Elevators are widely used in modern city. The electric machine for elevator traction drive has been developed from DC machine to AC permanent magnet machine for last 100 years. The traction drive of elevator is a kind of position controlled servo drive with more than 200m moving distance less than 5mm error bound. In this speech some developments of electric machine drive technology for elevator will be introduced from 25 years’ experience in the design of traction drive of elevators. From the drive technology for 240m/min high speed elevator based on 40KW the induction machine to 1080 m/min world fastest elevator based on 9 phase 1.2MW permanent magnet AC machine will be discussed. And, the regenerative drive technology for low speed elevator, where usually the regenerative energy had been released as heat in the braking resistor, will be presented.

Seung-Ki Sul (S'78, M'87, SM'98, F'00) was born in Korea, in 1958. He received the B.S., M.S., and Ph.D. degrees in electrical engineering from Seoul National University, Seoul, Korea, in 1980, 1983, and 1986, respectively. From 1986 to 1988, he was an Associate Researcher with the Department of Electrical and Computer Engineering, University of Wisconsin, Madison. From 1988 to 1990, he was a Principal Research Engineer with LG Industrial Systems Company, Korea. Since 1991, he has been a member of faculty of School of the Electrical and Computer Engineering, Seoul National University, where he is currently a Professor. He was promoted as a fellow of IEEE with the contribution to PWM technology. Prof. Sul is one of pioneers in the area of carrier based PWM technology applied to the control of the power converters. From 2005 to 2007, he was the Vice Dean of the Engineering College of Seoul National University. In addition, from 2008 to 2011, he was the President of the Electrical Engineering Science Research Institute funded by the Korean Government. He has 130 IEEE journal papers and a total of more than 300 international conference papers in the area of power electronics. He was the program chair of IEEE PESC’06 and general chair of IEEE ECCE-Asia, ICPE, 2011. He has been actively involved in various industry projects sponsored by many Korean, Japanese, and American companies. For his sabbatical year from 2003 to 2004, he worked as an acting director of research center of Yaskawa Electric Company, Japan. From 1998 to 2003, he was a board member of Hyundae Elevator Co., which is the largest elevator maker in Korea. From 2011 to 2014, he was a board member of LS Industrial System Co., which is the largest power electronics related product maker in Korea. He holds 14 U.S.A patents, 7 Japanese patents, 11 Korean patents, and granted 38 Ph.Ds under his supervision. For last three years, he had served as Editor-in-Chief of the Journal of Power Electronics, which is a SCIE registered journal, published by the Korean Institute of Power Electronics (KIPE), Seoul, Korea. From, 2015, he is the president of  KIPE. His current research interests include power electronic control of electrical machines, electric/hybrid vehicles and ship drives, High Voltage DC transmission based on MMC, and power-converter circuits for renewal energy sources.