Bose received his B. Bose organized its power electronics teaching and research program for 15 years. He is recognized as world-renowned authority and pioneer in power electronics for his many contributions that include high frequency link power conversion, advanced control techniques by microcomputers, fuzzy logic and neural networks , transistor ac power switch for matrix converters, adaptive hysteresis-band current control, etc. He also pioneered power electronics applications in environmental protection that help solving climate change problems. Bose is an innovator, educator, and mentor to many members of the industry all over the world. He has been a reference for many engineers and scientists working in the area of power electronics and motor drives.
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Contributed by Bimal K. The BEC was an old institution, established in , and renowned for undergraduate education. There were, of course, many regional degree- and diploma-granting engineering colleges. Engineering education was not very developed after India established its independence in Students seeking higher engineering degrees normally studied in the universities of the United Kingdom.
Gradually, after independence, the government of India established a number of Indian Institutes of Technologies IITs that grew to be world-class in educational quality and standard of research. Professor Ralph Benedict from the University of Wisconsin, Madison, visited us for one year and taught a course on mercury-arc rectifiers. We had two lab experiments on glass-bulb mercury-arc rectifiers. One was a single-phase, full-wave, diode rectifier with center-tapped transformer, where we started the arc through an auxiliary anode by tilting the bulb.
The other was a six-phase, half-wave, grid-controlled rectifier, where the arc was initiated by a current pulse through an auxiliary anode. Power Engineering in India in the s After graduation, I started my career as a power engineer in India in the mids.
I was an engineer in a hydroelectric power company in the early days, and then I started teaching power engineering courses generation, transmission, distribution, and electric machines at BEC. The so-called power electronics field was unknown in those days. Gas-tube electronics, based on thyratrons and ignitrons, and glass-bulb and steel-tank mercury arc and ignitron rectifiers were widely used in industry. In India, most of the power conversions and control were based on traditional rotating machines, but gradually mercury-arc converters were introduced.
In , Bardeen, Brattain, and Shockley of Bell Laboratories invented the transistor that started the solid-state electronics revolution. This was the beginning of the second electronics revolution or age of solid-state power electronics.
Silicon power diodes started appearing in s, replacing the old selenium, copper oxide, and gas-tube diodes, and they created a lot of excitement. Besides education, the TCM organized an excellent program for my all-round experience with the American educational system.
Under the terms of this program, I was required to teach in an Indian university for a minimum period of three years. The University of Wisconsin was famous for its power engineering program. Benedict was my thesis adviser, and he also taught me in an industrial electronics course. There was an industrial electronics laboratory, where we conducted experiments on a thyratron dc motor drive and ignitron welding control, etc.
I conducted my M. With the help of a harmonic wave analyzer, I could demonstrate the distribution of harmonics along the line and the resonance voltage boosting effect with a particular harmonic.
It was a different world, where people looked so lively and prosperous. With an Indian friend, I rented an apartment where I used to cook Indian food, but during the day, I ate American food in the university cafeteria. The streets and the two lakes, Mandota and Manona, in Madison were completely frozen.
I found it difficult to walk on the sidewalks and roads with a heavy coat and my briefcase in hand. I could hardly believe that men were ice-fishing on the lakes. I did my doctoral research at Calcutta University on Ramey magnetic amplifiers from to Calcutta University was very famous for research activities in those days and produced a large number of brilliant scientists. Although thyristors were available at that time, Dr.
I grew close with Dr. Storm through professional correspondence. There was an era of magnetic amplifiers with saturable core reactors before the modern thyristor era, which were functionally similar to gas-tube or solid-state power electronics. Magnetic amplifiers were bulky but more rugged and reliable than gas-tube electronics, and they were promoted very heavily during World War II and postwar periods, particularly in Germany.
The analytical study of MAs was much more complex than that of thyristor converters. My research was somewhat hybridized with MAs with silicon diodes , power transistors, and thyristors. My research projects included a magnetic servo amplifier for position control with a two-phase induction servomotor, and multi-channel telemetry encoding systems using MAs with transistors and thyristors.
From to , before immigrating to the United States, I supervised many MA-based research projects at BEC, including a four-quadrant analog multiplier, a dc-to-dc converter, a magnetic servo-amplifier, and a digital voltmeter. The ambitious career opportunities in USA always fascinated me, and unfortunately the political conditions in India were fast deteriorating at that time. Benedict inspired my emigration to USA. This was quite a challenge for me as an Indian whose strength was mainly in magnetic amplifiers.
