Experimental Study On Pollution Accumulation Of High Voltage Direct Current Lines And Ground Equipment And The Inhibition Characteristics

The high voltage direct current(HVDC)has the advantages of flexible control mode,large transmission capacity,narrow line corridor and low line cost,which has been widely used at home and abroad in recent years.However,considering the overall economy,HVDC transmission lines generally run in corona discharge state,which will result in lines around the space there are a large number of ions.There are a large number of particles in the air,the charged particles are easily under the action of electric field force and polarization force attached to the HVDC transmission lines on the surface and ground equipment.When the HVDC transmission lines pass through the converter station area,the corona discharge intensity increases,and the pollution problem will be more serious.Based on this,the paper explored the pollution characteristics of HVDC transmission lines and ground equipment through the pollution experiment platform independently built,and proposed to suppress the pollution accumulation by covering with film on the surface of transmission lines.And through the control experiment of bare conductors and covered conductors,the inhibition effect of conductors covered with film on the contamination of transmission line and ground equipment is explored.The main research results are as follows:The pollution characteristics of ground equipment under different experimental conditions were studied.The experimental results show that: before the conductor corona,the pollution mass of ground equipment is small,conducting materials and insulating materials on the surface of ground equipment have the same pollution mass,the pollution mass of ground equipment increases linearly with the increase of particle concentration,the pollution mass under negative polarity is slightly greater than that under positive polarity.After the conductor corona,the pollution mass of ground equipment increased significantly,the pollution mass of conducting material on the surface of ground equipment is greater than that of insulating material,and the difference is more obvious with the higher voltage grade,with the increase of particle concentration,the pollution mass of ground equipment is gradually saturated;the pollution mass under positive polarity is greater than that under negative polarity.The pollution principle and the pollution characteristics of transmission lines under different experimental conditions were studied.The experimental results show that: the pollution of conductor is mainly caused by the particles under the action of polarization force,which has nothing to do with the electric field force of the particles.The pollution mass of conductor increases with the increase of conductor diameter,but the pollution mass per unit area of conductor decreases with the increase of conductor diameter.No matter before and after the conductor corona,the pollution mass of conductor increases linearly with the increase of particulate matter concentration.Conductor pollution does not have the polarity effect of ground equipment pollution.The inhibition characteristics of transmission line covering on pollution of ground equipment and transmission line were studied.The experimental results show that: the conductor covered with film by increasing the radius of the conductor and the accumulation of heterogeneous charges on the surface of the dielectric two ways to inhibit the pollution of the ground equipment and conductor.No matter XLPE material or PVC material,under positive polarity and negative polarity,the conductor covered with film has obvious inhibition effect on pollution of ground equipment and transmission line.Due to the difference of different film,compared with PVC material,XLPE film has a better effect of suppressing pollution of ground equipment and transmission line.