上海南汇风电场柔性直流输电示范工程研究

A Demonstration Project of Flexible DC Power Transmission in Shanghai Nanhui Wind Power Station

上海南汇风电场柔性直流输电示范工程是国内首条采用柔性直流输电电缆的工程。针对这些电缆,通过脉冲电声测试方法得到了空间电荷的分布规律,在温控电极系统中研究了不同温度和电场下绝缘材料电导率的变化规律,进而计算得到了电缆绝缘层的电场分布。介绍了直流电缆敷设时为消除与附近交流电缆的感性耦合影响所需采取的相应措施以及电缆附件安装关键工艺等。研究结果表明:进行电缆附件设计时需重点考虑电缆绝缘层与附件绝缘层交界面上累积空间电荷的影响;且2种绝缘材料的电导率与介电常数之比越接近,则界面电荷越少。

Shanghai Nanhui Wind Power Station Flexible DC Power Transmission Line is a demonstration project that applies flexible DC power transmission cables for the first time in China. According to these cables, we obtained the distribution of space charge using the pulsed electro-acoustic testing method, investigated the conductivity distribution of the insulating material under various temperatures and electric fields in a temperature controlled electrode system, and calculated the electric field distribution in the cables＇ insulation layers. Additionally, we put forward necessary measures and key processes of cable accessories installation to eliminate the inductive coupling effect caused by nearby AC cables. It is obtained that, in designs of cable accessories, it is important to take into account the impact of accumulated space charges on the interface between cable insulating layer and cable accessory insulating layer, where the charge amount decreases when the difference between the ratios of conductivity to dielectric constant of the two layers＇ materials gets smaller.