Network Reconfiguration of Unbalanced Distribution System through Hybrid Heuristic Technique

Abstract

Electrical power distribution systems are critical links between the utility and customer. They are constructed by one of the three types: radial, open loop and network. They are usually arranged to be radial in operation to simplify over-current protection. Usually, distribution systems are designed to be most efficient at peak load demand. Utilities are constantly looking for newer technologies that enhance power delivery performance. One of the several important issues is the control of power loss. Several strategies can be employed to minimize power losses in a distribution network. They are inclusion of capacitor banks, phase balancing, feeder reconfiguration of distribution system, etc. Among these, feeder reconfiguration helps to operate the distribution system at minimum cost and at the same time improves the system reliability and security. Network reconfiguration is the process of changing the topology of distribution system by altering the open/closed status of switches to find a radial operating structure that minimizes the system real power loss while satisfying operating constraints. This paper proposes an efficient algorithm based on Plant Growth Simulation Algorithm (PGSA), Greedy and Fuzzy. The optimization approach based on PGSA provides detailed description on switch states for calculation. The inclusion of Greedy improves the efficiency of optimization by reducing the number of load flow execution. In addition, heuristic fuzzy has been incorporated to handle constraints along with objective. With the use of proposed algorithm, the system loss has been reduced convincingly, composes proper loading at the branches and make up buses voltage within the limit and which provides solution under different conditions such as normal and abnormal conditions of the system. Furthermore, the solution algorithm is implemented through J2EE (Java 2 Enterprise Edition) architecture to reduce software couplings and to achieve software reusability. The effectiveness of the proposed approach is demonstrated by employing the feeder switching operation scheme to unbalanced standard 25- bus distribution system and modified IEEE- 125 bus distribution system.