基于场路结合的35kV变电站雷电侵入波分析

发布时间：2018-05-07 05:56

本文选题：雷电侵入波 + 35kV变电站　；参考：《华北电力大学(北京)》2017年硕士论文

【摘要】：35kV变电站在我国电力系统中所占比重大,对整个电力系统的安全、稳定运行有着重要影响。由于35kV系统的绝缘配置不高,因此在线路落雷时产生的雷电过电压波侵入变电站时,对变电站内设备尤其是变压器会造成严重的安全威胁。实际运行经验表示,在现有的防雷措施配置下,35kV变电站内变压器因雷电侵入波而损坏的情况依旧较为严重。本文结合实际运行情况以某35kV变电站为例展开研究。首先利用有限元法对本文所涉及的35kV变压器进行静电场、静磁场分析,提取雷电冲击下变压器建模所需的相关参数,如纵向电容、对地电容以及绕组电感等,建立变压器在雷电冲击下的电磁暂态模型。将变电站与进线段相结合视作整体,建立了包括输电线路、杆塔、绝缘子串以及变压器等电气设备在雷电冲击下的仿真计算模型。在考虑雷击点、雷电流大小以及杆塔接地电阻等因素并计及工频电压的情况下,利用电磁暂态仿真软件ATP-EMTP仿真进线段发生绕击和反击事故,分析进线段落雷时雷击对进线段线路的影响以及雷电侵入波在变压器绕组中的波过程。最后根据仿真结果从经济、实用的角度提出对35kV变电站进线段杆塔架设线路避雷器同时在变压器高压绕组中性点装设避雷器的防雷优化措施。经仿真验证,此防雷优化方案可有效降低雷电侵入波对变压器的威胁,同时大幅提高了进线段线路的耐雷水平。
[Abstract]:The 35kV substation occupies a large proportion in the power system of our country and has an important influence on the safety and stability of the whole power system. Because the insulation configuration of 35kV system is not high, the lightning overvoltage wave generated when the line falls into the substation will pose a serious security threat to the equipment, especially the transformer, when the lightning overvoltage wave invades the substation. The actual operation experience shows that the transformer in 35 kV substation is still damaged by the lightning intrusive wave under the existing lightning protection measures. In this paper, the actual operation of a 35kV substation as an example to carry out the study. Firstly, the static field and static magnetic field of 35kV transformer are analyzed by finite element method, and the relevant parameters such as longitudinal capacitance, ground capacitance and winding inductance are extracted. The electromagnetic transient model of transformer under lightning shock is established. Based on the combination of substation and line entry section, the simulation model of electric equipment including transmission line, tower, insulator string and transformer under lightning shock is established. Considering the lightning strike point, the lightning current and the grounding resistance of the tower, and taking into account the power frequency voltage, the electromagnetic transient simulation software ATP-EMTP is used to simulate the fault of winding and counterattack of the incoming line segment. The influence of lightning stroke on the line entry line and the wave process of lightning intrusive wave in transformer windings are analyzed. Finally, according to the results of simulation, from the economic and practical point of view, the lightning protection optimization measures for installing lightning arresters in the neutral point of transformer high-voltage winding at the same time are put forward. It is proved by simulation that the lightning protection optimization scheme can effectively reduce the threat of lightning intrusion wave to the transformer and improve the lightning resistance level of the incoming line line by a large margin.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM863

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