Distributed simulation

A new modeling technique is applied to a HALE UAV power system using detailed subsystem simulations of the turbine engine, generators, and loads.

Aircraft power systems have historically been divided into separate mechanical and electrical subsystem simulations. In the mechanical subsystem simulation, the turbine engine has mainly been modeled with a small steady-state load representing the electrical subsystem interaction. Similarly, the electrical subsystem was modeled assuming the turbine engine was an infinite mechanical source. This decoupling of the power system provided sufficient accuracy since the electrical subsystem used only a few percent of the available mechanical power.

However, with the size of aircraft electrical subsystems continuing to grow as a result of electric actuation and high-power pulsing loads, the interactions between the turbine engine and electrical subsystems can no longer be neglected under certain flight envelopes. Specifically, the electrical-power system capacity for high-altitude long-endurance (HALE) UAVs is limited under high-altitude flight due to the decreased output power of the turbine engine when compared to sea-level conditions.