Optimizing Bus Coupler Configuration of a Subsystem in Network Configuration considering Operational Constraints
Robbyo Ardiles Pakpahan, Lesnanto Multa Putranto, Fransisco Danang Wijaya · 2025
The Java, Madura, and Bali (JAMALI) power system is critical to Indonesia's electrical infrastructure.In 2023, reliability issues were identified in the Krian-Gresik subsystem of East Java, particularly at the 500/150 kV Inter-Bus Transformer (IBT), which operated above 60% of its rated capacity, violating the N-1 contingency criterion.While IBT expansion was proposed to alleviate this loading, it introduced the risk of short-circuit currents exceeding circuit-breaker ratings.This study conducts the optimal bus coupler configuration to mitigate excessive short-circuit currents using a comparative analysis of Genetic Algorithm (GA) and Particle Swarm Optimization (PSO).The optimization incorporates operational constraints based on short-circuit current, bus voltage, and transformer loading indices to ensure system operational stability.Simulations conducted on a 44-bus model under different IBT expansion within the Krian-Gresik subsystem demonstrate that GA outperformed PSO, achieving the same optimal solution with a significantly higher success rate of 82.5% compared to 13.8% for PSO, and a 15.2% reduction in total computational time.The optimal configuration successfully reduces the IBT loading index from 42.36 to 34.36 and decreases the short-circuit current index from 187.81 to 120.54.The short-circuit currents at the TNDES, SWHAN, and RNKUT substations were reduced by up to 50%.Meanwhile, the voltage stability index increased from 77.93 to 104.70, indicating only minor voltage deviations within permissible limits.The overall system performance improved by 15.74%, establishing the Genetic Algorithm as a highly effective and efficient approach for enhancing security in the JAMALI power system.