Andrzej Rusek

Electric-field-induced optical path length change in LiNbO3:MgO crystals: spatial anisotropy analysis.

In this paper we describe the methodology behind the calculation of the indicative surfaces (ISs) of the electric-field-induced optical path length change (EFIOPC) in anisotropic crystal materials accounting for the piezoelectric deformation. It is considered in detail for a particular case of 3m point group symmetry and applied to LiNbO(3) single crystals doped with 7 mol. % MgO (hereafter LiNbO(3):MgO). The contribution of the inverse piezoelectricity into EFIOPC appears to be considerable and, in many cases, modifying, for instance, the spherical coordinates of the extreme directions or even leading to the appearance of new directional maxima on relevant ISs. The ISs of EFIOPC are of considerable practical importance as they allow us to determine an optimal geometry for electro-optic coupling. The spatial anisotropic analysis of EFIOPC in LiNbO(3):MgO crystals suggests that the lowest effective driving voltage is provided by electro-optic cells representing the rectangular slabs of X/50° crystal cut. The modulation efficiency of such electro-optic cells is about 1.5 times better than ones fabricated in the usual way (i.e., as rectangular crystal slabs with the faces parallel to the principal crystallographic directions).

Most efficient geometries of the electro-optic effect in crystalline materials of different symmetry

The general method of determination for optimal geometries of the electro-optic interaction is used for characterization of frequently applied crystalline materials of different symmetry. The most efficient geometries of the electro-optic effect are determined in KDP, KD*P, ADP, AD*P, BaTiO₃, KTP, LiNbO₃, LiNbO₃:Mg, LiTaO₃, LiIO₃, HIO₃, KNbO₃ crystals by the extreme surfaces method.

Information technology for most efficient application of bulk and nanocrystalline materials as sensitive elements for optoelectronic devices

The information technology for most efficient and stable application of bulk and nanocrys-talline materials as sensitive elements for electro-, acousto-optic and nonlinear optical cells has been developed and approved. It is based on 3D-analysis of spatial anisotropy for appropriate induced optical effects. Our approach has been checked on example of bulk crystals: pure and MgO-doped lithium niobate, beta barium borate, KTP, langasite etc., as well as will be applied for modelling and creating the nanocrystalline materials based on investigated crystals and nanoporous Al2O3 or SiO2 matrices.

Global maxima of linear electro-optic effect for selected widely used crystalline materials

Using extreme surfaces method we have found the global maxima of linear electro-optic effect for optical path difference in selected crystalline materials which now widely use as working elements in optoelectronic devices. So, for LiNbO3, LiNbO3:MgO, ADP, AD∗P, LiIO3, BaTiO3 and a-HIO3 crystals the magnitudes of global maxima, their angular parameters and relevant application performance enhancement coefficient (APEC) have been found and calculated. The large magnitudes (from 1.5 up to 5.3 times) of these APECs demonstrate the large hidden reserves to enhance the application performance of such crystalline materials that have yet never been used and often even quantitatively not been studied.

Power effective work of PMSМ in electric vehicles at the account of magnetic saturation and iron losses

In this paper the improved model of permanent magnet synchronous machine (PMSM) considering iron losses and magnetic saturation is developed. The optimal dependences between projections of armature current for maximum energy efficiency of PMSM is calculated. To determine the point of transition from the first to the second zone of speed regulation, the information about the references on projections of inverter voltage is used. The simulation model of control system of PMSM for electric vehicle, which operates with maximum power efficiency at wide range of speed and is insensitive to parametric changes of PMSM, is implemented. Streszczenie. W artukole opracowano polepszone modeli matematyczne i komputerowe maszyny synchronicznej o magnesach trwalych (PMSM) z uwzglednieniem nasycenia magnetycznego oraz strat w zelazie. Obliczono krzywe optymalne skladowych prądu twornika dla maksymalnej efektywności energetycznej pracy PMSM. W celu ustalenia punktu przejścia od pierwszej do drugiej strefy sterowania predkości proponuje sie wykorzystac informacje o zadaniu napiecia falownika. Stworzono model komputerowy ukladu sterowania napedem pojazdow elektrycznych na bazie PMSM, ktory dziala z maksymalną wydajnością w szerokim zakresie predkości obrotowej oraz jest nieczuly na zmiany parametryczne. (Energooszczedna praca PMSM w pojazdach elektrycznych z uwzglednieniem nasycenia magnetycznego i strat w zelazie) q q d d q pm p

A general form of the mathematical model for the analysis of transient states of complex electro-mechanical systems with distributed parameters

In the paper a literature review concerning development and application of mathematical models for the analysis of transient states of complex electro-mechanical systems with distributed parameters is presented. Special attention is paid to real-life systems and to presentation of results of digital simulations. In the paper the assumptions for the analysis of transient states of complex electro-mechanical systems in the context of occurrence of vibrations in the rotation transmission system. A general form of the mathematical model for the analysis of transient states of electro-mechanical systems is given, which makes it possible to describe in the continuous form the system of rotation transmission for any of its components. The final form of the equations of the mathematical model, which makes it possible to carry out the digital simulations and to obtain the results as 3D planes that depict the vibrations in reference to time and to real fragments of rotation transmission chain for chosen quantities under examination, is presented.

