Costly distributed converters are used in traditional offshore wind turbine generators (WTGs); recently, centralized voltage source converters (CVSC) have been utilized to replace the distributed ones for cost reduction. This method, however, reduces the wind energy that can be harvested from the environment, since all WTGs' synchronous rotational speeds depend on the frequency of the same CVSC but their wind speeds are generally different. To solve this problem, in this paper, a novel power optimization model is developed based on the aerodynamic characteristics of the wind in contact with the turbines. It is followed with the proposal of a novel maximum power generation strategy, using the particle swarm optimization algorithm. The proposed optimal power extraction (OPE) strategy can achieve the maximum power generation, and at the same time limit the excess power output to enhance operational safety. Simulation studies are conducted in this paper to validate the proposed OPE strategy for WTGs, which demonstrate the superiority of the proposed OPE strategy in harnessing the maximum energy from wind, in comparison to the existing method.