Balancing Operational Efficiency and Regulation Performance, for Guiding Pumped-storage Day-ahead Scheduling

Pumped-storage plants (PSPs) have significant potential to regulate intermittent energy sources. However, achieving coordinated optimization of regulation stability and operational efficiency has been a long- standing challenge. This study proposes a new soft linking model to address the limitation that current scheduling methods fail to account for both efficiency and second-level stability simultaneously, aiming to improve the day-ahead scheduling strategies for PSP. Firstly, a Pumped-Storage Hydroelectric System (PSHS) model is developed to reflect the regulation stability of PSP, considering the transient characteristics of hydraulic, mechanical, and electrical subsystems. Then, by analyzing transient responses under various operating working conditions, the study integrates the transient variation laws of the power plant into a regulation stability dataset (RSD). Finally, using RSD as the coupling interface, with regulation stability and operational efficiency as the objective functions, a Pumped-Storage Power Day-ahead Scheduling (PSPDS) model is established. An actual PSP is used as a case study to evaluate the effects of four operational scenes with varying optimization objectives on operational efficiency and subsystem performance. The results indicate that controlling load change magnitude and increasing the load decrease working conditions effectively enhance the stability of PSP subsystems. In addition, although the proposed scheduling scheme increases water consumption by 0.0213% compared to traditional scheduling method, it improves regulation stability by at least 15.14%. The findings suggest that a minor compromise in operational efficiency can lead to a significant improvement in regulation stability. This study provides new perspectives and methods for the management and optimization of PSPs.