In this paper, we propose the design and control algorithm to improve the power stability for a wave energy converter (WEC). Among the various WEC system, we have considered the Archimedes Wave Swing (AWS) which is a fully-submerged system. For solving the concerned problems in AWS, it is necessary to analyze the power fluctuation occurrence. The static synchronous compensator (STATCOM) which is based on the flexible AC transmission systems (FACTS) has good potential to maintain those difficulties. In order to design a feasible robust controller, the nonlinear systems are converted to the Takagi-Sugeno (T-S) fuzzy systems, which are used as a basic framework to synthesize the fuzzy controller. Simulation results for concerned system are demonstrated to visualize the feasibility of the proposed method.