Defense scheme to avoid voltage collapse in transmission lines: A case study of paiton- situbondo transmission lines

Reliability, and continuity of service to customers is the top priority in the power system defense scheme. One important criterion is avoiding instability. Most conventional stability analysis is related to power swings due to frequency variations because the frequency is directly affected by power plant performance. However, in the transmission line, voltage instability is crucial because it practically give direct impact on customers. Especially for high voltage consumers, poor voltage quality is very influential on the performance of industrial equipment such as electric motors, textile machinery, and other electronic equipment, so the voltage quality must be maintained to avoid complaints from these consumers. The merge of frequency and voltage criteria instability is becoming the main focus in recent studies. In a large power system, voltage stability problem usually happens due to excess of electrical demand and deficiency of power generation. To avoid voltage instability, under-voltage load shedding can be an option to remove buses with unstable voltage in the power system. This paper focuses on the Paiton-Situbondo 150 kV transmission lines as the backbone of the power transfer from Java to Bali to investigating the role and effectiveness of the combination of frequency and voltage threshold to maintain the system stability when the faults occur on the transmission lines.