Hybrid meta-heuristic and non-dominated Sorting based optimization for DG and FCL placement considering long-term economic profitability

Abstract

The increase in global electricity demand has revealed the limitations of traditional centralized power generation, such as transmission losses, degraded power quality and protection issues. Consequently, DG units have been increasingly integrated into power systems to mitigate these issues. However, higher DG penetration increases fault current levels, potentially exceeding the circuit breaker limits. This may lead to significant economic losses due to equipment damage during short-circuit faults. Therefore, to ensure both system reliability and economic viability, the placement and sizing FCLs must be performed alongside DG optimization. In this study, a multi-objective optimization algorithm is proposed to simultaneously optimize DG and FCL units. The proposed algorithm is validated on IEEE 118-Bus test system using PSO, GA, and GWO. The proposed single-objective optimization achieved 26 % reduction in total power losses and successfully limited fault currents below 25 kA circuit-breaker threshold. In the multi-objective cases, algorithms provide Pareto-optimal solutions spanning 27-29 % variation in power losses, 200-290 % range in FCL costs, and over 3900 % diversity in economic profit, demonstrating the trade-off between technical improvement and economic profitability. The results highlight the importance of a balanced optimization perspective in DG and FCL planning for both economic performance and system reliability.