Frequency Constrained Unit Commitment dan Economic Dispatch di Sistem Jawa Madura Bali Menggunakan Kekangan Cadangan Fast Response Untuk Meningkatkan Stabilitas Frekuensi.

IMRON ROSYADI, Husni Rois Ali, S.T., M.Eng., Ph.D., DIC., SMIEEE ; Ir. Lesnanto Multa Putranto, S.T., M.Eng., Ph.D., IPM., SMIEEE.

2026 | Tesis | S2 Teknik Elektro

Operasi sistem tenaga listrik Jawa Madura Bali (JAMALI) menghadapi tantangan stabilitas frekuensi seiring dengan rencana peningkatan penetrasi pembangkit intermiten berbasis Energi Baru Terbarukan (EBT) yang bersifat non-inersia. Penelitian ini bertujuan untuk mengintegrasikan keamanan frekuensi, yang meliputi Rate of Change of Frequency (RoCoF), frekuensi nadir, dan cadangan fast response, ke dalam model optimasi Unit Commitment (UC) dan Economic Dispatch (ED). Metodologi yang digunakan adalah pemodelan optimasi Mixed-Integer Linear Programming (MILP) dengan pendekatan Piecewise Linear Cost pada perangkat lunak MATLAB, yang divalidasi melalui simulasi dinamik di Digsilent PowerFactory dan diimplementasikan pada software operasional jROS (joint Resources Optimization and Scheduler). Hasil penelitian pada model di MATLAB menunjukkan bahwa kekangan cadangan fast response menjadi dominan dibandingkan yang lain dalam optimasi UC ED untuk memitigasi gangguan pembangkit terbesar. Implementasi model di sistem real time JAMALI menggunakan jROS menunjukkan bahwa integrasi kekangan cadangan fast response secara signifikan meningkatkan stabilitas frekuensi pasca-gangguan (N-1), dengan pencapaian frekuensi steady state sebesar 49,825 Hz dibandingkan 49,792 Hz pada ED tradisional untuk gangguan 1000 MW. Namun, peningkatan keandalan ini menyebabkan kenaikan biaya operasional sebesar Rp 1,37 miliar per hari akibat pergeseran pembebanan ke unit PLTGU yang lebih mahal untuk memenuhi kebutuhan cadangan. Selain itu, peningkatan partisipasi AGC hingga 100% terbukti mampu menekan biaya operasional sebesar Rp 0,57 miliar per hari melalui optimalisasi penggunaan PLTU yang lebih murah. Penelitian ini memberikan gambaran mengenai trade-off antara biaya operasi dan keandalan sistem dalam mendukung transisi energi bersih di sistem JAMALI.

The operation of the Java-Madura-Bali (JAMALI) power system faces frequency stability challenges alongside the planned increase in intermittent renewable energy (RE) penetration, which is characterized by non-inertial properties. This study aims to integrate frequency security constraints—including the Rate of Change of Frequency (RoCoF), frequency nadir, and Fast Frequency Reserve (FFR)—into the Unit Commitment (UC) and Economic Dispatch (ED) optimization models. The methodology employs Mixed-Integer Linear Programming (MILP) optimization with a Piecewise Linear Cost approach using MATLAB software. The model was validated through dynamic simulations in Digsilent PowerFactory and implemented within the jROS (Joint Resources Optimization and Scheduler) operational software. Results from the simplified model in MATLAB indicate that the FFR constraint becomes dominant over other factors in the UC-ED optimization for mitigating the largest generation contingency. Implementation of the model in the real-time JAMALI system using jROS demonstrates that integrating a 2-minute FFR constraint significantly improves post-contingency (N-1) frequency stability, achieving a steady-state frequency of 49.825 Hz compared to 49.792 Hz in traditional ED for a 1,000 MW disturbance. However, this enhanced reliability leads to an increase in operational costs of IDR 1.37 billion per day due to the shifting of loads to more expensive Combined Cycle (PLTGU) units to meet reserve requirements. Furthermore, increasing Automatic Generation Control (AGC) participation to 100% is proven to reduce operational costs by IDR 0.57 billion per day through the optimized utilization of more cost-effective coal-fired power plants (PLTU). This research provides a guideline regarding the trade-off between operational costs and system reliability in supporting the clean energy transition within the JAMALI system.

Kata Kunci : Unit Commitment, Economic Dispatch, Stabilitas Frekuensi, Fast Frequency Reserve, Sistem JAMALI