Microgrid Voltage Control with On-Line grid Parameters Estimation

In this paper, we propose a controller that regulates the output voltage at the point of common coupling in a microgrid. This controller has the ability to estimate the grid parameters on-line to ensure good regulation results. We deal with a system composed of a voltage source inverter (VSI), an LC filter, a coupling inductor and a resistive load. The main goal is to enforce the output voltage to track a given reference using the backstepping technique. For the grid parameters estimation, we use a method based on the variation of the active and reactive power injected by the VSI in the main grid. The simulation results and formal analysis show that the output voltage tracks perfectly the reference voltage with a global asymptotic stability. Furthermore, the estimated values of the grid parameters are equal to their real values. The simulations have been carried out under different conditions in both microgrid modes: grid connected and islanded.