STUDI AKTIVASI AUTO RECLOSE PADA OUTLET PEMBANGKIT LISTRIK TENAGA PANAS BUMI TERHADAP STABILITAS SISTEM: STUDI KASUS SISTEM SULAWESI UTARA DAN GORONTALO

Dimas Angga Putra, Dr. Ir. Avrin Nur Widiastuti, S.T., M. Eng., IPM.

2026 | Tesis | S2 Teknik Elektro

Saluran outlet pembangkit memiliki peran penting dalam menjaga kontinuitas penyaluran daya dan kestabilan sistem tenaga listrik. Pada sistem Sulawesi Utara dan Gorontalo PLTP Lahendong merupakan salah satu pembangkit utama yang berkontribusi signifikan terhadap suplai daya sistem, sehingga gangguan pada saluran outletnya perlu ditangani secara cepat, selektif dan aman. Salah satu skema proteksi yang dapat mempercepat pemulihan sistem setelah gangguan adalah auto reclose. Namun penerapan auto reclose pada outlet pembangkit tidak dapat hanya mempertimbangkan kecepatan penormalan, karena proses penutupan kembali pemutus tenaga dapat memengaruhi stabilitas sistem. Penelitian ini bertujuan memberikan rekomendasi penerapan skema Single Pole Auto Reclose dan Three Pole Auto Reclose pada saluran outlet PLTP Lahendong. Evaluasi dilakukan melalui pemodelan sistem menggunakan DIgSILENT PowerFactory dengan kriteria teknis berupa critical clearing time, power surge, secondary arc, dan synchrocheck. Model sistem divalidasi melalui analisis kondisi tunak dan validasi dinamis menggunakan data gangguan aktual. 

Hasil penelitian menunjukkan seluruh penghantar yang dianalisis layak diterapkan skema SPAR dengan rekomendasi 1 shot low speed. Nilai CCT gangguan satu fasa berada pada rentang 258 hingga 304 ms, sedangkan power surge berada di bawah batas 50%, yaitu 25,513 hingga 31,195%. Evaluasi secondary arc menunjukkan skema low speed lebih sesuai agar busur sekunder padam sebelum reclose. Untuk skema TPAR gangguan dua fasa masih dapat diterapkan dengan rekomendasi 1 shot low speed with synchrocheck, sedangkan gangguan tiga fasa diblokir karena nilai CCT hanya 154 hingga 198 ms. Validasi dinamis menunjukkan rekomendasi SPAR dan TPAR secara umum mampu mempertahankan kestabilan sistem meskipun TPAR pada penghantar LHD 56 KWK dalam kondisi padam satu penghantar perlu dipertimbangkan kembali karena menyebabkan kondisi isolated. Rekomendasi tersebut kemudian diimplementasikan pada relai Alstom MiCOM P545 melalui pengaturan parameter dan logic auto reclose. Hasil pengujian menunjukkan relai mampu menjalankan fungsi trip, reclose, blocking, lockout, dan supervisi synchrocheck sesuai rancangan.

The outlet transmission lines of Lahendong Geothermal Power Plant play an important role in maintaining power delivery continuity and power system stability. In the North Sulawesi and Gorontalo system, Lahendong Geothermal Power Plant is one of the main power plants that contributes significantly to the system power supply therefore, disturbances on its outlet lines must be handled quickly, selectively, and safely. One protection scheme that can accelerate system recovery after a disturbance is auto reclose. However, the application of auto reclose on power plant outlet lines cannot only consider the speed of system restoration, because the reclosing process of the circuit breaker may affect transient stability, synchronization, and equipment operational security. This study aims to evaluate the feasibility of applying Single Pole Auto Reclose and Three Pole Auto Reclose schemes on the outlet lines of Lahendong Geothermal Power Plant. The evaluation was carried out through system modeling using DIgSILENT PowerFactory with technical criteria consisting of Critical Clearing Time, power surge, secondary arc, and synchrocheck. The system model was validated through steady state analysis and dynamic validation using actual disturbance data.

The results show that all analyzed transmission lines are feasible for the implementation of the SPAR scheme with a 1 Shot Low Speed recommendation. The CCT values for single-phase faults range from 258 to 304 ms, while the power surge remains below the 50% limit, namely 25.513 to 31.195%. The secondary arc evaluation shows that the low speed scheme is more suitable to ensure that the secondary arc is extinguished before reclosing. For the TPAR scheme, two-phase faults can still be applied with a 1 Shot Low Speed with Synchrocheck recommendation, whereas three-phase faults are blocked because the CCT values are only 154 to 198 ms. Dynamic validation shows that the SPAR and TPAR recommendations are generally able to maintain system stability, although TPAR on the LHD 56 KWK line under a single-conductor outage condition should be reconsidered because it results in system islanding. The recommendation was then implemented on the Alstom MiCOM P545 relay through auto reclose parameter and logic settings. The test results show that the relay is able to perform trip, reclose, blocking, lockout, and synchrocheck supervision functions according to the designed scheme.

Kata Kunci : Auto reclose, stabilitas transien, critical clearing time, power surge, secondary arc, synchrocheck.