Patent Publication Number: US-2015076900-A1

Title: Power distribution architecture and aircraft comprising power distribution architecture

Description:
TECHNICAL FIELD 
     The present disclosure relates to a power distribution architecture and an aircraft comprising a power distribution architecture, in particular for the power distribution among cabin and cargo loads in an aircraft. 
     BACKGROUND 
     Modern aircraft power distribution architectures usually employ solid state power controller (SSPC) devices. The underlying principle for a SSPC is based upon one or more semiconductor switching devices coupled in series with a sensing device for detecting the switch current. Depending on the detected switch current by the sensing device, a control unit is configured to implement guarding functions for the switching devices in case of a failure in any of the components of the SSPC device. 
     Such SSPC devices are usually employed in so-called secondary power distribution boxes (SPDBs) of aircraft which provide cabin and cargo loads of the aircraft with electrical power. In order to ensure operation safety of the aircraft the power supply lines are commonly additionally protected by so-called remote controlled circuit breakers (RCCBs) which are implemented in the power supply lines between the power supply and the SPDBs and which protect the loads against overloading in the case of insulation or equipment faults. 
     Supply lines are usually designed with a specific load capacity so that after exceeding the maximum load capacity the respective RCCBs and SSPCs will trip and cause the power supply for the respective power supply line to be shut down. Depending on the type of aircraft, multiple cabin and cargo loads will have to be supplied with power. A trade-off has usually to be made between the number of separately protected power supply lines and the number of loads commonly supplied by a single supply line. The usage of loads in an aircraft may vary a lot, particularly depending on the flight phase, the time of the day, the types of loads and similar circumstances. Thus, load management in an aircraft is a daunting task. 
     The document WO 2010/037934 A2 discloses methods and systems for supplying and distributing electrical power of several sources on a power network while ensuring the continuity of power supply in the case of a failure or interruption of one of the sources. 
     SUMMARY 
     However, there is still a need for solutions which optimizes load management with as little additional hardware and safety-relevant components as possible. 
     A first aspect of the disclosure is directed to a power distribution architecture, comprising at least one power distribution box including at least two solid state power controllers, SSPCs, at least two main power supply lines, each of the main power supply lines being coupled to a respective one of the SSPCs and being configured to supply power to the respective one of the SSPCs, at least two main remote controlled circuit breakers, RCCBs, each of the at least two main RCCBs being coupled in a respective one of the main power supply lines, and at least one balancing RCCB coupled in a power balancing path connected between two of the main power supply lines. 
     A second aspect of the disclosure is directed to an aircraft, comprising a power distribution architecture according to the first aspect of the disclosure. 
     One idea on which the present disclosure is based is to combine the advantages of power supply line separation for loads or load groups with selective interconnectivity between separate power supply lines via protection elements in load balancing paths. 
     Advantageously, this achieves power supply line redundancy for different loads or load groups so that the peak load is increased. Thus, loads may be more flexibly associated with load groups while keeping the number of overall load groups larger. In the event of failure, defect or overload in one of the loads or load groups the remaining load groups may continue to operate. 
     More importantly, this effect is achieved without significant additional wiring requirements which lead to less space taken up and less weight being generated by the power distribution architecture. Weight saving is particularly advantageous for applications in aviation and avionics. 
     Furthermore, the parallel power supply line topology with security enhanced interconnection lines allows for the selective shutdown of specific power supply lines and their associated load groups, respectively. This is especially advantageous for separating safety-critical and non-safety-critical loads like flight entertainment systems or ground supply loads on one hand and fire protections systems or emergency lighting systems on the other. 
     According to an embodiment of the power distribution architecture, the power distribution architecture may further comprise a power supply coupled to the at least two main power supply lines and configured to provide power to the SSPCs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be explained in greater detail with reference to exemplary embodiments depicted in the drawings as appended. 
