One of the most prolific contributors to increasing the use of power electronics to benefit power systems, Hirofumi Akagi’s pioneering work on power conversion techniques has led to energy-saving applications in industrial and residential systems and has been integral to advances in renewable energy systems, electric/hybrid vehicles, and energy storage. Akagi presented the first paper on the theory of instantaneous active and reactive power in three-phase circuits. Known as “p-q theory,” Akagi applied it to a three-phase reactive power compensator consisting of switching devices without any bulky energy storage component. He also experimentally verified innovative operating characteristics that had until then been impossible to obtain through the application of conventional reactive-power theory in single-phase circuits. Considered a fundamental theory for three-phase circuits, Akagi’s p-q theory has allowed students and power engineers to gain insight into the instantaneous concept of voltage, current, active power, and reactive power. It has provided breakthroughs in the control of static synchronous compensators and unified power flow controllers in high-voltage transmission systems, as well as pure and hybrid active filters. Akagi’s work on developing the three-level neutral-point-clamped (NPC) inverter has impacted high-power converters for medium-voltage motor drives and grid-tied applications. Marking the beginning of multilevel converter technology, the NPC concept has been used around the world in photovoltaic inverters, general-purpose inverters, steel mill drives, and bullet trains. Akagi has tackled the detrimental effects of electromagnetic interference (EMI) encountered in power conversion systems with innovative research leading to active and passive filters for reducing conductive EMI and bearing current in motor-drive systems. Akagi is also well known for his innovations regarding pure and hybrid active filters for power conditioning.
An IEEE Fellow and recipient of the 2008 IEEE Richard H. Kaufmann Award, Akagi is a Distinguished Research Professor with the Department of Electrical and Electronic Engineering at the Tokyo Institute of Technology, Tokyo, Japan.
With a career dedicated to improving the performance and availability of modern electric drives, Marian P. Kazmierkowski’s pioneering innovations to processing and controlling the flow of electric energy using power electronic converters have impacted applications ranging from industrial machines to transportation systems to renewable energy sources. Kazmierkowski developed the first speed sensorless vector control system for high-power current-source inverter-fed induction motor drives. He also invented current control methods for transistor voltage source inverters with reduced switching frequency that have been used in a commercial series of transistor pulse-width-modulation (PWM) inverter-fed alternating current (ac) servo drive systems manufactured in Poland. His digital-signal-processing-based sensorless control system has improved the performance of induction motors used for drives in trams, trolleys, and subways, permitting a wide range of speed and torque adjustments while enabling full utilization of the direct current voltage supply. The work done by Kazmierkowski and his team has had important implications for renewable energy applications. He has created methods for ac sensorless direct power control of three-phase grid connected PWM converters based on the concept of "virtual flux," which have been used for active and reactive power estimation. He has also developed power electronics grid interfaces for Europe’s Wave Dragon offshore ocean-wave renewable energy converter. Controllers based on his theories can also be found in photovoltaic systems and wind farm converters. In 2003 Kazmierkowski founded the Centre of Excellence in Power Electronics and Intelligent Control for Energy Conservation at the Warsaw University of Technology, which has become an internationally recognized leader of power electronics research and teaching.
An IEEE Life Fellow and Full member of the Polish Academy of Sciences, Kazmierkowski is a professor with the Institute of Control and Industrial Electronics, Warsaw University of Technology, Warsaw, Poland.
The pioneering work of Arun Phadke on computer-based protection equipment for providing precise, real-time data on power transmission system conditions has provided the backbone for today’s wide-area measurement and control systems used to ensure power grid reliability and prevent disruptions from leading to large-scale blackouts. Phadke developed synchrophasors for measuring the flow of electricity through the power grid. Synchrophasors are time-synchronized numbers that represent both the magnitude and phase angle of the sine waves found in electricity and are time-synchronized for accuracy. Phadke also developed the phasor measurement unit (PMU) for measuring synchrophasors. PMUs have proven to be the main tool for the monitoring, protection, and control of the grid and are considered a quantum leap over analog technology, quickly providing the information needed to maintain grid stability over a wide region. During the 1990s, Phadke helped develop the concept of adaptive relaying. Using the computing and communications capability of computer relays, this concept allows for automatic adjustment of protective relay characteristics to match prevailing power system conditions to avoid unnecessary trips of equipment as a catastrophic power system event evolves. Phadke’s efforts on advancing computer-based protective relaying began in the early 1970s when his implementation of protective algorithms in an IBM minicomputer and its subsequent installation in a 138-kV substation near Roanoke, Virginia, represented the world’s first communicating relay and fault recorder. Also, his digital symmetrical component distance relay was a significant contribution to the distance protection of transmission lines. His early work on Fourier transforms for voltage and current calculation serves as the foundation for most of the digital relays installed throughout the world today.
