PNNL

Abstract

Accurate representation of wind power plants (WPP) in both offline and online power system stability studies has gained importance because of the rapid increase in installation of wind generation around the world. On the other hand, reduced WPP representation is preferred due to computational efficiency. To improve the accuracy, other authors have proposed changes in structure of the reduced model for large WPPs. The use of model validation and calibration is an alternative to improve the accuracy of the reduced WPP model. In this paper, we compare accuracy improvements brought by changes in model structure with accuracy improvements brought by validation and calibration of the reduced WPP model with minimal changes in structure. We illustrate our findings using a 168-machine WPP connected to the IEEE-39-bus test system. The parameters of the reduced WPP model are either calculated with current equivalencing techniques or validated and calibrated against a more accurate model. The changes in structure of the reduced model are 1-machine or 2-machine reduced models connected with a 1-line or 2-line collector equivalents. We show that the most accurate response is obtained by calibrating the parameters of the reduced model with minimum changes in structure.