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 anddistorted supply voltage. In this work, the strategy received from instantaneous power theory formulations applied to unbalanced and nonlinear systems is analyzed. A study iscarried out about its performance in compensation by means of two indices measured in the source currents aftercompensation: 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 simplemethod 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 compensatesload harmonics, reactive power and unbalance. Finally simulation is performed using PSCAD/EMTDC software, and results are presented to demonstrate effectiveness of the proposed.

Keywords:

active power filter (APF) , current harmonic , flexible distributed generation (FDG) , vectorial theory , photovoltaic (PV