Grzegorz Szymański

Active power loss in thick plate generated by one side inductor heater

A method of calculation of electromagnetic field and eddy-current losses produced in semi-infinite magnetic solid by a.c. flowing through parallel conductors in presence of a magnetic shunt in cylinder form is presented in the paper. The integral equation approach is applied, which permits to obtain an approximate solution of the problem considered. The distribution of the active power density on the surface of the conducting solid is considered.

Power losses analysis in the windings of electromagnetic gear

Presents 3D method for the computation of the winding current distribution and power losses of the electromagnetic gear. For a prescribed current obtained from measurement, the transient eddy current field is defined in terms of a magnetic vector potential and an electric scalar potential. From numerically obtained potentials the power losses are determined. The winding power losses calculation of an electromagnetic gear shows that a given course of the current generates skin effect and significantly changes the windings resistances. Also presents the designing method for reducing power losses.

3D eddy current model for the relay in steady state

This paper presents a numerical method for steady state calculations for a relay. For this purpose the A, A-V method has been selected. The nonlinearity of the materials are taken into account. In this method the three dimensional eddy current equations are formulated in terms of a magnetic vector potential A and an electric scalar potential V in the conducting region and only the magnetic vector potential elsewhere. In the paper it is assumed that the material has orthotropic characteristics.

Electromagnetic torque calculation in 3D systems with rotating field

An algorithm to study a 3D system with rotating field using complex A, A‐V formulation in finite difference solution is presented. Torque calculations are performed using volume Maxwell stress tensor. An eddy current tachometer is investigated. The numerical results are compared with those obtained by measurement.

Application of Time-Frequency Analysis of Acoustic Signal to Detecting Flat Places on the Rolling Surface of a Tram Wheel

The article presents the problematic aspects of detection of flat places on tram wheels using time-frequency analysis of acoustic signals. A number of pass-by tests were conducted during real life exploitation. The objects of research are light rail vehicles exploited in Poznan. Some of them were characterized by flat places on tram wheels. The research aimed to apply the wrought method for detection of flat places on tram wheels.

Analysis of measurement points sensitivity of vibration signals on the stand of jet engine

The diagnostic testing of internal combustion engine can be made by using working processes and methods which take advantage of leftover processes. Working processes give information about general condition of internal combustion engine. Leftover processes give information about condition of particular subassemblies and kinematic couples; hence they are used as autonomous processes or as processes supporting other diagnostic methods. Methods based on analysis of vibrations and noise changes to determine technical condition of object are named as vibroacoustic diagnostics. In papers about vibroacoustic diagnostics of engine, problems connected with difficulty to select test point and to define diagnostic parameters containing essential information about engine’s condition, are most often omitted. Selection of engine’s working parameters and conditions of taking measurements or recording vibration signal are usually based on references, researcher’s experience or intuition. General assumptions about taking measurements of signal closest to its source are most often used. This paper presents a new approach to vibroacoustic diagnostics of jet engine. Selection of measurement points of vibration signals on the basis of tests stand results was suggested and perform a sensitivity analysis of measurement points on the engine support.

Parallel Computations of Multi-Phase Voltage Forced Electromagnetic Systems

This research presents a methodology to parallel computations of the finite element models of electromagnetic systems excited from voltage source. In the model an electric circuit equations, field equations and motion equation are sequentially coupled. The circuit equations for each phase are calculated parallel using client – server system.

Magnetostrictive actuator control taking hysteresis into account

Dynamics of magnetostrictive actuators exhibit hysteresis, which must be incorporated in control design. Finite element method model defined in terms of magnetic vector potential combined with magnetic hysteresis model is proposed to describe underlying phenomena. Closed loop control is coupled to the actuator model. The performance of a linear controller is studied.

Torque calculation of the asynchronous motor in short-circuit test

The paper presents the application of a calculation method of electromagnetic torque for asynchronous motors in short-circuit tests. The A/spl I.oarr/, A/spl I.oarr/-V formulation with a complex notation for time harmonic systems in the finite difference method is used to solve the nonlinear three-dimensional problem. The volume Maxwell stress tensor is used for force and torque calculations. These numerical results are compared with measurement data.