[gravatar email=”wells@pcka.com” class=”alignleft” size=”96″ default=”https://pcka.com/wp-content/uploads/2010/08/gravatar.jpg”]J. R. Wells received the BSEE, MSEE, and PhD from the University of Illinois at Urbana-Champaign in 2000, 2003, and 2005, respectively.  He is currently a Director of Engineering Services at PCKA. In this position, he serves as principal investigator  and technical lead of numerous research and development efforts including simulation software development efforts as well as modeling, simulation, analysis, and design of More Electric Aircraft (MEA) power and distribution systems. In this latter role, he has developed several design changes that have markedly improved the overall performance of the systems. His research interests include modeling, simulation, and control of electric machinery and power electronics and he has authored or co-authored over 20 technical papers. Selected Publications J. R. Wells, “Utilization of Ultra-Capacitors in an Electrical Accumulator Unit for a More-Electric Aircraft,” Advanced Capacitors World Summit 2009, March 2009. M. Amrhein, J. R. Wells, E. A. Walters, A. F. Matasso, T. R. Erdman, S. M. Iden, P. T. Lamm, A. M. Page, I. H. Wong, “Integrated Electrical System Model of a More Electric Aircraft Architecture,” 2008 SAE Power Systems Conference, November 11-13, 2008, Bellevue, WA. Paper #2008-01-2899. J. R. Wells, S. M. Iden, M. Amrhein, E. A. Walters, A. F. Matasso, P. T. Lamm, “Electrical Accumulator Unit (EAU) for the Energy Optimized Aircraft,” 2008 SAE Power Systems Conference, November 11-13, 2008, Bellevue, WA.      . J. K. Engelsman, J. R. Wells, E. A. Walters, P. T. Lamm, M. Daniels, “Development of a Simulation Model for an Aircraft Electrical Main Generator,” Proceedings Applied Power Electronics Conference, February  2008, pp. 1679-1684. Khaligh, J. R. Wells, P. L. Chapman, P. T. Krein, “Dead-Time Distortion in Generalized Selective Harmonic Control,” IEEE Transactions on Power Electronics, vol. 23, May 2008, pp. 1511 – 1517. S. Iden, J. R. Wells, “Challenges of the More Electric Aircraft Optimal Architecture and Controls,” (Keynote Address), Proceedings IEEE Workshop on Evolvable and Adaptable Hardware, April 2007. J. R. Wells, “Modeling and Simulation of Power Electronics/Machines,” (Professional Education Seminar), Applied Power Electronics Conference, February 2007. E. A. Walters, S. Pekarek, J. R. Wells, B. P. Loop, “Multi-Fidelity Models for Design and Analysis of Directed Energy Weapon Power Systems,” Directed Energy Professional Society Symposium, October 2006. S. Ramalingam, A. Green, P. Lamm, H. Barnard, E. A. Walters, J. R. Wells, “Integrated Hardware-in-the-Loop Simulation of a Complex Turbine Engine and Power System,” 2006 SAE Power Systems Conference, November 7-9, 2006, New Orleans, LA. M. Corbett, J. Williams, M. Wolff, E. A. Walters, J. R. Wells, “Transient Turbine Engine Modeling and Real-Time System Integration Prototyping,” 2006 SAE Power Systems Conference, November 7-9, 2006, New Orleans, LA. J. R. Wells, P. L. Chapman, P. T. Krein, “Modulation Based Harmonic Elimination,“ IEEE Transactions on Power Electronics, vol. 22, issue 1, January 2007, pp. 336-340. M. Amrhein, J. W. Kimball, A. Kwasinski, J. T. Mossoba, B. Nee, Z. Sorchini, W. W. Weaver, J....
Read MoreIntegrated Hardware-in-the-Loop Simulation of a Complex Turbine Engine and Power System
Suraj Ramalingam, Aaron Green, Peter Lamm, U.S. Air Force Research Laboratory; Hank Barnard, Scientific Monitoring, Inc; E. A. Walters, J. R. Wells, PC Krause and Associates, Inc. The interdependency between propulsion, power, and thermal subsystems on military aircraft such as the F-35 Joint Strike Fighter (JSF) and F-22 Raptor continues to increase as advanced war-fighting capabilities including solid-state radars, electronic attack, electric actuation, and Directed Energy Weaponry (DEW) expand to meet Air Force needs. Novel analysis and testing methodologies are required to predict these interdependencies and address adverse interactions prior to costly hardware prototyping. As a result, the Air Force Research Laboratory (AFRL) has established a dynamic hardware-in-the-loop (HIL) test-bed wherein transient simulations can be integrated through advanced real-time simulation with prototype hardware for integrated system studies and analysis. This paper details a test-bed configuration where a dynamic simulation of an aircraft turbine engine is utilized to control a dual-head electric drive stand. The drive stand is connected to an electric generator and associated power system implemented in hardware. The electromagnetic torque produced by the generator is measured and fed back into the turbine engine simulation as a load to the shaft. The HIL capability of this test-bed configuration enables reduced cost altitude testing, supports the design and analysis of integrated starter / generators and alternative power / propulsion architectures, and sets the stage for advanced integrated turbine engine / generator control design. 2006 SAE Power Systems Conference, November 7–9, 2006, New Orleans, LA. 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 MoreElectrical Accumulator Unit for the Energy Optimized Aircraft
J. R. Wells, M. Amrhein, E. A. Walters, PC Krause and Associates, Inc; Â 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...
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