Comparing conventional wind power plants withfrequency controlled wind power plants and quantifyingand investigating the improvement of frequency stability

Conventionally operated full power converter windplants show high short-term power output variability caused byvariable winds, and does not contribute to the power systeminertia due to the decoupled generator speed and grid frequency.There is, however, abundant inertial resources in wind plantrotors for both smoothing of output power and for syntheticinertia contribution. Together with added frequency controllingfunctionality, this could facilitate inclusion of wind power inislanding systems, enabling greater system loads and enhancingpower system stability. This paper describes modeling of powersmoothing and frequency controlling wind plants and assessesdifferent control strategies as well as the grid frequencyperformance gains achievable over hydro powered islandingsystems and over islanding systems incorporating both hydropower and conventional wind plants. The results show that windplant power output could be smoothed in the short time frame,and support frequency in both primary and secondary frequencycontrol timescales including droop functionality.

Keywords:

Frequency control , FPCWT , inertia , PMSG , powersmoothing , primary frequency control , wind power.