Evaluation Of Power System Structure Safety And Emergency Dispatch Strategy Under Typhoon Environment

Power transmission corridors exposed to external environment are always damaged by typhoons because of their great destructive power.In recent years,the construction of power grids has grown rapidly which means that the number of power transmission channels in the areas with complex topography and severe weather conditions has gradually increased,bringing extremely severe challenges to the power operation departments.Therefore,understanding the influence of geography and meteorology on the power grid,reducing the impact of catastrophic natural disasters on the power grid,and ensuring the safety and the reliability of the power grid is an urgent problem for the state grid.In order to improve the early warning capability of power grids during typhoons,this paper proposed that in a short time,the simple prediction of typhoon tracks is better than the similarity prediction method commonly used in meteorological stations.As the probability distribution of predictive error of radius and angle based on simple prediction is sampled by accept-rejection method,the problem of inadequate samples regarding historical data of typhoon tracks is resolved and then it creates the predicted area of typhoon tracks.At the same time,the global geographical elevation information is integrated with the geographic information of the transmission towers.With this geographical information,the wind load of the transmission towers is corrected by the altitude information of the tower.In case study,based on the analysis of the actual data loss in power transmission corridors under the influence of Meranti in 2016,it is verified that this method is effective and can be used pragmatically in an actual system operation.In order to describe the influence of typhoons on the power grid.This paper establishes a wind field model based on automatic meteorological station measurement.The method is based on the measured data of multiple automatic weather station to identify the maximum radius of the eye of the storm,to obtain accurate accurate radius information for the eye of the storm.By further analyzing the actual damage inflicted,it was found that the inverted towers were concentrated in a small area.According to the characteristics of the local inverted towers,a geographical model of the inverted towers in the area of Xiamen during Meranti was constructed.Based on the actual typhoon situation,FLUENT was used to simulate and analyze the numerical fluid dynamics to restore its microtopography and micrometeorology.The fault probability curves of the microtopography were established totowers in the area of Xiamen during Meranti was constructed.Based on the actual typhoon situation,FLUENT was used to simulate and analyze the numerical fluid dynamics to restore its microtopography and micro-meteorology.The fault probability curves of the microtopography were established to analyze the fault probability of the tower under the microtopography during a typhoon.Furthermore,this paper also presents an optimal security power flow model which adheres to safety restrictions in strong typhoon conditions.This is achieved by considering the combination of high fault probability scenarios which may occur during a typhoon and calculating the optimal results while satisfying all the constraints to formulate an optimal adjustment scheme.Compounding the above,this paper elucidates that the result of the maximum probability scheme corresponding to the power flow calculation could be used as an emergency control plan,which could provide referential real-time control information for subsequent risk assessments.To conclude,by comparing the influence of Typhoon "Rananim" and "Khanun" on Taizhou power grid,this paper points out that the destructive power of rainstorms on transmission towers should not be underestimated.This paper uses the Logistic model to fit the relationship curve between the rainfall and the ultimate wind speed,and proposed a joint failure probability curve model which was suitable for the failure evaluation of the tower in the typhoon.In order to avoid the accumulation effect of the smaller failure probability in the series system,this paper uses the threshold screening method to warn the towers with the highest probability of failure in the transmission channel.By drawing from typhoon "Mujigae" and "Meranti" as examples for early warning analyses,the results are suitable to actual circumstances.