非线性复合绝缘材料有助于解决电力系统绝缘设备或部件电场分布不均匀的难题。为此介绍了Zn O压敏陶瓷微球及其复合绝缘材料的制备方法,实现了同时具有非线性电导特性和非线性介电特性随外加电场而自适应变化的复合材料。材料的非线性...非线性复合绝缘材料有助于解决电力系统绝缘设备或部件电场分布不均匀的难题。为此介绍了Zn O压敏陶瓷微球及其复合绝缘材料的制备方法,实现了同时具有非线性电导特性和非线性介电特性随外加电场而自适应变化的复合材料。材料的非线性特性主要由压敏微球填料决定,而对于绝缘材料基体的要求较为宽松;当材料中的压敏微球体积分数超过30%时,复合物具有很好的非线性特性,其电导非线性系数可达到16.9而介电常数也能够比线性区增加5倍以上;材料的压敏电压也能够根据填料体积分数进行一定范围内的调节。采用非线性电导特性和非线性介电特性的复合材料取代传统电缆附件中控制电缆接头电场应力的压控管和应力锥的材料对电场的应力控制效果更好,对于110 k V的交流电缆终端内电场分布的仿真计算表明,在应力锥绝缘部分采用非线性材料能够将关键位置处的场强从采用固定材料时的4.7 k V/mm降低至2.2 k V/mm以下,并且材料的电导率越大、非线性系数越大时,均匀场强的效果越好。展开更多
The influence of soaking time on the nonlinear electrical behavior and dielectric properties of TiO2-based varistor ceramics was investigated. Based on single sintering process, six disk samples of （Sr, Bi, Si, Ta）-...The influence of soaking time on the nonlinear electrical behavior and dielectric properties of TiO2-based varistor ceramics was investigated. Based on single sintering process, six disk samples of （Sr, Bi, Si, Ta）-doped TiO2-based varistor ceramics were fabricated by sintering at 1 250 ℃ for 0.5-5.0 h. The samples were characterized by X-ray diffraction, voltage-current characteristics, energy spectra, metallographs, breakdown voltages, and apparent dielectric constant. It is found that the breakdown electrical field intensity at a current density of 10 mA/cma decreases from 5.5 to 4.1 V/mm first and then increases to 7.0 V/mm, the nonlinear coefficient increases from 2.39 to 2.62 first and then decreases to 2.42, and the apparent dielectric constant increases from 98 200 to 1l5 049 first and then decreases to 73 865 with the soaking time increasing from 0.5 to 5.0 h. These indicate that the optimal soaking time is 2.0-3.0 h considering both nonlinear electrical behavior and dielectric properties.展开更多
文摘非线性复合绝缘材料有助于解决电力系统绝缘设备或部件电场分布不均匀的难题。为此介绍了Zn O压敏陶瓷微球及其复合绝缘材料的制备方法,实现了同时具有非线性电导特性和非线性介电特性随外加电场而自适应变化的复合材料。材料的非线性特性主要由压敏微球填料决定,而对于绝缘材料基体的要求较为宽松;当材料中的压敏微球体积分数超过30%时,复合物具有很好的非线性特性,其电导非线性系数可达到16.9而介电常数也能够比线性区增加5倍以上;材料的压敏电压也能够根据填料体积分数进行一定范围内的调节。采用非线性电导特性和非线性介电特性的复合材料取代传统电缆附件中控制电缆接头电场应力的压控管和应力锥的材料对电场的应力控制效果更好,对于110 k V的交流电缆终端内电场分布的仿真计算表明,在应力锥绝缘部分采用非线性材料能够将关键位置处的场强从采用固定材料时的4.7 k V/mm降低至2.2 k V/mm以下,并且材料的电导率越大、非线性系数越大时,均匀场强的效果越好。
基金Project(50872001) supported by the National Natural Science Foundation of ChinaProjects(KJ2007B132, KJ2009A006Z) supported by the Scientific Research Foundation of Education Department of Anhui Province, ChinaProject(XJ200907) supported by the Foundation of Construction of Quality Project of Anhui University, China
文摘The influence of soaking time on the nonlinear electrical behavior and dielectric properties of TiO2-based varistor ceramics was investigated. Based on single sintering process, six disk samples of （Sr, Bi, Si, Ta）-doped TiO2-based varistor ceramics were fabricated by sintering at 1 250 ℃ for 0.5-5.0 h. The samples were characterized by X-ray diffraction, voltage-current characteristics, energy spectra, metallographs, breakdown voltages, and apparent dielectric constant. It is found that the breakdown electrical field intensity at a current density of 10 mA/cma decreases from 5.5 to 4.1 V/mm first and then increases to 7.0 V/mm, the nonlinear coefficient increases from 2.39 to 2.62 first and then decreases to 2.42, and the apparent dielectric constant increases from 98 200 to 1l5 049 first and then decreases to 73 865 with the soaking time increasing from 0.5 to 5.0 h. These indicate that the optimal soaking time is 2.0-3.0 h considering both nonlinear electrical behavior and dielectric properties.
