The integration of large amounts of wind power in power systems presents huge challenges. In particular, with the increase of wind power generation, more regulation reserves would be necessary, the capability of the power system to offer conventional regulating power would be reduced and the dynamic stability of the grid frequency under large disturbances would be compromised. The aim of this study is to investigate the integration of large scale wind power generation in power systems and its active power control.Novel methods and solutions dealing specifically with the electric frequency stability and high wind power penetration or in islanding situations are addressed. The review of relevant theoretical concepts is supported by measurements carried out on an isolated power system characterized by high wind power penetration. Different mathematical and simulation models are used in several particular views. These models were developed and verified during this work, basedaround a particular manufacturer’s wind turbine and on said isolated power system withwind power. The capability of variable speed wind turbines for providing Inertial Response is analysed. To perform this assessment, a control algorithm for wind turbine inertial response is developed and the performance is simulated for asingle wind turbine. It is shown that wind power is able to provide valuable inertial response when combining a large number of wind turbines in a wind plant. Active power control architectures for wind power generation were studied considering a large share of wind power in the system. Results show the abilities of the architectures to manage the variability of the generated wind power, reducing the impact on the grid frequency and providing suitable frequency regulation service when required. The coordination between the developed control systems and the conventional plants responses is studied. A methodology for determiningthe necessary wind power reserve and control parameters such as frequency response characteristic (droop) and deadband is presented. The performance and the capability for supporting the grid in normal operation and during large load events are demonstratedwith accurate computational simulations.