Donald W. Novotny, a researcher and educator whose understanding of alternating current (ac) machine dynamics opened the door to predicting their performance and behavior, is being honored by IEEE with the 2009 Nikola Tesla Award. The IEEE is the world's largest technical professional association.
The award, sponsored by the Grainger Foundation and the IEEE Power & Energy Society, recognizes Novotny for pioneering contributions to the analysis and understanding of ac machine dynamic behavior and performance in adjustable-speed drives. The award will be presented on 24 September 2009 at the IEEE Energy Conversion Conference and Exposition in San Jose, Calif. (ECCE 2009).
The development of variable frequency power electronic drives, also known as adjustable-speed drives, for ac electrical machines came with a number of unexpected results, including very unusual dynamic behavior, such as instabilities, especially at low frequencies. The major contributions of Novotny have been concerned with developing a basic understanding of the unexpected nature of machine dynamics over a range of frequencies, and he successfully clarified the nature of these responses and showed they were inherent in all induction machines. This resulted in a method for quickly evaluating individual machines to determine the global influence of specific machine parameters and to predict general trends over an entire range of machine ratings, leading to the development of the modern ac drive. With applications focused on process control and energy conservation, these motor drives are used in fans for ventilation systems of large buildings as well as for pumps and machine tools.
Working jointly with his graduate students, Novotny has contributed much to understanding ac motor drives over the past 40 years, including introducing to the U.S. community the European approach of using time-domain complex variables for motor transient behavior. He was also the first to describe how saturation affects self-excitation of induction machines and to publish a paper on hysteresis control of current in an ac motor drive, which is now the standard technique for current control. Other innovations include online efficiency optimization of a motor drive and addressing the effects of parameter errors in vector control algorithms, work that, over 20 years later, is still stimulating new research efforts.
Important to power electronic circuit implementations was Novotny's description of a unique transformer that drastically reduced leakage inductance. He was also the first to recognize the impact of bearing currents in inverter drives and propose a method of analysis. His more recent work on a technique for achieving field weakening of a surface permanent magnet machine is an important aspect of speed control of the machine.
An IEEE Life Fellow, Novotny is the coauthor of two textbooks on electromechanical systems, has published more than 100 technical articles and has received 15 prize paper awards from the IEEE Industry Applications Society. He received his bachelor's and master's degrees in electrical engineering from the Illinois Institute of Technology, Chicago, and his doctorate from the University of Wisconsin, Madison. Since 1961 he has been a member of the faculty at the University of Wisconsin, Madison, where he is currently the Emeritus Professor, and recently completed his 50th year of teaching.
