This paper presents an algorithm to design a decentralized robust controller for static synchronous compensators (STATCOMs) using minimax linear quadratic output-feedback control design approach. There is an increase in the available (dynamic) transfer capability of power systems with fixed-speed wind generators due to the designed decentralized controllers. The effects of the integration of various types of wind generators into power systems based on transfer limit have also been analyzed in this paper. The effectiveness of the suggested control strategy is validated by simulations on a benchmark two area power system. The performance of the designed controller is also compared to a conventional proportional-integral-based STATCOM controller. Simulation results show that both the dynamic voltage stability and the transient stability can be improved by using the robust STATCOM control proposed in this paper.