Case Study on Scale Optimization of Pump-storage Variable Speed Units Based on Power System Operation Simulation

Abstract

Pumped-Storage Hydro (PSH) power units, especially variable speed units, have great roles in guaranteeing power system operation safety, stability and efficiency. As the investment cost of pumped-storage variable speed unit is higher than fixed speed unit, it is necessary to study its optimal scale. This paper used a scale optimization model for variable speed units based on power system security constrained unit combination model, which can demonstrate the most economic scale of variable speed units in all new pumped-storage power units under a given power supply planning. And then, calculation examples of multi-category regions in China were done, which shows that in a given power plan, demand on pumped storage variable speed units in the peak shaving and valley filling category region is the highest, followed by safety guarantee category, and demand on pumped storage variable speed units in feed end areas in proportioned new energy absorption category is relatively low.