“…Frequency and voltage control, as well as power sharing, are presently challenging topics in autonomous (islanded or stand-alone) MGs, thus requiring advanced control techniques, with robust control design being an illustrative example. Among powerful robust control design frameworks, the H ∞ approach is perfectly suited for offering the required flexibility in order to generally guarantee robustness to parameter uncertainties [3], [4], [5], [6], [7], [8], [9], [10], [11], topology changes [7], interaction dynamics [7], [12], system inertia and damping property uncertainties [9], [10], wide range of MG operating conditions [10], measurement noise [3], [10], dynamics of phase-locked loop with measurement delay [10], as well as robust rejection of disturbances originating from all types of source and/or load variation, including RES generation [9], [10], [13], [14], possibly nonlinear and/or unbalanced loads [6], [11], [12], [13], load harmonics [11]. H ∞ techniques may be successfully combined with some other well-known controller designs -e.g., droop characteristics improved by integrating power derivative and integral terms [3], multiple droop control [7], decentralized static output feedback technique [13], mixed-sensitivity optimization [3], [4], [5], [8], [12], [14], virtual-inertia-injection technique [9], [10], loop-shaping metho...…”