Research On Ice-coating Prediction And Ice-melting Decision Of Transmission Lines

The icing disaster will cause serious losses to the power grid,damage the transmission lines and towers,and even cause the power supply to be interrupted in some areas.Based on the analysis of the mechanism of transmission line icing,this paper establishes a transmission line icing thickness prediction model,and based on the prediction results,proposes a multi-objective optimization ice melting decision model.The main contents are as follows:First,the mechanism of transmission line icing is analyzed in detail from the meteorological causes of transmission line icing,icing process and conditions,icing influencing factors and types.At the same time,two major hazards caused by icing are analyzed,namely mechanical faults and electrical faults.Then,for a small sample of transmission line icing data,an icing prediction model based on VMMD-IGWO-LSSVM was established.Variational modal decomposition(VMD)is used to decompose the ice thickness data to obtain sub-components with different center frequencies.And the improved gray wolf algorithm(IGWO)is used to optimize the parameters of the penalty factor and the width of the kernel function.The least squares support vector machine(LS-SVM)prediction model is established for each sub-component,and integrated into the total prediction value.The monitoring data of transmission lines of Guizhou power grid is selected,and the simulation experiment analysis is carried out to verify the accuracy of the model.Finally,a multi-objective optimal ice melting decision model is established.According to meteorological data,the ice thickness of transmission lines is predicted by the VMD-IGWO-LSSVM ice thickness prediction model.And according to the predicted icing thickness,the total load of the transmission line is calculated.Then,the outage probability of the transmission line is calculated by the stress-strength interference model,which is used to analyze the risk of the system during icing.The particle multi-objective swarm optimization algorithm(MOPSO)is used to solve the problem,and then the optimal ice melting decision plan is selected by the step-by-step screening method.The IEEE RST-79 reliability test system is used to simulate and analyze the model proposed in this paper,which verifies the validity and superiority of the model.