Transient Turbine Engine Modeling with Hardware-in-the-Loop Power Extraction

Increasingly high aircraft power demands require that the interactions between an aircraft’s electrical subsystem and the engine subsystem be considered in dynamic, systemlevel tests. Traditionally, system-level dynamics have only been captured in completely assembled aircraft systems. Component-level or subsystem-level optimization is no longer appropriate because highly interdependent dynamics between subsystems only become apparent during system-level analysis. In an effort to reduce the high cost of testing integrated power and propulsion systems in an altitude-simulating wind tunnel, alternatives such as modeling and simulation are considered. Synchronizing and coupling simulations of vastly different time scales is possible, but the resulting system simulation runs very slowly. For this reason, hardware-in-the-loop (HIL) becomes an ideal test platform where simulations and hardware components can be integrated for system-level testing when time scales are drastically different or actual hardware prototype components are available. The work documented in this paper demonstrates the capability of conducting propulsion/power system-level tests with a simulated engine and a hardware generator. It more importantly shows that when using a validated engine model, HIL is capable of greatly reducing time, effort, and cost (by several orders of magnitude) associated with full system hardware validation.