高可再生能源渗透率下波动性可再生能源容量价值再审视

Adequacy is a key concern of power system plan-ning,which refers to the availability of sufficient facilities to meet demand.The capacity value(CV)of variable renewable energy(VRE)generation represents its equivalent contribution to system adequacy,in comparison to conventional generators.While VRE continues to grow and increasingly dominates the generation portfolio,its CV is becoming non-negligible,with the corresponding impact mechanisms becoming more complicated and nuanced.In this paper,the concept of CV is revisited by analyzing how VRE contributes to power system balancing at a high renewable energy penetration level.A generalized loss function is incorporated into the CV evaluation framework con-sidering the adequacy of the power system.An analytical meth-od for the CV evaluation of VRE is then derived using the sta-tistical properties of both hourly load and VRE generation.Through the explicit CV expression,several critical impact fac-tors,including the VRE generation variance,source-load corre-lation,and system adequacy level,are identified and discussed.Case studies demonstrate the accuracy and effectiveness of the proposed method in comparison to the traditional capacity fac-tor-based methods and convolution-based methods.In the IEEE-RTS79 test system,the CV of a 2500 MW wind farm(with 40％renewable energy penetration level)is found to be 6.8％of its nameplate capacity.Additionally,the sensitivity of CV to var-ious impact factors in power systems with high renewable ener-gy penetration is analyzed.