直流电缆料工作温度和击穿特性的纳米改性研究

Study on the Nanoparticle-modification of Working Temperature and Breakdown Characteristics for Insulating Materials in DC Cables

为改善目前商用直流电缆料的绝缘性能并提升其工作温度和击穿性能,通过向商用直流电缆料添加纳米Mg O和纳米Al(OH)3这2种不同的纳米填料,制备了纳米Mg O和纳米Al(OH)3的复合直流电缆料样品。分别对其不同温度下的电导率进行了测试,并利用脉冲电声(PEA)法空间电荷测量系统测量了其不同温度下的空间电荷特性,同时还对其不同极性下的击穿特性进行了测试。研究结果表明:添加纳米Mg O和纳米Al(OH)3都能减小温度对电导率和空间电荷特性的影响,提升其高温下的电导率和空间电荷性能,减少直流电缆中的电场畸变;但添加纳米Al(OH)3能提升直流电缆料的短时击穿性能25%,而添加纳米Mg O则不能提升。因此添加纳米Al(OH)3填料对提升商用直流料的工作温度和击穿性能更有效。

In order to improve the insulation performance of commercial DC cable materials, including raising their working temperature and enhancing their breakdown performance, we added MgO nanoparticles and Al（OH）3 nanoparticles to commercial DC cable materials, respectively, and fabricated two kinds of nanocomposite specimens. Moreover, we tested the conductivity under different temperatures, space charge distribution under different temperatures（using the PEA method）, and breakdown characteristics under different polarity of the specimens. The results show that adding either MgO or Al（OH）3 nanoparticles to the DC cable materials will reduce the thermal influence on both conductivity and the space charge characteristics, increase the materials＇ electrical conductivity under high temperature, enhances their space charge properties under high temperature, and reduce the electric field distortion in DC cables made of the materials. In the meantime, adding Al（OH）3 can obviously improve the materials＇ short-termbreak down performance by up to 25 percent, whereas adding MgO nanoparticles fails to get any similar improvement. Hence it is concluded that adding Al（OH）3 nanoparticles is more effective in improving the performances of commercial DC cable materials in the aspects of increasing the working temperature and enhancing the breakdown performance.