摘要
套管是电力变压器的重要附件,其安全稳定运行至关重要。为此,常采用在线监测技术对其运行状态进行实时监测。在电网内部,变压器套管在线监测系统已有一定应用。然而,监测数据不仅取决于套管自身绝缘性能,而且受温度、湿度和系统运行电压等环境因素影响,且当前各套管监测厂家推荐的预警策略各异,难以满足应用要求。因此研究适宜的在线监测预警策略至关重要;文中对广东电网在运变压器套管的介损值历史监测数据进行了统计分析。研究发现变压器套管在线监测应用过程中会出现短时性、间歇性的数据异常,异常率接近1%,导致监测系统告警。剔除这些异常数据后,套管介损在线监测数据相对平均值在±15%范围内小幅波动,数据分布近似服从正态关系,进而提出在线监测时介损值相对变化应小于30%的新预警策略,优化了原有的预警策略,新的预警策略适应了不同类型变压器套管的出厂值差异,适用性更强。
In power grid, many on-line monitoring devices of transformer bushings have been used. However, monitoring data not only depend on insulation condition of the bushing, but also are affected by environmental condition, including such as temperature, ambient humidity and working voltage. In addition, the existing early warning strate- gies recommended by different bushing manufactures are diverse, which brings difficulty to the application of on- line monitoring. Therefore, proper warning strategy is essential for diagnosis of insulation defects. In this paper, the mathematical statistics are used to analyze the historical on-line monitoring data of in-service transformer bushings in Guangdong Power Grid, and about 1% of data exception are found, which cause false alarm. After removing these abnormal data, the data sample fluctuates slightly around the mean value within the range of±15% and is subject to approximate normal distribution. Furthermore, a novel warning strategy, i.e., the relative offset of the dissipation factor is limited within the range of 30%, is proposed and tested. The new warning strategy adapts to different rated dielectric loss of various types of transformers, and has better applicability.
作者
夏健
丁卫东
孙旭东
王亚楠
苟杨
王嘉琛
闫家启
钱凯洋
XIA Jian;DING Weidong;SUN Xudong;WANG Yanan;GOU Yang;WANG Jiachen;YAN Jiaqi;QIAN Kaiyang(School of Electrical Engineering,Xi＇an Jiaotong University,Xi＇an 710049,China)
出处
《高压电器》
CAS
CSCD
北大核心
2018年第9期171-176,共6页
High Voltage Apparatus
关键词
变压器套管
在线监测
介损
绝缘缺陷
预警策略
transformer bushings
on-line monitoring
dielectric loss
insulation defects
warning strategy
