The work presented in this paper analyses, with the help of experiments on a 2.2 kW test bench, the possibility to participate in the primary frequency control with a variable speed wind generator. A power reserve is obtained with the help of the generator torque control by following a power reference value lower than the maximum power which must be extracted from the wind. This approach allows also using a part of the kinetic energy in the blades inertia to contribute to this reserve. The dynamic tests carried out on the test bench, by using medium and high variable wind speeds, confirm the capacity of the wind turbine generator (WTG) to participate in the primary frequency control. (C) 2008 Elsevier Ltd. All rights reserved.