Load inertia estimation using white and grey-box estimators for power systems with high wind penetration

The increasing penetration of wind farms in power systems has increased concerns over the frequency behaviour and control of synchronous power systems due to a low contribution from modern wind turbines to overall system inertia. With this trend of conventional generators being displaced by variable speed wind turbines, the contribution from load inertia becomes more significant. The need for greater consideration towards load inertia estimation, or even on-line tracking of load inertia, seems to be required. A white-box method for estimation of load inertia is examined using system frequency and generator output power signals from previous generator forced outages. A grey-box identification method is also applied to estimate the inertia of synchronous generators. The impact of sampling rates, time shifting and signal averaging on parameter estimation is also considered. The method is shown to be robust enough to be applied for load inertia estimation in control centres.