Simplified active power and reactive power control with MPPT for three-phase grid-connected photovoltaic inverters

This paper presents the simplified active power and reactive power control with the maximum power point tracking (MPPT) for three-phase grid-connected photovoltaic (PV) inverters. With the proposed control strategy, the perturbation and observation method is used for the simple MPPT algorithm and the current command on the rotating reference frame is regulated by the feedback and feedforward controller. In order to guarantee the all maximum power is transferred to the grid, the d-axis current or active power command is calculated from the PV power. Moreover, the design guidelines of phase-locked loop (PLL) and current controller are also presented. Validity of the proposed grid-connected inverters is confirmed by simulation.