Value Evaluation Method for Pumped Storage in the New Power System

When integrating the generation of large-scale renewable energy,such as wind and solar energy,the supply and demand sides of the new power system will exhibit high uncertainty.Pumped storage power stations can improve flexible resource supply regulation in the power system,which is the key support and important guarantee for building low-carbon,safe,and efficient new power systems.Limited by the current operation mode and electricity price mechanism,the pumped storage power station cost cannot be effectively recovered,and the value cannot be reasonably compensated,resulting in difficult return on investment,single investment subjects,and notable industry development difficulties.According to the operational requirements of the new power system,combined with the various functions of pumped storage power stations,the value of pumped storage power stations in the new power system was analyzed.Based on the equivalent value substitution principle and system operation simulation,a pumped storage value evaluation method for the new power system was proposed.The new power system operation was simulated considering the dispatching model of wind and photovoltaic power abandonment penalties.Under the same dispatching objectives,the output of various power sources and power generation operating costs with and without pumped storage power stations in the system were compared.From economic,safety,social,and environmental benefit perspectives,a quantitative model of the pumped storage power station value was established,covering seven dimensions:asset investment savings,power generation operating cost reduction,flexible adjustment capability improvement,system resilience enhancement,power outage loss reduction,renewable energy consumption,and emission reduction promotion.Based on the new power system operation and planning data for southern China,the value of typical pumped storage power stations was analyzed,and the results showed that with new power system’s construction and development,the value of pumped storage power stations is increasing,and the value structure is closely related to power grid characteristics.This value evaluation method could provide references for pumped storage investment decisions,subsidy policies,and price mechanisms to fully utilize the role of pumped storage power stations and promote high-quality development of new power systems.

Analysis of triple-band binary metamaterial absorber based on low-permittivity all-dielectric resonance surface

Different from the conventional metamaterial absorbers(MAs),which used metal resonance surface and ternary structure(metal–dielectric-backplane),as an alternative route,the all-dielectric resonance surface(ADRS)made of single low-permittivity dielectric is proposed to design binary(dielectric backplane)metamaterial absorber(BMA).As an illustration,a triple-band BMA composed of ADRS with a metallic backplane is designed and fabricated,where the ADRS incorporates two dielectric layers with different hole-array structures.The absorbing mechanisms of this kind of absorber are analyzed via analyzing configurations of power loss density,electric field and magnetic field,as well as investigating dependences of absorbing properties on structure dimensions.The study indicates that the structural design of ADRS leads to reverse magnetic field rings distributed inside the dielectric,forming the strong couplings at the resonance frequencies.The proposed BMA relies on low-permittivity ADRS,with the rapid preparation and low cost greatly simplifying the design of MAs.The current concept is also suitable to design multi-band and broadband MAs worked at other bands,by changing the structural design of ADRS.