Minimizing energy import cost for load demand with optimal penetration of renewable energy generation sources by using an efficient walrus optimization algorithm

This paper presents a novel and effective approach for determining the optimal penetration of renewable distributed energy resources (RESs) in radial distribution networks (RDNs), accounting for time-varying generation and consumption. The walrus optimization algorithm (WaOA), inspired by walruses' intelligent behaviors in the wild, is introduced to solve this optimization problem. Two different cases are conducted to evaluate the performance of the suggested algorithm. While the first case considers the connection of RESs solely to minimize power losses at peak load, the second case study uses a multi-objective function that accounts for economic and technical aspects. In that case, the main target is to minimize the electricity generation cost of the main power source and the total network power loss. By determining appropriate installation parameters of RESs, the reduction in losses amounted to 69.08% compared to the base network for the first case. In the second case, the cost of electricity purchased from the primary grid via the substation is reduced by 79.57%, and power loss is cut by 95.06% compared to the original network. In addition, the bus voltage improvement and branch congestion reduction are greatly enhanced, with the weakest voltage rising from 0.9090 pu to 0.9785 pu, and the largest branch current decreasing sharply from 387.1941A to 163.7125A. Moreover, the collected simulation results also prove the superiority of WaOA over other methods in addressing the above problem under the same conditions.