Bulent H. ERTAN
Professor, Department of Electrical and Electronics Engineering, Middle East Technical University, Turkey
induction motors, switched reluctance motors, high frequency power supplies, field oriented drives
A novel boost type inverter topology for motor drives
In existing technology an inverter has a pulse-width-modulated output with a fundamental component at the desired frequency and magnitude. The converter used in such applications is essentially a buck type converter. Therefore its output voltage magnitude is limited by the DC link voltage. As a consequence; if the application involves a motor drive, the highest drive frequency at which the motor can be run without field weakening is also restricted. In uninterruptable power supply applications, when this technology is employed, operation of the UPS has to be stopped when the battery voltage drops and the desired voltage magnitude cannot be obtained, although there is energy available in the battery set. This technology also limits the amount of energy that can be extracted from the battery set in electrically driven automobiles. Similar problems occur in other applications when converting energy from a DC bus to AC. There are two important issues to be addressed in DC to AC conversion technology. One is to obtain a purely sinusoidal output, so that, for example, insulation stress in motor applications can be reduced. Secondly, to enable DC to AC conversion at DC voltage levels lower than possible with buck type of converters used in the present technology. This paper is focused on seeking a solution to these issues. In this context the first part of this paper investigates topologies that can be used to achieve the goals stated above. In the second part a topology is proposed which promises to give a purely sinusoidal output from a DC bus and achieve rated voltage output even if the DC bus is 30% below the levels required for conventional inverters. The performance of this topology is illustrated with experimental results.
Bulent H. ERTAN received B.S. and M.S. degrees in Electrical and Electronics Engineering in 1971 and 1973 respectively from the Middle East Technical University (METU) in Ankara, Turkrojects since 1977. He led the Intelligent Energy Conversion Group at TUBITAK (Turkish Scientific and Technological Research Council) Information Technologies and Electronics Research Institute (BILTEN) in Ankara Turkey, between 1999-2006. He has published more than 150 journal and conference papers so far. He is co-editor of two books entitled "Modern Electrical Derives", Kluwer Academic Publishers, Netherlands, 2000 (NATO ASI series) and "Transformers: Analysis Design and Measurement" (CRC press, 2013). His research interests are on electrical machine design and drive systems. Professor Ertan is member of the international steering committee of the International Conference on Electrical Machines (ICEM) and founder of the Aegean International Conference on Electrical Machines and Power Electronics (ACEMP). He is member of editorial board of Electromotion Journal and also steering committee member of a number of international conferences. He is a member of Turkish Chamber of Electrical Engineers and a member of IET (UK) and IEEE.