Analysis of Power Line Emergency Modes Using Phase Coordinates

Normal and emergency operating conditions in electric networks featuring a complex asymmetry are analyzed using the phase coordinate method. Investigation of the operating conditions of networks represented by three-phase equivalent circuits with simulating simultaneous short circuits and phase wire breaks involves the need to use more accurate but at the same time simple techniques. The article describes a methodology for carrying out experiments on emergency mode calculations using a software that forms and solves a system of equations for three-phase equivalent circuits. The conditions for modeling network elements, wire breaks, and shunts using, respectively, impedances and admittances are described. The results of computational experiments on studying emergency modes by using the electric network equivalent circuits in phase coordinates involving a single-phase short circuit fault with a simultaneous one-sided phase break are given. A single-phase automatic reclosing with automatic shunting of the faulty phase is considered. It has been demonstrated that by using the proposed methodology it is possible to obtain the operation mode parameters through representing short circuits and breaks in three-phase equivalent circuits in a natural manner.