Abstract: The fundamental principle and three kinds of load-control strategies of bearingless switched reluctance motors (BSRMs) are introduced. The methods to determine the control parameters of these control strategies are analyzed. Since the origin of vibration and acoustic noise of switched reluctance motor is magnetic radial force ripple acted on stator, the stator magnetic radial forces of bearingless switched reluctance motor under these three different control strategies are calculated by combining the methods of Maxwell stress tensor and magnetic circuit method. Due to the differences of constraint conditions for three kinds of control strategies, even under the same load, the main winding current, the suspended winding current and the advanced angle obtained by calculation are different, therefore the performances in the stator magnetic radial force are also different. Effects of control strategies on stator vibration of bearingless switched reluctance motor are obtained by using time domain analysis and frequency domain analysis upon the stator magnetic radial force. Finally, conclusions reached by theoretical analysis are verified by experiments.

Key words: bearingless switched reluctance motor, control strategy, magnetic forces, time domain analysis, frequency domain analysis, stator vibration