基于四阶电路模型的特高压变压器雷电冲击电压试验波形调试研究  

Study on Debugging of Lightning Impulse Voltage Waveform for UHV Transformer Based on the Fourth Order Circuit Model

作　　者：窦圣霞 严绍奎 田瑞 DOU Shengxia;YAN Shaokui;TIAN Rui(Marketing Service Center of State Grid Ningxia Electric Power Co.,Ltd.,Yinchuan 750002,China)

机构地区：[1]国网宁夏电力有限公司营销服务中心(计量中心),银川750002

出　　处：《电瓷避雷器》2021年第6期102-107,共6页Insulators and Surge Arresters

基　　金：江苏省高校自然科学研究重大项目(编号:17KJA470003)。

摘　　要：雷电冲击电压波形正确与否对于雷电冲击电压试验的有效进行至关重要。本研究利用EMTP软件搭建接入变压器后的四阶雷电冲击电压试验回路,分析波头电阻选取对波前时间和峰值过冲系数的影响。讨论将四阶系统电路简化为三阶电路时变压器等效电感和电阻选取的限值。针对波头电阻选取存在的困难,分析阻尼装置对电压波形参数调整的作用。研究结果表明:波头电阻的增加能够有效抑制雷电冲击电压波形的振荡,降低峰值过冲系数;当且仅当回路内部电感和负荷电容都较小时,存在波头电阻选择区间使得波前时间和过冲系数同时满足标准要求,否则波前时间或过冲系数难以同时符合标准要求,回路中需要额外增加阻尼装置。阻尼装置时能够有效降低峰值过冲系数,使得产生的波形更加容易达到标准。当变压器等效电感和电阻处于一定限值区间内时,四阶雷电冲击电压试验回路能够转化为三阶电路以简化分析。Whether the lightning impulse voltage waveform is correct or not is critical to the effective implementation of the lightning impulse testing for UHV transformer. The fourth order circuit for generating the lightning impulse voltage waveform after interconnecting the transformer was established in EMTP. The influence of wavefront resistance on the front time and overshoot rate were discussed. The limit values of the equivalent load resistance and inductance for matching the response of fourth order to third order lightning impulse circuit were also determined. Finally, the damping device was also introduced in the equivalent circuit to solve the selection problem of wavefront resistance. Research results show that: the increase of wavefront resistance can effectively suppress the oscillation of the lightning impulse voltage waveform and reduce the overshoot rate. Only when the internal inductance and the load capacitance are both lower, the limit of wavefront resistance exists for meeting the requirements of the standard, otherwise making front time and overshoot rate maintain the standard simultaneously is impossible. Adding damping device can inhibit overshoot effectively and this can make it easy for generation of standard waveform. There exists a limit range for the equivalent load resistance or inductance which makes it possible to convert fourth order lightning impulse circuit into a third order lightning impulse circuit.

关 键 词：雷电冲击电压 特高压变压器 过冲 波前时间 四阶电路 

分 类 号：TM866[电气工程—高电压与绝缘技术] TM41