Compensating the rotating mass kinetic energy in grids including high shares of renewable

Abstract

The growing number of renewable energy production plants have caused a problem that conventional inertia response to frequency variations has reduced. As a consequence the amplitude and frequency of frequency variations has grown. Renewable power plants such as wind and solar PV do not inherently respond to the frequency variations. However, also renewable energy systems (RES) can take part on the frequency regulation by including such controls to the system. In the current day power grid the connected rotating synchronous mass, that is the inertia, represents certain amount of kinetic energy. This energy can be replaced by synthetic inertia of RES, but the main questions are what kind of dynamics are required from the energy sources and are they capable of executing the required performance. Another issue is how different energy sources should take part in the frequency regulation. This paper focuses on the available kinetic energy in a grid where power production is based mostly on renewables. Key technologies investigated include wind, solar, and battery energy storages. As a result kinetic energies for each technology is calculated for small island environment that is assumed to operate independently.