Three-phase grid-connected photovoltaic system with SVPWM current controller

Effective control strategies for reliable photovoltaic (PV) grid-connected systems are needed to efficiently use solar energy, an abundant and clean renewable energy source. A space vector pulse width modulation (SVPWM) has been widely applied in the current control of three-phase voltage source inverters (VSIs). The control strategy combines a constant voltage tracking method for the variable photovoltaic power with SVPWM-based proptional-intergral (PI) current controller in a single stage three-phase PV grid-connected system. The controller mimics deadbeat control in the synchronous d-q reference frame, and is very simple and robust to implement. With the necessary grid voltage detection in Photovoltaic systems for protection, grid harmonics disturbance is effectively suppressed through feed-forward compensation. The simulation results show that the current controller makes the PV grid-connected VSI output current to be in phase with the grid voltage and has an excellent steady-state response as well as an extremely fast dynamic response.