Control of an offshore wind power plant: emulated inertia

Undoubtedly, the energy sector is moving towards a more renewable and sustainable path. This means renewable energy will increase their penetration into the electric power grid. Wind Energy, in particular Offshore Wind Energy, is becoming the leader of the renewable energy in terms of future possibilities, and their technology is evolving to a more controllable devices. Double Fed Induction Generator Wind Turbines (DFIG), also known in the industry as Type 3 Wind Turbines, and Fully Rated Converter-based Wind Turbines, Type 4, use power electronics to decouple the generator from the grid. Type 3 does this partially and Type 4 decouples completely the generator from the system. This allows variable wind speed operation and higher controllability for grid support. They improve the grid support provided by Fixed Wind Speed Turbines, except for the Fast Primary Frequency Response which is related directly with the inertia stored in the system. These types of wind turbines are not able to provide natural inertia response due to their decoupling from the grid. If we increase the penetration of this kind of wind turbines without giving a solution to the Fast Primary Frequency Response we will be lowering the Frequency Response and enable disturbances in the grid. This project proves how the Frequency control improves Frequency Response of the system in front of a sudden frequency drop even when the Percentage of Wind Energy Penetration is at the 30% level. We also prove how Control values of inertia constant, Droop and operational wind speeds affects the Frequency Response, being a fundamental step to take into account the operational point of the turbine depending on the working wind speed and the tune of the Frequency control values depending on the turbine characteristics