ANALYSIS OF ADAPTIVE ISLAND OPERATION IN UNGARAN SUBSYSTEM CENTRAL JAVA

• Main Author: Nurzikry, Deliar
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/87110
• Institution: Institut Teknologi Bandung

Ungaran is one of the important subsystems in the Central Java system. This subsystem is the main supplier of consumers to the significantly growing industrial area in the north coast region, and also supplies the business center and the government offices in Semarang, the capital city of Central Java province. During its operation, potential interruption of Inter-Bus Transformer (IBT) 500kV/150kV supply or frequency drop exceeding certain limits can cause the Ungaran Subsystem to form Island Operation. On May 30, 2020, the Ungaran Subsystem experienced a total blackout due to N-2 IBT disturbance, the island failed to form. Thus, due to its importance, maintaining the integrity of island operation in the Ungaran Subsystem is of high priority. The installed defense scheme is still static so that it is not flexible enough to cope with change of the distribution load and changes in the operating pattern of the power plant so that the success percentage of this static defense scheme is small. To increase the success rate of the island operation in the contingency event of loss of supply from the 500 kV system (IBT 500/150 kV) and frequency drop to 48.3 Hz, an adaptive island operation scheme is proposed. The success of the island operation scheme in the Ungaran subsystem can save the Tambaklorok Power Plant to avoid startup costs and speed up the recovery process. Based on the performed simulations, the proposed scheme could maintain the generation load balance during island operation and results in successful island operation.