风电经柔性直流输电并网系统频率响应特性分析方法OA

Aimed at the frequency response characteristics of a doubly-fed wind farm grid-connected system via modular multilevel converter-based high voltage DC(MMC-HVDC)transmission,a detailed frequency response model includ⁃ing the dynamics of a control system is derived in this paper based on the small-signal linearization theory.Compared with the existing simplified frequency response model which is established mainly by using an inertia link instead of de⁃tailed models of the control system,the new model solves the problem of deviation between the simplified frequency re⁃sponse characteristics of the system and its actual frequency response characteristics.On this basis,the H2 and H∞norms from the robust control theory are introduced as quantitative indexes to evaluate the system capability in suppress⁃ing the frequency disturbances.The H2 and H∞norms of a transfer function between the frequency change and load dis⁃turbance of the system are calculated,the influence of the system's frequency adjustment parameters on frequency re⁃sponse characteristics is analyzed,and a tuning method for the system's frequency adjustment parameters based on H2 and H∞norms is proposed.The effectiveness of the established detailed frequency response model and system frequency response characteristics analysis method is verified through simulations,providing a theoretical basis and reference for studying the precise frequency response characteristics and tuning for frequency adjustment parameters of the wind pow⁃er grid-connected system via MMC-HVDC.