Comprehensive stability analysis of pumped storage power station under wide-load operation across the full head range: Quantitative evaluation and global sensitivity

With the integration of large-scale intermittent energy sources into grids, pumped storage power stations (PSPSs) are required to operate under wide-load operation across the full head range (WLO-FHR), imposing higher demands for operational stability. However, existing research primarily focuses on some representative operating conditions, and systematic analysis of the PSPS stability under WLO-FHR remains insufficient. In this study, a stability analysis model for PSPS was established. The dimensionless stability region area was introduced to quantify the PSPS stability. Subsequently, the variation law of the PSPS stability with the operating conditions was revealed. Further, a global sensitivity analysis (GSA) of the PSPS stability was conducted. Finally, a parameter optimization strategy for enhancing stability is proposed. The results indicated that the head of the pump-turbine had minimal effect on the PSPS stability, whereas a higher output led to poorer stability. The PSPS exhibited the poorest stability under the rated head and output conditions. The system stability was primarily determined by the independent effects of the parameters. The water inertia time constant of the penstock (Tw) had the most significant impact on the stability, followed by the unit inertia time constant (Ta) and pump-turbine characteristic parameters (s2 and s4), whereas the head loss coefficient (k) and pump-turbine characteristic parameters (s1 and s3) had smaller effects. Reducing Tw significantly improved the system stability, and increasing Ta, decreasing s2, and increasing s4 also contributed to enhanced stability.