Control strategy for inverter based micro-grid

Demand for electricity is ever increasing. In order to balance the growing needs, distributed generation (DG) can help to a large extent. Micro-grids (MG), mainly inverter based, are gaining more and more importance as they can accommodate various types of DGs effectively and for their superior power quality. A MG can be operated in two modes, grid connected and islanded mode. Each mode has its own control strategy. In this paper a control strategy for inverter based MG which can ensure stability and proper power sharing among the inverters, in islanded mode, is proposed. In a MG, the output impedance of inverter can have much impact on load sharing of inverters. The proposed control scheme uses second order general integrator in conjunction with indirect operation of droop method, to enhance the stability and power sharing in MG.