An Adaptive Control Approach for Improved Power Quality and Power Ripple Mitigation in a Self-Synchronized Grid-Tied VSG

This article proposes an elevated adaptive integrated control strategy (EAICS) for a photovoltaic generator (PVG) integrated to three-phase grid-tied virtual synchronous generator (TPGTVSG) system to attenuate the harmonics in grid current and dampen the oscillations in power occurring due to the PVG dynamics. The proposed control strategy has a modified proportional resonant current (MPRC) controller with adaptive power control in a VSG technique. Furthermore, under distorted grid voltage conditions, the injected grid current harmonics are suppressed using a phase-corrected reference current (PCRC) generator, which also dampens the power and frequency oscillations during grid voltage swells and sags. Therefore, collaborating all three control techniques in EAICS control makes the system frequency more adaptive without using a phase lock loop (PLL). In addition to stabilizing the oscillations in power, the grid frequency is accomplished by appropriately adjusting the control coefficients using the VSG control loop. Therefore, this article adopts small-signal modeling of the VSG's control to scrutinize the influence of parameters perturbation on power and frequency. Finally, the system's response using the proposed EAICS control strategy is analyzed in MATLAB/Simulink and also validated experimentally using a laboratory prototype.