复杂条件下交直流特高压输电线路无线电干扰和可听噪声特性的基础研究

The development of transmission lines is limited by the radio interference (RI) and audible noise (AN), especially for the UHV transmission lines, the reason is that the empirical formulas fixed from experimental data can not represent the essential principle of the RI and AN. The mesoscopic discharge characteristics are investigated in this issue based on the characteristic forms on the conductor surface, the intrinsic characteristics of the RI and AN, as well as the relationship between them and the corona current, are clarified, and the effects of the altitude and the other climatic factors on the corona current, as well as the corona electromagnetic and audible fields, are investigated. The model and numerical method for the transmission of the corona current along the conductor and for the corona electromagnetic and audible fields in space are proposed, the space charge distribution caused by DC corona will be measured, and the influence of the ionization zone in the vicinity of the AC and DC conductor and the effect of the space charges from the DC discharges on the transmission characteristics will be revealed. The distribution characteristics of corona currents on UHV AC and DC transmission lines and the spectrum characteristics of the corona induced RI and AN under complex conditions (including the high altitude, the humidity, the rain, the dust, et al.) are clarified based the characteristics and the random probability of the mesoscopic corona discharges coupled with the experiments for the UHV test lines and the practical UHV lines by the theory of the statistical electromagnetics, and then the numerical methods for predicting the macroscopic characteristics of RI and AN for UHV AC and DC transmission lines are proposed. The research findings can be applied for the transmission lines under different voltage classes.

无线电干扰和可听噪声制约输电线路的建设，而特高压线路尤为突出，其根源是目前基于试验数据的拟合公式无法反映二者产生的本质。本课题基于介观尺度的导线表面特征形态放电特性的研究，揭示输电线路无线电干扰和可听噪声的本征特性，探求无线电干扰和可听噪声与电晕电流的关联特性及其产生机理，分析海拔高度及其它气候因素对电晕电流特性、电晕电磁场和声场的影响特性；提出电晕电流沿导线传播模型、电晕电磁场和声场的空间传播模型及数值计算方法，揭示直流电晕空间电荷分布特性，研究导线表面电离层及空间电荷对传播特性的影响；基于介观尺度的电晕放电特性和随机概率分布，结合模型试验和真型导线试验，采用统计电磁学理论揭示复杂条件下（包括高海拔、湿度、雨、尘等）交直流特高压线路的电晕电流分布特性、无线干扰和可听噪声的频谱特性，建立预测交直流特高压线路无线电干扰和可听噪声宏观特性的计算方法。研究成果适用于不同电压等级输电线路。

我国的能源基地和大型负荷中心分离，能源基地分布在西部地区，而大型负荷中心则分布在东部。须采用特高压输电技术来实现远距离大容量的电能传输。而特高压输电线路电晕放电产生的电磁环境效应问题更加突出，已成为制约特高压输变电工程建设的关键问题，是输变电工程的技术经济要求和环境保护要求的矛盾的集中体现。.课题组围绕项目研究内容，重点研究了交直流特高压输电线路的无线电干扰和可听噪声的产生机理、本征特性和计算方法。从介观尺度层面研究了电晕放电的电晕电流特性、离子运动特性、空间电荷分布特性；揭示了电晕产生的无线电干扰和可听噪声的本征特性；研究了电晕电流与无线电干扰和可听噪声之间的关联特性，揭示了复杂条件下（包括海拔、湿度、降雨等因素）交直流特高压线路的无线电干扰和可听噪声的特性。最终建立了反映交直流特高压输电线路无线电干扰和可听噪声本质特征的宏观特性计算方法。.本项目为我国特高压输电线路的建设提供了科学理论依据和关键技术支撑，使我国特高压输电线路的电磁环境机理研究处于国际领先地位；同时为我国特高压输电线路的导线选择与结构设计提供科学技术支持，促进了输变电工程建设的环境友好性，同时也确保了电力建设的经济性；使我国特高压系统的电磁环境效应问题研究达到了研究方法先进、预测结果合理、改进措施有效的国际领先水平。课题的研究成果还提升了我国电气工程学科水平、培养了一批特高压输变电技术的高层次人才，并推进了气体放电理论、计算电磁学、计算数学等学科的发展。