An Improved Immune Genetic Algorithm for Distribution Network Reconfiguration

On the basis of analyzing the insufficiency of genetic algorithm in the solution of distribution network reconfiguration, an improved immune genetic algorithm (IIGA) is proposed. The key of IIGA lies in the construction of vaccine pool and the design of immune operator. The vaccine pool can be created and updated automatically, and the immune operator consists of vaccination and immunoassay. In addition, the encoding method based on the fundamental loop, hyper-mutation and tournament selection operator with big selection pressure parent-offspring competition are adopted. Simulation results of IEEE 33-bus system and IEEE 69-bus system show that IIGA conforms to the feature of distribution network reconfiguration and can effectively restrain both degeneration and fluctuation phenomena during the evolution; it possesses fast convergence speed while the quantity of the solution is ensured. Comparing with traditional genetic algorithm (CGA) and allied algorithms in related literatures, IIGA promises excellent performance not only in convergence speed but also in quality of solution.