Andrzej Waindok

Finite-Element Analysis of the Magnetic Field and Electromechanical Parameters Calculation for a Slotted Permanent-Magnet Tubular Linear Motor

We have calculated magnetic field distribution and integral parameters for the slotted, five-phase, permanent-magnet tubular linear motor (PMTLM). We used a finite element (FE) model for the field analysis. We carried out the field analysis for different values of the exciting current and for variable mover position. To obtain experimentally the field distribution and its integral parameters, we developed and tested a physical model of the motor. We compared the calculation results with the measured ones and found a good conformity.

The influence of the leg cutting on the core losses in the amorphous modular transformers

Purpose – In a modular transformer with a wounded amorphous core, the authors should make some cutting to limit the eddy currents in its magnetic ribbon. The purpose of this paper is to deal with 3D magnetic field analysis, including the eddy currents induced by varying frequency of power. The influence of the core leg cutting on the power losses values, in the three variants of a one-phase modular transformer structure, has been presented. Design/methodology/approach – 3D field problems including eddy currents of various frequency were analysed using the electrodynamic potentials and V within the finite element method. The wave method and iterative one of the laminated core homogenization, have been employed. The values of the calculated losses have been verified experimentally. Findings – The reduction of the core losses by axial cutting of the transformer legs is an efficient approach for the loss limitation. The wave method is not acceptable for homogenization of the amorphous core for its operation a...

Tubular Linear Actuator as a Part of Mechatronic System

Electromagnetic tubular linear actuators are very important in mechatronic systems. The new construction of the linear actuator is presented in the paper. Many calculations with magnetic field analysis have been carried out for the new construction of the object. It was a five-phase permanent magnet tubular linear actuator. The static and dynamic parameters of the actuator have been calculated and measured, as well. A good correlation between the results validates the mathematical modeling of the actuator.

Electromagnetic and Temperature 3-D Fields for the Modular Transformers Heating Under High-Frequency Operation

Core losses in two different transformers under high-frequency (f=10 kHz) operation have been simulated using 3-D FEM modeling. For the first transformer, we assumed an amorphous core, while the ferrite core has been established for the second one. The equivalent electrical conductivity values have been assumed. The values of core losses were included into 3-D modeling of the temperature field. For both transformers, the temperature of the cores and windings was calculated versus the heating time. The calculation results have been compared with the ones from tests of our prototypes, and a good agreement has been obtained.

Transient Analysis of a Railgun with Iron Core

A calculation and measurement results of transients for an iron-core electrodynamic launcher have been presented in the paper. The magnetostatic field calculations have been made with using the Maxwell-ANSYS software, while the circuit part of the mathematical model has been implemented in MATLAB/Simulink package. The measurement verification has been carried out with using the original laboratory stand. The transients of excitation current, capacitor voltage and projectile velocity have been compared. A good conformity between calculation and measurement results has been obtained. Streszczenie. W pracy przedstawiono wyniki obliczeń i pomiarów sygnałów zmiennych w czasie dla wyrzutni elektrodynamicznej z rdzeniem ferromagnetycznym. Do obliczeń pola magnetostatycznego wykorzystano program Maxwell-ANSYS, natomiast część obwodową modelu matematycznego zaimplementowano w pakiecie MATLAB/Simulink. Porównano ze sobą przebiegi prądu wzbudzenia, napięcia na kondensatorach oraz prędkości wylotowej elementu ruchomego (pocisku). W obliczeniach dodatkowo wyznaczono siłę działającą na pocisk oraz jego przyspieszenie. (Analiza dynamiki akceleratora szynowego z rdzeniem ferromagnetycznym).

