Optimal Power Sharing and Black Start Procedure in Photovoltaic Energy-Based Microgrids

Nowadays, the use of photovoltaic energy-based systems as distributed generation facilities in the operation of microgrids has been increasing considerably. This entails some issues that must be considered when maintaining the microgrid parameters within suitable values owing to the inherent intermittency and variability of the solar energy throughout the day. Hence, a well-selected and designed control strategy allows the improvement of the dynamic performance by accomplishing the control tasks and maintaining the voltage and frequency within suitable levels, as well as reducing power losses, where it is also important to consider proper power sharing among the grid-feedings by covering the needs of the connected load. In this paper, an optimization method is employed in a Hierarchical Control Structure to optimally distribute the power supplied by photovoltaic energy-based grid-feedings, which allows obtaining the minimal generation cost. A passivity-based control strategy is developed at the primary control level, and the black start procedure for microgrid performance in simulation is obtained. As part of the validation method, the models used in the simulation results consider all the system dynamics to show the detailed response with the operation scenarios.