Juri Jatskevich University of British Columbia; E. A. Walters, C. E. Lucas, PC Krause and Associates, Inc; Peter T. Lamm U.S. Air Force Research Laboratory In this paper, a parametric average-value modeling approach is applied to a high-frequency six-phase aircraft generation subsystem. This approach utilizes a detailed switch-level model of the system to numerically establish the averaged dynamic relationships between the ac inputs of the rectifier and the dc-link outputs. A comparison between the average-value and detailed models is presented, wherein, the average-value model is shown to accurately portray both the large-signal time-domain transients and the small-signal frequency-domain characteristics. Since the discontinuous switching events are not present in the average-value model, significant gains can be realized in the computational performance. For the study system, the developed average-value simulation executed more than two orders of magnitude faster than the detailed simulation. SAE Transactions Journal of Aerospace, July 2005, pp. xxx, and 2004 SAE Power Systems Conference, November 2-4, 2004, Reno, NV, Paper...
Read MoreTransient Turbine Engine Modeling and Real-Time System Integration Prototyping
Michael Corbett, Jessica Williams, Mitch Wolff, E. A. Walters, J. R. Wells, PC Krause and Associates, Inc; Peter Lamm, U.S. Air Force Research Laboratory Aircraft power demands continue to increase with the increase in electrical subsystems. These subsystems directly affect the behavior of the power and propulsion systems and can no longer be neglected or assumed linear in system analyses. The complex models designed to integrate new capabilities have a high computational cost. This paper investigates the possibility of using a hardware-in-the-loop (HIL) analysis with real time integration. A representative electrical power system is removed from a turbine engine model simulation and replaced with the appropriate hardware attached to a 350 horsepower drive stand. In order to update the model to proper operating conditions, variables are passed between the hardware and the computer model. Using this method, a significant reduction in runtime is seen, and the turbine engine model is usable in a real time environment. Scaling is also investigated for simulations to be performed that exceed the operating parameters of the drive stand. Similar results are generated with and without the scale factor implemented. Excellent agreement is shown between the HIL and stand alone model results. These results validate the capability of HIL experimentation and provide the opportunity for significant future propulsion configuration studies with minimal cost. 2006 SAE Power Systems Conference, November 7–9, 2006, New Orleans, LA. Paper...
Read MoreModeling, Analysis, and Control Design for an Intermittent Megawatt Generator
B. P. Loop, M. Amrhein, S. D. Pekarek, A. Koenig, B. Deken, E. A. Walters, PC Krause and Associates, Inc; L. Sorkin, Innovative Power Solutions An Intermittent Megawatt Generator (IMG) has been designed by Innovative Power Solutions (IPS) to meet the needs of future directed energy loads on high-performance aircraft. These loads significantly impact the electrical, mechanical, and thermal performance of the generator, load, and aircraft. If representative simulation models of the generator and other important subsystems can be obtained, the impact on system performance can be analyzed and optimized before the generator is deployed. The objective of this work was to utilize various modeling techniques to obtain accurate electrical, thermal, and mechanical performance models of the IMG, and to apply these models to analyze dynamic response transients to sudden load changes as seen for directed energy loads. Additionally, the models have been used to optimize the IMG control to mitigate voltage transients during these load changes. 2008 SAE Power Systems Conference, November 11-13, 2008, Bellevue, WA. Paper...
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