Design and Expansion Planning of Parallel Inverter Based AC Microgrids - An Approach for Improved Stability Margins

and expansion planning of an inverter based autonomous AC microgrid. The objective is to find out ideal location for placement of additional components which can include new inverter-based sources, microgrid damping controller, etc., ensuring sufficient stability margins. These objectives are achieved by first identifying the weakest and the strongest nodes in the system with respect to the system stability and then observing the effects of choosing various nodes for design and expansion on overall system stability. The weakest and the strongest nodes are identified
using the impedance based stability analysis of the microgrid by dividing the system in various possible partition points while the impact of choosing different locations on stability is analyzed by eigen value analysis as well as time-domain MATLAB/Simulink simulations and experimental results.