Simulation of Transient Processes in a Generator-Transformer-Load System with Non-Symmetry of Phase Windings of the Stator and Saturation of the Magnetic System

Abstract

Transient processes of a generator-transformer-load system are considered taking into account the saturation of its magnetic system. A method is proposed for numerical simulation of the transient processes of a synchronous machine with the possibility of taking into account the asymmetry of the stator winding and the saturation of the magnetic system. The appearance of asymmetry is possible if the synchronous machine is damaged, in particular, during inter-turn short circuits in the stator winding. It is based on the direct solution of the differential equations of equilibrium of the emf and voltage drops in the windings in phase coordinates together with the equation of motion of the rotor. In this case, the contour of each phase winding of the stator is described by a separate equation, and different phase parameters can be taken into account. The mathematical model of the system is realized in the software package MATLAB. The model takes into account one of the possible types of nonsymmetry – an unequal number of turns in phase windings, which makes it possible to simulate interturn short circuits without taking into account the appearance of additional short-circuited circuits. The model was verified by comparing the transient calculation results obtained using the developed model and using the MATLAB Simulink tools. The simulation results for the idle and load modes are analyzed. The obtained results allowed to draw a conclusion about the adequacy of the realized model