Persistent severe smog and dust weather exists in many regions of China.Particles accu-mulate on the surface of high‐voltage transmission lines,which affects the surface morphology of the transmission line and induces corona discharge.This work mainly studies the influence of electric field and photocatalysis on the corona characteristics of transmission lines.In this work,plasma spraying is used to prepare a dense,smooth and excellent photocatalytic TiO_(2)coating on the surface of transmission wires.An electron microscope and a white light interference profilometer is used to study the surface condition of the samples.The variation in the surface condition of the samples is observed under different fouling,light time and electric field intensity.The corona characteristics of power transmission lines under different surface conditions are studied.The results show that light and applied electric field promote the photocatalytic effect of TiO_(2),which helps to decompose the contamination on the surface of power transmission wires and thus reduce the corona discharge of transmission lines.The increase in corona inception voltage reduces the corona current pulse repetition rate and the ion current density during corona discharge.
Conductor corona performance is significant in the evaluation of electromagnetic environment for high voltage power transmission lines. The influence of artificial contaminated conductors on corona discharge was studied and turned out to be complicated. The ionized field strength on the corona cage was measured by field mill. Meanwhile, photos of corona plumes were photographed and grayed to quantitate the corona discharge intensity. Subsequently, a calculation model for equivalent electric field strength coefficient was established to evaluate the discharge intensity of conductors in coaxial cylindrical electrode. It could be found the computational results achieved an agreement with the observed experimental phenomena. By means of simulation results, a reasonable explanation was given to the finding that the closer the distance between the two protrusions was, the lower the corona discharge intensity and higher corona inception voltage of the conductors would be. In summary, the distributions of corona sources played an important role in the corona discharge and this work would provide an important reference for the evaluation of corona effects on the surface of contaminated conductors.
为了深入研究在正极性电压下导线表面污秽对可听噪声频谱特性的影响,在实验室搭建了基于电晕笼的单电晕点可听噪声测量实验平台。分别测量了单电晕点表面附着氯化钠、高岭土、碳粉等不同种污秽下的可听噪声频谱特性,并且对不同表面状态下单电晕点在不同电压下的可听噪声频谱进行了长期的统计。结果表明:随电压增加,干净单电晕点的可听噪声不同频率分量的变化有较大差异。相对于干净导线,污秽对单电晕点噪声频率<1 k Hz分量的影响较小,对噪声频率>1 k Hz分量影响较大。对噪声高频分量的影响主要由于电子及离子在高场强下,运动速度较快,所含的能量较大,从而引起其周围空气强烈震动,产生高频噪声。
As the surface conditions play a significant role on corona discharge and its related effects of the conductors,the influence of fine particulate matter on positive-polarity,direct-current conductors was studied experimentally in this study.The surface morphologies of the conductor could be discovered from the experiments.The typical morphologies are the parallel chains of particles.To evaluate the surface condition quantitively,the surface roughness of the conductors is measured.It is found that the applied voltage and testing time have a great influence on the surface condition.After that,the corona characteristics of conductors are tested.It reveals that the total ground level electric field and ion flow density increases with the surface roughness growing.
