Variation Characteristics of Regional Synchronous Wind in Hami, Xinjiang of Northwest China

From several towers in Hami, Xinjiang of Northwest China, built by the national wind power resources professional observation network, we selected three towers with synchronous 10-min average wind speed data for one year (May 2011-April 2012) under strict quality control. The towers are located where large-scale wind power development is projected. We analyzed the frequency and variation of extreme wind speed at low wind condition (LWC), rated wind condition (RWC), and cut-out wind condition (CWC), which may significantly impact the electric power grid configuration in large-scale wind power development. The correlation between duration and frequency of LWC/RWC/CWC is obtained. Major findings are: 1) The frequency of CWC is the lowest among all conditions, its synchronous rate at all three towers tends to be zero, and the frequency of LWC is always greater than that of RWC. 2) Among the three towers, the synchronous rate of RWC steadily increases with height, and LWC differs little between different levels. The synchronous rate of LWC concentrates in winter, while that of RWC mainly occurs in spring and summer. Diurnal variation of LWC/RWC during the entire year is significantly different. 3) During the study year, the longest durations of synchronous LWC and RWC among the three towers are up to 640 and 700 min, respectively. The duration and frequency of LWC/RWC can be quantitatively well described by a logarithmic function. Consequently, the synchronous rates of LWC and RWC over any duration in the region can be easily calculated by using the fitting function equation from observed data. These results are of value to the planning of large-scale wind power transmission and grid dispatching in this area.