Bounded Voltage Regulation in a Direct Current Microgrid Using Barrier Lyapunov Function With Uncertain Load Current

A distributed control methodology for steady-state voltage regulation, along with a bounded transient response in a Direct Current (DC) microgrid, is proposed in this letter. The idea of asymmetric barrier Lyapunov function (ABLF) is used in realizing the prescribed constraints on the voltage magnitudes while considering the uncertain nature of the load current. By proposing a suitable load current estimator, we show that the voltage regulation is achieved within prescribed limits, and the closed-loop system remains stable under the proposed controller. We also obtain explicit bounds on the voltage and current errors, virtual controller, and estimated load current in the post-design analysis. Simulations illustrate the theoretical findings and the robustness of the proposed scheme to load perturbations.