Modeling and Control of Variable Speed DFIG Pumped Storage Turbine Based on RTDS

Hundreds of megawatt level variable speed Doubly Fed Induction Generator (DFIG) pumped storage turbine will play an important role in voltage and frequency regulation, system stability, active and reactive power control etc.. However, similar but different from the DFIG wind turbines, such power rating and reversible pump-turbine with small capacity converter to control the whole variable speed system is challenging. In this paper, mathematical analysis and modeling of variable speed DFIG pumped storage turbine including reversible pumped turbine, DFIG and back to back converter is build first. On this basis, the control method is presented. The grid side converter stabilizes the dc-side voltage and control the grid-connected current sinusoidal. The rotor-side converter can control and decouple the active power and reactive power independently. Finally, the real time simulation results of 300MW pumped storage turbine based on Real Time Digital Simulator platform indicate the proposed control strategy can achieve good performance in different working conditions of pumping and generation. The system has fast response and good stability.