Recent investigations indicate that relatively high integration of inverter-based distributed generators (DGs) and renewable energy sources (RESs) have some negative impacts on the power grid performance, dynamics and stability. Future power grids face new technical challenges arising from the increasing penetration of power-electronic-connected loads and DGs via the Microgrid (MG) concept. These impacts may increase at the expected penetration rates over next several years. An important source of these impacts is the reduction of the overall inertia. Compared to conventional power systems with bulk power plants, the modern power grids with DG/RES units have less rotating mass and damping property, as inverter-based resources increasingly replace synchronous generators. Reduced rotational inertia in the grid, in particular, erodes frequency, voltage and system control and leads to degraded performance of traditional control schemes. Indeed, increasing inverter-based resources drive the need for additional regulation solutions and ancillary control services. This speech presents a thorough understanding of the control challenges in low-inertia power grids penetrated by numerous DGs/RESs and MGs. Probable solutions and new synthesis perspectives will be also addressed.
