Electric field distribution characteristics and discharge ablation mechanism of insulated conductors considering tree barrier types
After the occurrence of line tree barriers,it is difficult to successfully reclose the line,which can easily cause line shutdown.There are multiple major power outages caused by tree barriers both at home and abroad,but the electric field distribution characteristics and discharge mechanism of insulated conductors with different types of tree barrier are still unclear.Therefore,electrostatic field models of insulated conductors with different types of tree barrier were established on the basis of finite element theory in this paper,and the erosion mechanism of tree barrier discharge was revealed according to the obtained electric field distribution and gas-solid discharge theory.The results show that the tree barrier types of insulated conductor are mainly divided into four categories:single side wedge-shaped penetration defects,flat cut defects,double wedge-shaped penetration defects,and critical contact between wood throns and defects tree barrier-wire types.The electric field undergoes distortion at the defects of tree barrier,and the wedge-shaped penetration defects can cause gas breakdown and discharge at the site of tree branch-insulation wire,which poses the greatest damage to the surface of insulation wire and the erosion of tree branches.The field strength at the defect site is affected by the degree of defect and air gap,and the maximum electric field strength of the wood thorn penetrating into the insulation layer is 2.64 times higher than that of the wood thorn penetrating only into the shielding layer.The wind disturbance causes the critical contact between the wood thorn and defect to generate air gap,and its electric field is 2.54 times higher than that without air gap(5.65 kV/mm).The research results provide a theoretical basis for different types of tree barrier defense methods,avoiding the drawbacks of cutting tree indiscriminately.
tree barrier typeinsulated conductorelectric field distributiondischarge ablation
万方数据
维普
