摘要
变压器等输变电主设备的油纸介质已越来越不能满足特高电压等级对大容量、小型化、高可靠性绝缘系统的严格要求。为了解决输电电压等级提高带来的高性能变压器油及油纸绝缘问题,基于纳米改性技术,开展具有优异电气性能的新型纳米油纸复合绝缘系统的研究。采用变压器油纳米添加改性技术,研究了纳米改性变压器油的制备方法,得到了纳米改性提高变压器油破坏特性的最佳配比,并对纳米改性变压器油在交流、直流、雷电冲击下的破坏特性和局部放电起始电压进行了对比研究。研究发现纳米改性可以提高在较大间隙下变压器油的击穿电压,并且能显著提高其局放起始电压,改善其雷电冲击下50%放电伏秒特性曲线。基于纳米粒子介质球在电场中的极化理论,研究了粒子表面极化电荷密度分布和产生的势阱,并指出纳米粒子界面对载流子的捕获和流注的阻挡作用是较大电极间隙下纳米改性变压器油绝缘性能提高的原因。研究结果说明了纳米改性对于变压器油纸绝缘系统的性能提高提供了新的可能途径。
The oil-paper insulation used in main power apparatuses such as transformer may not meet the strict demands of insulation system with large capacity,miniaturization and high reliability at ultra-high-voltage level.However,the liquid sol formed by nanoparticles and transformer has good dielectric characteristics,which may bring an effective way to solve the insulation problems.Based on the modifying technology of nanoparticles,a new kind of transformer oil modified by nanoparticles was studied.The preparation methods of transformer oil modified by nanoparticles were investigated,and the best percentage of nanoparticles was obtained.Moreover,the breakdown process and partial discharge inception voltage of nanoparticles modified transformer oil were compared with normal transformer oil.The experimental results show that nanoparticles modifying could increase the breakdown voltage of transformer oil at comparatively long gap,significantly increase the partial discharge inception voltage,and improve the voltage-time curve by 50% at lightening impulse.Based on the polarization model of dielectric spherical nanoparticles,the distribution of polarized charge on the surface and hence induced potential were studied.It is pointed that the improvement of nanoparticles modified transformer at comparative long gap lies in the interface of nanoparticles,where the carriers are captured and the streamers are blocked.Nanoparticles modifying technology provides a new effective way to improve the performance of oil-paper insulation system in transformers.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2010年第5期1155-1159,共5页
High Voltage Engineering
基金
国家自然科学基金(50438070)
教育部博士点基金(200800030040)
教育部新世纪优秀人才支持计划(NCET-04-0095)~~
关键词
纳米改性
油纸复合绝缘
变压器油
破坏特性
伏秒特性
极化
nanoparticles modifying
oil-paper insulation
transformer oil
breakdown characteristics
volt-second characteristics
polarization
