O1-1 Design of low-speed PM generators using FEM – Invited lecture, Marian GRECONICI
The paper deals with the design, FEM analysis, and testing of a surface-mounting permanent magnet (PM) generator with an inner rotor for wind applications. The main task was to build a low-speed PM generator with simple structure, good performances, and very low cogging torque as a part of a low-power wind-plant. During the classical design process, a numerical simulation 2D-FEM of the PM generator has been performed to analyze, verify, and improve some design parameters in order to achieve the optimal results of the generator.
For a four-pole PM generator with inset magnets in rotor, by using 2D-FEM simulations, is analyzed the inverse saliency effect and the influence on the voltage compensation capability for maintaining almost constant output voltage at different loads.
O1-2 Efficient 2D finite element models of multi-level Litz wires, and the coils made thereof, Szabolcs GYIMÓTHY and Sándor BILICZ
Two efficient 2D finite element models are proposed for the efficient simulation of eddy current losses in multi-level litz wires and the coils made thereof. One of them is a one-step explicit model, whereas the other is based on bundle-level homogenization and recursive current repartitioning. The developed methods are applied for various wires and coils, and verified by 3D FEM simulation.
O1-3 The influence of unbalanced current in bus bars on magnetic field distribution, Miodrag MILUTINOV, Karolina KASAŠ-LAŽETIĆ, Teodora SPASIĆ and Miroslav PRŠA
In this paper, the analysis of magnetic field and current density distribution in case of three phase bus bar system with current of 500 A, is presented. The impact of position of neutral conductor on magnetic field and current density distribution is investigated. The main goal of the calculations was to find the position of neutral conductor which produces the lowest magnetic field and current density in case of current unbalance. The numerical calculations were performed in COMSOL Multiphysics program package on simplified 2D model. The calculation results are presented graphically, as the diagrams of the magnetic flux and current density magnitude distribution in the three-phase bus bar system plane, perpendicular to the system’s axe. The obtained results show that in both cases (current balance and current unbalance), the position of neutral conductor influences the magnetic flux density distribution.
O1-4 Analysis of absorbed component of instantaneous magnetising power for ferrite toroidal core, Srđan DIVAC, Dejan JANJIĆ, Branko KOPRIVICA and Alenka MILOVANOVIĆ
The aim of this paper is to present the analysis of absorbed component of magnetising power for a toroidal sample made of N87 ferrite material. Its time waveforms and mean values (power loss) are analysed. Absorbed magnetising power is calculated using the magnetic field strength and magnetic flux density waveforms obtained during hysteresis loop measurement. Measurements have been made at different frequencies and amplitudes of the magnetic flux density Bmax, as well as varied temperatures of the sample. Furthermore, new absorbed magnetising power waveforms for the frequencies and Bmax of interest are estimated by interpolating amplitudes and phases of harmonics of measured absorbed magnetising power. Measurement results, calculation principle, as well as adequate discussion of the results obtained is also presented.