Whither motor drives: A case study in switched reluctance motor drives

Variable speed motor drives and power electronics are at crossroads as their engineering and technology have matured, and products have found wide acceptance in world markets. A debate is going on about the future of both in academic and to a smaller extent in industrial circles with a broad consensus and agreement that there is no more fundamental work possible or breakthrough required in these disciplines. During this time American industries have almost decimated R&D in these disciplines indirectly reinforcing the notion that current technologies are sufficient to address the existing or emerging market needs. This is happening at a time when the energy crisis is at full blast and environmental concern is on upswing. It is illusory to think that these challenges can be faced by incremental work in product development as is the general trend and not by fundamental work. By reviewing the past it is demonstrated that the root cause of present situation and how the challenges of emerging market and societal demands can be met through a case study. This paper presents the rise of power electronics and motor drives from late 1950s to present. The developments in semiconductor devices, power electronic converters and motor drives progressed from fundamental concepts and breakthroughs to tackling secondary problems and that path is briefly traced. In turn, this has contributed to the notion that the engineering in this field has matured. Many of these fundamental developments have come about due to market pressure and demands (a fact usually overlooked in academia) and that correlation is derived. The same market and environmental concerns can and do open up opportunities for fundamental work. A case study of recent work in switched reluctance motor drives is presented highlighting emerging newer directions in motor drives research and development driven primarily by the emerging markets and applications. It is demonstrated that there is no paucity of fundamental problems (but may be a lack of attention to market needs) that can provide the keys to happy kingdom of research and development for a newer generation of engineers, scientists and professors.