An IEEE Life Fellow and member of the U.S. National Academy of Engineering, Phadke is a University Distinguished Research Professor with the Faculty of Engineering at the Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
A world authority on high-frequency power conversion design, modeling, and control, Fred C. Lee has pioneered technologies that provide more efficient power conversion and improved reliability in devices and systems, impacting applications ranging from personal computing and mobile devices to military and industrial equipment. Dr. Lee introduced “soft switching” technologies during the 1980s to combat the undesired switching losses, electrical and thermal stresses, and electromagnetic interference caused by high-frequency power conversion. His zero-voltage switching for resonant, quasiresonant, multiresonant, and pulse-width-modulated converters have become core components of modern power electronics equipment and systems. During the 1990s, Dr. Lee and his students developed a novel multiphase voltage regulator (VR) module for new generations of Intel microprocessors. Dr. Lee and his students have generated 25 U.S. patents addressing key areas such as power delivery architecture, modularity and scalability, control and sensing, integrated magnetics, and advanced packaging and integration. Today, every PC and server microprocessor is powered with this VR. These technologies have been further extended to high-performance graphical processors, server chipset and memory devices, networks, telecommunications, and all forms of mobile electronics. Dr. Lee has helped power electronics industries realize their full power-saving potential by overcoming the cost and reliability roadblocks caused by using nonstandard components and labor-intensive manufacturing. He and his team have developed advanced integration concepts and technologies suitable for standardization and automation using integrated power electronics modules (IPEMs) that have provided improvements in performance and cost reduction. IPEMs have been commercialized and are widely used today in powering the new generation of microprocessors, photovoltaic converters, variable-speed motor drives, and electric/hybrid vehicles.
An IEEE Fellow and member of the US National Academy of Engineering, Dr. Lee is currently a University Distinguished Professor with the Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
An international authority on the design and analysis of electric machines and power electronics drives for over 40 years, Thomas A. Lipo’s innovative contributions have advanced the state of the art and improved the efficiency and reliability of motors and drives. Prof. Lipo began his pioneering work in 1968 with the analysis, simulation, and control of early alternating-current motor drives, impacting electric traction control for subway cars and open pit mining equipment, among other applications. He has pioneered or improved upon electrical machine topologies, including flux switched machines, high torque vernier machines, axial flux permanent magnet machines, brushless doubly fed reluctance machines, open winding machines, and double air gap machines. He also pioneered modern, multiphase fault-tolerant machines, demonstrating that a new family of five-phase induction and synchronous reluctance motors could provide more torque and higher robustness compared to traditional three-phase motors. Prof. Lipo’s work with his students on permanent magnet motors has provided a key element for the design of traction applications in hybrid and electric vehicles, known as the “characteristic current.” Also among his trend-setting research that has helped move power technology from concept to practical applications, Prof. Lipo and his students were the first to investigate methods of eliminating the effects of input voltage unbalance on motor drives. This work has been widely referenced and used in many commercial applications. In 1980, Prof. Lipo cofounded the Wisconsin Electric Machines and Power Electronics Consortium at the University of Wisconsin, WI, USA, which has become an internationally renowned collaborative effort of industry sponsors, professors, and students in the research and development of new power electronics technologies.
An IEEE Life Fellow and member of the US National Academy of Engineering and the UK Royal Academy of Engineering, Prof. Lipo is an Emeritus Professor with Department of Electrical and Computer Engineering at the University of Wisconsin, Madison, WI, USA.
Hermann W. Dommel’s development of landmark computer methods for analyzing and modeling the effects of electromagnetic transients and optimizing power flow in power systems has played a critical role in advancing the electric power grid. His pioneering work during the 1960s set the foundation for the electromagnetic transients program (EMTP) software that has become an indispensable tool in the power industry. Electromagnetic transients can occur due to network switching, system faults, or lightning and can cause power surges detrimental to the electric grid. Dr. Dommel’s EMTP technology, which can be found in well-known commercial software packages today, helps utility companies predict these surges for more reliable and efficient operation. Dr. Dommel’s development, further enhancement, and support of the technology have earned him recognition as the “Father of EMTP.” Dr. Dommel also developed methods for optimal power flow with W.F. Tinney in 1968 that were quickly implemented in power system operations centers for real-time monitoring and analysis of the power grid. The paper detailing this work (published in the IEEE Transactions on Power Apparatus and Systems) was voted the fifth-most important paper concerning 20th Century power system analysis. Dr. Dommel’s optimal power flow solutions still play an important role in the efficient operation of large power systems.
