Impact of Converter-Interfaced Generators on Power System Stability

In recent years, electric power systems have experienced a significant transformation characterized by an increased penetration of Renewable Energy Sources (RES) and Distributed Energy Resources (DER). These resources, comprising mainly wind and photovoltaic generators, together with various storage technologies, are interfaced with the network via power electronic converter technologies, altering the dynamic behavior of the power system. A key effect is the reduction of the system's physical inertia, as conventional power plants are gradually replaced by Converter-interfaced Generators (CIGs). The whole spectrum of dynamic phenomena, ranging from electromagnetic transients to voltage stability, is impacted by CIGs. On the other hand, with proper design of the converter controls, CIGs can contribute to power system control and provide most of the services traditionally provided by conventional generators, such as voltage/reactive power control, active power control, frequency response, and ride-through for both voltage and frequency disturbances. In this context, the investigation of the capabilities of Grid-following (GFL) and Grid-forming (GFM) converters to support the dynamic security of the system becomes a topic of primary importance. For a practical implementation, the financial incentives provided to different market players to support grid stability through appropriate control of CIGS need to be considered.

A non-exhaustive list of topics of interest includes

•CIGs' effects on the dynamic behavior of power systems

•Estimation and enhancement of system Inertia in CIGS-dominated power systems

•GFL and GFM converter controls to support frequency and voltage.

•Interactions and optimal allocation of GFL and GFM converters

•Market Incentives to support ancillary services by CIGs.