Stability of metaheuristic PID controllers in photovoltaic dc microgrids

This article presents the stability assessment of metaheuristic PID controllers in the hierarchical control system of photovoltaic DC microgrids. Stability is a critical aspect of DC microgrid systems. PID controllers are utilized at the primary, secondary and tertiary control levels of the DC microgrid’s hierarchical control system. Tuning of multiple PID controllers using traditional methods such as Ziegler-Nichols and Cohen-Coon tuning techniques becomes challenging under dynamic conditions of photovoltaic DC microgrids. Metaheuristic optimization algorithms are used to construct self-tuning PID controllers with improved stability. Experiments are performed to assess the stability of PID controlled system. Results exhibit that metaheuristic-tuned PID controllers of photovoltaic DC microgrids achieved superior performance in comparison with the traditional methods.