RPI is a private university with a great reputation; the students were brilliant and constantly tested my knowledge in power electronics. To my knowledge, the only other university in the United States that had a power electronics program then was the University of Missouri, Columbia.
I completed a number of projects such as the development of a transistor ac switch and its application in matrix converter; triac speed control of induction motors; three-phase ac power control with transistors; and a thyristor-saturable core self-oscillating inverter.
This again was a challenge, but the project turned out very well. I showed for the first time that a cycloconverter could be used at programmable leading or lagging line displacement power factor DPF , and as a static VAR compensator SVC in extreme cases.
Having spent sixteen years in university career, I always felt that I had a large gap in my education and expertise. As a graduate student, I did not have much experience getting my hands dirty in fabricating large power converters with complex electronic circuits, or solving the real world EMI electromagnetic interference problems of large converters.
My doctoral studies were rich with analytical work using complex waveforms, equations, etc. Naturally, I promoted similar analytical studies among my graduate students. As a professor, I had few opportunities to come across practical projects. I advised my students in lab experiments on what oscilloscope waveforms should look like, with lots of sketches on black boards, but I was hesitant to put my hands on breadboards on complex projects.
Obviously, I was somewhat nervous with large projects that involved higher levels of power. Power electronics is such an application-oriented practical subject, however, and it was time for me to fill these gaps if I wanted to have real impact as a university professor in the future. GE-CRD was then considered the ivory tower of power electronics worldwide, and power electronics specialists from all over the world used to visit its labs in Schenectady.
I thought it would be very unwise not to accept the GE offer. My office was in the historic Building 37 in Schenectady, where Ernst Alexanderson , Gabriel Kron , Philip Alger , and other famous scientists had offices.
It was a thrilling experience to see so many world-renowned scientists in the hallways and offices. All researchers regardless of background had the title of Electrical Engineer. This was a bit humiliating for me because I had been a university professor for many years. Bill is the founding father of power electronics, and the world bows to his memory with deep respect.
All of his papers, particularly those on thyristor-forced commutation techniques, are considered classic contributions in power electronics. His research set the stage for the modern power electronics evolution. He deeply loved mathematics and filled pages after pages with complex equations, which were strewn all over his table and the floor. After a generalized analysis, he loved to draw normalized graphical plots. I was surprised to see that such a world-famous scientist had barely a chair and desk with a telephone in his office.
Bill was a chain smoker, and the room was always filled with smoke. In the later part of his life, he suffered from emphysema, which was the cause of his death. He rarely spoke with others. A young lady secretary with a noisy typewriter sat in the same room.
Although I sat next to Bill, I could rarely speak with him informally. He insisted that I make an appointment for any discussion. Once we rode together to Auburn, New York, where GE manufactured thyristors, and he did not talk to me during the entire six-hour journey.
He seemed to be thinking the whole time. The thoughts linger most of the time beyond the office hours and often new ideas come when I am taking a bath, walking alone in the evening, or even in the midnight when I suddenly wake up with the flash of new idea. There is no difference between scientific research and transcendental meditation. The most prestigious were assessed fund projects, which required invention, analysis, simulation as needed , and laboratory experimentation.
It was an honor to have the opportunity to work with a world-famous scientist. The other classes were government- and product department-funded projects, respectively. Some projects required bench-type development work, which were done mainly by B. Of course, engineers like McMurray were exceptions. Externally funded projects, with deadlines for completion, were very demanding.
If a project required study of background fundamentals, there was no company time allotted for it. It had to be done in the evening or weekends which we were supposed to spend with our family. Sometimes, meeting the project deadline required a lot of extra hours in office and home. We had to fill up time cards every week for our work.
Allocation of company time for the projects was often a difficult task. In , my branch manager, Robert H. This was a big surprise. I noticed that most innovative projects terminated only in U.
The company encouraged us to write as many patent disclosure letters as possible, some of which were only conceptual ideas. There was a handsome bonus for a disclosure letter if patent application was filed on it. Some of my colleagues working in power electronic circuits had more than U. GE had received a large contract from the U. This was the first major initiative by the U. Gasoline became very scarce and its price shot up.
First-Hand:My Life in Power Electronics
Bimal K. Bose
Bimal Kumar Bose