PROTEKSI TERHADAP ARUS GANGGUAN PADA SISTEM JARINGAN LISTRIK

Protection system becomes an important factor in the electrical network system. Various calculations necessary to estimate the fault of current as a basis for designing the protection system to be used, such as planning the installation of power equipment in order to determine the trip-specifications, conductors will be used, the thermal capacity of the current transformer, relays and reactor. The fault of current is calculated not only at the point of interruption, but also its influence on the flow in each branch in the network leading to the interruption point. Disturbance will cause an unbalance in the current and voltage in network systems, both single phase to ground disturbance, phase to phase, phase-phase and three phase land and interference (with and without ground). In this case the current transformer plays an important role in detecting a very large fault current conformed to the rating estimated. Fault current magnitude must be estimated to find the limits of protection standards that will be designed in the system. For that need to be calculated source impedance (the reactance), the transformer reactance, and impedance feeders based on the estimated percentage of fault current that can be estimated. The accuracy of the estimated fault current will determine the quality of protection through a rating system security tool that is used to do the trip at the right time. For that we need regulation (setting) devices such as relays flow properly. In a protection system with multiple safety devices need to do a timer setting (grade) at each relay controlling the CB so that the protection system can operate with accuracy and speed and has a high sensitivity.