基于真空断路器预击穿特性的海上风电场集电网合闸暂态过电压仿真研究  

Simulation Study on Transient Over-voltage in Power Collection Network of Offshore Wind Farm Considering Prestrike Characteristics of Vacuum Circuit Breaker

作　　者：吴俊臣 王灵矫[1] 任志华 郭亚勋 WU Junchen;WANG Lingjiao;REN Zhihua;GUO Yaxun(School of Information Engineering,Xiangtan University,Hunan Xiangtan 411105,China;Guangzhou Bureau,EHV Power Transmission Company of China Southern Grid,Guangzhou 510700,China;State Grid Yueyang Electric Power Supply Company,Hunan Yueyang 414000,China;School of Electric Power,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]湘潭大学信息工程学院,湖南湘潭411105 [2]南方电网超高压输电公司广州局,广州510700 [3]国网岳阳供电分公司,湖南岳阳414000 [4]华南理工大学电力学院,广州510640

出　　处：《高压电器》2019年第10期38-43,共6页High Voltage Apparatus

摘　　要：海上风电场中压电缆集电系统真空断路器在闭合空载变压器操作中,真空断路器预击穿会在机端变压器的高压侧产生暂态过电压,该过电压与电缆作用产生高频振荡过电压将对变压器绝缘产生损坏。文中研究真空断路器预击穿产生高频暂态过电压的机理,在PSCAD/EMTDC暂态分析软件上搭建真空断路器预击穿现象的自定义模型,并将此模型应用于简化的海上风电场中压电缆集电系统模型,研究合闸初相角、电缆长度和机端变压器位置对暂态过电压的影响。仿真结果表明机端变压器位于机舱且合闸初相角为15°过电压陡度最大,在机端变压器加装扼流线圈和并联小电容的过电压保护装置后,暂态过电压陡度得到了明显的抑制。In closing operation of vacuum circuit breaker for no-load transformer in medium-voltage cable power collection grid of offshore wind farm, the prestrike of the vacuum circuit breaker will produce transient over-voltage on the high-voltage side of the generator transformer, and this over-voltage, interacting with the cable, will produce high -frequency oscillation over-voltage to cause damage to the transformer insulation. In order to reveal the producing mechanism of high-frequency transient over-voltage in prestrike of the vacuum circuit breaker, this study employs the transient analysis software PSCAD/EMTDC to build a self-defined model which can reflect the prestrike phenomenon of vacuum circuit breaker. This model is applied to a simplified simulation model of the medium-voltage cable power collection grid of offshore wind farm to analyze the influences of initial phase angle of closing, cable length and generator transformer position on the transient over-voltage. Simulation results show that the over-voltage steepness is the largest when the generator transformer is located in the engine room and the initial phase angle is 15°,and the transient over-voltage steepness is obviously suppressed after the over-voltage protection device including choke and parallel small capacitor is installed on the generator transformer.

关 键 词：海上风电场 真空断路器预击穿 暂态过电压 扼流线圈 

分 类 号：TM614[电气工程—电力系统及自动化] TM743