Small Signal Stablity Analysis in SMIB & 3 Machine 6 Bus System using GWO Optimization Technique

Abstract

A power system is a complicated network which has the task of fulfilling various consumer power demands continuously. But in its process too many disturbances occurs. These disturbances may be a common single line to ground fault, double line, double line to ground fault, three phase fault or it could be small signal disturbances. To eliminate it is utmost importance to resume the continuity of power supply which in turn ensures its reliability. Hence, a power system is always equipped some kind of controllers to come back to its original operating status after this disturbances. Here, a SMIB system more specifically a Modified Phillip-Heffron's model is presented which has Static Synchronous Series Compensator (SSSC) as the controller. To further improve its dynamic performance a nature inspired optimization technique is utilized. This is Grey Wolf Optimization (GWO). The system is tested for electrical power deviation, power angle deviation and speed deviation under two different cases. The first case is when reference voltage setting is increase by 5% step and the second case is the step increase of 10% in mechanical torque. The results of GWO based SSSC are compared and tabulated with SMIB without any controller and with Gravitational Search Algorithm (GSA) based SSSC. The further analyses consider the more real scenario of multi machine system (MMPS) which has 3 machine and 6 bus. It utilizes GWO based coordinated damping controller consisting of SSSC and PSS. This model is tested under different fault conditions as mentioned above and then its results are compared with MMPS without any controller and with conventional power system stabilizer (CPSS). For simulation both the above model of SMIB and MMPS MATLAB/SIMULINK is used.