Validation Simulation Model and Stability Analysis of Interconnecting Two Weak Subsystems

Borneo is one of Island in Indonesia besides Sumatera, Sulawesi, Java, and Papua. It has three subsystems, West Borneo, East - North Borneo, and South - Center Borneo. There are a lot of option to increase the power, one of the solutions is transferring the power between subsystems. This paper will expain the study of interconnecting two subsystemss, East - North Borneo with South - Center Borneo with the impacts to the system. Nowadays, that two subsystems is weak, which total generation of East – North Borneo is 400 MW and the South - Center Borneo is 500 MW, both of the subsystems has limited spinning reserved (10%), the spread of the load is not evenly converging in some area with long distance transmission and there is only one generation as the base load carrier for each subsystem. In 2015, the developing of electric generation in South - Center Borneo will be growth rapidly than East - North Borneo, whereas the load itself lighter. So there is a planning to interconnect between two subsystems to get realiblity and economical value, because of some diesel generation that was full of fuel will be switched off. This stability study includes power flow, voltage stability, small signal stability and transient stability. This study uses power system simulation software Digsilent. The output of the study is a technical recommendation for The headquarter of state electricity company as a policy taker about this interconnecting plan.