Evaluation of Predictive Direct Current and Direct Power Control for Grid-connected PV Systems

Predictive control provides many advantages over conventional control techniques. Thus, in this paper, a comparative study between the predictive direct current control (PDCC) and predictive direct power control (PDPC) is investigated. The study focuses on applying these control strategies with renewable energy systems (RESs), especially photovoltaic (PV) ones. RESs are integrated with high penetration into the grid, and they must satisfy certain regulations to sustain the grid stability. The studied system consists of a PV array and boost converter followed by two-level inverter to enable the grid connection, where the maximum power point tracking (MPPT) function is accomplished by an adaptive step-size method. The adopted technique here is perturb and observe (PO) method. The control of active and reactive power is performed using PDPC and PDCC for the purpose of evaluation in terms of power quality, total harmonic distortion (THD), average switching frequency, implementation, calculation burden, etc. The system is validated by simulation results via Matlab platform under various operating conditions.