Digital Simulation of Power Distribances and Protective Relaying

This paper describes simulation of power system disturbances and protective relaying performance by means of a digital computer. Line-to-line faults, faults involving ground and open conductors in a power system including both of single-and parallel double-circuit lines are dealt with, that is, voltage distribution under independent or simultaneous occurrence of such faults are calculated. The protective relaying can optionally be simulated by adding or modifying its own subprograms, and the following relayings are herewith detailed as examples: a) Combined phase and directional comparison carrier relaying for extra high voltage system. b) Out-of-step system-split relaying with distance relay of rectangular characteristics. c) Single-and three-phase reclosing systems.