ANALISA STABILITAS TRANSIENT UNTUK MENENTUKAN CRITICAL CLEARING TIME DENGAN METODE TIME DOMAIN SIMULATION DI PT. PETROKIMIA GRESIK

In order to maintain the continuity of electricity supply for all regions in PT Petrokimia Gresik, the stability of the electricity system needs to be maintained to avoid blackouts that cause huge losses for the company. In a reliable electrical system must have good protection. Relay is a protective equipment that functions to trigger a circuit breaker (CB) to open when there is a problem that endangers the system. But this will not guarantee the stability of the system can be maintained. For this reason a transient stability analysis is needed. In this final project a transient stability analysis is carried out by determining the Critical Clearing Time (CCT) due to a three-phase short circuit in the medium voltage distribution network by observing 16 buses. CCT is the determination of critical termination time after experiencing a disturbance, where interference must be disconnected before the critical time (before the CCT value). However, if the interference is cut beyond the CCT value, the system condition becomes unstable. To determine the CCT value, the method used is Time Domain Simulation (TDS) by observing the rotor generator angle, frequency and voltage response. After simulation and analysis 7 busses from 16 buses were obtained whose conditions at CB disconnection were not safe because they still exceeded the CCT value. For this reason, it is necessary to improve the relay time settings to make the system more reliable