No load shedding defence scheme as reinforcement in Aceh province network

Indonesia consists of many isolated electrical power system networks. Sumatera power system is one of the power system networks in Indonesia. It consists of 2 major networks, which are Northern Sumatera system and Central-Southern Sumatera system. Northern Sumatera system supplies two provinces, which are North Sumatera province and Aceh province. North Sumatera province has a loop topology while Aceh province has a radial one. In the last 3 years, there are four significant disturbances in the system that caused blackout situation in Aceh province. It caused so many complaints from customers and local government. The root cause of the problem came from the big power transfer along the radial topology and significant Force Outage Rate (FOR) along the transmission line. This situation was happened since more than 50% of power supply come from North Sumatera province and significant rate of lightning flash along the transmission line. This paper will give details about the implementation of No Load Shedding (NLS) Scheme in Aceh province network. With a a complete and smart combination with other special protection scheme, NLS scheme will increase reliability of electricity power supply to the local customer. This paper will explain the steps in designing the scheme, the need of coordination meeting with other stakeholder, and some constraints faced by the team in implementing NLS Scheme to the system. Finally, this paper will tell lesson learned in implementing NLS scheme and the benefit of this scheme to increase reliability of the system.