核电汽轮发电机负序运行转子槽楔涡流损耗研究
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摘要
为了研究发电机不同工况下转子槽楔涡流损耗,以1407MVA大型核用半速汽轮发电机为例,通过建立该发电机二维电磁场数学模型,基于时步有限元法计算发电机由负载不对称引起稳态负序运行时转子槽楔上感生的涡流损耗。建立动态分析的场—路耦合时步有限元模型,分别计算当发电机外部发生单相短路、相间短路、两相接地短路故障后瞬间和故障稳定后的转子槽楔涡流损耗,得到不同外部短路故障下转子不同位置的槽楔暂态和稳态涡流损耗分布。对比研究了发电机额定运行和空载运行时外部短路故障后槽楔涡流损耗的变化规律。分析结果表明外部短路故障后,负序电流会使发电机转子槽楔产生涡流损耗,威胁着发电机的安全运行,其中单相短路故障影响最为严重。
In order to study the generator rotor slot wedge eddy current loss under different conditions. The1407 MVA turbo generator at half speed is researched as an example. Mathematical model is established in 2 D electromagnetic field. Then the eddy-current losses of the rotor slot wedge is calculated according to time step finite element method,which is under the circumstance of generator steady negative sequence operation leaded by the asymmetrical load. The field-circuit coupled time-stepping finite element model is established for dynamic analysis.In an instant and stability of the single phase short-circuit fault,two phases to ground short-circuit fault and the interphase short-circuit fault,the eddy-current losses of the rotor slot wedge is calculated. Then the distribution of eddy-current loss in transient and steady state of the different rotor slot wedge is revealed. The changing rule of eddy-current loss of the rotor slot wedge when external circuit happens in rated and no-load operation condition.The analysis result shows that after external circuit,the eddy-current losses are induced by the negative-sequence current,which has great influence on generator steady operation. The most serious impact happens in the single phase short-circuit fault.
In order to study the generator rotor slot wedge eddy current loss under different conditions. The1407 MVA turbo generator at half speed is researched as an example. Mathematical model is established in 2 D electromagnetic field. Then the eddy-current losses of the rotor slot wedge is calculated according to time step finite element method,which is under the circumstance of generator steady negative sequence operation leaded by the asymmetrical load. The field-circuit coupled time-stepping finite element model is established for dynamic analysis.In an instant and stability of the single phase short-circuit fault,two phases to ground short-circuit fault and the interphase short-circuit fault,the eddy-current losses of the rotor slot wedge is calculated. Then the distribution of eddy-current loss in transient and steady state of the different rotor slot wedge is revealed. The changing rule of eddy-current loss of the rotor slot wedge when external circuit happens in rated and no-load operation condition.The analysis result shows that after external circuit,the eddy-current losses are induced by the negative-sequence current,which has great influence on generator steady operation. The most serious impact happens in the single phase short-circuit fault.
引文
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[11]张鹏鹏.大型半速汽轮发电机不对称短路及其负序分量的研究[D].哈尔滨:哈尔滨理工大学,2014:37.
[12]JACK A G,STOLL R L.Negative-sequence Currents and Losses in the Solid Rotor of a Turbo-generator[J].IEE Proceedings of Generation,Transmission and Distribution,1980,127(2):53-64.
[13]胡笳,罗应立,刘晓芳,等.汽轮发电机时步有限元计算参数对大扰动仿真结果的影响[J].中国电机工程学报,2009,29(27):59-66.
[14]汤蕴璆.电机内的电磁场[M].北京:科学出版社,1981.
[15]李永生.负序电流及其对汽轮发电机的危害[J].华北电力技术,1994(9):9-12.
[16]陈丕璋,严烈通,姚若萍.电机电磁场理论与计算[M].北京:科学出版社,1986.
[2]POLLARD E I.Effects of Negative-sequence Currents on Turbinegenerator Rotors[J].Transactions of the American Institute of E-lectrical Engineers,1953,72(2):404-406.
[3]孟大伟,王秀兰,施道龙.大型电机铁心片间短路故障实验与数值仿真分析[J].哈尔滨理工大学学报,2016,21(2):78-83.
[4]霍丽华,谭洪涛,戈宝军.基于ANSYS的抽水蓄能电机饱和同步电抗的计算[J].哈尔滨理工大学学报,2006,11(1):112-115.
[5]HOSSAIN M A.Mixed Convection Flow of Micropolar Fluid Over an Isothermal Plate with Variable Spin Gradient Viscosity[J].Acta Mechanic,2007,70(3):87-95.
[6]TRAXLER-Samek G,LUGAND T,SCHWERY A.Calculation of Power Losses in the Damper Winding of Large Hydro-generators at Open-circuit and Load Conditions[C]//Electrical Machines,ICEM,2008.th.
[7]RANLOF M,LUNDIN U.The Rotating Field Method Applied to Damper Loss Calculation in Large Hydro Generators[C]//Electrical Machines(ICEM),2010 XIX International Conference on,6-8 Sept.2010.
[8]徐永向,胡建辉,邹继斌.表贴式永磁同步电机转子涡流损耗解析计算[J].电机与控制学报,2009,13(1):63-66.
[9]李伟力,孙佳慧,孙宏丽.汽轮发电机稳态与负序工况下转子涡流损耗计算和温度场分析[J].电工技术学报,2012,27(9):174-182.
[10]薛易,李伟力,王立坤.转子导磁导电槽楔材料对汽轮发电机参数和转子表面损耗影响的研究[J].中国电机工程学报,2015,35(7):1768-1774.
[11]张鹏鹏.大型半速汽轮发电机不对称短路及其负序分量的研究[D].哈尔滨:哈尔滨理工大学,2014:37.
[12]JACK A G,STOLL R L.Negative-sequence Currents and Losses in the Solid Rotor of a Turbo-generator[J].IEE Proceedings of Generation,Transmission and Distribution,1980,127(2):53-64.
[13]胡笳,罗应立,刘晓芳,等.汽轮发电机时步有限元计算参数对大扰动仿真结果的影响[J].中国电机工程学报,2009,29(27):59-66.
[14]汤蕴璆.电机内的电磁场[M].北京:科学出版社,1981.
[15]李永生.负序电流及其对汽轮发电机的危害[J].华北电力技术,1994(9):9-12.
[16]陈丕璋,严烈通,姚若萍.电机电磁场理论与计算[M].北京:科学出版社,1986.