With the increasing proportion of wind energy in electrical energy systems, increased grid frequency fluctuations occur due to varying wind speeds. Previous solutions are often based on external energy storage systems, which result in high investment costs. Alternative approaches that use the kinetic energy of the rotor directly are available, but often lead to a loss of performance or require complex control interventions.
Technical Description
The system uses two main input variables: the mains frequency and the rotor speed. An intermediate signal is formed from these, which measures the deviation of the mains frequency from the setpoint. Based on this, a power adjustment signal is determined, which integrates the kinetic energy of the rotor into the control of the mains frequency. At the same time, a reference signal is calculated which determines the point of maximum power extraction of the wind turbine. The combined reference signal controls the power output of the wind turbine in such a way that frequency fluctuations in the grid are reduced while the wind turbine remains in the optimum operating range. The technology has a modular structure and can be flexibly adapted to different grid requirements.
The method was tested in simulation environments based on a model of the Irish electricity grid for the year 2040. The results show a 66.7% reduction in frequency deviations compared to conventional methods.
Possible Applications
The method is suitable for wind turbine operators and energy supply companies that feed a high proportion of renewable energy into the grid and need to ensure grid stability. It is particularly useful in regions or grids with a highly fluctuating wind supply and high wind energy penetration.
