Type of Awards: SBIR Phase I with IEDC and Phase II Contract Numbers: FA8650-07-M-2781and FA8650-08-C-2859 Agency: U.S. Air Force Research Laboratory Status: On Going Periods: 4/2/07 to 1/2/08 and 4/2/08 to 8/11/11 Principal Investigator: B. P. Loop Abstract: The primary objective of the proposed work is to investigate design techniques to improve torque density, power density, and efficiency in wound-rotor synchronous machines. The underlying principle of the proposed design technique is to alter the flux paths in the machine to increase torque production. This will be achieved through optimally altering the stator tooth geometry, rotor tooth geometry, and magnetic material properties. The design process is automated by an evolutionary optimization algorithm that employs a finite element analysis program as an objective function evaluation engine. Finite element modeling in the Phase I effort showed a potential increase of 12.2% in average torque production for the F18E/F generator. In the proposed Phase II effort, prototype machines will be built based on the designs obtained in the Phase I. Hardware validation of the approach will be performed with the help of GE Aviation. In order to investigate optimization of machines at high-speeds, additional research will be carried out to enhance the finite element modeling capabilities. These enhancements include saturation, eddy current effects, and skew. Finally, extensive statistical analysis of the performance of the genetic optimization procedure will be carried out to improve the design technique. The result will be a commercially viable machine design software package that could be adopted by government agencies and...
Read MoreMulti-Fidelity Models for Design and Analysis of Directed Energy Weapon Power Systems
E. Walters, PC Krause and Associates, Inc; S. Pekarek, O. Wasynczuk, Purdue University; A. Koenig, J. Wells, B. P. Loop, PC Krause and Associates, Inc; P. Lamm, U. S. Air Force Research Laboratory Historically, the design of aircraft electrical systems has been divided into separate mechanical (turbine engine) and electrical subsystems, wherein the coupled dynamics have been ignored until hardware integration. However, future loads such as Directed Energy Weapons (DEW), a coupled multi-physics design and analysis capability is required to evaluate system feasibility and establish optimal components in the context of a system-level architecture. In this paper, modeling and simulation techniques that provide a backbone for such design and analysis is set forth. Simulation techniques include a distributed heterogeneous simulation toolbox for interconnecting dynamic component models created using different simulation packages and/or operating systems. Modeling tools include a partitioned finite element technique and a field reconstruction technique that dramatically reduces the computational effort required to perform fields-based simulation of electric machines. Herein, the multi-physics tools are demonstrated for a multi-MW DEW system. The impact of the DEW load on the electrical, mechanical, and energy storage are evaluated under both transient and steady-state conditions and an attempt is made to search for architectures/ designs that minimize weight subject to maintaining stable system performance. 9th Annual Directed Energy Symposium, October 30-November 2, 2006, Albuquerque, NM. Contact Information:...
