Application of Calorimetric Method for Loss Measurement of a SynRM Drive System

Abstract

Abstract-Synchronous reluctance motors (SynRMs) are gaining in popularity in industrial drives due to their permanent magnet-free, competitive performance and robust features. This paper studies the power losses in a 90 kW converter-fed SynRM drive by a calorimetric method in comparison of the traditional input-output method. After the converter and the motor were measured simultaneously in separate chambers, the converter was installed inside the large-size chamber next to the motor and the total drive system losses were obtained using one chamber. The uncertainty of both measurement methods is analyzed and discussed.Index Terms-Calorimeter, converter, efficiency, electric drive, induction motor, measurement, synchronous reluctance motors power loss, temperature, uncertainty, variable speed drive, voltage-source converter. I. INTRODUCTIONLECTCRIC MOTORS form the most important type of load in the industry, consuming about 65-70% of the electric energy [1]. Hence, thermal and efficiency issues are among the hot topics in the electrical machines and drives community [2]. In general, the electric motor efficiency is continuing to improve and this poses new challenges to the motor loss determination. New and more efficient constructions have to be verified by measurements. The usage of permanent magnets is rising the machine efficiency [3], but due to high prices, supply problems and temperature dependence of permanent magnets, there is a high demand for magnet free motor such as switched reluctance (SRM) [4] and SynRMs. In principle, the SynRMs represent an established and mature Manuscript received March 9, 2015; revised August 24, 2015; accepted October 8, 2015.Copyright © 2015 IEEE. Personal use of this material is permitted. However, permission to use this material for any other purposes must be obtained from the IEEE by sending a request to pubs-permissions@ieee.org L. Aarniovuori, A. Kosonen, M. Niemelä, and J. Pyrhönen are with the Department of Electrical Engineering, Lappeenranta University of Technology (LUT), Lappeenranta, Finland (e-mail: lassi.aarniovuori@lut.fi; antti.kosonen@lut.fi; markku.niemela@lut.fi; juha.pyrhonen@lut.fi) J. Kolehmainen is with ABB Motors and Generators, Vaasa, Finland (email: jere.kolehmainen@fi.abb.com) H. Chen is with the Queens University of Belfast (QUB), Belfast, Northern Ireland UK (e-mail: h.chen@qub.ac.uk) W. Cao is with the School of Engineering and Applied Science, Aston University, Birmingham, U.K. (email: w.p.cao@aston.ac.uk) technology, but the modern frequency converter control may lead to new features and properties of the motor.Synchronous reluctance motors establish a promising technology with potentials to replace permanent-magnet synchronous motors (PMSMs) and induction motors as the main motor in industrial variable-speed applications. The SynRM rotor has neither windings nor magnets, thus improving the rotor reliability and eliminating the reliance on rare-earth-based permanent magnets. A high-inductance-ratio rotor structure is manufactured from p...

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