MODELING OF ELECTROMECHANICAL TRANSIENTS IN ASYNCHRONOUS MOTORS BASED ON THE USE OF TCHEBYSHEV’S POLYNOMIALS

Abstract

The article is dedicated to development of numerical method of electromechanical transient processes calculation in asynchronous motors. Electromechanical transient processes might be quite continuous that causes the calculation time increase and accumulation of errors due to use of modern software solutions. The aim of this work is to design more accelerated method of calculation of electromechanical transient processes in asynchronous motors and to create the convenient and practical model scheme of method. The method is based on approximation of state equations solution with the help of expansion of the solution with orthogonal Chebyshev’s polynomials. The scheme interpretation of this method is presented; it considers the rotor rotation frequency as some current. The given method allows to substitute operations with momentary values of currents by operations with currents images, which are interpreted as constant currents at equivalent circuit. As the result the initial integro-differential equations of state are substituted by the algebraic equations of current images. Also there is method of calculation of production image of the currents which are present at electrical machine. CPU time is decreased more than twice compared to common methods due to calculation of transient process in asynchronous motor according to the given method. Considered method is convenient for calculations of transient processes in complex circuits that include not only asynchronous motors but other electrical machines