With high wind power penetration, imbalance between generation and consumption is increased, and as a consequence the frequency deviation from the nominal value will be magnified. For frequency control purpose in conventional power systems, the synchronous generators are only responsible. However, it is expected that the renewable energy sources (RESs) are also needed to contribute in frequency control issue in near future. In this, impacts of high wind penetration on the frequency control are studied, and an approach is introduced for creating the secondary reserve for doubly fed induction generator (DFIG) wind turbines. This reserve can contribute to load frequency control (LFC) task. Simulation results on updated standard IEEE 39-bus system are presented and it is shown that the wind turbines can contribute in LFC service, successfully.