Rajib Mikail, a 5th year doctoral student in the Department of Electrical and Computer Engineering at NC State University, won 2nd place in the 8th Annual Graduate Student Research Symposium. The symposium was held on March 19 at the McKimmon Center and was open to any graduate student from NC State. This year’s symposium featured over 200 posters.

Mikail is a part of the Future Renewable Electric Energy Delivery and Management (FREEDM) Systems Center and is being advised by Dr. Iqbal Husain.

This research project was funded by Nexteer Automotive, Saginaw, MI.

Rajib’s research was on "Switched Reluctance Machine (SRM) for Electric Power Steering Application".

Abstract: Power steering creates the necessary torque assist for the driver while rotating the steering wheel. Electric motor is recently used in power steering for better steering feel. To meet the torque ripple and noise level according to the standard specification is a challenging step for power steering system design. Non-permanent magnet machines are the key focus of researchers and industries due to the cost and availability issues of rare earth permanent magnet. SRM is the only non-permanent magnet machine which is highly reliable and inherently fault tolerant for steering application. With the current design and control technology, SRM has unsuitable torque ripple and acoustic noise for steering application. In this project the machine was redesigned and a new controller algorithm is proposed and implemented experimentally to achieve the required torque ripple and noise performance. A novel current profiling approach covering the speed range of operation is proposed. In addition to the current profiling method a predictive current control method is analyzed to follow the current profiles with minimum error and desired switching frequency. With the achieved improvement SRM can be used on other torque ripple sensitive high performance applications.