共查询到20条相似文献,搜索用时 62 毫秒
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1问题的提出随着电力系统的发展,发电机的单机容量越来越大,转子钻长度增加,横截面相对下降。这样,整个轴系统就不能再看成为一转动刚体,而应看作为两端自由“质量一弹簧”系统。这种情况下,电力系统因故障或运行方式改变而引起的电力系统与机械系统的相互耦合作用,可能导致发电机组的轴系扭振。轴系扭振会缩短机钻的使用寿命,严重的会造成轴系损坏。这个问题已为国内外实际运行情况和分析所证实。所以,传统的轴系承载能力、设计标准、运行规程和沿用的概念正在受到冲击。我国电力系统300MW以上的大容量机组不断增多,500kV超高… 相似文献
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本文介绍了对发电机励磁电流进行正弦调制来激发汽轮发电机组轴系扭振的方法.并且给出了在动模机上试验的结果. 相似文献
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汽轮发电机转子扭振的研究 总被引:1,自引:0,他引:1
应用扭动计算程序,对300MW汽累发电机组轴系进行了扭振计算分析,得出了机组轴系在各种设计工况下的扭振固有频率以及两相突然短路时轴系的最大剪切应力与最大扭矩。介绍了实验室扭振模型实验的建立及扭振模式方法,对模型系统的扭振固有频率进行了计算与测试,计算结果与测量结果非常接近,从而也验证了测量系统的可靠性。 相似文献
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基于场路耦合方法,对大型汽轮发电机组轴系扭振进行了仿真与分析,考虑了动态饱和特性和转子本体涡流特性的影响。对一台600MW汽轮发电机组在单机无限大系统中,由于突然短路故障,非同期并网以及重合闸管电力系统扰动引起的轴系扭振进行了仿真计算,结果令人满意。 相似文献
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The article generalizes the results obtained from investigations of torsional vibration in the shaft system of the T-175/210-12.8 turbine set installed at the Omsk CHPP-5 combined heat and power plant. Three different experimental methods were used to determine the lowest natural frequencies of torsional vibration excited in the shaft system when the barring gear is switched into operation, when the generator is synchronized with the grid, and in response to unsteady disturbances caused by the grid and by the turbine control and steam admission system. It is pointed out that the experimental values of the lowest natural frequencies (to the fourth one inclusively) determined using three different methods were found to be almost completely identical with one another, even though the shaft system was stopped in the experiments carried out according to one method and the shaft system rotated at the nominal speed in those carried out according to two other methods. The need to further develop the experimental methods for determining the highest natural frequencies is substantiated. The values of decrements for the first, third, and fourth natural torsional vibration modes are obtained. A conclusion is drawn from a comparison between the calculated and experimental data on the shaft system’s static twisting about the need to improve the mathematical models for calculating torsional vibration. The measurement procedure is described, and the specific features pertinent to the way in which torsional vibration manifests itself as a function of time and turbine set operating mode under the conditions of its long-term operation are considered. The fundamental measurement errors are analyzed, and their influence on the validity of measured parameters is evaluated. With an insignificant level of free and forced torsional vibrations set up under the normal conditions of turbine set and grid operation, it becomes possible to exclude this phenomenon from the list of main factors influencing the crack formation processes in low-pressure rotors. The importance of experimentally confirming the fact that the shaft system has been detuned from resonances at the 50 and 100 Hz excitation frequencies is pointed out. 相似文献
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计算轴系扭振固有特性的Riccati法 总被引:1,自引:0,他引:1
本文将Riccati传递矩阵法推广到轴系扭振固有特性的计算,理论分析和数值计算表明,这种方法具有编制程序简单、占有内存少、运算速度快、数值稳定和计算精度高等特点。因此这是一种较为理想的计算轴系扭振固有特性的方法。 相似文献
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本文结合我国大型汽轮发电机组轴系扭振在线监测分析系统(简称TSA)的开发研制,概括介绍了目前国内外比较关注的大型汽发机组轴系扭振与监测问题。TSA系统的应用对于机组的扭振事件分析、经济运行与安全保证是非常重要的。 相似文献
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对传统的负序电流近似计算法进行了分析和探讨,针对其不足,提出了基于MATIAB语言的负序电流计算程序。采用此程序计算负序电流,可提高计算精度和计算效率,程序还可同时绘出正序电流、负序电流、不对称三相电流的相量图。 相似文献