Longya Xu’s high-efficiency and high-reliability electric machine design and control techniques are driving advances in electric vehicles and in harnessing wind power. His development and enhancement of the first doubly fed brushless machine led to a sensorless and brushless wind-power generation system with high reliability compared to conventional motor and generator systems. He designed a brushless wind turbine generator that allows flexible AC or DC connection to power grids. Xu also developed the dual-mechanical-port (DMP) machine concept, which allows multiple mechanical subsystems to effectively interact with electrical subsystems for optimal performance and flexible power-flow control within a single electric machine frame. A major contribution to meeting the needs of high-efficiency electric vehicles, his DMP system was successfully installed on a 2.8-ton SUV capable of driving 125 km/hour at grades up to 30%.
An IEEE Fellow, Xu is a professor at The Ohio State University, Columbus, OH, USA.
Considered one of the most successful multiphysics researchers, Adel Razek’s modeling and design tools are responsible for making commercial energy conversion devices more efficient and reliable. He was among the first to develop coupled electromagnetic and circuit analysis and further developed the multiphysics field by adding coupled thermal and mechanical analysis. His work has led to the better understanding of electromagnetics in electrical machinery and electromagnetic devices and has allowed engineers and scientists to achieve higher accuracy in determining the different variables governing the operation of industrial systems and to account for realistic system operation. Other areas impacted by Razek’s work include traction in electric vehicle drives, electromagnetic compatibility, nondestructive testing, smart material actuation, robotics, and biomedicine.
An IEEE Life Fellow, Razek is senior research director (emeritus) and professor (honorary) with the National Center for Scientific Research and Centralesupelec, Gif Sur Yvette, France.
The patented work of Bruno Lequesne has driven advances leading to the realization of “more electric automobiles” that use electrical and electromechanical systems for improved fuel economy, reduced greenhouse emissions, and better safety. With innovations recognized by multiple awards from industry leaders such as Delphi and General Motors, Lequesne’s work on linear actuators provided closed form solutions to identify the best configurations for engine-valve motion or suspension. His work on encoders for brushless motors helped overcome torque ripple in electric power steering systems, contributing to a fuel-saving feature now standard in most vehicles. His camshaft and crankshaft position sensors for engine control help to reduce emissions, and his wheel speed sensors for anti-skid braking have made vehicles safer. He also developed one of the first induction belt-driven starter generators, which has enabled start-stop functionality to help eliminate idling losses in engines.
An IEEE Fellow, Lequesne is president of E-Motors Consulting, LLC, Menomonee Falls, WI, USA.
With research ahead of its time and many books that are considered the best resources in the field, Ion Gheorghe Boldea has introduced many firsts in electric machine technology for better industrial productivity, energy savings, and air pollution reduction. He developed an optimum goodness factor for designing high-speed linear induction motors to address factors such as mechanical vibrations and bending. He introduced the Magnibus-01, a 4-ton magnetic levitation test vehicle featuring linear homopolar synchronous motors for passive guide-way integrated magnetic propulsion and levitation. Dr. Boldea’s active flux concept is a unifying force for simplifying sensorless control of ac motor drives that has been implemented in many industrial applications. His work on torque vector control has become an industrial standard for electric motor drives.
An IEEE Life Fellow, Dr. Boldea is a Professor Emeritus with the University Politehnica Timisoara, Romania.
Hamid A. Toliyat’s pioneering development of multiphase induction motors has provided industry with more reliable and efficient power alternatives for transportation applications. His cutting-edge work on fault-tolerant five-phase motors during the late 1980s improved on traditional three-phase motors. He demonstrated that multiphase motors can produce more than a 15% improvement in torque while using the same amount of copper and iron as in three-phase machines. Multiphase machines are also more fault tolerant, resulting in more reliable operation. Prof. Toliyat also extended his work to synchronous and permanent magnet motors, realizing the same benefits. His contributions are integral to today’s electric motor applications for aircraft, electric and hybrid vehicles, and electric ship propulsion.
