A modified sine cosine algorithm with ensemble search agent updating schemes for small signal stability analysis

Abstract

In this paper, a modified sine cosine algorithm (MSCA) is proposed and is applied to design the power system stabilizer (PSS) and lead lag compensator-based static synchronous series compensator (SSSC) controller to enhance the power system stability. Two test systems: single machine infinite bus (SMIB) and multi-machine power system (MMPS) working under various loading conditions are taken as case studies. The objective of the work is to enhance the stability of the system by minimizing the rotor speed deviation of the generator. For this, the optimal controller parameters of PSS and SSSC are determined by using the MSCA technique. In the proposed MSCA method, two newly proposed search agent updating schemes (ie, SCA/rand-target and SCA/best-target) with parallel use of sine, cosine operators have been ensemble to generate the new search agents. The proposed MSCA method combines the exploration property of SCA/rand-target search agent updating scheme with exploitation property of SCA/best-target search agent updating scheme, which enhances the chances of attaining the near optimal solutions in fewer generations. The simulation results obtained from the proposed MSCA method have been applied on the two test system configurations of power system, which shows significant reduction in oscillations as compared with some well-known heuristic algorithms. The mean rotor speed deviation achieved using the proposed method for SMIB system and MMPS is 0.0013858 and 0.00046857 pu, respectively. Extensive statistical analysis on obtained results using Wilcoxon signed rank test, and Friedman and Nemenyi hypothesis test ensure the reliability and robustness of the proposed method.