Power management on aircraft: Flight-phase-dependent network design for electrical networks with limited resources

Besides aircraft safety, reducing weight is one major objective of aircraft system development. Aircraft weight reduction is an essential contributor to minimizing aircraft fuel consumption and direct operating costs. Various investigations to lower the weight of the electrical system have been performed and some been put in place. Specific approaches are based on an effective Power Management function to optimize the weight of that part of the electrical system, which supplies non-flight relevant loads only. That part of the electrical system is also referred to as Cabin and Cargo electrical distribution system. In the scope of the optimization of the Cabin and Cargo power distribution system based on an effective Power Management function, the question of how far distribution capacities can be reduced had continually been raised. An answer to that question based on a newly introduced Mean Time Between Under-Capacities allows dimensioning the Cabin and Cargo electrical power distribution system based on the actual power demand of loads during flights. This paper describes an extension of this method to a flight-phase-dependent approach using mission-based fault tree analysis and so allowing for further weight reduction when optimizing the electrical network.