Statistical Analysis of Frequency Response of Island Power System under Increasing Wind Penetration

This paper provides statistical analysis of frequency response characteristic of the Irish Electric Power System as function of increasing wind power penetration. This analysis is based on 3-year (2007-2009) record data of unit trips at different conditions of the system including variation of wind generation. The analysis is carried out in terms of dynamic stiffness assessment and prediction of initial frequency deviations in response to conventional unit trip under different levels of instant wind generation on the system. Using a generalized dynamic model of the system allows assessing power system characteristics with wind levels beyond experienced up-to-date. It supports theoretical predictions of reducing overall system stiffness as a result of displacement of inertial conventional units with wind generation units majority of which are of non-inertia type (DFIG, full-converter etc.). The system stiffness reduction manifests itself in more severe frequency dips on the system with higher wind penetration.