Development of a method to determine the dependencies of load moments and elastic moments on element parameters during the rolling process for dynamical states of a drive system for the rolling machine- roller table

The article presents general dependencies for the design of the load torque of a hot-rolling mill stand with respect to the rolling parameters. For the analysis of the electromechanical system a computer-aided model of an induction asynchronous motor taking into account iron losses has been developed. A simplified version of the mathematical model of rolling for a single mill stand has been assumed. The calculation results have been presented as time dependencies. On the basis of the calculation results the characteristics of the rolling process with respect to the maximum values of the elastic moments on motor clutches and the clutch coupling the mill stand on the thickness of the rolled component as well as the dependency of the maximum elastic moments on the connections as well as the dependency of the average value of currents of mill stand stator on thickens of the rolled product are presented.

Mathematical model for analysis of dynamical states of a drive system containing rolling mill and roller table including the selected parameters of a rolling process

In the paper the structure of the electromechanical system containing a rolling mill and a roller table is presented. A two-mass system is under consideration. The second type Lagranges equation is used in order to formulate the equations of the abovementioned drive system including the electrical motor of a rolling mill and the electrical motors of a roller table as well as the mechanical system with its elasticity and variable masses of the rolled element and the transported element. The temperature dependency of a specific gravity and a deformation factor for a detail is taken into account. The transformation of mathematical model given in general form into computational equations was carried out. Moreover, the simulation of the exemplary dynamical states were made. The constructional-exploitative parameters of rolling mill - roller table set were taken into account. The results of simulation are presented as graphs of time changes of the selected variables.

Mathematical model of electric drive for rolling mill

In the paper the analysis of electromechanical processes in drive system for rolling mill with rigid torque transmission is presented. The abovementioned drive system, that bases on lumped parameters, consists of two high-power induction motors driving the rolls of rolling mill. The method based on the modification of Hamiltons principle was used in order to formulate the state differential equations. The numerical simulations of rolling-mill operation are made for three examples. The results are presented as graphs. Streszczenie. W pracy poddano analizie procesy elektromechaniczne w ukladzie napedowym walcarki o sztywnej transmisji ruchu. Badany uklad sklada sie z dwoch silnikow indukcyjnych duzej mocy, ktore napedzają cylindry walcarki. System rozpatruje sie jako uklad o parametrach skupionych. Dla formowania rozniczkowych rownan stanu wykorzystano metode, ktora bazuje na modyfikacji zasady Hamiltona. Przeprowadzono symulacje numeryczne pracy ukladu walcarki dla trzech przypadkow obliczeniowych. Wyniki przedstawiono w postaci graficznej (Model matematyczny napedu elektrycznego walcarki).

The electromagnetic transformer of mechanical energy into heat for wind turbine

In order to reduce the cost of stand-alone vertical axes wind turbines (VAWT) and to extend their functionality, this paper suggests accumulating wind energy in the form of heat. For this purpose a special transformer of mechanical energy into heat (TMEH) was developed, which operates on the electromagnetic principle. A simplified method for calculating the magnetic and electric fields in the work parts of the TMEH was developed. The paper gives the results of its FEM-analysis. Using the developed technique the design of pilot TMEH was optimized. Streszczenie. Dla zmniejszenia kosztow zainstalowania silowni wiatrowych z pionową osią obrotu (WAWT) o prace autonomicznej oraz rozszerzenie ich funkcjonalności oferowano akumulowac energie wiatru w cieple. W tym celu opracowano specjalny przetwornik energii mechanicznej na cieplo (TMEH), ktory dziala na zasadzie elektromagnetycznej. Stworzono uproszczoną metode obliczania pol magnetycznych i elektrycznych w elementach konstrukcyjnych TMEH, przedstawiono wyniki FEM-analizy. Wykorzystując opracowane techniki zoptymalizowano konstrukcje projektu badawczego TMEH. (Elektromagnetyczny przetwornik energii mechanicznej w cieplo dla silowni wiatrowej)