Research ArticleMulti-Input Single Output SSSC based damping controller design by a hybrid Improved Differential Evolution-Pattern Search approach

•A novel MISO controller is proposed for the SSSC based damping controller.•Hybrid improved DE and PS approach is applied to optimize the controller parameters.•Control parameters F and CR are varied during optimization runs in improved DE.•Both Single Machine Infinite Bus and multi-machine power systems are considered.•Superiority of proposed design approach is shown by comparing some published approaches.

In this paper, a hybrid Improved Differential Evolution and Pattern Search (hIDEPS) approach is proposed for the design of a PI-Type Multi-Input Single Output (MISO) Static Synchronous Series Compensator (SSSC) based damping controller. The improvement in Differential Evolution (DE) algorithm is introduced by a simple but effective scheme of changing two of its most important control parameters i.e. step size and crossover probability with an objective of achieving improved performance. Pattern Search (PS) is subsequently employed to fine tune the best solution provided by modified DE algorithm. The superiority of a proposed hIDEPS technique over DE and improved DE has also been demonstrated. At the outset, this concept is applied to a SSSC connected in a Single Machine Infinite Bus (SMIB) power system and then extended to a multi-machine power system. To show the effectiveness and robustness of the proposed design approach, simulation results are presented and compared with DE and Particle Swarm Optimization (PSO) optimized Single Input Single Output (SISO) SSSC based damping controllers. It is observed that the proposed approach yield superior damping performance compared to some approaches available in the literature.