A Seamless Control of Grid-Connected PV System for Alleviating PV Penetration in Rural Grid Using Supercapacitor Accompanying With DSTATCOM and Improved CTF Control

Increased photovoltaic (PV) penetration in the remote power grid reduces system inertia and brings severe grid instability resulting in the deterioration of power quality. Thus, a high-performance control and system topology is required to ensure smooth operation. Hence, a two-stage grid-tied PV topology is proposed in cooperation with the distribution static compensator and supercapacitor (SC) in a common dc-link. The system is also equipped with a unified control scheme. The improved character triangular function innovated with an enhanced second order generalized integrator prefilter-phase locked loop (ESOGIPF-PLL) is presented to estimate reference grid currents by extracting active fundamental components of nonlinear load currents. In anomalous grid situations, the ESOGIPF-PLL elicits positive sequence components of grid voltages and permits a precise estimate of unit templates (UTs). Under varying circumstances, these UTs maintain sinusoidal and balanced grid reference currents. An adaptive sparrow search algorithm tuned fractional order tilt integral derivative controller is developed to manage the dc-link and grid voltage associated with PV feed-forward compensation for adapting PV input dynamics. To enhance the frequency response, the SC voltage is adjusted in accordance with the grid frequency deviation. The proposed control improves the system response to noise by mimicking the inertia response of traditional generators without the need for frequency derivative. The efficiency of the devised control approach for the proposed system is verified using MATLAB and the OPAL-RT real-time simulator test bench.