Largely variable inertia power system

With the decline of the limited fossil fuel energy resources as well as the climate change, parts of the traditional generators and loads are being replaced by modern ones connected through power electronics. This technology can work with any type of current shape, thus providing the flexibility needed for the renewable energy sources such wind turbines or photovoltaic panels. However, while traditional synchronous machines naturally support the grid frequency trough the kinetic energy stored in their rotating masses, power converter connected machines do not naturally participate to the grid inertia. Although, the use of renewable has undeniable positive effect, a too strong integration in an unprepared grid can seriously jeopardize its frequency stability. This master thesis focuses on the study of grid frequency dynamic with an important share of renewable. Grid areas with realistic parameters are performed and analyzed. Later on, a detailed model of a permanent magnet synchronous wind turbine with a a controller emulating its inertia and thus supporting the grid frequency is then proposed. Indeed, with the increasing amount of power module connected through power electronics it is important to find solution so that they can also play a role in the grid frequency stability