Influence and multi-objective optimization on three-stage guide vane closure scheme of a pumped storage power plant

Abstract

Selection of the guide vane closure scheme was a critical issue for the load rejection transients of a pumped-storage power plant. To fully and accurately assess the influences of the guide vane closure scheme on the transient performance and pressure fluctuation, the load rejection transients adopting the original two-stage and optimized three-stage guide vane closure schemes were simulated adopting the one- and three-dimensional coupled approach. Results suggested that the guide vane closure schemes significantly influenced the transient performances and pressure fluctuations during load rejection transients. Compared with adopting the original two-stage guide vane closure scheme, adopting the optimized three-stage guide vane closure scheme could improve the maximum rotation speed, maximum and minimum fluctuating pressures in the pumped-storage power plant, and suppress the local backflow vortexes close to the high-pressure inlet of runner and their induced low-frequency and high-amplitude pressure fluctuation close to the no-load conditions. The study results provided theoretical reference for selecting the optimized guide vane closure scheme.