大型水轮发电机定子绕组分布电容对位移电压影响分析  

Analysis of impact of distributed capacitance in stator windings of large hydroelectric generators on displacement voltage

作　　者：司雨欣 桂林[1] 张琦雪[2] 刘政 杨勇 王祥珩[1] SI Yuxin;GUI Lin;ZHANG Qixue;LIU Zheng;YANG Yong;WANG Xiangheng(State Key Laboratory of Power System Operation and Control,Department of Electrical Engineering,Tsinghua University,Beijing 100084,China;Nanjing NARI-Relays Electric Co.,Ltd.,Nanjing 211102,China;Dongfang Electrical Machinery Company Limited,Deyang 618000,China)

机构地区：[1]清华大学电机系新型电力系统运行与控制全国重点实验室,北京100084 [2]南京南瑞继保电气有限公司,江苏南京211102 [3]东方电气集团东方电机有限公司,四川德阳618000

出　　处：《电力自动化设备》2024年第10期172-178,共7页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(52077115)。

摘　　要：景洪电站发电机三相电势对称,且静态实测三相对地电容近似相等,在此条件下发电机正常运行时中性点仍有明显的位移电压,集中参数电路模型无法解释该现象,因此提出基于准分布电容参数模型的中性点位移电压分析方法。通过电路分析,得到定子绕组对地准分布电容与中性点位移电压的关系式,理论解释了分布电容不均匀会导致位移电压出现。采用兰州电机厂制造的12kW实验样机进行了实验验证,并针对准分布电容中偏大或偏小电容所在位置以及电容不均匀度对位移电压影响的实验结果进行了定量分析。针对由分布电容不均匀所带来的位移电压偏大的问题,提出在机端外挂电容的解决方案,理论求解外挂电容值,并通过仿真实验验证了方案的有效性。The centralized parameter circuit model cannot address the issue of excessive neutral point dis⁃placement voltage in Jinghong generators when the three-phase potentials are symmetrical and the static measured three-phase-to-ground capacitances are approximately equal.Therefore,a neutral point displace⁃ment voltage analysis method based on the quasi-distributed capacitance parameter model is proposed.By circuit analysis,the relationship formula between the stator winding quasi-distributed capacitance to ground and the neutral point displacement voltage is obtained.Through theoretical analysis,it is verified that non-uniform distributed capacitance leads to the appearance of displacement voltage.Experimental validation is conducted by using a 12 kW dynamic simulation generator manufactured by Lanzhou Electric Machinery Factory.Quantitative analysis is then carried out on the experimental results regarding the impact of the positions of larger or smaller quasi-distributed capacitance and quasi-distributed capacitance unevenness on displacement voltage.In response to the issue of excessive displacement voltage caused by non-uniform dis⁃tributed capacitance,a solution involving the addition of external capacitance at the machine end is proposed and the external capacitance value is theoretically calculated.The effectiveness of the retrofit solution is verified through simulation experiments.

关 键 词：大型水轮发电机 中性点位移电压 准分布电容参数模型 集中参数电路模型 定子单相接地故障 

分 类 号：TM312[电气工程—电机]