CAJ | 학술논문

为研究引入皱纹纸对环氧材料介电特性的影响，通过介电谱及热刺激去极化电流(thermally stimulated depolarization current，TSDC)测量技术，对特高压直流干式套管用环氧及环氧/皱纹纸材料复介电常数、TSDC 特性进行了测量分析。提出了基于相对介电常数一阶导数的改进差分进化优化算法，该方法能有效分析环氧材料内各介电弛豫过程。试验结果表明：皱纹纸的引入使环氧复合材料复介电常数实部、虚部均变大(高温中频区除外)，其高温直流电导率也显著增大。与纯环氧相比，环氧/皱纹纸复合材料α(温度低于175℃时)、β、δ过程的弛豫时间均减小；α过程弛豫强度减小、δ过程弛豫强度显著增大；β过程活化能减小，δ过程活化能增加；环氧/皱纹纸复合材料中陷阱深度较浅、但陷阱密度显著增加。以上结果，可为干式套管绝缘材料配方评估、工艺改进提供方法及理论指导。
위연구인입추문지대배양재료개전특성적영향，통과개전보급열자격거겁화전류(thermally stimulated depolarization current，TSDC)측량기술，대특고압직류간식투관용배양급배양/추문지재료복개전상수、TSDC 특성진행료측량분석。제출료기우상대개전상수일계도수적개진차분진화우화산법，해방법능유효분석배양재료내각개전이예과정。시험결과표명：추문지적인입사배양복합재료복개전상수실부、허부균변대(고온중빈구제외)，기고온직류전도솔야현저증대。여순배양상비，배양/추문지복합재료α(온도저우175℃시)、β、δ과정적이예시간균감소；α과정이예강도감소、δ과정이예강도현저증대；β과정활화능감소，δ과정활화능증가；배양/추문지복합재료중함정심도교천、단함정밀도현저증가。이상결과，가위간식투관절연재료배방평고、공예개진제공방법급이론지도。
The dielectric properties of epoxy resin and epoxy/crepe paper composites which used in the ultra high voltage direct current (UHVDC) dry-type bushing were studied by the broadband dielectric spectrum and thermally stimulated depolarization current (TSDC) measurement. A modified differential evolution optimization method based on the derivative of the relative permittivity was proposed to resolve the dielectric relaxations in epoxy resin and its composites. Results show that the epoxy/crepe paper composites have larger relative permittivity and dielectric loss factor (except for in moderate frequency at high temperature), and dc conductivity at the high temperatures as well. The relaxation time ofα(<175℃),β,δ process decreases with the addition of crepe paper; the dielectric relaxation strength ofα process decreases, whereas it increases forδ process; activation energy ofβprocess decreases, whereas it increases forδ process. Trap density increases with the trap depth decreasing in epoxy/crepe paper composites compared with pure epoxy resin. The results are beneficial for theassessment of insulation material and manufacturing process improvement of dry-type bushing.