An IEEE Fellow, Prof. Toliyat is a professor and the director of the Electric Power and Electronics Program at Texas A&M University, College Station, TX, USA.
Norio Takahashi is a world-renowned expert in developing finite element analysis methods for designing electric machines. His pioneering work allows for the design of electric machines under real operating conditions, taking into account the effects of external voltage sources, stress, and temperature. His techniques have become indispensible tools for the development of highly efficient miniature motors and actuators and have led to significant cost savings. Dr. Takahashi has written hundreds of papers and several books on finite element analysis techniques. His methods have become standard in many commercial software packages and are part of the design process for electric machines and devices around the world. He is also known for developing a new type of electrical steel with low-iron loss and new design methods for high-efficiency transformer cores.
An IEEE Fellow, Dr. Takahashi is a professor with the Department of Electrical and Electronic Engineering at Okayama University, Japan.
Manoj R. Shah’s innovative methods for analyzing and designing electric machines have provided fault-tolerant equipment that can operate at higher efficiency more reliably. Dr. Shah developed an electromagnetic analysis method for General Electric generators using electric vector and magnetic scalar potentials. His method provided a greater level of accuracy in calculating the intensity of magnetic fields to address the geometric complications of winding and structural configurations and nonlinear aspects of magnetic materials in the end region of generators. His method has been incorporated in many General Electric air- and hydrogen-cooled generators produced over the last 15 years. Dr. Shah also developed an advanced wound-field motor for the U.S. Navy, providing greater power output for ship propulsion in a smaller package. His methods for monitoring the health of stator cores can help prevent catastrophic equipment failures that could lead to prolonged power outages. He also contributed to strengthening the fault-tolerant characteristics of permanent magnet machines, increasing their industry acceptance.
An IEEE Fellow, Dr. Shah is currently a senior engineer with General Electric Co.’s Global Research Center, Niskayuna, NY, USA.
Nady Boules’ visions for the potential of permanent magnetic brushless motors have become reality as key components of electric/hybrid vehicles. When General Motors (GM) invented modern rare-earth magnets, Dr. Boules saw the possibilities during the early 1980s for improved motor technology and has since championed the advancement of permanent magnet motors. He designed the first brushless motor-driven electric power steering prototype for GM, which was tested in a Corvette in 1984. His development of a torque ripple-free brushless motor enabled high-volume production of Delphi Automotive Systems’ electric power steering in 1998, creating a multibillion-dollar business. Dr. Boules developed the drive motor for GM’s Sunraycer, the solar-powered vehicle that won the 1987 World Solar Challenge race in Australia at a record speed. This drive design is considered the “grandfather” of the propulsion systems seen in today’s electric vehicles.
An IEEE Fellow, Dr. Boules is director of the Electrical and Controls Integration Research Laboratory at General Motors Global Research & Development, Warren, MI.
As the architect of modern reference frame theory, Dr. Paul C. Krause has made the analysis and understanding of the operation of electric machines more straightforward. In the 1960s, he determined that the different mathematical transformations that comprised reference frame theory could be established from one transformation, which he called the “arbitrary reference frame” transformation. He subsequently extended this original work to establish the concept of multiple reference frame analysis; thereby, forming the basis of modern reference frame theory and making the analysis less intimidating. His accomplishments have impacted the emerging use of electric drives for vehicles, aircraft, ships, and in electric power grid applications. He has focused his fundamental concepts of reference frame analysis on commercial applications through his company, PC Krause and Associates (West Lafayette, IN), which he started in 1983.
An IEEE Life Fellow, Dr. Krause recently retired from Purdue University and is currently the president and chief executive officer of PC Krause and Associates.
