Adaptive virtual resistance load sharing for resistive microgrids

This paper proposes an adaptive virtual resistance load sharing method in αβ frame, where the α-component of the virtual resistance is used to share the active power and the β-component of the virtual resistance is used to share reactive power. Using the proposed method for photovoltaic systems makes the active and reactive power sharing sensitive to the varying nature of the solar energy. It will be shown that the proposed adaptive active power sharing significantly reduces the energy required from a fossil-fuelled auxiliary generator. The proposed adaptive reactive power sharing reduces the reactive power exchanged with the auxiliary generator and the switching stress on each distributed generator's converter through, seamlessly, reducing the reactive power contribution of the units with higher active power contribution. This is all achieved without any communication between distributed generation units. Whilst the proposed method is also applicable on inductive microgrids, this paper focuses on a resistive microgrid since most microgrids are likely to be located on the low voltage side of the grid (where the network is mainly resistive). Different load sharing methods in a resistive microgrid are also categorized and briefly reviewed to justify the chosen approach in the paper. MATLAB/SIMULINK simulations are used to validate the proposed method.