摘要
10 kV架空裸导采用并联间隙的单相安装方式可以有效提升线路耐雷水平,但使得线路与设备之间的绝缘水平差异进一步扩大,配电设备更易损坏。提高配电设备的绝缘水平及设备前端氧化锌避雷器(MOA)的通流容量在经济性上并不可行,笔者采用在10 kV线路末端加装耦合地线的方法解决该问题。研究了耦合地线的分流原理,认为其跨越的杆塔数和杆塔接地电阻是影响分流效果的主要因素。建立了并联间隙单相安装方式下的10 kV架空裸导线路过电压仿真模型,计算结果表明,在典型配置的10 kV架空线路中,当感应雷的感应点在配变前4基杆塔时,流经配变高压侧MOA的最大过电流能量超过了其安全运行的阈值;此时,在配变前2基杆塔架设耦合地线,且无需对杆塔进行接地处理,即可限制流经高压侧MOA的过电流幅值和热电荷传送值到安全阈值以下,分别最大降低69.4%和83.5%。所提方法对降低配电设备的故障率,调节线路和设备之间的绝缘水平差异具有重要作用。
The 10 kV overhead bare conductor adopts the single-phase installation mode with parallel gap, which can effectively improve the lightning resistance level of the line, but it further expands the difference in insulation level between the line and the equipment, and the power distribution equipment is more vulnerable to damage. It is not economically feasible to improve the insulation level of power distribution equipment and the current capacity of the zinc oxide arrester(MOA) at the front end of the equipment, the author adopts the method of installing coupling ground wire at the end of 10 kV line to solve this problem. The shunt principle of the coupled ground wire is studied, and it is considered that the number of poles and the grounding resistance of the poles are the main factors that affect the shunt effect. A 10 kV overhead bare-conducting line overvoltage simulation model under the parallel gap single-phase installation mode is established. The calculation results show that in a typical configuration of 10 kV overhead lines, when the induction point of the induced lightning is 4 base poles before the distribution transformer, the maximum overcurrent energy of MOA passing through high voltage side of distribution transformer exceeds the threshold of safe operation;at this time, the coupling ground wire is installed on the two base poles before the distribution transformer, and the poles and towers do not need to be grounded to limit the flow of the MOA on the high-voltage side, it can limit the overcurrent amplitude and thermal charge transfer value of MOA flowing through the high voltage side to below the safety threshold, the maximum reduction is 69.4% and 83.5%, respectively. The proposed method plays an important role in reducing the failure rate of power distribution equipment and maintaining the safe and stable operation of the distribution network.
作者
蒋凌峰
杨鑫
吴文锋
王延夫
汤昕
JIANG Lingfeng;YANG Xin;WU Wenfeng;WANG Yanfu;TANG Xin(School of Electricaland Information Engineering,Changsha University of Science&Technology,Changsha 410114,China;Changsha Electric Power Technical College,Changsha 410131,China)
出处
《电瓷避雷器》
CAS
北大核心
2022年第2期20-30,共11页
Insulators and Surge Arresters
基金
国家自然科学基金面上基金项目(编号:52177015)
湖南省自然科学基金项目(编号:2021JJ30725)。
关键词
并联间隙
单相安装方式
过电流
热电荷传送值
耦合地线
parallel gap
single phase installation
overcurrent
thermal charge transfer value
coupling ground wires
