Modeling and Power Regulation Strategy of Variable‐Speed Pumped Storage Unit With Full‐Size Converter in Pump Mode

ABSTRACT The variable‐speed pumped storage unit (VSPSU) with full‐size converter (FSC) is characterized by its wide regulation range and exceptional regulation performance, with particular emphasis on its remarkable flexibility in power regulation in pump mode. In this paper, first, by applying MATLAB/Simulink, a numerical model of variable‐speed pumped storage plant with FSC is established, and the control strategy is developed. Second, the proposed model is verified through the comparison with a widely‐used commercial software SIMSEN and the test prototype data. Third, the characteristics of VSPSU with FSC are revealed and quantified: (1) For static characteristics, the power regulation range in pump mode is considerably widened to 11.4% ~ 100%, which significantly exceeds the range of VSPSU based on doubly fed induction machine (DFIM). (2) For dynamic characteristics, the unit accomplishes 10% and 50% power regulation within 10 s and 22 s, respectively. The corresponding average power regulation speed is 2.3%/s, and a power command change rate of 0.1 pu/s is recommended. (3) Compared to the VSPSU based on DFIM, the VSPSU with FSC greatly increases the power regulation range in pump mode. This paper could contribute to characteristic understandings and analytical methodology for practical operation of VSPSUs with FSC.