真实直流超高压长电缆中空间电荷分布的激光压力波法测量技术与方法的研究

The proposal hopes to study the measurement technology and the method of space charge distribution for the real long cable under ultra high DC voltage. The laser PWP method (pressure wave propagation method) will be used, to measure the space charge distribution in the real long cable with 20-30mm thickness and under 200-500kV applied voltage. The power pulsed laser acts on the outer screen of cable, and the measuring signal is also drawn from the outer screen of cable.In this project, we will present the suitable physical model for the measurement, and the suitable method for the treatment of measuring data. The raltive experimrntal technology, the method to calibrate the electric filed distribution and space harge distribution will be obtained. On this measurement technology, to heat the inner condutor of cable, the experimental method to measure space charge distribution in cable under the real running condition of high voltage cable. To study the effect of gradient temperature field, and to get the suitable experiemntal dada treatement for space charge measurement in cable are also the goal on this project. At first it is necessary to test the small cable in the laboratory for checking the exparimental model, then the measuring system for a long real ultra-high voltage cable will be setup in the high voltage test hall. The raltive experimental technology and the relative method for data treatement will be obainted during this project.

本项目建议对于真实的直流超高压长电缆在直流工作电压条件下的空间电荷测量技术与方法进行研究。拟采用激光压力法，对绝缘介质厚度约为20-30mm的真实超高压长电缆在200-500kV的直流高电压情况下测量其空间电荷分布。大功率激光脉冲作用于电缆的外层屏蔽上，测量信号也同样取自电缆的外层屏蔽。在项目研究中将提出合适的物理模型与实验数据处理方法，同时总结出相应的实验技术，提出电场校正方法与电荷分布标定方法。在此基础上，用感应加热的办法对电缆的内导体进行加热，在模拟高压电缆实际运行条件的情况下测量超高压电缆中的空间电荷分布。研究温度梯度场对于测量的影响，并提出在温度梯度场情况下的测量电场与空间电荷测量的数据校正方法。先进行实验室小规模试验的基础上，然后在高压试验大厅中组建用于真实长电缆在超高压下进行空间电荷分布测量的专用测量系统，总结相应的实验技术，并建立相应的数据处理方法。

本项目完成了真实直流超高压长电缆中空间电荷分布的压力波法测量原理、测量系统与相关的测量技术的研究，提出了对同轴圆柱结构（电缆）的压力波法测量的物理模型与解释表达式，完成了在320kV条件下真实长电缆的激光压力波法的空间电荷分布测量，还完成了在温度梯度条件下电缆中空间电荷分布的测量。.本项目的主要理论研究成果——同轴结构压力波法测量的物理模型与解析表达式首次发表在国内期刊“物理学报”上，关于电缆测量的技术讨论与分析的研究结果发表在IEEE Trans on DEI，其他成果部分在国际会议上作过交流，将在期刊陆续发表。.本项目的研究成果，奠定了用压力波法测量真实长电缆的空间电荷分布的理论与实验技术基础，目前已经实现能够在真实长电缆上仅将电缆的护套与铠装打开一小段窗口而不破坏外半导电屏蔽层的情况下，进行激光压力波法的空间电荷分布测量。