A Multifunctional Grid-Tied Solar Energy Conversion System With ANF-Based Control Approach

This paper presents a two stage three-phase grid-interfaced solar photovoltaic (SPV) energy conversion system with an adaptive notch filter (ANF)-based control algorithm. The proposed SPV system is a multifunction grid-interfaced SPV energy conversion system, which along with the conversion of dc-power from SPV to ac mains is capable of reactive power compensation, harmonics currents elimination, and load balancing in a three-phase ac distribution system. Compared with multiple devices with different functionalities, a multifunction grid-interfaced SPV energy conversion system is capable of saving substantially capital investment, space, and maintenance cost on behalf of multifunctional features. The ANF successfully extracts a single sinusoid of a possibly nonstationary nature from harmonics corrupted load currents at point of common coupling. The control algorithm is adaptive with respect to the fundamental frequency of the system as compared with other methods, and provides instantaneous values of the fundamental signals. Simulation and experimental results verify the validity of the presented algorithm and confirms its desirable transient and steady state performances. The total harmonics distortion of grid currents is found well under IEEE-519 standard, even under nonlinear loads.