Insertion of 275 kV Network in Jawa Bali System-jakarta Area Case Study

High short-circuit current and voltage excursion are two major great concerns for an electricity provider in Indonesia, named PLN. These two problems are mainly remarkable in Jakarta area, i.e., the central load of Jawa Bali system. In order to achieve both decrease in the short-circuit current and increase in the voltage level, Insertion of the intermediate 275 kV networks together with the change in the 150 kV networks from loop structure to radial structure is examined with several scenarios. Genetic Algorithm multi-objective optimization technique is also applied for selecting the 275/150 kV transformer reactance in terms of the aforementioned two requirements. The performance of each scenario is verified using the short circuit index, the voltage index and the number of installed 275 kV transmission lines and transformers. Three subsystems in Jakarta area which are Bekasi, Gandul and Kembangan are selected, because these subsystems include most of the issues related to the short-circuit current and the voltage level. The selected scenario successfully reduces the short-circuit currents and increases the voltage level in 150 kV system.