Read MoreBenjamin P. Loop
[gravatar email=”loop@pcka.com” class=”alignleft” size=”96″ default=”https://pcka.com/wp-content/uploads/2010/08/gravatar.jpg”]B. P. Loopreceived the BSEE (Highest Distinction), MSECE, and PhD from Purdue University in 2000, 2002, and 2005, respectively. He joined PCKA in 2005 as a Senior Engineer. In 2007 he was promoted to a Director of Engineering Services where he has conducted research in the modeling and simulation of the electric power grid and aircraft power systems and in distributed finite element techniques. His research interests include modeling, simulation, and control of electromechanical systems, stability analysis methods, and optimization techniques. In 2002 he co-received the Charles M. Manly Memorial Medal for the best paper relating to the theory or practice in the design or construction of, or research on, aerospace engines, their parts, components, or accessories from the Society of Automotive Engineers for the paper entitled “Analysis and Simulation of a UAV Power System.” Selected Publications Loop, M. Amrhein, S. D. Pekarek, A. Koenig, B. Deken, E. A. Walters, L. Sorkin, “Modeling, Analysis, and Control Design for an Intermittent Megawatt Generator,” SAE Transactions Journal of Aerospace month 2009, pp. 843-851 and 2008 SAE Power Systems Conference, November 11-13, 2008, Bellevue, WA. 2008. B. P. Loop, M. Hasan, M. Gualtieri, E. A. Walters, “Multi-Fidelity Modeling of Wound-Rotor Synchronous Machines” 2008 Electric Machines Technology Symposium, August 12-13, 2008, Philadelphia, PA. S. D. Sudhoff, B. P. Loop, J. Byoun, A. M. Cramer, “A New Procedure for Calculating Immittance Characteristics Using Detailed Computer Simulations,” Proceedings IEEE Power Electronics Specialists Conference, June 2007, pp. 901–908. B. P. Loop, C. E. Lucas, E. A. Walters, M. Hasan, S. Field, N. Kumbar, “Improvements in the Distributed Heterogeneous Simulation of Aircraft Electric Power Systems,” 2006 SAE Power Systems Conference, November 7–9, 2006, New Orleans, LA. B. P. Loop, S. D. Sudhoff, “A Basis Function Approach to the Nonlinear Average Value Modeling of Switched Reluctance Machines,” IEEE Transactions on Energy Conversion, vol. 21, issue 1, March 2006, pp. 60–68. B. P. Loop, S. D. Sudhoff, S. H. Żak, E. L. Zivi, “An Optimization Approach to Estimating Stability Regions Using Genetic Algorithms,” Proceedings of the 2005 American Control Conference, vol. 1, June 8-10, 2005, pp. 231–236. B. P. Loop, S. D. Sudhoff, P. Lamm, “Analysis and Simulation of a UAV Power System,” SAE 2002 Transactions Journal of Aerospace, September 2003, pp. 703–710. S. D. Sudhoff, B. P. Loop, P. Lamm, “Analysis of Switched Capacitive Machines for Aerospace Applications,” SAE 2002 Transactions Journal of Aerospace, September 2003, pp. 730–735. B. P. Loop, S. D. Sudhoff, “Switched Reluctance Machine Model Using Inverse Inductance Characterization,” IEEE Transactions on Industry Applications, vol. 39, issue 3, May-June 2003, pp....
Read MoreImprovements in the Distributed Heterogeneous Simulation of Aircraft Electric Power Systems
B. P. Loop, C. E. Lucas, E. A. Walters, M. Hasan, PC Krause and Associates, Inc; S. Field , N. Kumbar, Naval Air Systems Command Two recent enhancements to Distributed Heterogeneous Simulation (DHS) are variable communication rates and higher-order predictors. Variable communication automatically controls the communication interval between any two subsystems in an attempt to achieve a desired accuracy during transient periods and maximize speed during steady-state periods. Higher-order predictors can better estimate the values of exchanged variables between data exchange instances, which can improve accuracy and possibly require fewer exchanges. A comparison between a single-computer simulation of an aircraft electric power system and an equivalent three-computer DHS show that the variable communication technique enables more accuracy and higher speed distributed simulations than fixed-step communication. In addition, higher-order predictors are shown to increase accuracy in some cases. 2006 SAE Power Systems Conference, November 7–9, 2006, New Orleans, LA. Paper...
Read MoreMulti-Fidelity Modeling of Wound-Rotor Synchronous Machines
B. P. Loop, M. Hasan, M. Gualtieri, E. A. Walters, PC Krause and Associates, Inc. In this paper, methods for transitioning between different types of wound-rotor synchronous machines models are examined. The specific transitions investigated are (1) finite element to circuit-based machine models and (2) circuit-based to average value models of machine/rectifier systems. Good agreement between simulation results obtained using the different model types is achieved. This work sets the stage for a software environment that enables both component and system level analysis of electrical power systems. 2008 Electric Machines Technology Symposium, August 12-13, 2008, Philadelphia,...
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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