Power quality and reliability enhancement in distribution systems via optimum network reconfiguration by using quantum firefly algorithm

Network reconfiguration (NR) is the process of varying the topological arrangement of distribution feeders by changing the open/closed status of sectionalizing and tie switches. This paper presents a method to improve the power quality (PQ) and reliability of distribution systems by employing optimal NR. Optimal NR is applied independently to a system in a specified period to minimize the number of propagated voltage sags (Nsag) and other reliability indexes such as the average system interruption frequency index, sustained average interruption frequency index, and momentary average interruption frequency index. The quantum-inspired binary firefly algorithm (QBFA) is used to find the optimal NR. The QBFA performance for the application of optimal NR to minimize Nsag is first compared with other established optimization methods such as the standard binary firefly algorithm and gravitational search algorithm. Case studies are conducted by using other objective functions, and reliability assessment is performed to observe the reliability improvement caused by the new network topology. Simulation results show that the proposed optimum NR effectively enhances system reliability level and PQ.