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Field application of test methods for generator grounding system parameters |
JIANG Jianming |
China Energy Science and Technology Research Institute Co., Ltd, Chengdu 610091 |
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Abstract The parameters of the stator winding capacitance to ground are the basis for the design of various earthing devices, and whether the earthing device meets the requirements needs to be verified through testing. For small-capacity generators with small capacitance currents, the grounding device parameters are designed by means of the centralized capacitance of the stator winding to ground, and almost no tests are carried out to verify this. For large and medium sized hydro generators, the capa- citance current is large and the measured concentrated capacitance has an error of more than 17% compared to the distributed equivalent capacitance, which may cause safety accidents due to improperly designed earthing device parameters if not verified through tests. The paper proposes test methods for four parameters: generator neutral asymmetric voltage, displacement voltage, single-phase grounding maximum capacitance current and single-phase grounding maximum fault current. Before and after the neutral point of the generator is connected to the grounding device, the parameter test of the generator neutral grounding system is carried out by simulating faults to determine whether the generator neutral grounding method and the parameters of the grounding device meet the engineering requirements. This has been verified on several large and medium-sized hydro generators and individual turbine generators, and the earthing devices designed with the test parameters of this test method are stable and reliable in operation.
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Received: 07 February 2023
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[1] 刘国慧. 水电站发电机中性点高阻接地应用分析[J]. 建筑工程技术与设计, 2016(9): 1472. [2] 乔照威, 李洪超. 发电机中性点接地装置阻抗参数设计[J]. 上海大中型电机, 2016(2): 16-18. [3] 中性点不接地系统电容电流测试规程: DL/T 308—2012[S] DL/T 308—2012[S]. 北京: 中国电力出版社, 2012. [4] 李张秀, 郭玉恒. 集高电阻和电抗器功能为一体的接地装置在二滩电站的应用[J]. 水电站机电技术, 2021, 44(2): 27-29. [5] 刘云平, 梁得亮, 罗永刚, 等. 大型水轮发电机中性点接地装置对中性点位移电压的影响[J]. 东方电气评论, 2018, 33(1): 40-44. [6] 刘亚青, 张丹丹, 朱钊, 等. 巨型水轮发电机中性点接地装置加电抗对中性点位移电压影响的研究[J]. 大电机技术, 2020(3): 47-50. [7] 刘亚青, 朱钊, 张丹丹. 巨型水轮发电机组中性点接地装置参数配置研究[J]. 人民长江, 2019, 50(6): 143-147. [8] 毕大强, 王祥衍, 王维俭. 大型水轮发电机中性点接地方式的若干问题分析[J]. 电工技术学报, 2002, 7(4): 7-12. [9] 熊再豹, 卢伟, 郭宗香, 等. 谐振补偿在大型发电机中性点接地中的应用[J]. 电网与清洁能源, 2012, 28(6): 8-12. [10] 沈兵, 陈坤, 李国正. 某水电站发电机中性点接地装置的设计[J]. 电工技术, 2017(7): 13-14. [11] 邹祖冰, 陈铁. 1000MW水轮发电机中性点接地方式探讨[J]. 水力发电, 2017, 43(8): 91-93. [12] 发电机中性点经变压器接地成套装置技术条件: T/CSEE 10290002—2019[S]. |
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