Effect of partial loading on a three‐area hydro‐thermal system integrated with realistic dish‐Stirling solar thermal system, accurate model of high‐voltage direct link considering virtual inertia and energy storage systems

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 hydrothermal 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 List of Symbols and Abbreviations: ESS, energy storage systems; B i , frequency bias factor of ith area; FSDS, fixed speed DSTS system; ΔF i , frequency deviation of ith area; GRC, generation rate constraint; G, gate; GHA, grasshopper algorithm; HHO, Harris Hawks optimization; T ghi , mechanical governor time constant of ith area; K DSTs , T DSTS , gain and time constant of DSTS; K CESi , T CESi , gain and time constant of CES; K SMESi , T SMESi , gain and time constant of SMES; K RFBi , T RFBi , gain and time constant of RFB; K Psi , power system inertia gain of ith area; NS, not settled; US, under shoot; TF, transfer function; RDSTS, realistic DSTS; ΔP tiei-j , tie-power deviation of from ith to jth area; R i , speed regulation of ith area; T di1, T di2 , time constant of FSDS; i, area number (i = 1,2, and 3); T pi , power system time constant of ith area; T wi , hydro turbine time constant of ith area; T SCi , steam turbine time constant of ith area; T RH , reheater time constant; T ij , synchronizing coefficient from ith to jth area; T pi , power system time constant of ith area; T co , cross-over time constant; T gi , speed governor time constant of ith area; VSC, voltage source converter; AHVDC, accurate model of high-voltage direct link; OS, overshoot; ST, settling time; DSTS, dish-Stirling solar thermal system; BSA, bird swarm algorithm.

Chaotic butterfly optimization algorithm based cascaded PI‐TID controller for frequency control in three area hybrid microgrid system

“…LFC for the conventional system has been researched substantially and some of the recent good works are available in References 7–13. FPIDN‐FOPIDN controller, optimized for LFC in an interconnected system comprising of the thermal and thermal hydro gas system 7 .…”

“…Frequency excursions due to the presence of RE in conventional power system is less detrimental as compared to microgrid because the former has comparatively higher inertia. Further, frequency/voltage regulation of multi‐area power systems have been researched recently considering realistic a dish Stirling solar thermal plant, 9 virtual inertia, 10 electric vehicle, 11 several energy storage units, 12 redox flow battery 13 . The performance of the control strategies considered in these works has been satisfactory.…”