1.浙江大学 电气工程学院 浙江省电机系统智能控制与变流技术重点实验室 浙江 杭州;2.华北电力大学 高电压技术与电磁兼容北京市重点实验室 北京;3.浙江华云电力工程设计咨询有限公司
1.Zhenjiang Provincial Key Laboratory of Electrical Machine Systems,College of Electrical Engineering,Zhejiang University;2.Key Laboratory of High Voltage Electromagnetic Compatibility,North China Electric Power University;3.Zhejiang Huayun Power Engineering Design Consulting Company
随着城市的发展与供电需求的增大, 架空线-电缆混合线路以其结构灵活等优点得到越来越广泛的应用,混合线路的合闸操作所引起的过电压已成为系统安全可靠运行的重要影响因素。本文采用PSCAD仿真软件对某地区220 kV超高压架空线-电缆混合线路合闸过电压特性进行研究,建立了过电压仿真模型,仿真分析了混合线路合闸操作时产生的合闸过电压特性,探讨了影响合闸过电压的影响因素。结果表明：考虑三相不同期性时合闸过电压比三相同期合闸过电压幅值增加了10%~20%；合闸过电压与合闸相角有关,且合闸过电压幅值与合闸电阻大小呈反比关系；通过合闸时间的配合,合闸电阻分级投入,使能量逐级释放,在此基础上发现采用多级合闸电阻可更有效地限制操作过电压。研究工作为超高压架空线-电缆混合线路的设计提供了参考依据。
With the development of the city and the increase in power supply demand, overhead line-cable hybrid lines have become more and more widely used due to its flexible structure. The overvoltage caused by the closing operation of the hybrid line has become important factors affecting the safe and reliable operation of the system. In this paper, PSCAD simulation software is used to study the closing overvoltage characteristics of 220 kV extra high voltage (EHV) overhead line-cable hybrid lines in a certain area. An overvoltage simulation model is established, and the closing overvoltage characteristics generated during the closing operation of the hybrid line are simulated and analyzed. The factors affecting the closing overvoltage are discussed. The results show that: when considering the different periods of the three phases, the closing overvoltage is increased by 10%~20% compared to the three same period closing overvoltage amplitude; the closing overvoltage is related to the closing phase angle, and the closing overvoltage amplitude, which is inversely proportional to the closing resistance; through the matching of the closing time, the closing resistance is input in stages to release energy step by step. On this basis, it is found that the use of multi-level closing resistance can more effectively limit the operating overvoltage. The research work provides a reference for the design of EHV overhead line-cable hybrid line.