Integration and Control of Renewable Energy-Based Rural Microgrids

The world energy system is slowly turning toward renewable energy resources. The concepts of distributed generation and microgrids are into implementation but still in the deliberation phase. The benefits of a small power system are its cost, easy installation, integration of renewable with non-renewable energy sources, and switching between on-grid/off-grid modes. Renewable energy-based microgrids have the main challenges of maintaining their frequency-voltage characteristics and the system becomes more complex when they are interconnected. These sources being intermittent in nature need to be supported by other resources like diesel/biogas-based system such that at time of small variation in load or natural sources (wind/solar), the power requirement is met through the support provided by diesel/biogas-based systems. Also, the controller should be fast enough to minimize the changes such that the system reaches a steady state. In this paper, renewable-based rural microgrids consisting of Wind, Solar, and Biogas are modeled and interconnected through the Low voltage DC line. Control approach has been developed in such a way that whenever there is a disturbance in the system due to an increase/decrease in load or input to the renewable energy sources the biogas-based system of individual microgrid increases/decreases its generation to support the system requirement. No extra power is drawn through the interconnecting network. Modeling of the system and its dynamic Study has been carried out in Matlab/Simulink.