Power control for grid connected applications based on the phase shifting of the inverter output voltage with respect to the grid voltage

• A new control strategy for grid connected system has been described and developed.
• The control strategy is based on phase shifting of Vinv with respect to the Vgrid.
• The strategy requires few ma to achieve a high PF > 0.99 over wide range of Iout.
• A digital implementation on FPGA platform.
• Validation of simulation results by experimental tests.

In photovoltaic (PV) systems connected to the grid, the main goal is to control the power that the inverter injects into the grid. According to the grid demands, injected power does not only include the control of the active power, but also the control of the injected reactive power. This paper presents, a digital control strategy based on the phase shifting of the inverter output voltage with respect to the grid voltage, in order to control the power factor with a minimum number of Digital Sinusoidal Pulse Width Modulation (DSPWM) patterns and for a wide range of the inverter output current. This proposed method has been described, simulated and validated by experimental results.The proposed control strategy requires few hardware and computational resources. As a result, the inverter implementation is simple, and it becomes an attractive solution for low power grid connected applications.