Keandalan sistem pembangkit menjadi salah satu perhatian dalam operasi sistem tenaga listrik, Penelitian ini bertujuan untuk menganalisa indeks keandalan sistem pembangkit pada unit pembangkitan PT Pertamina EP. Bunyu kabupaten bulungan. Unit pembangkitan PT Pertamina EP. Bunyu memiliki 4 unit pembangkit dengan kapasitas daya 1000 KW per-unit. Penelitian ini menggunakan metode indeks keandalan Loss Of Load Probability (LOLP) yang dipengaruhi durasi gangguan unit pembangkit berdasarkan Forced Outage Rate (FOR) dari hasil penelitian diperoleh nilai LOLP sebesar 0,00000019999% dengan probabilitas padam 0,00000019999 hari/tahun. Mengacu pada standar Rencana Usaha Penyediaan Tenaga Listrik (RUPTL) 2018-2027 yaitu LOLP harus lebih kecil dari 0,274% atau setara dengan probabilitas padam 1 hari/tahun, Berdasarkan analisa perhitungan indeks keandalan di unit pembangkitan PT Pertamina EP Bunyu pada tahun 2022 dapat dikategori andal.

Kata kunci: Unit Pembagkit, Keandalan, Probabilitas, LOLP, FOR

The reliability of the generating system is one of the concerns in electric power system operation. The present research aimed to analyze the reliability index of the generating system in the generation unit of PT Pertamina EP. Bunyu, Bulungan Regency. The generation unit of PT Pertamina EP. Bunyu had 4 generating units with a power capacity of 1000 KW per unit. This research employed the Loss of Load Probability (LOLP) reliability index method which was influenced by the duration of disruption of the generating unit based on the Forced Outage Rate (FOR). From the research results obtained the LOLP value of 0.00000019999% with a blackout probability of 0.00000019999 days/year. Referring to the standard of the Electricity Supply Business Plan (ESBP) for 2018-2027, namely, the LOLP had to be smaller than 0.274% or equivalent to a blackout probability of 1 day/year. Based on the analysis of the calculation of the reliability index in the generation unit of PT Pertamina EP Bunyu in 2022 was categorized as reliable. Keywords: Generating Unit, Reliability, Probability, LOLP, FOR