Author(s): Fabiana Guimaraes; Tatiane Pereira; Klebber Formiga

Linked Author(s): Tatiane Souza Rodrigues Pereira, Klebber Formiga

Keywords: Calibration window; Multi-objective optimisation; NSGA-II; SCADA; Sewage pumping station; Time-of-use tariff

Abstract: Wastewater pumping stations are major energy consumers and often rely on fixed level thresholds that ignore time-of-use tariffs and inflow variability. This paper evaluates how the calibration-window length used to optimise simple ON/OFF rules affects long-term performance and robustness. Using 5-minute SCADA data from the Águas Claras station (Brasília, Brazil), inflow was reconstructed by mass balance for a two stage wet well and used to drive a bi-objective NSGA-II optimisation of four daily control periods (ON and OFF levels and pumping rates). The objectives were the total energy cost and the overflow volume. Rules were calibrated using four September 2022 windows (daily mean, daily maximum, one week and one month) and validated over one year. All optimised rules reduced costs by about 10% compared with observed operations, mainly by shifting pumping away from the 18:00–22:00 peak tariff period. Overflow outcomes depended on representativeness: weekly and monthly windows reduced overflow from 82,738 m³ to 6,430 m³ and 5,803 m³, whereas daily-mean calibration increased overflow. One-at-a-time ±20% perturbations showed that inflow, tariff and efficiency dominate cost sensitivity, while initial storage has a minor influence. Calibration windows spanning both dry and wet conditions produced rules with lower overflow risk, while preserving PLC-ready simplicity.

DOI: https://doi.org/10.64697/iahr.proc.hic2026.216

Year: 2026