J. R. Wells, M. Amrhein, E. A. Walters, PC Krause and Associates, Inc; Steve Iden, Austin Page, Peter Lamm, U.S. Air Force Research Laboratory; Anthon Matasso, Lockheed Martin Corp. The movement to more-electric architectures during the past decade in military and commercial airborne systems continues to increase the complexity of designing and specifying the electric power system. In particular, the electrical power system (EPS) faces challenges in meeting the highly dynamic power demands of advanced power electronics based loads. This paper explores one approach to addressing these demands by proposing an electrical equivalent of the widely utilized hydraulic accumulator which has successfully been employed in hydraulic power system on aircraft for more than 50 years. 2008 SAE Power Systems Conference, November 11-13, 2008, Bellevue, WA. Paper...
Read MoreIntegrated Electrical System Model of a More Electric Aircraft Architecture
M. Amrhein, J. R. Wells, E. A. Walters, PC Krause and Associates Inc; Anthony F. Matasso, Tim R. Erdman, Lockheed Martin Corp; Steven M. Iden, Peter T. Lamm, Austin M. Page, U.S. Air Force Research Laboratory; Ivan H. Wong, Northrop Grumman Corp. A primary challenge in performing integrated system simulations is balancing system simulation speeds against the model fidelity of the individual components composing the system model. Traditionally, such integrated system models of the electrical systems on more electric aircraft (MEA) have required drastic simplifications, linearizations, and/or averaging of individual component models. Such reductions in fidelity can take significant effort from component engineers and often cause the integrated system simulation to neglect critical dynamic behaviors, making it difficult for system integrators to identify problems early in the design process. This paper utilizes recent advancements in co-simulation technology (DHS Links) to demonstrate how integrated system models can be created wherein individual component models do not require significant simplification to achieve reasonable integrated model simulation speeds. Such techniques enable the system integrator to observe system dynamics and interactions at fidelities which were previously impractical. This paper utilizes the electrical power system of an MEA to illustrate the capabilities and performance of the proposed approach. Specifically, the paper identifies the system modeling approach, addresses key challenges which were overcome to enable system level modeling at this fidelity, discusses the component models, and presents results from the integrated system model. 2008 SAE Power Systems Conference, November 11-13, 2008, Bellevue, WA. Paper...
Read MoreArc Fault Protection Modeling and Analysis
K. McCarthy, B. P. Loop, PC Krause and Associates, Inc. Charles Singer, Naval Air Systems Command The primary objective of this effort was to enable rapid evaluation of under voltage conditions resulting from arc faulting onboard naval aircraft. This faulting reduces the main bus voltage and, if not cleared fast enough, will result in loss of power to mission-critical loads. Hardware fault tests were used to develop and validate a system-level model including a Naval aircraft generator, cabling, arc faulting behavior, and thermal and arc fault circuit breakers. Specifically, a genetic algorithm-based optimization technique was used to identify parameter values for the generator, exciter system, and arc fault models such that the error between the behavior predicted by the model and the true hardware response was minimized. A graphical user interface for the model was then developed to facilitate rapid deployment of fault studies. The model is capable of simulating single, multiple simultaneous, or multiple sequential faults. Additionally, the base loading, power factor, cable lengths and gauges, fault location and duration, and circuit breaker ratings and trip curve characteristics can all be altered to evaluate the faulting effects under different system configurations. Several fault studies were performed with the model encompassing different combinations of base loading and circuit breaker ratings. The time required to clear the faults were recorded for each study, and these results were compared to military standards for power quality to determine the success of the protection system. The modeling work performed under this effort is a first step toward quantifying the performance of one part of the electric power protection system. The behavior of the system is very complex; however, efforts were taken to ensure the accuracy of the model by conducting extensive comparisons to hardware data. With such a model, advanced fault mitigation strategies can be implemented and tested in a virtual environment under worst-case scenarios in an effort to prevent catastrophic failures in the field. Propulsion – Safety and Affordable Readiness (P-SAR) Conference, March 24-26, 2009, Myrtle Beach, SC. Proceedings not available. Contact information:...
Read More