Improved power control bandwidth of grid-forming sources in a CERTS microgrid

Grid-forming sources allow islanded operation of microgrids by providing closed-loop regulation of the microgrid voltage and frequency. Dynamic control of the voltage magnitude and frequency around their rated values provides the means for balancing the reactive power and real power using CERTS droop algorithms. Power-regulating algorithms are also applied to constrain operation within the power limits of each source, but the power regulation bandwidths are typically low because of low system damping. The limitations to increasing the power regulation bandwidth are derived, and two methods for increasing the bandwidth are introduced using either active damping or loop-shaping techniques. A combination of analysis and experimental verification are used to demonstrate the effectiveness of these techniques for raising the power control gains in order to increase the power regulation bandwidth without degrading microgrid stability.