Measurement-based Estimation of Wind Farm Inertia

The inertia of fixed-speed wind turbine generators (WTGs) helps to mitigate under-frequency transients, promotes fault ride-through and damps inter-area oscillations. It is therefore important to quantify this inertia. The authors use measured wind farm responses during under-frequency transients to provide this information. They discuss the extent of the data and the criteria used to select certain events for further analysis. The estimation of WTG inertia is based on a induction generator model. The basis of the model will be described. The manner in which the model is applied to estimate the inertia from the measured data is then explained. Finally, the implications of the results for power system operation are assessed.