Optimal configuration of underground cables to maximise total ampacity considering current harmonics

This study presents an efficient algorithm to find optimal underground cable configuration with maximum ampacity in a concrete duct bank. The current´s harmonics and its effects on the sheath losses are considered in the proposed algorithm. To find the optimal configuration of the cables in the duct bank, two heuristic optimisation methods are applied: the first algorithm is the well-known particle swarm optimisation (PSO), and the second one is the shuffled frog-leaping algorithm (SFLA) which has attracted considerable attraction in recent years. The objective function of these methods which has to be optimised is total ampacity. Calculating the total ampacity for a required configuration by using PSO/SFLA is a convex optimisation problem. The interior point method is utilised to solve this problem. The proposed method has been implemented on four test cases to show the importance of considering the current harmonics in determining the optimal configuration. To evaluate the performance of the PSO and the SFLA, the obtained results are compared in different test cases.