Stabilization of DC-link voltage is indispensable for the satisfactory operation of three-phase electronically coupled photovoltaic (PV) system. Practically, a challenge is to promptly and effectively settle the DC-link voltage with minimum peak magnitude and settling time to its pre-disturbance level when exposed to disturbances in the load and solar insolation level. The classical methods of DClink voltage stabilization employ a proportional-plus-integral (PI) compensator, and its gain coefficients are modulated through a cumbersome trial-and-error approach. Nevertheless, this approach does not yield superior results, especially under the wide interruptions in operating conditions due to nonlinear and timevarying characteristic of the PV module. These concerns have resulted in the emergence of multiple meta-heuristic techniques to optimally tune PI compensator gain coefficients. Nevertheless, most of these methods call for the ingrained paradox between computational efficiency and dynamic performance. Driven by this drawback, a proposal based on grey wolf optimizer (GWO-PI) is described in this paper to serve the following control targets: (a) be able to improve harmonic filtering with computational effectiveness, and (b) to ensure superior performance under exposure to interferences in the load and solar insolation level. Good agreement in MATLAB/Simulink simulation studies and experimental evaluations establish that the proposed GWO-PI outperforms the existing standardized optimization techniques such as particle swarm optimization (PSO-PI) and gravitational search algorithm (GSA-PI) in aspects of peak magnitude and settling time. Besides, it practically enables an improved harmonic filtering LIST OF SYMBOLS AND ABBREVIATIONS: K p , proportional gain coefficient of PI-controller; K i , integral gain coefficient of PI-controller; i LR , i LY , i LB , load currents; i L0 , zero-sequence component of the current; i Lα , i Lβ , i L0 , stationary reference frame currents; i Ld , active current component; i Lq , reactive current component; φ, grid voltage phase-angle; i * dc , d-axis reference current; i dc , DC-link VCL output; i Ldh , load harmonic current; i α , i β , i 0 , reference compensating currents; i Cα , i Cβ , i C0 , actual compensating current; V DC , measured DC-link voltage; V DCref , reference DC-link voltage; E SS , steady-state error; O f , objective function; M p , peak magnitude; T s , settling time; α, alpha; β, beta; δ, delta; ω, omega; D !