Ant algorithms for the optimal restoration of distribution feeders during cold load pickup

The ant colony algorithm is a new technique for combinatorial optimization borrowed from swarm intelligence. This paper outlines an ant colony algorithm to compute the optimal order of restoring sections in a power distribution system. Restoration of distribution feeders after long interruptions creates cold load pickup conditions due to loss of diversity among the loads. The distribution system load may have to be restored step-by-step using sectionalizing switches under such conditions to prevent overheating of substation transformer. The restoration time is dependent on the order in which sections are restored. Results obtained using this method for two test cases are presented including a comparison with the simulated annealing algorithm.