Optimal Fractional UPFC Based Damping Action for Variable Solar Penetration

Enhancement of dynamic stability of UPFC Fractional lead-lag (FOLL) has been proposed for this present work. Multimachine system with solar integrationhas been experimented with step and discrete variation in solar power, with different operating condition of generators. A multi-objective modified DE has been takenfor tuningparameters of FOLL. The variation in speed observed with respect to local oscillations subject to three generators and eigen distribution being observed. The performance of proposed FOLL-UPFC controller is found to be better than only UPFC control action and performance of modified DE is superior to conventional DE & PSO. In this work sudden and random variation in solar sources have been implemented and the observations show that due to the variation in these solar penetrations power system oscillations are further excited. Proposed control action which is MDE tuned FOLL-UPFC can provide better damping torque as compared to only UPFC action. From the present study it has been observed that the closed loop system performance with fractional UPFC control action is much enhanced in comparison to conventional UPFC based lead lag control action. The oscillations due to random solar penetrations are heavily damped in proposed control action thereby enhancing oscillatory stability by a large extent.