Design of Networked Microgrid's Control towards Power Coordination and Voltage - Frequency Regulation

One of the state-of-the-arts of smart grid system is the concept of networked microgrid that provides flexible integration and coordination of distributed renewable energy resources in multiple microgrids. However, due to the variable nature of renewable generations, load changes and grid contingencies, the system suffers from significant fluctuations of power, voltage and frequency. This paper seeks to present comprehensive converter control solutions for power sharing coordination and stabilization of voltages and frequency to ensure high power quality and reliability in a networked microgrid system regardless of its grid-connected and islanded modes of operation. The control solutions are provided in d-q axes for both active and reactive powers. The multilevel inverter topology that is designed to interface the distributed energy resources results in better suppression of output harmonics compared to that with a conventional 2-level inverter. The paper also features an interlinking algorithm framework of particle swarm optimization (PSO) to tune the control parameters for the optimized performance of converters. A prototype of grid-connected system of three microgrids is simulated in PSCAD platform to validate the efficacy of the proposed solution.