Controlling a 4-wire PV-AF system in existence of unbalanced and distorted supply voltages

This paper presents a 4-wire photovoltaic power generation and active filter (PV-AF) system for local load supply and harmonic compensation with unbalanced and distorted supply voltage. In this work, the strategy received from instantaneous power theory formulations applied to unbalanced and nonlinear systems is analyzed. A study is carried out about its performance in compensation by means of two indices measured in the source currents after compensation: the source current total harmonic distortion (THD) value and the neutral current root mean square (rms) value. The control strategy using vectorial theory and a simple method for maximum power point tracking (MPPT) are proposed. The vectorail theory and simple MPPT method are used as reference current generator for PV-AF system that injects maximum available power of PV array and compensates load harmonics, reactive power and unbalance. Finally simulation is performed using PSCAD/EMTDC software, and results are presented to demonstrate effectiveness of the proposed.