Simulation Study Of Fouling Accumulation Of Non-regular Particles In High Voltage Insulators

Electricity is an important source of energy for modern society and is an essential part of industrial production and daily life.As the grid is the carrier of electricity transmission and distribution,it is important to ensure its continuous and stable operation.As one of the main factors affecting the normal operation of the power grid,the maintenance department of the power grid needs to clean the insulators in operation with regular outages to avoid fouling accidents.In this paper,we study the fouling characteristics of insulators with nonregular particles by simulation and experimental methods to provide a basis for insulator maintenance and fouling resistance design.The fouling accumulation process of insulators consists of two processes:the movement of haze particles and the collisional adsorption of insulators.In this paper,the fouling accumulation process of XP-70 type porcelain insulator is studied by the multi-field action of non-regular haze particles in the turbulent field around the insulator and the highvoltage DC ion flow field.Unlike spherical particles,the process of adsorption of nonregular particles and insulator wall is multiple collision-bounce-collision again-tumblingfinal adsorption.In this paper,the Discrete Element Method(DEM)is used to numerically model the non-regular haze particles.The electric field around the insulator is calculated by considering the effect of the ion flow field formed by the wire breakdown air,and the Poisson equation coupled with the current continuity equation is used to solve the synthetic electric field distribution around the wire insulator.The flow field of the insulator is modeled by k-εturbulent flow.The simulation results show that the uncharged particles are mainly adsorbed on the leeward area of the upper surface of the insulator and the groove of the lower surface just below that.As for the charged particles,its fouling amount is significantly higher than that of uncharged particles.The negatively charged particles mainly attach to the upper surface of the insulator and the fouling amount is much higher near the grounding end than that near the high voltage end,while the positively charged particles mainly attach to the lower surface of the insulator and the fouling amount is much higher near the grounding end than that near the high voltage end and the middle insulator.In terms of experiments,natural accumulation experiments and particle size distribution measurement experiments,haze particle adhesion measurement experiments,and insulator wind tunnel experiments were conducted.The average particle size of the accumulated particles is 10.9 μm.The adhesion force of the particles to the insulator surface is measured by the probe method.The size measured by the scanning electron microscope is used to provide shape parameters for the DEM model of the particles.The wind tunnel is used to measure the wind field around a single insulator and compare it with the flow field calculation model to verify the validity of the turbulence model of the insulator.