Analysis and mitigation of vibration and acoustic noise in switched reluctance machines.

摘要

The limited resource of rare earth metals and environmental challenges have driven the electric machine industry towards nonrare earth solutions. In this respect, Switched Reluctance Machines (SRMs), which feature low cost, rugged structure, high fault tolerance capability and wide speed/constant power range, have received substantial attention in the past decades. However, SRMs can produce high levels of acoustic noise, which poses a significant shortcoming in the adjustable speed drive systems considered for noise sensitive applications, i.e. office/home appliances, automotive. Hence, a thorough investigation and mitigation of the acoustic noise in SRMs is of vital importance.;In this dissertation, fundamental understanding of the energy conversion process and electromagnetic force calculation in SRMs are introduced first. Accordingly, vibration of the stator frame in SRMs is investigated analytically to shed light on its origins. Based on the understanding of the origins, an analytical model is developed for prediction of the vibration. Furthermore, a precise and computationally efficient approach using rotor position and electrical inputs, i:e: current and voltage, is proposed to calculate the stator surface acceleration, then acoustic noise of the SRM can be computed via the Boundary Element Method. Finally, general considerations in the design of SR drives are discussed to reduce the acoustic noise. Multiple simulations and experiments are conducted to validate the claims made in this research.