A New Framework for Microgrid Management: Virtual Droop Control

Microgrids can provide the most promising means of integrating large amounts of distributed sources into the power grid and can supply reliable power to critical loads. A generalized control framework is required to regulate microgrid voltage and frequency, maintain system stability, maintain power quality, and manage distributed generations. A microgrid control framework for power management and voltage and frequency regulation is proposed in this paper. The proposed method, virtual droop control, is described and formulated and compared with the existing natural droop control technique. Unit commitment algorithm has also been implemented to manage nonrenewable sources to improve the system efficiency. The proposed technique operates the microgrid at a constant voltage and frequency, and uses communication for power sharing. It also provides the means to operate the microgrid in case of lost communication and sabotage on communication network. The proposed method has been applied to Fort Sill microgrid and the modeling results have been compared with natural droop control technique. A laboratory setup, which consists of a 100 kW natural gas generator, 56 kWh Li-ion based battery with 250 kW inverter, and 100 kW load bank, has been built and tested. The results of the setup have been provided, which confirms the viability of the proposed technique.