  26 . This disclosure is not limited to embodiments where the cooling fluid F is fuel, although this disclosure may have particular benefits in that instance, as will be appreciated from the below. Other example cooling fluids include liquid dielectrics and glycol coolants. 
     The passageway  30  further includes a fluid outlet  34 , which directs the cooling fluid F downstream from the cold plate  28  and, in this example, ultimately to the gas turbine engine  26  for combustion. As the fluid F flows through the cold plate  28 , the fluid F absorbs heat from the electronic components mounted to the cold plate  28 . 
     The increase in the temperature of the fluid F (by virtue of the fluid F flowing through the passageway  30 ) is desirable and leads to more efficient combustion in the gas turbine engine  26 . In one example, the temperature of the fluid F at the inlet  32  may be about 93° C. (197.6° F.). In that example, the temperature of the fluid F at the outlet  34  may be about 101° C. (213.8° F.). 
     Some of the electronic components in the controller  22  are adequately cooled by the fluid F flowing through the cold plate  28  alone. However, the controller  22  includes some components with a lower maximum operating temperature that require additional, local cooling. 
     The controller  22  includes at least one power module  36  (there are three power modules  36 A- 36 C in one example, see  FIG. 2 ) and at least one magnetic component  38 , each of which are directly mounted to the cold plate  28 . In this example, the power modules  36  and the magnetic components  38  may have maximum operating temperatures of 150° C. (302° F.). Thus, these components are adequately cooled by being directly mounted to the cold plate  28 . As illustrated, the power module  36  is directly mounted to an upper surface of the cold plate  28 , and the magnetic component  38  is directly mounted to a lower surface of the cold plate  28 . 
     The terms “upper” and “lower” are used herein with respect to the orientation of the cold plate  28  in  FIG. 1 , and are not intended to otherwise be limiting. Further, the term “directly mounted” in this disclosure does not preclude an intermediate thermal paste or compound between components. Rather, as will be appreciated from the below, “directly mounted” means that the components are mounted to the cold plate  28  without an intermediate thermoelectric cooler. 
     The controller  22  further includes a plurality of electronic components that require additional cooling, such as capacitors  40  and printed wire boards  42  (PWBs). In this example, the capacitors  40  may have a maximum operating temperature of 65° C. (149° F.), and the PWBs  42  may have a maximum operating temperature of 100° C. (212° F.). 
     In order to provide additional cooling to the components that are rated substantially near, or below, the temperature of the cooling fluid F, intermediate thermoelectric coolers (TECs)  44 ,  46  are provided between these components and the cold plate  28 . Thus, these components are not “directly mounted” to the cold plate. 
     The TECs  44 ,  46 , may be known types of thermoelectric coolers. TECs operate by the Peltier effect, and include hot nodes  44 H,  46 H, and cold nodes  44 C,  46 C. When current flows through a TEC, the current brings heat from the cold nodes  44 C,  46 C of the device to the hot nodes  44 H,  46 H, so that one side gets cooler while the other gets hotter. In some embodiments, multiple coolers can be cascaded together to achieve additional cooling. 
     In the example of  FIG. 1 , a first TEC  44  is directly mounted to an upper surface of the cold plate  28 . In turn, in order to further insulate the capacitors  40  from the cold plate  28 , a base plate  48  is mounted to the first TEC  44 . The capacitors  40  are mounted to a capacitor support plate  50 , which is connected to the base plate  48  by way of a plurality of bus bars  52 . The bus bars  52  provide a buffer (or, space)  54  between the base plate  48  and the capacitor support plate  50 . The buffer  54  prevents additional, conductive heat transfer from the base plate  48  and provides an appropriate level of thermal insulation for the capacitors  40 . 
     In this example, a second TEC  46  directly contacts a lower surface of the cold plate  28 . The second TEC  46  is connected to a first PWB support plate  56 . The PWBs  42  are supported between the first PWB support plate  56  and a second PWB support plate  58  opposite the first PWB support plate  56 . 
     As illustrated, the hot nodes  44 H,  46 H of the first and second TECs  44 ,  46  are directly mounted to the cold plate  28 . The cold nodes  44 C,  46 C are opposite the cold plate  28 . Thus, the TECs  44 ,  46  direct heat away from the electronic components and toward the cooling fluid F. 
     Each of the first and second TECs  44 ,  46  are in communication with a control unit C. The control unit C is in communication with first and second temperature sensors  60 ,  62 , which provide information to the control unit C indicative of the temperature of the capacitors  40  and the PWBs  42 , respectively. The control unit C then provides an appropriate level of current to the first and second TECs  44 ,  46  to adjust the cooling of the capacitors  40  and PWBs  42 . While illustrated separately, the control unit C could be incorporated into the controller  22 . 
       FIG. 2  is a top, schematic view of the controller  22 . As illustrated in  FIG. 2 , the inlet  32  and outlet  34  of the passageway  30  may be provided on the same side of the cold plate  28  (while not illustrated that way in  FIG. 1 ). Additionally, the inlet  32  and outlet  34  may include quick connect fittings. 
     Further, in order to thermally insulate the electronic components that require additional cooling, the cold plate  28  includes a cutout  64  substantially extending along the entire width W of the cold plate  28 . The cutout  64  extends through the entire thickness T of the cold plate  28  (see  FIG. 1 ) and essentially separates the cold plate  28  along its length L into a relatively high temperature components side (e.g., the left side, relative to  FIG. 2 , of the cutout  64 ) and a relatively low temperature components side (e.g., the right side of the cutout  64 ). 
     The cutout  64  does not obstruct the flow of cooling fluid F through the cold plate  28 . The cold plate  28  includes narrow portions  66 ,  68  that allow a flow of cooling fluid F on opposite ends of the cutout  64 . The heat conducted through the cold plate  28  (e.g., from the left side to the right side) is limited to the relatively narrow portions  66 ,  68 , which substantially impedes heat transfer from the relatively high temperature components to the relatively low temperature components on the opposite side of the cutout  64 . 
     The disclosed arrangement of the motor controller  22  allows for higher cooling fluid F inlet temperatures, and a correspondingly higher cooling fluid F outlet temperatures. Thus, the disclosed arrangement increases combustion efficiency without compromising the operation of the electric components that require additional cooling. 
     Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. 
     One of ordinary skill in this art would understand that the above-described embodiments are exemplary and non-limiting. That is, modifications of this disclosure would come within the scope of the claims. Accordingly, the following claims should be studied to determine their true scope and content.