Improved frequency regulation in mini-grids with high wind contribution using online genetic algorithm for PID tuning

Mini-grids with high wind contribution tend to be relatively more dynamic and less stable than wind integration in large interconnected grids. This instability is primarily due to frequency fluctuations introduced from highly variable wind generation, multiple single-phase distribution branches with highly unbalanced single-phase loads, large pseudo-instantaneous changes in load, over compensation of reactive power, and lower machine inertias providing less damping. The objective of this research is to investigate the use of a genetic algorithm (GA) based proportional integral derivative (PID) diesel speed controller to improve frequency regulation in standalone high contribution wind-diesel mini-grid systems. A dynamic model of a standalone high contribution wind-diesel system was developed to study frequency regulation under variable wind and load conditions. The results using GA-based PID diesel speed control demonstrate improved frequency regulation as compared to standard diesel speed controls.