超高压输电线路工频过电压影响分析  

Effect on Power Frequency Over-Voltage of EHV Transmission Line

作　　者：王立强 曹斌[1] 武海燕 原帅[1] 郑东青 WANG Liqiang;CAO Bin;WU Haiyan;YUAN Shuai;ZHENG Dongqing(Inner Mongolia Power Research Institute,Hohhot 010020,China;Ningbo Jinfeng Green Energy Co.,Ltd.,Ningbo 315000,China)

机构地区：[1]内蒙古电力科学研究院,呼和浩特010020 [2]宁波金风绿能能源有限公司,宁波315000

出　　处：《内蒙古电力技术》2020年第3期1-5,共5页Inner Mongolia Electric Power

基　　金：内蒙古电力(集团)有限责任公司2017年科技项目“大规模新能源并网的电磁暂态平台开发及工程应用”(2017-05)。

摘　　要：针对超高压输电线路易发生的工频过电压问题,结合某500 kV输变电工程工频过电压计算中出现的母线控制电压偏低情况,利用Ward等值方法,基于戴维南多电源等效理论,分析等值参数、线路参数及输送潮流对线路工频过电压产生的影响。分析结果表明:该工程控制电压值偏低的主要原因为网架结构导致的等值参数偏大,等值参数与工频过电压呈线性影响关系。其中,等值电势对工频过电压的影响相比于等值阻抗敏感度更高;线路参数与等值参数关联度较小,甩负荷后工频过电压随线路长度增加呈增大趋势,并通过仿真验证了结论的准确性;另外,重潮流使得母线控制电压进一步降低,线路输送潮流对甩负荷后工频过电压影响较小,但潮流的增加会导致等值电源初始电压降低,进而增加首末端电压抬升幅度并形成偏低控制电压。建议工程启动计算前,通过增大线路输送潮流,来保证计算结果的准确性和适用性。For the problems of EHV transmission line with power frequency overvoltage,combined with the low bus control voltage appeared in the power frequency overvoltage calculation of a 500 kV power transmission and transformation project,the influence factors such as equivalent parameters,line parameters and transmission power flow on power frequency over-voltage are analyzed based on the actual 500 kV power transmission and transformation project with Ward equivalent technology and the Thevenin multi-power equivalent theory.The results show that the low control voltage value of this project is mainly due to the large equivalent parameters caused by the grid structure.The equivalent parameter has a linear relationship with the power frequency voltage,and the influence of the equivalent potential on the power frequency voltage is more sensitive than equivalent impedance.The correlation between the transmission line parameters and the equivalent parameters is small.The power frequency voltage increases with the length of the line after load rejection and the simulation verifies the accuracy of the conclusion.In addition,the heavy power flow makes the bus control voltage lower,and the transmission power flow has little effect on the power frequency voltage after the load rejection.The increase of power flow will cause the initial voltage of the equivalent power supply to decrease and form a lower bus control voltage.The adjustment method should be used to realize the large transmission flow of the line to ensure the accuracy and applicability of the results before the calculation starts.

关 键 词：超高压输电线路 工频过电压 WARD等值 潮流 等值参数 等值电势 

分 类 号：TM866[电气工程—高电压与绝缘技术]