This paper presents an in-depth comparative analysis of the variable speed drive (VSD) performance between an IEC frame size 90 four-pole three-phase induction motor (IM) and the equal line-start ...interior permanent magnet synchronous motor (LSIPMSM). Employing measurement data from no-load tests, load tests, and temperature-rise tests of the aforementioned motors and different cage materials as well, the motors' no-load and load characteristics are first examined in detail and then the drives' characteristics are analyzed in open-loop volts per hertz ( V / f ) control by using the same voltage-source inverter and the aforementioned IM or LSIPMSM in both constant torque and constant power operation. It has been established that particularly the motors' current and power factor characteristics have distinct impact on the consequent VSD performance in terms of loss and efficiency. Furthermore, it has been shown that the lower loss of the LSIPMSM enables a significant increase of the VSD's constant power range.
This paper shows the use of the hybrid finite-boundary element method (HM) in the analysis of complex grounding systems (GS) designed for protection of power and industrial systems. In the field ...calculation a three-dimensional (3-D) linear finite element and a 3-D mixed boundary element were applied. The program solution used is suitable for any GS and for isotropic or anisotropic soil properties.
The paper deals with the Finite Element Method (FEM) based procedure for determination of operating point dependent inductances of a Linear Synchronous Reluctance Motor (LSRM). Special attention is ...paid to the effects of cross magnetization and saturation on the inductances of LSRM under load conditions. To achieve a deeper insight into the cross magnetization and the saturation phenomena a standard two-axis LSRM dynamic model is modified. The modified dynamic LSRM model contains explicit terms for the direct and the quadrature axis self-inductances and explicit terms for the cross coupling inductances. The last ones appear as a consequence of the cross coupling between the direct and the quadrature axis. All inductances of the modified LSRM model are current dependent.
The paper presents a finite element method (FEM) based analysis of interior permanent magnet synchronous motor, designed for flux-weakening operation. Flux-weakening performance determined from the ...FEM analysis on the proposed permanent magnet motor structure is presented in order to verify the suitability of the design concept for flux-weakening operation. The influence of iron losses on the output power capability is included in the analysis by posterior iron loss calculation. The presented interior permanent magnet motor shows an extremely wide constant-power speed range which exceeds 5:1.
The paper describes the determination of the parameters of the two-axis model of a synchronous motor with permanent magnets using the results of the measurement of load conditions at different sine ...voltages and constant frequency. For the determination of parameters of the two-axis model the modified conventional method was used. The machine parameters are determined from measurement data by the results of the calculation of the induced voltage E/sub i/ and internal load angle /spl delta//sub i/. Computational difficulties at parameters determination owing to random inaccuracies in the measurements data are overcome with use of orthogonal polinoms approximation. Detailed determination of parameters values reveal an important influence of the interaction of the direct and quadrature axis excitation on the parameters variation.
This paper deals with the calculation of the electric field in the vicinity of a high-voltage overhead transmission line (TL). Since analytical formulas cannot be used to calculate the electric field ...in cases when the ground surface under a TL is not flat or when conducting bodies are located under it, we present the use of finite element method (FEM) for this purpose. The electric field distribution has been analyzed for two characteristic high-voltage TLs. A graphical comparison of the electric field strength E 1 m above ground surface is included.
Electromagnetic theory presents difficult task for the student. The essence of the problem is not the pretentious mathematical treating of the field, but in the field presentation and understanding ...of field interaction with the material. The paper presents our program tools (FIELD_EDU) for teaching of electromagnetic field, based on the finite element method (FEM). The program concept enables the student to build in the very simple way an arbitrary problem, without being burdened with specific demands of FEM at field analysis. When doing this, the students can help themselves with the library of simple geometrical objects, which have already predefined material properties and boundary conditions. The program tools enable a complete graphical and numerical analysis of one or more examples at the same time
The paper presents the analysis of iron loss in interior permanent magnet synchronous motor over a wide-speed range of constant output power operation. The analysis is based on finite element method ...and uses the information on local flux density variation in the motor components. The total iron loss is calculated by summing up separately the hysteresis, classical eddy current and excess losses for each element of discretization over one electrical cycle of magnetic field variation in all parts of motor iron. The results of iron loss calculation were compared with the results obtained from experiments on the actual machine.
The paper presents iron loss calculation in rotational electrical machines by using different iron loss models. The accuracy of each iron loss model was determined by the comparison of measured and ...calculated iron losses in the case of distorted elliptically rotating flux density waveforms, generated inside the fully 2D waveform controlled rotational single sheet tester for different magnetizing frequencies of fundamental flux density waveform ranging in the intervals (25
Hz⩽
f⩽200
Hz).
This paper presents a finite-element method-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 root mean square current flowing through the windings than the same motor supplied with sinusoidal currents. The results of the analysis are partially verified with measurements.
