摘要
假设雷电直击在一条配电线路的不同位置上,该配电线路一端接入一台带中心抽头的单相变压器。配电线路采用改进的JMarti模型进行建模,该模型包含了随着频率变化的接地电阻率和土壤介电常数。然后将变压器视为一个具有宽频率范围的等效二端口模型,同时利用实际破坏性试验参数对变压器高压端绝缘的击穿进行建模,为了方便,建模过程中将变压器接地阻抗简化为接地电阻率来处理。使用不同的计算参数对变压器二次侧电压进行建模计算。研究表明,分散式接地参数对变压器相对中性点的电压,通过变压器传输至低压侧之后的数值不具有显著的影响。
In this study,a direct lightning strike is assumed at different points of a distribution line terminated at a 10 k VA 7. 967 k V/240-120 V single-phase transformer with center-tapped secondary. The distribution line is modeled using the modified JMarti model to include the variation with frequency of the ground resistivity and permittivity. The transformer is represented as a two-port model validated in a wide frequency range. Insulation breakdown is modeled using the disruptive effect method and for simplicity the grounding impedances are represented as simple resistances.Voltages transferred to the transformer secondary are calculated for different conditions. It is shown that considering dispersive ground parameters does not have a significant influence on phase-to-neutral voltages transferred through the transformer to its low-voltage side in the investigated cases.
作者
秦培林
吕泽红
QIN Peilin;LU Zehong(Department of Electrical Engineering,Guangxi Technological College of Machinery and Electricity,Nanning 530007,China;Guangxi Boyang Electric Power Survey ＆ Design Co.Ltd.,Nanning 530072,China)
出处
《实验室研究与探索》
CAS
北大核心
2018年第6期48-51,共4页
Research and Exploration In Laboratory
关键词
输电线模型
频变接地参数
多频模型
雷电过电压
transmission line model
frequency-dependent ground parameters
wideband model
lightning over-voltages