Donald W. Novotny’s insight into the complex behavior of alternating current (ac) machines enabled the motor drive technology revolution. By developing a basic understanding of the unexpected nature of machine dynamics over a range of frequencies, he clarified the nature of these responses, showing they were inherent in all induction machines. This resulted in the ability to evaluate individual machines to determine the global influence of specific machine parameters and to predict general trends over an entire range of machine ratings. This work was the first to demonstrate the strong influence of magnetic saturation on dynamic response as well as on self-excitation in induction machines.
He published one of the first papers on hysteresis control of current in an ac motor drive, now a standard technique for current control. Another of his papers was on the impact of bearing currents in inverter drives and a proposed method for analyzing the phenomenon. More recently he introduced and analyzed the coaxial winding transformer as a means of drastically reducing leakage inductance, thus extending the frequency range of many power electronic circuits.
An IEEE Life Fellow, Dr. Novotny is an emeritus professor at the University of Wisconsin, Madison.
T. J. E. Miller is founder and director of the Scottish Power Electronics and Electric Drives Consortium (SPEED), an engineering collaboration between the academic and industrial world used daily by more than 100 companies and 1,500 engineers in Europe, the United States, Japan, South America and the Far East. Dr. Miller led the development of theoretical methods, design techniques, and software used in the manufacturing of everyday machinery, including washing machines, refrigerators, power tools, and a wide range of industrial products. The SPEED software combines many of the advanced analytical techniques based on his published research in electrical engineering. The SPEED Laboratory at the University of Glasgow is acknowledged as the world’s leading supplier of design software for electric machines. An IEEE Fellow, Dr. Miller is the author of more than 200 publications in the fields of motors, drives, power systems and power electronics, including eight books.
Thomas Nehl is a leader in designing tools to improve automotive processes. At GM Research Labs in Warren, MI, and later Delphi in Shelby Township, MI, where he is a group leader, he developed novel approaches to the modeling of electronically operated drive and actuator systems that have been used widely within the automotive industry.
Dr. Nehl’s math-based tools have a wide range of automotive applications, including fuel injectors, transmission control solenoids, controlled dampers, relays, rotary and linear actuators, accessory drives, electric power steering, traction drives for electric and hybrid vehicles and a variety of sensors (position, speed, torque). His tools have impacted a number of automotive products, including pivoting armature injectors for General Motors (GM) trucks and sport utility vehicles, port fuel injectors for GM passenger vehicles, linear EGR valves, wheel speed and crankshaft position sensors, low torque ripple PM drives for electric power steering (Delphi) and MR dampers for controlled suspensions (Delphi).
Dr. Nehl holds bachelors, masters and doctoral degrees, all in electrical engineering, from Virginia Polytechnic Institute and State University (Virginia Tech) at Blacksburg, VA.
Dr. Konrad Reichert has made seminal contributions to the introduction of numerical field methods, especially the finite element method for electrical machine simulation and design. He also developed computer programs based on systems analysis and numerical field calculation methods that advanced new motor technologies.
The finite element design packages for electrical machines, developed by him and his staff at the Swiss Federal Institute of Technology in Zurich (ETH), have made it easier and safer to develop machines via computer-aided design. They enable simulations to define machine operating characteristics and parameters such as voltages, inductances, demagnetization limits, local loss distribution, and torque and torque ripple. His programs are used extensively today in commercial and scientific applications in electrical machine design, permanent magnet manufacturing and university research worldwide.
His expertise has been critical to the design of large permanent magnet machines, such as gearless permanent magnet generators in windmill applications. He also made significant contributions to optimizing electrical machine performance in hybrid electric vehicle propulsion, low-torque ripple in steer-by-wire projects, and gearless drives for transportation. His research and the resultant software have indicated the influence of mesh shape and the importance of refining parasite machine effects like cogging torques.
Retired from ETH Zurich since 1997, Dr. Reichert is an IEEE Life Fellow. He has a Dipl. Ing., a doctoral degree and a senior doctoral degree, all in Electrical Engineering, from the University of Stuttgart in Germany.