Effect of partial loading on a <scp>three‐area hydro‐thermal</scp> system integrated with realistic dish‐Stirling solar thermal system, accurate model of high‐voltage direct link considering virtual inertia and energy storage systems
Sanjeev Kumar Bhagat, Lalit Chandra Saikia, Naladi Ram Babu
Abstract
This article presents the studies of automatic generation control (AGC) on a three-area hydro-thermal system under various loading conditions. The study at various loading conditions is investigated because the model parameter of steam and hydro depend on their generation schedule. A maiden attempt has been made to design a three degree of freedom tilt integral derivative (3DOF-TID) controller as a secondary controller. Its gains are optimized using a novel bird swarm algorithm (BSA). Comparison of dynamic responses in a hydro-thermal system with the proposed 3DOF-TID reveals better performance over 2DOF-TID, 2DOF-PID controllers. It is also explored that the dynamic system responses are improved in thermal power plants and deteriorate in the hydropower plants when loading increases from its nominal values. Moreover, the dynamic system responses are analysed with the realistic dish-Stirling solar thermal system (RDSTS) considering fixed and random solar insolations. The comparative analysis suggests that RDSTS with fixed insolation enhances system dynamics by 5.72% over random insolation. Further, the comparison of dynamic responses of the system with AC tie-line and parallel AC/accurate high-voltage direct (AHVDC) tie-lines reveals that the system dynamics are improved with the parallel AC/AHVDC tie-lines. Furthermore, the inertia is emulated in the parallel AC/AHVDC tie-line using capacitive energy storage (CES), super magnetic energy storage (SMES) systems, and redox flow battery (RFB). Simulations show that the inertia emulated hydro-thermal-RDSTS system with RFB provides better dynamics. Sensitivity analysis suggests that 3DOF-TID parameters values at nominal condition are appropriate for higher value of disturbance without need for optimization.