Coupled field and space-vector equations of bearingless synchronous reluctance machine

Abstract

This paper presents a systematic approach for coupling the space-vector model of a synchronous machine with the static field equations and solve the whole system of equations with the finite element method. The aim of the approach is to reduce the computation time without losing the accuracy. The methodology is validated on a permanent magnet synchronous machine and then applied to a bearingless synchronous reluctance machine. Comparison of the results with the measurements and the time stepping finite element analysis shows that the method has great potential in reducing the computation time and reproducing accurate results.Index Terms--bearingless synchronous reluctance machine, computational electromagnetics, electromagnetic fields, finite element analysis, machine control, permanent magnet machine. VII. BIOGRAPHIESAnouar Belahcen (M'13-SM'15) received M.Sc. (Tech.) and Doctor (Tech.) degrees from Helsinki University of Technology, Finland, in 1998, and 2004, respectively. Since 2011 he is Professor of electrical machines at Tallinn University of Technology, Estonia and since 2013 he is Professor of Energy and Power at Aalto University. His research interest are numerical modeling of electrical machines, especially magnetic material modeling, coupled magnetic and mechanical problems, magnetic forces, and magnetostriction. . His research interests deal with numerical modeling of electrical machines as well as power losses and magnetomechanical effects in soft magnetic materials. Marko Hinkkanen (M'06-SM'13) received the M.Sc. (Eng.) and D.Sc. (Tech.) degrees from Helsinki University of Technology, Espoo, Finland, in 2000 and 2004, respectively. Since 2000, he has been with Helsinki University of Technology (part of Aalto University, since 2010). He is currently an Assistant Professor with the School of Electrical Engineering, Aalto University. His current research interests include power-electronic converters, electric machines, and electric drives.

Analysis of Electromagnetic Force Ripple in a Bearingless Synchronous Reluctance Motor

“…3 (a), (b) and (c) respectively. The flux density is computed after solving a quasi-static magnetic problem [12], [13]. Fig.…”

Comparative study of inner and outer rotor bearingless synchronous reluctance motors

“…Both motors are supplied with the same rated main winding current and additional winding current with sinusoidal waveforms. The total simulated time is 0.1 s. The time stepping simulation is preceded by a stationary dc computation to mitigate the transient behaviour in the time‐stepping simulations [15]. The torque, levitation force, and disturbance force (force in the x ‐direction) for the inner and outer rotor topology are shown in Fig.…”

A Computationally Effective Method for Iron Loss Estimation in a Synchronous Machine from a Static Field Solution

“…A suitable time resolution selection for the dynamic analysis and the effect of it on the solution accuracy is a separate topic, and no exact recommendation was found. For instance, the number of time steps per period and the number of electrical periods were used by [5], [6] 300-1000 steps per period and 2-10 electrical periods, respectively. However, all these factors lead to high computational cost for achieving the dynamic solution; consequently, the iron losses computation from this solution.…”

“…An ultrafast static field computation method has been presented in [5], by coupling the static field equations and space vector model within the same finite element solution. The method has given accurate results from a single static simulation compared to the measurement and time-stepping method.…”

“…Modeling a fast and accurate static field computation method is an independent topic of research by itself, which is out of the scope of this paper. Instead, our main goal is to develop the iron losses computation method by using the readily available static field computation method presented in [5], which can be an alternative method of the iron losses computation from the dynamic field solution in many applications. In this paper, the accuracy and computational cost of the developed method are validated with the conventional time-stepping method extensively.…”