Mike Koenigs

Flensburg University of Applied Sciences · Electrical Engineering

Space vector modulation (SVM) is a widely established method of modulating voltages in three-phase frequency inverters. The goal is to generate a three-phase sinusoidal current system to drive a motor. State-of-the-art SVM utilises a symmetrical switching pattern to minimise current ripple and switching losses. The question answered in this publica...

This is the third paper in a series on novel methods for calculating eddy current losses in permanent magnets (PM) and the shortcomings of previously conducted analyses. In the first paper, Ruoho’s work on homogeneous materials was discussed. The distribution of fields has been expanded to include the reaction field of the eddy currents within the...

This is the first of a series of papers on novel methods for the calculation of eddy current losses in permanent magnets (PMs) and the shortcomings of previously conducted analyses. Eddy current losses in PMs and their mitigation are significant factors when designing inverter-fed electric drives. Especially with the need for drives with high power...

This is the second of a series of papers on new methods for the calculation of eddy current losses in permanent magnets (PMs) and the shortcomings of previous analyses. Our first paper extended Ruoho’s work on harmonic field distributions to the reaction field of eddy currents within permanent magnets. The approach was based on the methods of the h...

In this paper a novel topology of the double-fed induction machine (DFIM) for variable speed operation is presented. The brushless variant of the DFIM is connected to the grid on the secondary side via a phase-shifting transformer instead of the commonly used voltage-source inverter. Mow the topology is controlled by variation of the amplitude and...

In this paper, an approach for a two-and-half-dimensional (2.5D) finite element method (FEM)-based analysis, or quasi-three-dimensional (3D) FEM analysis, of an axial flux machine is discussed. By cutting the 3D model laterally and thereby creating cylindrical surface cuts, the 3D model can be split into several cylindrical surfaces. Transforming t...

Eddy current losses in permanent magnets (PM) and their mitigation are significant factors in designing inverter fed electric drives. Especially with the need for high power density drives a trend towards increased rotational speeds and therefore higher fundamental frequencies and inverter switching frequencies is observable. Frequency components o...