ADVANCED CONTROL OF A THREE-PHASE VOLTAGE-SOURCE INVERTER CONNECTED TO THE GRID VIA A RESONANT LCL FILTER

Abstract

This master thesis focuses on the modeling and advanced control of a three-phase pulse-width modulated (PWM) voltage source inverter connected to a stiff electrical grid via a resonant LCL filter. The work includes system modeling in various coordinate frames, analysis of resonant phenomena within the LCL filter, and the implementation of both passive and active damping techniques. Special attention is given to the design of a cascaded control structure based on the regulation of the square of the DC-link voltage and the vector control of the grid current using a phase-locked loop (PLL).