Abstract:
A power loop is formed by a plurality of loop segments connectable by switches to form the power loop. The power loop is configured to receive power from a plurality of power sources. The switches connect the power loop to a plurality of components. A method is also disclosed and claimed.

Description:
BACKGROUND 
       [0001]    This application relates to power distribution for use on a vehicle, such as an aircraft, wherein the power is distributed across a loop that can be closed at any point through connecting the loop segments. 
         [0002]    Modern aircraft are typically provided with power buses that distribute power to a plurality of AC and DC users. Examples may be pumps for gas turbine engines, galleys, and any number of other components mounted on the vehicle. Typically, the power buses extend along the length of the aircraft, and have two distinct ends. 
         [0003]    Sources of power, typically gas turbine engines, drive generators to supply power to the buses. It is often the case that the components, including the power users, and the power sources, are connected or disconnected to and from the bus by electromechanical switches. Such switches can fail. 
       SUMMARY 
       [0004]    A power loop is formed by a plurality of loop segments connectable by switches to form the power loop. The power loop is configured to receive power from a plurality of power sources. The switches connect the power loop to a plurality of components. A method is also disclosed and claimed. 
         [0005]    These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  schematically shows an aircraft power loop. 
           [0007]      FIG. 2  shows a solid state switch. 
           [0008]      FIG. 3A  shows a first control scheme that is provided by the  FIG. 1  system. 
           [0009]      FIG. 3B  shows a second control scheme. 
           [0010]      FIG. 3C  shows another control scheme. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]      FIG. 1  shows an aircraft  20  incorporating a power ring or loop  22 . The power loop  22  is utilized in place of the prior linear power buses. While the term “loop” is utilized, it should be understood that the loop  22  is likely not circular, as illustrated. Rather, “loop” merely refers to the fact that the power loop  22  is a loop that can be closed at any point through connecting the loop segments, and has no apparent “end.” In a sense, it is likely the shape of the loop  22  would be dictated by the shape of the vehicle, such as aircraft  20 , and the location of the components that are interconnected by the loop  22 . 
         [0012]    Several sources of power  24 ,  26 ,  28 , and  30  supply power through switches  44  to the loop  22 . The sources of power  24 ,  26 ,  28 ,  30  may be gas turbine engines driving generators for either AC and or DC generation. The switches  44  may be traditional mechanical switches. 
         [0013]    The power loop  22  powers a number of components. As examples only, galleys  36  and  38 , pumps  32  and  34 , and AC/DC power converters  40  may receive power from the loop  22 . The power converters  40  convert AC power into DC power, and then communicate with any number of other components that are driven by DC power. While the power loop  22  is shown conveying AC power, with the local power converters  40  being AC/DC converters (they can also be AC/AC converters), it should be understood that the loop  22  could convey DC power, and the power converters  40  could be DC/DC converters. In addition, should the loop  22  convey DC power, the power converters  40  could also be DC/AC converters, allowing the provision of AC power to localized locations without the existence of a separate AC bus. 
         [0014]    When the loop  22  conveys AC power to local power converters  40 , it allows the elimination of the prior art DC busses. 
         [0015]    Further, converters  40  can include the connection of a battery, or other DC power source which may be charged from the loop  22  through the converters  40 . 
         [0016]    As can be seen, switches  46  connect the AC components to the loop  22 , such as pumps  32 ,  34  and galleys  36 ,  38 . The power converters  40  are connected to the loop  22  through switches  48 . The switches  46  and  48  may be semiconductor solid state switches, and could be called component switches. Embodiments of such switches are known in the art. An example of switch  46 ,  48  is shown in  FIG. 2  at  100 . 
         [0017]    As shown in  FIG. 2 , an exemplary switch  100  may have an input connection  102 , and an output connection  103 . A current sensing device  105  is incorporated into the switch  100 . In addition, a number of switching elements  104  are incorporated. This is merely an example of a semi-conductor solid state switch, and other examples of such switches would come within the scope of this application. 
         [0018]    Returning to  FIG. 1 , switches  50  connect or isolate each of the sources of power  24 ,  26 ,  28 , and  30  from the loop  22 . Switches  52  could be called bus switches. Switches  50  could be called source switches. In addition, switches  52  allow isolation of sections of the loop  22  as will be explained below. Switches  50  and  52  may also be semiconductor solid state switches. All of the switches  46 ,  48 ,  50 , and  52  are connected to a common control  80  such that the control can define switching patterns to provide power supply as is desired. The control can include one or more microcontrollers, memory, input/output interfaces, and/or additional circuitry configured to achieve the referenced control functions. 
         [0019]    With the power loop  22 , power can now flow from any one of the sources in either direction (clockwise or counter-clockwise) and any one of the power supplies can power any one of the components being powered. 
         [0020]    In addition, the closed loop nature provides powerful control schemes, such as shown in  FIGS. 3A ,  3 B, and  3 C. In  FIG. 3A , the power source  30  of  FIG. 1  has failed. Thus, its switches  50  are opened to isolate the power source from the loop  22 . Now, power can flow to all of the components from the power sources  24 ,  26 , and  28  in either direction. 
         [0021]    In addition, the opening and closing of the switches can be done in a similar manner to force the power supply from any one of the sources in only one direction. As an example,  FIG. 3B  shows one of the switches  50  open on the power source  30 . The power will flow in the opposed or clockwise direction. In this way, an imbalance in the amount of generated power from any one of the sources can be compensated for easily. 
         [0022]      FIG. 3C  shows another control scheme wherein an entire section  198  of the loop  22  is opened between a source switch  50  and a bus switch  52 , such as if components of lesser importance are depowered while components of greater importance remain powered. This scheme may be used, as an example, if there is a shortage of power. 
         [0023]    Alternatively, the control scheme as shown in  FIG. 3C  may be helpful should there be a failure in the components which are isolated from the power in the section  198 . 
         [0024]    The present invention thus provides the ability to have a smart power system with controls for all of the switches to achieve desired power supply for efficient and reliable operation. 
         [0025]    Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.