For enhancing the regulation performance and the efficient operation of the pumped storage power plant, this paper proposed to combine a hydro-generator set with a full-size converter to achieve the decoupling control of the machine and the power grid. On the basis of the model test, the regulation characteristics of a certain pump-turbine had been discussed and the implication for the converter was highlighted. At the same time, modeling and control for the machine side converter were

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... , the simulation results showed that the hydroelectric generator system based on a full-size converter could track the torque change properly through the control system and achieve variable-speed operation due to the decoupling from the fixed grid frequency. The analysis revealed that it is possible to operate the plant beneficially by adopting a full-size converter between the generator motor and the power grid to improve the dynamic performance of the system effectively.