FACTS Placement For Reactive Power Planning With Weak Node Constraints Using An Improved Symbiotic Search Algorithm

Abstract

In this paper, an Improved Symbiotic Organisms Search (ISOS) algorithm is proposed for effective Reactive Power Planning (RPP) as an Optimal Power Flow (OPF) issue on an IEEE 57 bus network. The objective of the work is two-fold: to reduce the energy loss and to enhance the voltage profile within the prescribed limit by ensuring the economic operation and reduced investment cost of Flexible AC Transmission Systems (FACTS) in the system. Furthermore, the optimal position of FACTS is determined by including the existing system controlling variables like reactive power generators output, transformer tapping, and capacitors connected at shunt. Here, two FACTS devices, Static Var Compensator (SVC) and Thyristor-Controlled Series Controller (TCSC), have been taken into consideration. The power flow method is used to determine the optimal positions for SVCs and TCSCs. The performance of the ISOS algorithm is compared with that of three other state-of-the-art optimization techniques: Symbiotic Organisms Search (SOS), Differential Evolution (DE), and Teaching-Learning-Based Optimization (TLBO). The ISOS algorithm yields a significantly more economical system than other algorithms applied for RPP. Non-parametric tests such as the Signed test, Wilcoxon signed rank test, and Friedman test is conducted for statistical analysis to investigate the superiority of the ISOS algorithm over other techniques. © 2023 by the authors.