摘要
近年来配电网管廊中10 kV三相电缆的金属屏蔽频繁被盗,无屏蔽层电缆极易引发绝缘问题,严重影响配电网管廊的安全性。为此以YJV22型10 kV无屏蔽层电缆为对象,针对深度为1.95 mm、2.45 mm、2.95 mm的划伤,100~300 Pa压强下的挤压变形,0~31.9 mm间距松散结构等状态开展电磁热结构场仿真研究。仿真结果表明:不同尺寸的划伤缺陷会引发电缆内部电场发生不同程度的畸变,且在缺陷充水情况下的畸变场强远高于缺陷充空气情况下的畸变场强;无屏蔽层电缆在受到不同大小挤压力后会发生不同程度的形变,进而影响电缆内部电场发生变化,受挤压位置处电场强度大;松散分布的无屏蔽层电缆交流电阻减小,导体温度降低,载流量增大。根据以上分析结果,提出必要的维修措施以避免由畸变场强造成的击穿事故。
In recent years,the metal shields of 10 kV three-phase cables in the distribution network pipe gallery are frequently stolen,the unshielded cables easily lead to insulation problems,which seriously affect the safety of the distribution network pipe gallery.Therefore,taking 10 kV YJV22 unshielded cable as the object,the electromagneticthermal-structural field simulation research is carried out for defects such as scratches with depths of 1.95 mm,2.45 mm,2.95 mm,extrusion deformation under 100~300 Pa pressure,and loose structure with spacing of 0~31.9 mm.The simulation results show that the different sizes of scratch defects will cause different degrees of distortion of the electric field inside the cable.The distortion field strength in the case of defect filling with water is much higher than that in the case of defect filling with air.The unshielded cable will deform in different degrees after being subjected to different extrusion pressures,which will affect the electric field distribution inside the cable.The electric field intensity is larger at the squeezed position.The AC resistance of loosely laid unshielded cable decreases,the conductor temperature decreases,and the ampacity increases.According to the analysis results,necessary maintenance measures should be taken to avoid breakdown accidents caused by distorted field strength.
作者
杨帆
方健
何嘉兴
黄柏
YANG Fan;FANG Jian;HE Jiaxing;HUANG Bai(Power Test and Research Institute of CSG Guangdong Guangzhou Power Supply Bureau,Guangzhou,Guangdong 510000,China)
出处
《广东电力》
2023年第3期122-130,共9页
Guangdong Electric Power
基金
南方电网广东广州供电局配电网类科技项目(GZHKJXM20200028)。
关键词
10
kV电缆
剥皮情况
有限元分析
多物理场仿真
绝缘缺陷
10 kV cable
peeled condition
finite element analysis
multi-physics simulation
insulation defects
