Coordinating regulation reliability and quality of pumped storage units for renewables by a novel scheduling-control synergic model

As the largest electricity storage facility, pumped storage is crucial for power systems but faces significant trade-offs between regulation quality for variable renewable energy (VRE) and the reliability of pumped storage units (PSUs). The flexible regulation requirement necessitates frequent startup-shutdown cycling, part-load operations, and accelerated wear of PSUs, thereby jeopardizing their reliability. Limited research on refined PSU-level scheduling strategies compromises the reliability of PSUs and the operation of VRE systems, especially given the diverse unit characteristics within a plant. This work innovatively couples the hydraulic characteristics of PSUs with reliability-based scheduling order, proposing a refined dual-layer scheduling strategy composed of unit commitment and load dispatch within a Wind-Solar-Pumped Storage Hybrid System (WSPSHS). Meanwhile, this work breaks from the traditional independent research paradigm between scheduling and control, establishing a refined synergic approach that integrates 15-min-level scheduling with second-level power control. Furthermore, this approach supports the development of a reliability assessment model that includes metrics on effectiveness and regulation losses of PSUs. In a North China case study, four cases with different combinations of hydraulic characteristics and reliability-based scheduling orders are comparatively evaluated. The results demonstrate that: (1) the refined strategy considering hydraulic characteristics and reliability significantly improves the reliability of PSUs by 9.91%. (2) the approach can effectively regulate PSUs and manage the WSPSHS, maintaining the operating efficiency of PSUs above 90% and achieving a VRE consumption rate of 95.47%. (3) The techno-economic performance of plants can be significantly improved, reducing operational intensity and risks, particularly for low-reliability PSUs, without negatively impacting the regulation quality of the hybrid system. This work can be extended to other energy systems with PSUs for effectively balancing VRE regulation demands with PSU reliability, and offering insights for reliable and efficient operation of power stations and grids.