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This paper aims to compare different static history-independent hysteresis models (mathematical-, behavioural- and physical-based ones) and a history-dependent hysteresis model in terms of parameter identification effort and accuracy.

The discussed models were tested for distorted-excitation waveforms to explore their predictions of complex magnetization curves. Static hysteresis models were evaluated by comparing the calculated and measured major and minor static hysteresis loops.

The analysis shows that the resulting accuracy of the different hysteresis models is strongly dependent on the excitation waveform, i.e. smooth excitations, distorted flux waveforms, transients or steady-state regimes. Obtained results show significant differences between predictions of discussed static hysteresis models.

The general aim was to identify the models on a very basic and limited set of measured data, i.e. if possible using only the measured major static loop of the material. The quasi-static major hysteresis loop was measured at B_max = 1.5 T.

The presented analysis allows selection of the most-suited hysteresis model for the sought-for application and appraisal of the individual limitations.

The presented analysis shows differences in intrinsic mechanisms to predict magnetization curves of the majority of the well-known static hysteresis models. The results are essential when selecting the most-suited hysteresis model for a specific application.

The purpose of this paper is to study the variation of the specific iron loss components of electrical steel sheets when applying a tensile mechanical load below the yield strength of the material. The results provide an insight into the iron loss behaviour of the laminated core of electrical machines which are exposed to mechanical stresses of diverse origins.

The specific iron losses of electrical steel sheets are measured using a standardised single-sheet tester equipped with a hydraulic pressure cylinder which enables application of a force to the specimen under test. Based on the measured data and a semi-physical description of specific iron losses, the stress-dependency of the iron loss components can be studied.

The results show a dependency of iron loss components on the applied mechanical stress. Especially for the non-linear loss component and high frequencies, a large variation is observed, while the excess loss component is not as sensitive to high mechanical stresses. Besides, it is shown that the stress-dependent iron loss prediction approximates the measured specific iron losses in an adequate way.

New applications such as high-speed traction drives in electric vehicles require a suitable design of the electrical machine. These applications require particular attention to the interaction between mechanical influences and magnetic behaviour of the machine. In this regard, knowledge about the relation between mechanical stress and magnetic properties of soft magnetic material is essential for an exact estimation of the machine’s behaviour.

Small highly saturated interior permanent magnet- synchronous machines (IPMSMs) show a very nonlinear behaviour. Such machines are mostly controlled with a closed-loop cascade control, which is based on a d-q two-axis dynamic model with constant concentrated parameters to calculate the control parameters. This paper aims to present the identification of a complete current- and rotor position-dependent d-q dynamic model, which is derived by using a finite element method (FEM) simulation. The machine’s constant parameters are determined for an operation on the maximum torque per ampere (MTPA) curve. The obtained MTPA control performance was evaluated on the complete FEM-based nonlinear d-q model.

A FEM model was used to determine the nonlinear properties of the complete d-q dynamic model of the IPMSM. Furthermore, a fitting procedure based on the nonlinear MTPA curve is proposed to determine adequate constant parameters for MTPA operation of the IPMSM.

The current-dependent d-q dynamic model of the machine models the relevant dynamic behaviour of the complete current- and rotor position-dependent FEM-based d-q dynamic model. The most adequate control response was achieved while using the constant parameters fitted to the nonlinear MTPA curve by using the proposed method.

The effect on the motor’s steady-state and dynamic behaviour of differently complex d-q dynamic models was evaluated. A workflow to obtain constant set of parameters for the decoupled operation in the MTPA region was developed and their effect on the control response was analysed.

The purpose of this paper is to focus on the frequency-dependent non-linear magnetization behaviour of the soft magnetic material, which influences both the energy loss and the performance of the electrical machine. The applied approach is based on measured material characteristics for various frequencies and magnetic flux densities. These are varied during the simulation according to the operational conditions of the rotating electrical machine. Therewith, the fault being committed neglecting the frequency-dependent magnetization behaviour of the magnetic material is examined in detail.

The influence of non-linear frequency-dependent material properties is studied by variation of the frequency-dependent magnetization characteristics. Two different non-oriented electrical steel grades having the same nominal losses at 1.5 T and 50 Hz, but different thickness, classified as M330-35A and M330-50A are studied in detail. Both have slightly different magnetization and loss behaviour.

This analysis corroborates that it is important to consider the frequency-dependency and saturation behaviour of the ferromagnetic material as well as its magnetic utilization when simulating electrical machines, i.e., its performance. The necessity to change the magnetization curve according to the applied frequency for the calculation of operating points depends on the applied material and the frequency range. Using materials, whose magnetization behaviour is marginally affected by frequency, causes a deviation in the flux-linkage and the electromagnetic torque in a small frequency range. However, analysing larger frequency ranges, the frequency behaviour of the material cannot be neglected. For instance, a poorer magnetizability requires a higher quadrature current to keep the same torque leading to increased copper losses. In addition, the applied iron-loss model plays a central role, since changes in magnetization behaviour with frequency lead to changes in the iron losses. In order to study the impact, the iron-loss model has to be capable to incorporate the harmonic content, because particularly the field harmonics are influenced by the shape of the magnetization curve.

This paper gives a close insight on the way the frequency-dependent non-linear magnetization behaviour affects the energy loss and the performance of electrical machines. Therewith measures to tackle this could be derived.

The purpose of this paper is to provide a comprehensive analysis of different material models when observing the magnetisation dynamics and power losses in non-oriented soft magnetic steel sheets (SMSSs).

During the analysis four different magnetic material models were used for describing the static material characteristics, which characterised the materials’ magnetisation behaviour with increasing accuracies: linear material model, piecewise linear material model, non-linear H(B) characteristic and the static hysteresis material model proposed by Tellinen. The described material models were implemented within a parametric magneto-dynamic model (PMD) of SMSSs, where the dynamic responses as well as power loss calculations from the obtained models were analysed.

The momentous influences of various levels of detail on the calculation of dynamic variables and power losses inside SMSS with non-uniform magnetic fields were elaborated, where various static material characteristic models were evaluated, ranging from linear to hysteretic constitutive relationships.

The resulting PMD model using different static models was analysed over a frequency range from quasi-static to f=1,000 Hz for different levels of magnetic flux density up to B _max=1.5 T.

The presented analysis provides fundamental insight when calculating dynamic electromagnetic variables and power losses inside non-linear SMSSs, which is instrumental when selecting an adequate model for a specific application.

This paper provides closer insight on the way non-linearity, magnetic saturation and hysteresis affect the energy loss and magnetisation dynamics in SMSSs through the level of detail in the used material model. The strongly coupled model addresses both induced eddy currents and the ferromagnetic materials’ magnetisation behaviour simultaneously using varying levels of detail so that the interplay between skin effect (i.e. eddy currents) across laminations and hysteresis can be resolved accurately. Therewith, adequate models for specific applications can be selected.