Dynamic performance analysis of a LC-filter grid-connected gas turbine under voltage-sag operation

The aim of this work is to analyze the dynamic behavior of a distributed generator based on gas micro turbine GMT using a grid-connected inverter with an output LC filter. In this paper, we focus, on what happen in case of disturbance on the network which induces a voltage sag on the output LC filter terminal. The proposed control strategy depends on the control of the output LC filter voltage with a resonant controller. We use a state feedback structure and pole assignment method to design the controller. Dynamic analysis was realized in case of a voltage sag operation caused by a three phase balanced default. The proposed control strategy is based on modification of the overall control system from a voltage control to a current control during a voltage sag occurrence. Real time simulations results have been discussed in the last part of this paper.