A rule-based approach for improvement of autonomous operation of hybrid microgrids

The work presented in the article proposes a new rule-based energy management algorithm to improve the autonomy of hybrid (AC/DC) microgrids consisting of higher quantum of heating loads and renewable energy sources. The objective of the algorithm is to make the microgrids more autonomous by reducing the power import from the utility grid, during generation deficits. The heating or lighting loads in this work are considered as non-critical loads, and all other voltage sensitive loads are classified as critical loads. The presented strategy makes the AC and DC non-critical loads operate in power saving modes during generation insufficiency by controlling the electric springs based on the voltage produced by the renewables. Usage of electric springs in the microgrids consisting of AC and DC loads and a couple of renewable sources to improve the autonomous operation of microgrids is probably the first attempt. The advantage of using the suggested methodology is that it operates the voltage insensitive loads, based on the prevailing power generation condition without completely curtailing them. Further, the effectiveness of the algorithm is tested by developing suitable simulation models in MATLAB and also a scaled down laboratory setup is developed using dSPACE 1104 real-time operating system. The simulation and experimental results prove that the algorithm is effective enough in reducing the power import from the main grid.