A VNS algorithm for the design of supplementary damping controllers for small-signal stability analysis

•A VNS algorithm for the design of the PSS and IPFC-POD controllers.•Efficient local improvement strategy based on the Fibonacci search.•Comparison of the VNS algorithm with a multi-start method.•Analysis of the efficiency of the controllers for inserting damping to the system.

This paper presents a variable neighborhood search (VNS) optimization algorithm for the design of the parameters of supplementary damping controllers: power system stabilizers (PSS) and the interline power flow controller-power oscillation damping (IPFC-POD) set. The objective is to insert damping to local and inter-area oscillation modes in multimachine power systems. The electric power system dynamics is represented by the current sensitivity model. Simulations were carried out using three systems: a test system known as Two-Area Symmetrical and two real systems, the New England and the Reduced Southern Brazilian. The VNS method was compared with a multi-start algorithm in terms of performance, showing better convergence rates. The proposal was also able to obtain solutions with high damping levels, that showed to be robust when changes on the operating point of the power system were considered. Finally, it has been verified that the PSS controllers were effective for damping the local mode oscillations, while the IPFC-POD set operated mainly damping the inter-area modes.