A Fast High-Precision Model of the Doubly-Fed Pumped Storage Unit

With an increase of renewable energy permeability in power grids, doubly-fed pumped storage units with excellent regulation performance have become a popular research topic. Current models of the doubly-fed pumped storage unit are mostly used in the study of electromagnetic transients while the generator model is complex and the pump-turbine system model is simple, which is not conducive to the research on electromechanical transients and pump-turbine control systems. To overcome this problem, a novel fast high-precision model of the doubly-fed pumped storage unit is proposed in this paper. First, a novel efficiency optimization method is proposed, and a high-precision variable speed control model of the pump-turbine is established according to the pump-turbine’s complete characteristic curves of. A doubly-fed induction generator (DFIG) control model is then used to construct a detailed model of the doubly-fed pumped storage unit. The DFIG control model is analyzed and simplified, and a fast high-precision model of a doubly-fed pumped storage unit is obtained. Finally, this fast high-precision model is verified in the turbine and pump modes. The results indicate that compared with the detailed model, the proposed fast high-precision model can better describe the characteristics of a variable speed unit. The new model is simple, has high accuracy and its simulation step (10−2 s) is larger than that of the detailed model (5 × 10−6 s), which makes the simulation speed improved effectively.