       The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments of the present disclosure and together with the description serve to explain the principles of the disclosure. Other embodiments of the present disclosure and many of the intended advantages of the present disclosure will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts. 
         FIG. 1  schematically illustrates an aircraft including a power distribution architecture according to an embodiment of the disclosure. 
         FIG. 2  schematically illustrates a power distribution architecture for an aircraft according to a further embodiment of the disclosure. 
         FIG. 3  schematically illustrates a further power distribution architecture for an aircraft according to a further embodiment of the disclosure. 
     
    
    
     In the figures, like reference numerals denote like or functionally like components, unless indicated otherwise. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein. 
     DETAILED DESCRIPTION 
       FIG. 1  shows a schematic illustration of an aircraft  20  comprising a power distribution architecture  10  on board of the aircraft. The power distribution architecture  10  may in particular be used to distribute power from an on-board power supply  1  of the aircraft  20  to power distribution boxes  6  and  7  which are arranged in the aircraft  20 . The power supply  1  may for example comprise a power source, for example a generator, a fuel cell or a high voltage battery. The power supply  1  may feed the power distribution boxes  6  and  7  via one or more power supply lines  2 . The power distribution boxes  6  and  7  in turn may provide the supplied power to attached loads in the aircraft  20 , for example cabin and cargo loads like in-flight entertainment systems, cabin lighting, galley, sanitary modules, electronic security systems or the like. The power supply line(s)  2  may for example run from the front of the aircraft  20  where a power supply  1  is typically located towards the back of the aircraft  20 . The power distribution boxes  6  and  7  may be provided at convenient locations along the longitudinal extension of the aircraft  20 , depending on where loads are located in the aircraft  20  that need to be supplied with electrical power. 
       FIG. 2  shows an exemplary illustration of a power distribution architecture  10 , for example for use in an aircraft  20  as exemplarily shown in conjunction with  FIG. 1 . The power distribution architecture  10  includes a power supply  1  which is coupled to a power distribution box  6  which may for example be a secondary power distribution box (SPDB) of an aircraft. The power supply  1  may be coupled to two main power supply lines  2   a,    2   b  which are configured to provide power to SSPCs or SSPC groups  6   a,    6   b  which are in turn included in the power distribution box  6 . 
     Each of the power supply lines  2   a  and  2   b  may be coupled to a respective SSPC or SSPC group  6   a  or  6   b,  respectively, i.e. the SSPCs or SSPC groups  6   a  and  6   b  are electrically separate from each other and the power supply of each of the SSPCs or SSPC groups  6   a  and  6   b  is secured via a corresponding one of the main power supply lines  2   a  and  2   b,  respectively. 
     In each of the main power supply lines  2   a  and  2   b  a remote controlled circuit breaker (RCCB)  3   a  and  3   b  is coupled in the current path between the power supply  1  and the power distribution box  6 . Between at least two of the main power supply lines  2   a  and  2   b  a balancing remote controlled circuit breaker, RCCB,  5   a  may be coupled in a power balancing path  5  connected between the two main power supply lines  2   a  and  2   b.  Since the power supply lines  2   a  and  2   b  are commonly running approximately along the whole length of an aircraft with the power supply  1  being connected at the end of the aircraft&#39;s nose, the power balancing path  5  may advantageously be provided at the opposite end near the rear of the aircraft. 
     Each of the SSPCs or SSPCs groups  6   a  and  6   b  may couple the power supply  1  with loads or load groups  8   a  and  8   b,  respectively. The SSPCs  6   a  and  6   b  may for example be hardware components including one or more controllable circuit breaking components which have to be enabled for the SSPC device to provide power from the power supply  1  to a particular one of the electrical loads  8   a  or  8   b.  The SSPCs  6   a,    6   b  may be under control of a controlling unit that monitors the operational state of the elements of the SSPCs  6   a,    6   b.  In particular, when any failure, defect or irregularity is detected that might lead to potential overloads or other harm to the associated electrical components of the power distribution architecture  10  the controlling unit is able to take measures to shut down the power supply  1  and/or the SSPCs  6   a,    6   b  for safety reasons. Usually, the required failure rates and failure response times are bounded by upper limits set by official regulations of aviation associations. 
