ISBN 9783868537925

978-3-86853-792-5, Reihe Ingenieurwissenschaften

Mohammad Nassar Albunni
Model Order Reduction of Moving Nonlinear Electromagnetic Devices

158 Seiten, Dissertation Technische Universität München (2010), Hardcover, B5

Zusammenfassung / Abstract

This dissertation delivers a contribution to the field of order reduction of large-scale nonlinear models of electromagnetic devices. In particular, it enables applying model order reduction techniques to an important class of electromagnetic devices that contain moving components and materials with nonlinear magnetic properties. Such devices in- clude among others rotating electrical machines, electromagnetic valves, electromagnetic solenoids, and electromechanical relays.

The presented methods exploits the trajectory piecewise linear (TPWL) approach in ap- proximating the nonlinear dependency of materials properties on the applied magnetic field. Additionally, the model nonlinearity that is caused by the movement of the device components is handled using a novel approach that updates the electromagnetic (EM) field model permanently according to the new components positions.

The order of the large-scale electromagnetic field model is reduced by approximating the original electromagnetic field distribution by a linear combination of few virtual field distributions that are found using the proper orthogonal decomposition (POD) approach. The challenge of selecting the number and the position of the linearization points in the TPWL model is tackled using a new approach that considers the change in the magnetic properties of the device materials among all the simulated state-vectors.

The new presented methods are extended to enable generating parametric reduced or- der models of moving nonlinear EM devices. Such models enable a fast and accurate prediction of the behavior of the EM device and its variations that result from changing the values of its design parameters. Additionally, several algorithms for generating an optimal reduction subspace of the parametric model are presented and compared. Finally, an approach for overcoming the challenge of generating reduced order models of EM devices while considering the strong influence of their power electronics driving circuits is introduced and applied to the example of a rotating electrical machine coupled to a power electronics driving circuit.

The new methods presented in this work are validated by applying them on the exam- ples of three industrial devices. An electrical transformer, an electromagnetic valve, and a rotating electrical machine.