Today's power system continues to expand exponentially due to extensive automated need for both domestic and industrial needs. The expansion of power transmission networks is limited due to environmental right of way and economic reasons. The ever growing demand of power system network has resulted in rotor angle oscillations and voltage instability. It is precisely due to the inability to generate the required reactive power and real power control that propounds the cause of voltage collapse and rotor oscillations. Therefore it is time to focus on the use of the shunt reactive compensation devices to alleviate this issue of voltage stability and series reactive compensation devices to improve the rotor angle stability. Flexible AC Transmission Systems (FACTS), which have recently been developed in power electronics, can make it easier to control the flow of power, boost power transfer capabilities, lower the cost of generating, improve security, and enhance the stability of power systems. The growth of large interconnected power systems demands faster response to maintain stability. Therefore it is also necessary to develop computationally intelligent controllers based FACTS devices for faster and more accurate control action. The objective of this paper is to analyses stability enhancements in power system networks by FACTS devices like GCSC and TSSC. In this work small signal stability and transient stability analysis of the above FACTS devices are investigated. From the analysis it is proved that TSSC is the best FACTS device for transient stability enhancements.

Every day, power piques our curiosity more and more. As a result, there is a quick power exchange that creates challenging power transmission issues as well as a stampeded increase in booked power that flows through the transmission line. Building more transmission lines or boosting the load capacity of the ones that already exist can remedy this issue. The cost-effectiveness of constructing new lines enables the proper positioning of (FACTS) devices to address this problem. This study suggests the artificial bee colony (ABC) algorithm and genetic algorithm as a method for selecting the ideal site and size. In this attempt, three objectives were taken into consideration. They are reducing installation costs and increasing system capacity to handle load and transmission loss. Transmission loss and costs Putting and sizing the FACTS devices in the ideal locations to minimize real power loss (PL), improve the voltage profile (VD), and boost voltage stability are just a few examples of modern nonlinear mathematical problems that can be solved using the objective of ABC and GA method. The findings demonstrate that power flows are greatly improved, and a higher voltage is generated. In electrical networks, voltage control and power loss reduction should be carried out as effectively as feasible. A novel method is presented to locate FACTS devices in a multi-machine power system optimally using ABC and Genetic Algorithm (GA). The recommended course of action using the optimization techniques and accounting for the temperature and voltage restrictions as well as to accurately assessing the number of devices and their ratings were discussed. The proposed technique is examined for use on the IEEE 5 and IEEE 14-bus systems, and it is determined that ABC is superior to GA optimization for loss reduction.