Implementation of Improved Mixed Droop Technique With Sliding-Mode Control for Active Power Distribution in a Grid-Interactive Microgrid

In this article, we introduce an active power distribution scheme for a grid-interactive hybrid microgrid system. To address the effect of climatic change on power generation from renewable energy sources, a combined energy storage unit (CESU) consisting of both battery and supercapacitor is employed in this study. An improved mixed droop technique (IMDT) is designed in this article to split the total power requirement in the microgrid into transient and average components for smooth power handling by the CESUs. A robust sliding-mode nonlinear controller (SMC) is implemented instead of the conventional propotional integral (PI) controller for the switching regulation of the dc/dc bidirectional converters connected across the CESU. Hence, a hybrid control algorithm is developed in this article by combining both IMDT and SMC for the distribution of active power among solar photovoltaic (PV), combined storage units, utility grid, dc load, and both linear and nonlinear ac loads. The performance adaptability of the proposed method is supported by both MATLAB simulation results and the results taken from laboratory-developed prototypes.