Parameter Estimation of Frequency Dependent Dynamic Load Model as seen from HV Nodes

In this paper, a dynamic model of the aggregate electric load as seen from the high-voltage nodes of the transmission network is developed. The proposed model allows the estimation of the active and reactive power deviations due to voltage and frequency fluctuations. The proposed model adds a frequency dependant function to the standard Exponential Recovery Load Model to infer the impact of the frequency excursions on the load behaviour. Given the wide variety and complexity of loads connected to the same HV node, a measurement-based approach is adopted to parameterize the proposed model. The parameters are estimated using three different optimization algorithms applied to experimental measurements recorded during power system restoration tests and during normal operation by means of PMUs connected to some primary substations of the Italian transmission grid.