Voltage stability analysis of a wind hub using Thévenin equivalent models estimated from measured data

This paper provides a method to estimate Thevenin equivalent models for voltage stability analysis of a wind hub with about 600 MW of rated generation. The estimation uses 24-hour SCADA data on two medium voltage transmission lines. The estimation is based on a recently developed method whose objective is to find, from long data records, a fixed Thevenin reactance value that yields a mostly fixed Thevenin voltage. This method is reliable as it does not perform curve fitting through data points that may be noisy and exhibit little variations. The load bus voltage calculated from the estimated Thevenin parameters matches well with the measured load bus voltage.