Composite reliability analysis of 500 kV Jawa-Bali system related to the Northern Jawa generation and transmission expansion plan

In the document of RUPTL 2016–2025, PT.PLN plan to build new power plants with a total capacity of 7,220 MW as part of 35.000 MW project and new transmission lines Tanjung Jati — Cibatu Baru that will be operated in 2019. These projects are located at the northern line of Java Island. Calculation of power system reliability indices is performed at the hierarchy level II which is a combination of generation (power plants) and transmission systems. This study calculates the energy that is not served (EENS) for one year (MWh/year) in 2019. The results showed that the value of composite reliability index EENS was 5,771.39 MWh/year with 0.0045% ratio. A large addition of generation and power flow changing on transmission lines after the construction of new power plants and new transmission lines influenced the reliability of the 500 kV Java-Bali power system. The larger addition of generation on the system, the greater power flow on the transmission lines. The addition of power plants and transmission lines to the system decreased the EENS value, thus it increased the reliability of the system.