Applications of EMTP for transient stability study of an islanded industrial power system

This paper introduces a method for obtaining relative rotor electrical angles between drifting machines, in an isolated faulted system. Results from the EMTP (Electromagnetic Transient Program) simulations are transferred to, and processed in an electronic spreadsheet to produce the desired curves. A case study is presented for an industrial system with synchronous machines. When subjected to a three phase fault, different size running machines depart from their original rotor angles, at varying rates. If the fault is not cleared within a specific period, drifting between these machines becomes irrecoverable, and the system becomes unstable. Results under different system operating conditions are presented and the suitability of EMTP to such applications is discussed