Patent Publication Number: US-2023133572-A1

Title: Back-up thrust reverser actuation system control

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to European Patent Application No. 21206425.7 filed Nov. 4, 2021, the entire contents of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     This disclosure relates to back-up actuation system control. In particular, this disclosure relates to back-up thrust reverser actuation system control. 
     BACKGROUND 
     Thrust reverser actuation systems enhance the stopping power of aircraft. When deployed, thrust reverser actuation systems redirect the rearward thrust of the jet engine to a forward direction, thus decelerating the aircraft. Since the jet thrust is directed forward, the aircraft will slow down upon landing. Thrust reverser actuation systems must not fail or suffer any permanent damage through use, as this can have catastrophic consequences on landing. Loads on thrust reverser actuation systems after deployment can cause the thrust reverser cowl to accelerate and impact the deployed end stops. 
     SUMMARY 
     There is provided a system architecture for a backup thrust reverser actuation system control. The system architecture includes an AC power supply of an aircraft, a power supply and a motor control adapted to control an electric motor of a thrust reverser actuation system. The system architecture further includes a backup power supply adapted to provide power to the electric motor in the event that the power supply fails. 
     The AC power supply may be connected to a rectifier to convert the AC signal to a DC signal. The rectifier may be connected to a DC link capacitor. Further, the motor control may be connected to an inverter via a motor control line. 
     The motor control may be connected to a brake control switch via a brake control switch line. The brake control switch may be connected to a brake resistor. Further, the DC link capacitor may be connected in parallel to the brake resistor and the brake control switch. The brake resistor and the brake control switch may be connected in parallel to the inverter to control the electric motor. 
     The backup power supply may be connected to the rectifier such that, in use, the backup power supply is configured to derive power from a DC supply of the rectifier in the event that the AC power supply and the power supply fail during operation. 
     The inverter may be a six switch inverter. 
     The rectifier may be connected to a backup motor control. Further, the backup motor control may be connected to a backup brake control switch and backup brake resistor via a backup brake switch control line. 
     The backup motor control may be connected to a backup four switch inverter via a backup motor control line. Further, the backup four switch inverter may be connected to the electric motor in order to, in use, control the electric motor in the event that the AC power supply fails during operation. 
     There is also provided a method for backup thrust reverser actuation system control. The method includes providing an AC power supply of an aircraft, providing a power supply and a motor control adapted to control an electric motor of a thrust reverser actuation system, and providing a backup power supply adapted to provide power to the electric motor in the event that the power supply fails. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows a schematic system architecture for back-up thrust reverser actuation system control. 
         FIG.  2    shows an alternative schematic system architecture for back-up thrust reverser actuation system control. 
     
    
    
     DETAILED DESCRIPTION 
     Electrical system architectures are shown in  FIGS.  1  and  2    for backup thrust reverser systems. Any description of ‘connected’ or ‘connection’ may be understood to be ‘electrically coupled’ or ‘electrically connected’. 
       FIG.  1    shows a system architecture  100  for back-up thrust reverse actuation system control to ensure safe system power down. As shown in  FIG.  1   , the system architecture  100  may include an aircraft AC supply  101  that connects to a power supply  102  and a motor control  103 . A motor control line  107  connects the motor control  103  to an inverter  108 . The inverter  108  may then power the electric motor M of the system architecture  100 . 
     The AC supply  101  may also be connected to a rectifier  104  to convert the AC signal to a DC signal. The rectifier  104  may be connected to a DC link capacitor  109 . As shown in  FIG.  1   , the motor control  103  may also be connected to a brake control switch  111  via a brake control switch line  106 . The brake control switch  111  is connected to a brake resistor  110 . The DC link capacitor  109  is connected in parallel to the brake resistor  110  and brake control switch  111 , which are further connected in parallel to the inverter  108  to control the electric motor M of the thrust reverser actuation system. 
     The rectifier  104  may also be connected to a backup power supply  105 , which can derive power from a DC supply of the rectifier  104  in the event that the AC supply  101  and power supply  102  fails during operation. The backup power supply  105  therefore acts as a fail-safe mechanism for a thrust reverser actuation system during operation on landing since it is sized to ensure a fail-safe and controlled power down of the system. Providing the backup power supply  105  in the overall system architecture  100  reduces overall weight and cost of a thrust reverser actuation system. For example, the backup power supply  105  enables the system to be switched off in a controlled manner, which, in turn, allows for the size of the end stops to be reduced since impact from uncontrolled end stops can be eliminated. 
       FIG.  2    shows an alternative example of a system architecture  200  for back-up thrust reverse actuation system control. The example shown in  FIG.  2    has the advantage of maintaining reduced system performance following a failure of a power supply or a six switch inverter. As shown in  FIG.  2   , the system architecture  200  may include an aircraft AC supply  201  that connects to a power supply  202  and a motor control  203 . A motor control line  207  connects the motor control  203  to a six switch inverter  208 . The six switch inverter  208  may then power the electric motor M of the system architecture  200 . 
     The AC supply  201  may also be connected to a rectifier  204  to convert the AC signal to a DC signal. The rectifier  204  may be connected to a DC link capacitor  209 . As shown in  FIG.  2   , the motor control  203  may also be connected to a brake control switch  211  via a brake control switch line  206 . The brake control switch  211  is connected to a brake resistor  210 . The DC link capacitor  209  is connected in parallel to the brake resistor  210  and brake control switch  211 , which are further connected in parallel to the six switch inverter  208  to control the electric motor M of the thrust reverser actuation system. 
     As shown in  FIG.  2   , the rectifier  204  may be connected to a back-up architecture. For example, the rectifier  204  may be connected to a backup power supply  212  and a backup motor control  213 . The backup motor control  213  may be connected to a backup brake control switch  221  and backup brake resistor  220  via a backup brake switch control line  216 . The backup motor control  213  may be connected to a backup four switch inverter  218  via a backup motor control line  217 . The backup four switch inverter  218  is then connected to the electric motor M in order to control the motor M in the event that the AC supply  201  fails. The four switch inverter  218  is sized for smaller loads and power and acts as a fail-safe substitute of the six switch inverter  208  should power fail from the AC supply  201 . The system architecture  200  shown in  FIG.  2    allows for a complete backup system of each of the ‘main’ power system components, for example, the power supply  202 , motor control  203 , brake resistor  210  and brake control switch  211 . Including the backup components in the system architecture  200  reduces cost and weight of otherwise complex thrust reverser actuation systems that are known in the art. 
     Although this disclosure has been described in terms of preferred examples, it should be understood that these examples are illustrative only and that the claims are not limited to those examples. Those skilled in the art will be able to make modifications and alternatives in view of the disclosure which are contemplated as falling within the scope of the appended claims.