An IEEE Fellow, Dr. Dommel’s many honors include the IEEE Power and Energy Society’s Charles Concordia Power Systems Engineering Award (2011). Dr. Dommel is a Professor Emeritus with the University of British Columbia’s Department of Electrical and Computer Engineering, Vancouver, BC, Canada.
The pioneering inventions and leadership of Edmund O. Schweitzer, III, in bringing computer-based protection and control methods to the marketplace have revolutionized safety, reliability, and efficiency in generating, transmitting, and distributing electric power. Dr. Schweitzer envisioned the concept of the “smart grid” long before the term was popularized, recognizing early in his career the importance of computer technology for power protection and control. Microprocessor-based methods, such as digital protective relays, use microcontrollers and software to detect electrical faults in a power system. Digital methods enable engineers to locate power outages more quickly and protect against widespread loss of service compared to traditional electromechanical protective relays. Dr. Schweitzer was not deterred by those in the industry who told him that applying digital technology to power systems was impractical. He founded Schweitzer Engineering Laboratories (SEL) in 1982 to develop and manufacture digital protective relays, driving his research to commercial application. Schweitzer’s innovations have allowed engineers of all backgrounds to monitor, control, and protect power systems in ways not previously imagined. The application of Schweitzer’s digital technology as replacement equipment or in new installations has led to reduced design work in protection and control systems, flexible operation options, and increased reliability, resulting in reduced cost. SEL equipment is in service around the world at voltages from 5 kV through 500 kV, protecting feeders, motors, transformers, capacitor banks, transmission lines, and other power apparatus.
An IEEE Fellow and member of the U.S. National Academy of Engineering, Dr. Schweitzer is currently president and chief executive officer of Schweitzer Engineering Laboratories, Pullman, Wash.
One of the earliest pioneers of digital power flow solutions for the electric power industry, William F. Tinney’s groundbreaking work during the late 1960s while with the Bonneville Power Administration enabled digital computers to solve the power flow problem. The ability to calculate the power flowing on the lines of a large grid given load and generation information is crucial to the planning, design, and reliable operation of the world’s power grids. Even with the advent of digital computers, it wasn’t until Tinney’s breakthrough solutions that computers could provide the analytical tools and services that have enabled the safe expansion of the power grid. Practically every electric power system network computer program developed over the past 40 years is based on his sparse network solution approach. Published in 1967, the sparse matrix technology concept became used worldwide in all power system computer applications requiring solution of power network equations. In 1968, with H.W. Dommel, Tinney introduced the optimal power flow problem and a method for its solution. The paper detailing this revolutionary work that was published in the IEEE Transactions on Power Apparatus and Systems (vol. 87, pp. 1866-1876) was voted the fifth-most important paper in 20th century power system analysis. Soon new power system operations centers were developed that utilized Tinney’s methods for real-time monitoring and analysis of the power grid.
An IEEE Life Fellow, Tinney worked for the Bonneville Power Administration, Portland, Ore., from 1950 to 1979. He is an independent consultant for vendors of power systems software.
For over 40 years, Prabha Kundur has been at the leading edge of development and application of technology that has made the operation of large-scale interconnected
power systems more safe, secure, and reliable. He has impacted many areas, including modeling and measurement tools, analysis methods, and control techniques that enhance power system stability. Dr. Kundur’s development and validation of comprehensive power plant models for dynamic analysis and control design have been incorporated in software packages that address transient stability, small signal stability, voltage stability, and dynamic reduction for large-scale power systems. Widely recognized and applied by the power industry, these models are important tools in testing whether the power system can handle and recover from disturbances without taking down a large portion of the grid. Dr. Kundur’s contributions to advanced excitation control designs have enhanced overall system dynamic performance. In addition to improving system security, the designs also improve efficiency since the system is able to operate at higher limits. Under Dr. Kundur’s leadership, Ontario Hydro, Canada was one of the first utilities to develop instrumentation technologies and conduct fault tests to identify and verify models and analytical tools being used for power system simulation. Dr. Kundur is the author of the book "Power System Stability and Control," which has been used by academics and practicing engineers worldwide and is considered an industry classic.
An IEEE Life Fellow, Dr. Kundur is currently president of Kundur Power Systems Solutions, Inc., Toronto, Ontario, Canada.