Transient Modeling and Dynamic Response Characteristics Analysis of Doubly-Fed Variable Speed Pumped Storage Unit Under Pumping Condition

In contrast to traditional fixed-speed pumped storage unit, doubly-fed variable-speed pumped storage unit (DFVSPSU) offer a spacious range of power regulation and higher working effectiveness. However, due to the diverse operating conditions and intricate mode transitions associated with DFVSPSU, a comprehensive analysis of their mode transition characteristics is essential. Firstly, we develop a mathematical model for the DFVSPUS under pumping conditions, incorporating the dynamic behavior of the fluid within the water conduit as well as the added frictional effects from the guide vane. Subsequently, a simulation model of the unit was built in Simulink, using both pumping and shutdown conditions as case studies, and validated the model through simulation. Finally, the results demonstrate that the model effectively manages the transition of operating conditions. When the active power reference value changes, the unit's power, speed, and guide vane opening accurately follow the reference or optimal values, confirming the accuracy and effectiveness of the proposed model, and the established model is validated through simulation.