Contents I. Introduction
With the aggravation of environmental pressure and energy crisis, using renewable energy sources, such as photovoltaics and wind turbines, becomes an effective and popular approach [1]–[4]. Unlike the traditional synchronous generator, inverters have no rotating mass to provide inertia support of systems [5]. With the penetration of renewable energy sources in microgrids, the characteristics of lack of inertia are prominent [6]. The microgrid is prone to power and frequency oscillations and even results in collapse [7].
