Comparison of PM line-start motors with surface-mounted and inserted magnets

Conference: IKMT 2019 – Innovative Klein- und Mikroantriebstechnik - 12. ETG/GMM-Fachtagung
09/10/2019 - 09/11/2019 at Würzburg, Deutschland

Proceedings: ETG-Fb 159: IKMT 2019

Pages: 7Language: englishTyp: PDF

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Huth, Gerhard; Schirmer, Hans-Georg (Institute for Mechatronic and Electrical Drive Systems, Department of Electrical and Computer Engineering, University of Kaiserslautern, Germany)

Improving the energy efficiency of AC line-start drives is the declared development goal of today. Due to the limiting physics of cage induction motors employed so far, motors with small frame size have difficulties to reach the high power density required to achieve efficiency class IE4. The solution are PM line-start motors instead of energy-inefficient cage induction motors. Commonly, PM line-start motors are manufactured with permanent magnets inserted in the laminated rotor core. An alternative rotor design enables the arrangement of permanent magnets directly on the rotor surface. Apart from describing their development and design, this study compares the two rotor variants, using the example of frame size AH 90, by contrasting simulation with measurement results. Both rotor designs have specific effects on the start-up and pull-in behavior as well as on the steady-state behavior in synchronism.