Research on daily operation optimization of Batang Hydropower Station based on flow prediction method and pre-discharge and refill concept

Abstract

[Objective] To address the operational demands of daily-regulated reservoirs without flood forecast conditions, and to overcome the dependence of traditional method on forecast data, an optimized “pre-discharge and refill” method based on flow prediction is proposed. [Methods] Taking the Batang Hydropower Station in Indonesia as the study object, a two-stage operation mode driven by the previous day's inflow was constructed. Based on the temporal correlation of inflow series, a method for estimating the current day's inflow was established. Taking an hour as the decision unit, the scheduling process of pre-discharge and refill was recursively generated based on the water balance equation, and the optimization effect was quantitatively evaluated based on observed runoff data. [Results] The results showed that when the flow prediction coefficient was 0.8, the proportion of effectively regulated days reached 42.6%, demonstrating the greatest potential for comprehensive scheduling optimization. On this basis, when 430.0 m was set as the pre-discharge water level, the power generation guarantee rate reached 99.4%, and the proportion of high-water-level operation time decreased to 8.95%. Compared with the scheme of pre-discharging to 427.5 m, these values increased by 0.1% and decreased by 3.45%, respectively. [Conclusion] On the basis of ensuring power generation efficiency, the proposed method can significantly reduce the duration of high-water-level operation. Under no-forecast conditions, it can effectively balance power generation with the risk of sedimentation-induced loss of storage capacity caused by high-water-level operation. It provides a novel approach for the multi-objective operation of reservoirs under no-forecast scenarios.

Keywords

hydraulic engineering / flow prediction / optimized operation / daily-regulated reservoir / pre-discharge water level / pre-storage time / runoff / Indonesia