A Generalized procedure to develop transfer function based models of electrical power systems

Abstract

More and more renewable electricity generating sources such as wind and solar power plants are being integrated into electrical power systems, which in turn complicates processes such as power system stability studies due to the complex nature of controls in these power plants. Since most such studies are done using simulations, it is necessary to have accurate dynamic models of those power plants which describe the behaviour of the power plant during a disturbance to the network or to an internal control or the power plant. Nevertheless, it might be difficult to obtain these detailed models from manufacturers due to proprietary concerns and even if the detailed model is available, modelling complicated power electronic components in the simulation environment might be a difficult without knowing how each component operates. Moreover, when parameters change over time, physical parameters of these models need to be updated and it cannot be done without standard practical measurements. These standard tests require the generating sources to be taken out of the system for testing purposes. Therefore, instead of a detailed model, a dynamic equivalent model could be used for achieving the same requirement. This research presents a generalized procedure that can be used to accurately estimate black-box dynamic equivalent models of synchronous generators, wind and solar power plants by utilizing measurements and estimating parameters of the dynamic equivalent model. Simulations have been conducted to estimate and verify the accuracy of the proposed methodology by comparing the accuracy of the actual model and the estimated models.