Virtual Synchronous Generator Control of Variable Speed Pumped Storage Hydropower with Ful1-size Converter

To allow power electronics interfaced variable speed pumped storage hydropower (PSH) providing adjustable inertia as well as frequency and voltage support, a virtual synchronous generator (VSG) control scheme of variable speed PSH with the full-size converter is proposed. First, the mathematical models of reversible pump-turbine are given. On this basis, the proposed VSG control strategy is presented, where the machine-side converter aims to provide a steady DC-link voltage and meet the reversible pump-turbine requirements while the grid-side converter conducts the VSG control. In this way, the original fixed inertia of reversible pump-turbine, which is wasted by the conventional control, and the equivalent inertia of intermedia capacitor could be controllable integrated into the adjustable system inertia to grid. Finally, the simulation study of a 5MW VSPSH is carried out on Matlab/Simulink to verify the effectiveness of the proposed control method. The comparative results of fixed speed PSH, variable speed PSH with conventional control and the proposed control demonstrate that the proposed control strategy has good reference tracking and presents adjustable inertia to grid, which is meaningful to facilitate frequency and voltage support of the power system.