Research and Application of Characteristic Curve Correction Method for Cascade Hydropower Stations Considering Runoff Inconsistency

The situation wherein a hydrological series does satisfy the assumption of “independent and identically distributed” is called runoff inconsistency. “Flow Inversion Phenomenon” is also a kind of runoff inconsistency in space that reflects errors in the hydrological modeling process and can provide a basis for curve correction. In this paper, the causes of the flow inversion phenomenon are analyzed, and a characteristic curve correction method for hydropower stations based on runoff inconsistency is proposed. “Interval Fallacy Rate” is proposed to quantify the flow inversion phenomenon, and with the goal of minimizing the interval fallacy rate, several characteristic curve correction methods, such as single-point discrete optimization, multi-point discrete optimization, overall translation optimization and partial translation optimization, are constructed to correct the turbine characteristic curve, discharge curve, and capacity curve of a hydropower station. In the case study, we take a six-reservoir cascade reservoir system in China as an example. After curve correction, the interval fallacy rate of each interval is reduced to varying degrees. This study provides a new idea for the correction of hydropower stations’ characteristic curves in basins lacking measured flow data.