Implementation of Solar Photovoltaic System With Universal Active Filtering Capability

In this paper, a novel technique based on a second-order sequence filter and a proportional resonant controller is proposed for the control of a universal active power filter integrated with a photovoltaic array (UAPF-PV). Using a second-order sequence filter and sampling it at zero-crossing instant of the load voltage, the active component of the distorted load current is estimated, which is used to generate a reference signal for a shunt active filter. The proposed method has good accuracy in extracting a fundamental active component of distorted and unbalanced load currents with reduced mathematical computations. Along with power quality improvement, the system also generates clean energy through the PV array system integrated to its dc link. The UAPF-PV integrates benefits of power quality improvement and distributed generation. The system performance is experimentally evaluated on a prototype in the laboratory under a variety of disturbance conditions, such as point of common coupling voltage fall/rise, load unbalancing, and variation in solar irradiation.