Frequency Stability Study of the Khatulistiwa-Sarawak Interconnection Decoupling

The interconnection between the Khatulistiwa System and the Sarawak System plays a crucial role in maintaining an adequate power supply for West Kalimantan. Currently, power from this interconnection constitutes the third-largest source of electricity supply in the Khatulistiwa System. However, in 2025, a load reduction scheme is planned to be implemented, which will require the interconnection load to be decreased or even maintained near zero. This change is expected to have a significant impact on the operation of the Khatulistiwa Grid System. Therefore, a frequency stability study is necessary to analyze the effects of this scheme's implementation on system performance. In this study, an analysis conducted on the impact of generation composition - comprising base load, load follower, and peaker units. A decoupling event will then be simulated using Root Mean Square (RMS) to determine the optimal generation proportion. By increasing the proportion of load-following units and large generators in operation, the system's frequency drop response can be improved from 48.68 Hz to 49.71 Hz during light load and 48.16 Hz to 49.35 Hz during peak load decoupling.