Akademik Veri Yönetim Sistemi
Journal of Materials Processing Technology, cilt.161, sa.1-2 SPEC. ISS., ss.79-82, 2005 (SCI-Expanded)
Electronically generated voltage waveforms have increasingly been used to energise small induction motors for speed and torque control due to low cost. The most popular such waveform is a pulse width modulation (PWM), which is obtained by logically comparing a reference voltage waveform with a carrier wave of different frequency. When a small induction motor is driven by a typical PWM voltage supply, additional power losses occur in its stator core due to a magnetisation process, which is very different to standard sine wave excitation. In this investigation flux density and power loss distribution under PWM and sinusoidal voltage excitations were measured in a small induction motor stator core using a system which set up flux distribution as would occur in a rotating 3-phase stator core. The iron loss increase was between 15 and 20% under PWM excitation. Surprisingly, the increase in iron loss in a typical induction motor stator core lamination was 3% lower than that in Epstein strips of the same electrical indicating an effect of the magnetic circuit geometry as well as the voltage waveform. © 2004 Elsevier B.V. All rights reserved.