| Based on the daily and hourly observation data of wind speed in Guangdong province for the period from 1961 to 2014,we analyzed the spatial and temporal characteristics of gale days and wind speed(mean,maximum and maximal wind speed).We further probe the contact between windy weather and different weather systems(tropical cyclone,severe convective weather and cold wave)in Guangdong.Meanwhile,by analyzing the the characteristics of spatial and temporal variation of trip-out and tower collapses caused by gale for 110kV and above transmission lines(main-grid)and combining with the characteristics of wind on microtopography,we studied the correlation between the transmission lines accidents caused by windy weather.Furthermore,we analyzed the correlation between wind speed and the loss caused by windy weather under various typical underlying surfaces for power grid.Finally,.the statistical diagnosis wind model based on PLS-MOS and the wind hazard precaustion model based on WRF-CALMET numerical simulation were established to provide theoretical basis and technical support for wind hazard precation system in Guangdong power grid.Firstly,we analyzed spatial and temporal the characteristics of gale days and wind speed(mean,maximum and maximal wind speed)in Guangdong province,using the observation data in recent 54 years.The results show that the spatial distribution of gale days and wind speed have obvious differences in different regions.Windy weather occur more in coastal area than inland area.In recent 54 years,the numbers of gale days show decreasing trend in most parts of Guangdong province,especially in East Guangdong,Jiangmen-Yangjiang coastal areas.After 2000,the numbers of gale days in western Guangdong,Shanwei-Huizhou,Jiangmen-Yangjiang coastal area started into an upgrade trend.Secondly,seasonal variation of windy weather in Guangdong Province in recently 54 years included mainly two forms:unimodal and bimodal.In addition,there is a significant interannual variability in the concentration of windy weather in the same area.Therefore,we used the gale-concentration degree(GCD)and gale-concentration period(GCP)to analyze the seasonal variation of gale days quantitatively.The results show that gale days appeared less in northern Guangdong and the gale-concentration period appeared relatively early,while appeares relatively later in southern Guangdong.In the recent 54 years,the gale-concentration degree in Guangdong province was increasing,especially in the coastal areas.The interannual variation of the gale-concentration period in Guangdong province was obviously decreasing.Meanwhile,we found significant correlation between the gale-concentration degree in Guangdong Province and the strength of polar vortex in northern hemisphere,Western Pacific subtropical high and Eurasian meridional circulation.In addition,by analyzing the correlation between weather and tropical cyclone,severe convective weather and cold wave,we found that gale days and the mean wind speed mainly related to the numbers of tropical cyclones which affected Guangdong province,and severe convective weather and cold wave showed a significant positive correlation to windy weather,while the maximum wind speed and the maximal wind speed in Guangdong showed a strong positive correlation with the intensity of tropical cyclones which affected Guangdong.Furthermore,by analyzing the the characteristics of spatial and temporal variation of trip-out and tower collapses caused by gale for 110kV and above transmission lines,we found that the wind hazard for regional power grid concentrated from July to October.After 2012,wind hazard accidents showed a significant increasing trend.The annual accident numbers rose from 81.2(2001-2012)to 134(2013-2015).Meanwhile,the analysis showed that the spatial distribution of wind hazard in Guangdong province varied with different regions,concentrating on western Guangdong area,Jiangmen-Yangjiang coastal area,Shanwei-Huizhou Coastal area and eastern Guangdong.The wind hazard accidents and maximum wind speed in these areas have a significant positive correlation.By analyzing the differences of wind speed on different terrain conditions in Guangdong,we found that wind speed appeared that coastal areas>Coastal Cities>lain windward slope>mountain>leeward slope>valley.Further,we analyzed the spatial distribution of Guangdong power grid damaged tower by typhoon named "Rainbow",and found that the damaged towers focused on the right side of typhoon landing area.Finally,based on annually historical data of gale in Guangdong and mesoscale numerical prediction model(WRF3.6),we used the methods of PLS-MOS and CALMET technology to establish a statistical diagnosis model and a high-resolution wind hazard precaution model.The historical tests showed that the statistics model and the numerical model behaved well in the forecast of the spatial distribution and temporal variation of wind speed,and this can provide technical support for the high-resolution wind hazard precaution system in Guangdong power grid. |
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