A novel I-PDF controller for LFC with AC/DC Tie-line

Abstract

This paper deals with the LFC (load frequency control) of two area power system. The two areas comprise of thermal-gas and thermal-hydro system. Later the standalone wind turbine system (WTS) is incorporated in area-1 and its variability impact on power system dynamics is studied. As HVDC tie-lines are considered as DC capacitors, this paper utilizes stored energy in HVDC tie-line to surpass the system dynamic performances. For that purpose, a virtual inertia based capacitive energy storage (CES) is incorporated in the system. The overall system is investigated in the presence of proportional (P)-integral (I)-derivative (D) controller with filter (F) i.e. PIDF controller and new I-PDF controller. To optimize the controller gains a metaheuristic Sine Cosine Algorithm (SCA) technique is adopted. Further sensitivity analysis is performed by variation in system parameters like thermal turbine and reheat turbine time constant to analyze the robustness of SCA based I-PDF controller.