The paper presents the use of the Dual Reciprocity Boundary Element Method (DRM) for the solution of the inverse problem described with Poisson's equation. The DRM approach has been chosen because it ...is ideal for the treatment of the nonhomogeneous part of Poisson's equation that determines the source distribution or the conductivity distribution of the inverse problem. The "mixed" boundary elements were used to discretize the problem. The presented DRM approach to the solution of the inverse problem is demonstrated on a 2D problem that has an analytical solution. The unknown conductivity distribution inside the 2D square conductivity domain is calculated.
The paper presents the evaluation of saturation and cross-magnetization effects in interior permanent magnet synchronous motor (IPMSM) over the entire range of direct and quadrature axis excitation. ...The conventional two-axis machine model is modified in order to include the influence of saturation and cross-coupling effects on the variation of self and cross-coupling inductances in the direct and the quadrature axis. The two-axis machine model parameters are evaluated by experiments performed on a IPMSM using a controlled voltage source inverter and are compared with parameters values evaluated by the finite element method. The evaluation of two-axis machine model parameters reveals significant saturation and cross-magnetization effects in both axes, especially in the flux-weakening regime.
Identification of linear synchronous reluctance motor parameters Stumberger, G.; Stumberger, B.; Dolinar, D.
Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications of Electrical Energy (Cat. No.00CH37129),
2000, Letnik:
1
Conference Proceeding
The paper deals with the identification of parameters of a two-axis linear synchronous reluctance motor (LSRM) dynamic model. The model parameters are identified by experiments performed on an LSRM ...using a controlled voltage source inverter. The current dependent direct- and quadrature axis inductances are identified by experiments and calculated by the finite element method. The calculated inductances are compared with the inductances identified by experiments. As the translation range of the tested LSRM is limited, the proposed parameter identification procedure has been verified indirectly through the comparison of simulation and experimental results in the case of kinematic control. Compared are the reference and the actual position, speed, current and voltage trajectories obtained by experiment and by simulation. The agreement of the results is good.
A lot of magnetic materials are anisotropic. In the 3D finite element method calculation, anisotropy of the material is taken into account. Anisotropic magnetic material is described with ...magnetization curves for different magnetization directions. The 3D transient calculation of the rotational magnetic field in the sample of the round rotational single sheet tester with circular sample considering eddy currents is made and compared with the measurement to verify the correctness of the method and to analyze the magnetic field in the sample.
The paper presents iron loss estimation in a three-phase induction motor by using different iron loss models for the posterior iron loss calculation. The iron losses were determined by using modeled ...properties of used electrical steel and calculated distribution of magnetic induction B(t) in all parts of the motor by using 2D finite element software for a complete cycle of field variation. The comparison between estimated and measured core losses for a 4kW induction motor at no-load in dependency on supply voltage is given.
The iron losses were determined by using modelled properties of used electrical steel and calculated flux distribution in the core of the four-pole permanent magnet synchronous motor, working in the ...flux-weakening regime. The distribution of the magnetic induction
B
(t)
in all parts of the motor was obtained by the numerical simulation of magnetic conditions using static 2D finite element software for a complete cycle of field variation. The results of iron loss determination were compared with the results obtained from experiments on the actual machine.
Rotations of vector
B
in a square rotational single sheet tester and a round rotational single sheet tester were compared. Two pairs of B coils (45° displaced) were used to control and verify the ...rotation of vector
B
at different coil diameters. It was clarified that two sinusoidal induced voltages in B coils do not ensure the rotational flux condition in the area inside the B coils in the sample, especially in a larger measuring region.
Round rotational single sheet tester is used for the measurement of magnetic properties in rotational and alternating magnetic fields. The influence of one and both side shields on the field ...homogeneity in the sample is investigated with finite element calculation. The aim of the calculation is to define the optimal position of one or both side shields in order to expand the rotational field homogeneity area. We want to reach the area of the homogeneous field as large as possible. The best result is achieved with two sides shielding.
The paper presents an FEM-based analysis of output power capability improvement in a six-phase flux-weakened permanent magnet synchronous motor with a third harmonic current injection. It is shown ...that the flux-weakened permanent magnet synchronous motor with the third harmonic current injection is capable of producing more output torque per RMS current flowing through the windings than the same motor supplied with sinusoidal currents. The results of the analysis are partially verified with measurements.
In the waterfowl census carried out in Slovenia on January 12th and 13th 2002 (IWC), 221 observers took part. On the basis of 577 reports, 56,009 aquatic birds were counted in seven count areas. 61 ...different species were registered. All water birds were counted. The most important in terms of the birds' numbers were the count areas of the Drava river, the lower Sava and the Slovene Littoral. The most abundant species during the census was the Mallard Anas platyrhynchos, followed by the Common Coot Fulica atra, Blackheaded Gull Larus ridibundus, Great Cormorant Phalacrocorax carbo, Tufted Duck Aythya fuligula, Common Teal Anas crecca, Common Goldeneye Bucephala clangula, Little Grebe Tachybaptus ruficollis, Mute Swan Cygnus olor and Grey Heron Ardea cinerea (> 1000 individuals). With the exception of the Littoral, all standing waters in the country were frozen over, including the reservoirs. On average, rivers were 25 % icebound but in certain sections, 100%. There was a marked horizontal shift of birds living along the overgrown banks towards open water surfaces, due to the icebound edges of the rivers. Thus the numbers of Little Grebes, Bitterns, Common Moorhens, etc. observed were greatest in the history of the IWC. The impact of hunting on the results of the counts was considerable, both locally and regionally.
