Capacity assessment for wind power integration considering transmission line electro-thermal inertia

Abstract

Considering differences in planning and construction period, there may exist a mismatch of between effective wind farms capacity and dedicated transmission line ampacity. Then, conflict appears while increasing wind power integrates into main system through limited transmission utilities. Once excessive wind power integration (WPI) causes transmission overload, wind power generation is preferably curtailed with certain scheme. However, transmission conductor electro-thermal characteristic in case of wind power fluctuation makes static thermal rating inaccurate for overload confirmation. Then this study centers on analyzing WPI considering wind power curtailment scheme which allows for overhead conductor dynamic electro-thermal inertia involving various time-varying ambient factors. Accordingly, this study presents a WPI capacity assessment method, which captures the dynamic features of WPI by synchronously simulating wind power generation as well as curtailment regulation, transmission line electro-thermal behaviors and ambient changes. The sequences of wind power and ambient factors with fixed time span given in advance are approximately treated as piecewise linear functions of time and incorporated into differential-algebra equations for WPI. Performances of power curtailment and network loss are explored by taking either static or dynamic thermal rating as transmission overload standard to adjust wind farm output.