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Despite transverse flux machines (TFMs) being intrinsically three-dimensional, it is still possible to model them analytically using relatively simple models. This paper aims to provide an insight into the behaviour of TFMs using a compact equation, which relates torque to the electric and magnetic loadings of the machine and a flux factor. The flux factor is also used to estimate the flux linkage...
This paper presents the electromagnetic transient analysis of a Permanent Magnet Synchronous Generator (PMSG) using the finite element method in two dimensions. A study case is modeled where the generator is connected to a three-phase load through an electronic converters. The PMSG was modeled in the finite element software Flux 2D and the control of the passive elements of the converters was modeled...
Direct-on-line synchronous reluctance motors (DOLSynRM) combine the characteristics of the induction motor (IM) and the synchronous reluctance motor (SynRM). Saturation of core materials, the eddy currents, and the asymmetry of the rotor core and cage make it difficult to predict to which kind of loads the motor can synchronize. In this paper, the DOLSynRM start-up is analyzed with a magnetic field...
Hard Ferrite Assisted Synchronous Reluctance Machines (FASRM) with 6, 8 and 10 poles are analyzed and compared in terms of torque production capability and quality along the entire torque/speed envelope, converter rating and capability to withstand transient short-circuit demagnetizing field. A generic low computational time analysis tool was developed. Medium sized personnel vehicle traction requirements...
In order to be competitive, companies aim at improving their technologies in terms of production process simplification and reduction in the overall price of products. However, the use of lower-cost materials and a simpler construction can often degrade the machine performance. One of the possible production process simplifications of electrical machines is the use of modular permanent magnet synchronous...
In this article a general analytical model for the analysis of permanent magnet synchronous machines with static eccentricity is presented. The model is a continuation of [1] and it is based on Fourier time-space series formulated in 2-D coordinates. The results of the model are corroborated by simulations of finite element method over two different machines. The results of the model show a good agreement...
Power plants are subject to introduce disturbances in the power grid, resulting from interactions with the dynamical behavior of the energy source subsystem. In the case of hydropower plants when used to compensate for variations of power generation and consumption, instabilities or undesirable disturbances may arise. They may be caused by phenomena such as part load vortex rope pulsations in the...
Combined star-delta windings in electrical machines result in a higher fundamental winding factor and cause a smaller spatial harmonic content. This leads to lower I2R losses in the stator and the rotor winding and thus to an increased efficiency. However, compared to an equivalent six-phase winding, additional spatial harmonics are generated due to the different magnetomotive force in the star and...
This paper examines the demagnetization of magnets of permanent magnet excited electrical machines in the case of a sudden three-phase short-circuit at the terminals. An analytical approach is applied and an FEM simulation is performed, and the results are compared for validation.
We have proposed a variable flux reluctance motor that requires only a set of coils for both the armature and DC-field currents. In this paper, the speed-torque characteristics of the motor are compared with those of IPM, switched reluctance and induction motors in terms of the power band. In addition, the phase current and motor efficiency are compared and discussed.
In this paper, the validation of a set of parameters of a 97MVA, 50Hz, 10.3kV hydro generator obtained both by simulation from finite element analysis and by experimentation from the no load curve and the short-circuit test is investigated. As each parameter of the synchronous generator determination involves some inaccuracy due either to the methods used or to the processing of the test data, a comparison...
In order to minimize the cogging torque and torque ripple for surface mounted permanent magnet (SPM) machines, this paper proposes a C-core modular stator which can be obtained by inserting flux gaps (FGs) into every stator tooth. The electromagnetic performances of C-core modular PM machines such as open-circuit flux linkage, phase back-EMF, cogging torque and torque ripple, etc. are comprehensively...
In this study, we address an electric power steering (EPS) motor using a T-shaped segmented stator-core. In the case of EPS motors, cogging torque should be minimized. When a segmented stator-core is applied, however, the manufacturing defects and error affect the peak cogging torque value and periodicity. We performed a 2D finite element analysis (FEA) in accordance with the ideal and non-ideal cases...
Cogging torque reduction with skewing techniques was explored on the MIT Robotic Cheetah. Skewed machines with either skewed rotors or stators were constructed, tested, and fielded on the robot. Results were compared with a convolution technique for predicting torque waveforms of skewed machines from the torque waveform of the unskewed machine. Fringing fields and axial offsets were investigated as...
The detailed analysis of electric machinery is essential for the design of modern high efficiency centrifugal pumps. The paper at hand deals with a new combined method, to reduce the degrees of freedom from finite element analysis (FEA). By extracting the time and current depending lumped parameters of a synchronous machine for a phase-domain model during its simulation, the complexity of the machine...
The paper analyzes the performance of vernier synchronous generators as compared to synchronous generator, both with spoke ferrite permanent magnets and outer rotor. An existing wind turbine synchronous generator of 3 kW / 350 rpm with internal rotor and surface NdFeB permanent magnets was taken as a reference. A semi-analytical multiphysics design optimization methodology, employing a deterministic...
Direct and soft starts of squirrel-cage induction motor are considered. Operation specificity due to nonsinusoidal supply voltage and equivalent circuit parameters changes due to variable voltage magnitude and frequency as well as magnetic circuit saturation and current displacement in rotor winding are studied. Consumed energy calculations show advantage of frequency converter start. Mathematical...
The inductances play an important role in the behavior of the interior permanent magnet (IPM) Machine. This paper investigates absolute, differential inductances as well as d- and q-axis inductances for different rotor structures and positions. It also analyses the saturation of the inductances at different current magnitudes. The AC and mixed current standstill tests are applied in the experiments...
A 2.5MW doubly-fed induction generator (DFIG) and a cascade doubly-fed induction generator (CDFIG) in energy conversion system are compared in order to investigate the cost and efficiency of the system. A reference doubly-fed induction generator and a scaling methodology are employed to design the cascade doubly-fed induction generator Using finite element analysis (FEA) and MATLAB/Simulink, both...
Analytical calculation of the operating performance of induction machines requires exact knowledge of the leakage inductances in both the stator and the rotor. In contrast to the flux coupling within the iron core where flux paths are two-dimensional and predominantly determined by permeabilities of different magnitudes (iron core vs. air gap/slots), thus making it easy to separately calculate main...
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