Calculation models of the electrodynamic accelerator (railgun)

The analysis of phenomena occurring in the railway accelerator (railgun) has been presented in the paper. The analytical and numerical models have been used. The formulas describing the forces acting on the accelerated element (bullet) for different models of the accelerator have been derived. The dimensions of rails and bullet for each model have been assumed to be the same. In case of numerical calculations the finite element method has been used. For a chosen accelerator type the field-circuit model has been made with using MATLAB-Simulink software. The selected model has been verified experimentally. Streszczenie. W artykule przedstawiono analizę zjawisk zachodzących w akceleratorze szynowym. Wykorzystano zarówno modele analityczne, jak i numeryczne. Otrzymano wzory opisujące siły działające na element przyspieszany (pocisk) dla różnych modeli akceleratora. Przyjęto identyczne wymiary szyn i pocisku dla każdego modelu. W przypadku obliczeń numerycznych wykorzystano metodę elementów skończonych. Dla wybranego typu akceleratora wykonano model polowo-obwodowy z wykorzystaniem oprogramowania MATLAB-Simulink. Model ten został zweryfikowany pomiarowo. (Modele obliczeniowe akceleratora elektrodynamicznego (działo szynowe)).

Modeling and Measurement of Transients for a 5-Phase Permanent Magnet Tubular Linear Actuator Including Control and Supply System

The mathematical and physical models of the permanent magnet tubular linear actuator (PMTLA) including control and supply system are presented in the paper. In the numerical analysis a field-circuit model is used. The field model is calculated using the finite element method (FEM), while the circuit model is implemented in Matlab/Simulink software. Both models are coupled using the look-up tables in Matlab software. To verify the calculations, the real drive system has been build. It consists of supply and control system, PC and sensors. The supply system is connected to the controller, which uses the Texas Instruments digital signal processor (DSP) TMS320F2812. The processor is linked with the PC, where the control algorithm as well as the graphical user interface (GUI) have been developed in the Matlab/Simulink package using the extended toolboxes. Data transfer is realized using the LPT port supported by the Real Time Workshop. With using this system, the calculation results obtained from the numerical model have been compared with the measured ones. A good conformity was obtained.

Determination of Temperature in the Construction of Permanent Magnet Tubular Linear Actuator

The calculation results for the thermal field of the permanent magnet tubular linear actuator (PMTLA) have been presented in the paper. For the analysis of heating, four different mathematical field models have been created and compared. Each of them uses the finite element method (FEM). In the most simplify model only the standard convective heat transfer coefficient has been implemented. In the most sophisticated model, thermal radiation, convective heat transfer and dependence of the coil resistance vs. temperature have been included. In all models the Joule losses have been assumed as the heat source. The numerical models have been verified experimentally with using the infrared camera and by measuring the coil resistance. Using the most precise model, the nominal current value has been determined for PMTLAs with two different permanent magnet types: NdFeB and SmCo. The conclusions are valuable in the designing process of many actuators with permanent magnets.

The Temperature Influence on the Linear Actuator Static Parameters

The thermal field model of the linear oscillating actuator [5, has been presented in the paper. The calculated temperature has been taken into account to obtain the correct characteristics of the permanent magnets, which are operating in raised temperature (above 293 K). The parameters of the NdFeB magnets change significantly with temperature increasing (the magnets are weaker). Thus, the phenomenon should be included in the designing of the actuators. We have determined the highest current density of the actuator winding, for which the actuator still operates properly. Using the thermal field analysis, the temperature of the whole actuator construction has been obtained. Using the correct parameters of the hot magnets in the calculation model, the static electromagnetic parameters of the actuator have been determined. They were compared with those obtained for the actuator, which is operating in the room temperature (To=293 K). It has been proved, that the parameters of the actuator are going down under the increasing of the temperature.

Tests of the controllers settings for a 5-phase permanent magnet tubular linear motor using Matlab/Simulink software

The mathematical and physical models of the permanent magnet tubular linear motor (PMTLM) including control and supply system are presented in the paper. In the analysis a field-circuit model is used. The field model is calculated using the finite element method (FEM), while the circuit model is implemented in Matlab/Simulink software. The control algorithm as well as the graphical user interface (GUI) have been developed in the Matlab/Simulink package using the extended toolboxes. The controller uses a Texas Instruments digital signal processor (DSP) TMS320F2812. Data transfer is realized using the LPT port supported by the Real Time Workshop. Thus, it is possible to compare the results from the numerical model with the measured ones. A good conformity is obtained.