开式循环抽水蓄能与常规水电站的协调削峰运行：多种运行模式、最优运行边界及其影响

Abstract The expansion of wind and solar energy necessitates the development of pumped-storage hydropower plant (PSHP). Integrating open-loop PSHP (OL-PSHP) with its in-stream reservoir-based hydropower plants (HP) results in a cooperation mode that is significantly more intricate than traditional closed-loop PSHP. With a focus on OL-PSHP, the primary goal of this study is three-fold: (1) derive the various peak shaving modes for OL-PSHP and HP and propose the corresponding cooperation model between them; (2) determine the optimal initial water level and daily average release from the OL-PSHP in-stream reservoir to maximize the OL-PSHP-HP peak-shaving benefit; (3) quantify the impact of OL-PSHP operations on intraday water level fluctuations and power output of the in-stream reservoir system. WaRang OL-PSHP located in the upper Yellow River Basin of China, relying on Laxiwa (LXW) in-stream reservoir, is selected as the case. Our findings suggest that: (1) OL-PSHP can operate in various modes to accommodate intraday fluctuations in renewable generation and load demand, including sequential pumping followed by generation, initial generation followed by pumping, or hybrid mode with alternating pumping/generation cycles within a single day. (2) Recommended initial daily water levels for the WaRang OL-PSHP upper and lower reservoirs are all approximately halfway between the dead water level and normal water level. The optimal daily average outflow of the LXW reservoir is suggested to be kept around 700 m 3 /s, with this value varying according to the operational modes of OL-PSHP. (3) The OL-PSHP exacerbates the daily fluctuations in the LXW reservoir water levels, resulting in a maximum daily decrease of 0.77 m and a maximum increase of 0.37 m. The annual power output of the LXW HP could increase by up to 547 × 10 4 kWh or decrease by up to 2312 × 10 4 kWh, representing approximately 0.06 and 0.26 % of the LXW HP’s average annual generation, respectively. These findings can offer valuable insights for the cooperation of OL-PSHP-HP located in other basins worldwide.