Open AccessSmoothing effects of distributed wind turbines. Part 2. Coherence among power output of distant wind turbines
Author(s) -
Nanahara Toshiya,
Asari Masahiro,
Maejima Tsutomu,
Sato Takamitsu,
Yamaguchi Koji,
Shibata Masaaki
Publication year - 2004
Publication title -
wind energy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.743
H-Index - 92
eISSN - 1099-1824
pISSN - 1095-4244
DOI - 10.1002/we.108
Subject(s) - wind power , turbine , smoothing , environmental science , wind profile power law , coherence (philosophical gambling strategy) , wind speed , meteorology , power (physics) , marine engineering , engineering , computer science , electrical engineering , mathematics , geography , statistics , aerospace engineering , physics , quantum mechanics , computer vision
Abstract Recently there has been a marked increase in wind power generation. From a power system point of view, because a wind turbine is an intermittent generator with large output fluctuation, any increase in the number of wind turbines gives rise to concerns about the adverse effects of wind turbines on power quality. The smoothing effects of wind turbine output fluctuation are of great importance in assessing the impacts of a large number of wind turbines. With regard to impacts on power system frequency (generation–demand balance), smoothing effects on a power system‐wide scale need to be examined in greater detail, because impacts of wind turbines on power system frequency are dominated by the total power output of wind turbines interconnected to the system. This article examines smoothing effects of wind power output on a power system‐wide scale. First a summary of wind measurements, in which observations were made at 16 sites, is presented. Next, correlation coefficients of wind power output of distant wind turbines are analysed; considerable differences are observed in the correlation coefficients from day to day. Then a new indicator for assessing the smoothing effects—average coherence—is introduced to resolve difficulties of conventional indicators such as coherence. Average coherence is evaluated for the measured data; the results show that smoothing effects among wind farms distributed over some hundreds of kilometres may not be so significant for periods of more than about 100 min. Copyright © 2004 John Wiley & Sons, Ltd.