XLPE电缆局放检测技术及其应用

介绍了上海市电力公司近年来在保障XLPE电缆稳定可靠运行方面做的一些工作,主要基于宽频电磁耦合技术,结合当前先进的超高频和超声局放测试技术,提出声电联合的测试思想,综合现场验收、日常巡检和重点监测三方面考量,采用便携、移动和固定安装相结合的策略,通过外购国内外成熟产品及与国内高校开展科研合作,全面提升上海市电力公司在X...     

基于分布式光纤测温传感器电缆温度监控系统

智能配电网中对电缆运行相关信息监控的集成已成趋势。介绍了一套基于分布式光纤测量技术的电力电缆温度实时监控系统。叙述了该系统的架构及方案设计,系统具有的显示界面清晰、工井三维显示、形成实时负荷温度响应曲线等功能特点。     

电缆附件温度在线监测方法研究

提出基于磁场感应和无线通信的温度监测方案具有较好的可行性,该方案分析了设计控制方法中的电源供给部分,给出了实验结果,检验了监测装置的安全性、可靠性与精度问题。     

35kV单芯电缆金属屏蔽层感应电压计算及接地处理方案

通过对单芯电缆金属屏蔽层感应电压的计算得出,在三相回路系统中,当三相平衡负载情况下以对称敷设(等边三角形敷设)时,电缆金属屏蔽层上的感应电压最小且相等.提出了多点接地的单芯电缆金属屏蔽层感应电压处理方案.该方案是中间直接接地、两端保护器接地方式的进一步发展,两端通过端保护器接地,而中间在一定范围内进行直接接地.采用该接...     

基于统计分析和模糊推理的运行交联聚乙烯电力电缆绝缘老化诊断(英文)

Cables that have been in service for over 20 years in Shanghai, a city with abundant surface water, failed more frequently and induced different cable accidents. This necessitates researches on the insulation aging state of cables working in special circumstances. We performed multi-parameter tests with samples from about 300 cable lines in Shanghai. The tests included water tree investigation, tensile test, dielectric spectroscopy test, thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), and electrical aging test. Then, we carried out regression analysis between every two test parameters. Moreover, through two-sample t-Test and analysis of va- riance (ANOVA) of each test parameter, we analyzed the influences of cable-laying method and sampling section on the degradation of cable insulation respectively. Furthermore, the test parameters which have strong correlation in the regression analysis or significant differ- ences in the t-Test or ANOVA analysis were determined to be the ones identifying the XLPE cable insulation aging state. The thresholds for distinguishing insulation aging states had been also obtained with the aid of statistical analysis and fuzzy clustering. Based on the fuzzy in- ference, we established a cable insulation aging diagnosis model using the intensity transfer method. The results of regression analysis indicate that the degradation of cable insulation accelerates as the degree of in-service aging increases. This validates the rule that the in- crease of microscopic imperfections in solid material enhances the dielectric breakdown strength. The results of the two-sample t-Test and the ANOVA indicate that the direct-buried cables are more sensitive to insulation degradation than duct cables. This confirms that the tensile strength and breakdown strength are reliable functional parameters in cable insulation evaluations. A case study further indicates that the proposed diagnosis model based on the fuzzy inference can reflect the comprehensive aging state of cable insulation well, and that the cable service time has no correlation with the insulation aging state.