Minimal Losses Based Optimal Voltage Control Scheme for VSC-HVDC Grids Systems

This paper proposes a method to find the optimal control scheme in the AC / DC converters considering the criteria of adjustment of voltage set points and the k-droop coefficient of each converter, with the objective of reduction losses in a HVDC grid. The differential evolution method is used for this optimization. To do this the control strategies and their characteristics is explained for each option of control system. The selection of the voltage control station (slack) is described together with the algorithm of selection of optimal voltage control scheme and the algorithm of optimization of voltage set points. Also, the CIGRE B4 DC grid test system benchmark is tested in steady and dynamic simulation to determine the advantages of the selected optimal control scheme and verify that the system maintains the stability when a fault has occurred.