Design And Analysis Of An Integrated Dq-Frame Control Strategy For Three-Phase Grid-Connected PV Systems

Abstract

To enhance the grid integration of single-stage, three-phase photovoltaic (PV) systems, this paper proposes a robust dq-frame control scheme for independent and precise regulation of active and reactive power. The proposed control algorithm generates reference currents directly from the desired active power (P) and reactive power (Q) power commands, which are then tracked by a dedicated current control loop to ensure fast dynamic response and improved stability under grid disturbances. When local loads are connected at the point of common coupling (PCC), the control strategy enables effective sharing of active and reactive power between the PV inverter and the utility grid according to predefined references, thereby maintaining voltage stability and reliable power delivery. In addition to basic power injection, the framework supports flexible power factor control for grid support and reactive power compensation. The paper presents the formulation of reference current generation, controller design, and grid synchronization methodology. MATLAB/Simulink simulation results validate the effectiveness of the proposed approach in terms of fast response, accurate power tracking, and enhanced operational reliability.