     The power supply  1  may for example be a generator, a fuel cell or a high voltage battery or accumulator, and may supply an input AC or DC voltage to the power distribution architecture  10 . In the power distribution architecture  10  of  FIG. 2  the main power supply lines  2   a,    2   b,  also called feeders, may be operated in parallel during normal operational conditions. The loads or load groups  8   a  and  8   b  are thus operated in parallel as well, just as the RCCBs  6   a ,  6   b.  This means that the current availability for each of the loads or load groups  8   a  and  8   b  is doubled by virtue of the power balancing path  5 . 
     The additional RCCB  5   a  is used to protect the wiring in the case of a failure, defect or overload. An overload would isolate the respective main power supply line  5  due to first the additional RCCB  5   a  opening and in short succession the respective main RCCB  3   a  or  3   b.  After such an overload event the power distribution box  6  is configured to shed all loads which may lead to an overload of the remaining main power supply lines  2   a  or  2   b,  while the remaining loads or load groups  8   a  and  8   b  remain operable. 
       FIG. 3  schematically shows a power distribution architecture  10  which mainly differs for the power distribution architecture  10  in  FIG. 2  in that four main power supply lines  2   a,    2   b,    2   c,    2   d  are employed with main RCCBs  3   a,    3   b,    3   c  and  3   d.    
     Each of the main power supply lines  2   a,    2   b,    2   c,    2   d  branches of at respective distribution nodes  4   a,    4   b,    4   c,    4   d  to two power distribution boxes  6  and  7  with respective SSPCs or SSPCs groups  6   a,    6   b,    6   c,    6   d  and  7   a,    7   b,    7   c,    7   d.  The SSPCs  6   a  to  6   d  and  7   a  to  7   d  are configured to supply loads or load groups  8   a  to  8   d  and  9   a  to  9   d,  respectively, in each case. 
     All main power supply lines  2   a,    2   b,    2   c,    2   d  may be interconnected at a common neutral point. The interconnection lines to the common neutral point may be power balancing paths  5  as well with additional RCCBs  5   a,    5   b  and  5   c —one for each interconnection between two main power supply lines  2   a,    2   b,    2   c,    2   d —coupled between the neutral point and the distribution nodes  4   a,    4   b,    4   c,    4   d.  It may also be possible to provide power balancing paths between the distribution nodes  4   a,    4   b,    4   c,    4   d  for two of the power distribution boxes  6 ,  7  as well. 
     It may also be possible to provide a respective additional RCCB  5   a,    5   b,    5   c  in each of the main power supply lines  2   a,    2   b,    2   c,    2   d,  i.e. four additional RCCBs in the architecture shown in  FIG. 2 , and to interconnect the main power supply lines  2   a,    2   b,    2   c,    2   d  with direct connections. This may prove advantageous in terms of ease of installation and RCCB placement. 
     The number of power distribution boxes  6 ,  7  is exemplarily shown as two in  FIG. 3 , however, any other number of power distribution boxes may be possible as well. Similarly, the number of main power supply lines or feeders  2   a  to  2   d  is exemplarily shown as four in  FIG. 3 , however, any other number of main power supply lines being coupled in parallel may be possible as well. 
     In the foregoing detailed description, various features are grouped together in one or more examples or examples with the purpose of streamlining the disclosure. It is to be understood that the above description is intended to be illustrative, and not restrictive. It is intended to cover all alternatives, modifications and equivalents. Many other examples will be apparent to one skilled in the art upon reviewing the above specification. 
     The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, to thereby enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated. In the appended claims and throughout the specification, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein,” respectively. Furthermore, “a” or “one” does not exclude a plurality in the present case.