共查询到19条相似文献,搜索用时 156 毫秒
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实践表明,阻尼绕组对定子绕组为开口槽的同步发电机空载电势波形影响很大。阻尼绕组节距t_2与定子齿距t_1不等、且相距较远时(例如t_2/t_1=0.7~0.8),电势波形较好;当t_2/t_1=1时,齿谐波电势急剧增大、波形变坏。例如KC—7500型同步补偿 相似文献
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文中改进了空载时主极磁场波形的计算方法;针对大中型凸极同步电机的特点改进了考虑阻尼绕组影响时齿谐波电势计算公式,对苏提出的半经验公式进行了实验验证,阐明此半经验公式不适用于分母为2的分数槽绕组,并根据实验结果提出了修正公式;提出了采用整数槽绕组(q=2、3)和分母为2的分数槽绕组时,阻尼绕组节距的较佳范围。 相似文献
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电力发生器空载电势波形的分析 总被引:2,自引:0,他引:2
本文针对电力发生器——一种新型高压发电机,采用有限元数值解法,对其样机空载电势波形进行了分析,针对不考虑阻尼绕组影响和考虑阻尼绕组影响两种情况,求取了空载波形畸变率。结果表明,该样机的空载电势波形满足国家设计标准要求。 相似文献
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为了研究集中非叠绕组永磁同步电机绕组因数对电势谐波的削弱作用,给出了集中非叠绕组的元件连接方式,推导了集中非叠绕组的齿/极配合关系,并在此基础上讨论了集中非叠绕组的节距类型,分析了节距因数和分布因数对电势谐波的影响。分析结果表明:集中非叠绕组的节距因数只能消除电势相数次或相数的倍数次谐波,当每极每相槽数的最简分式分子为1时,分布因数对电势谐波没有削弱作用。为消除电势中特定次谐波,进一步提出了利用槽口因数来消除特定次电势谐波的方法。实例分析和样机研究验证了本文分析的正确性和所提方法的可行性。 相似文献
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改善空载电压波形、降低阻尼条损耗发热是优化电能质量、保障发电机与电网运行稳定性的重要问题。为此,采用调节阻尼绕组节距与定子斜槽措施相结合的设计方案,对1台30MW的大型贯流式水轮发电机空载电压波形和额定负载工况的阻尼条损耗发热进行了优化设计,并利用多层运动电磁场场路耦合时步有限元模型和三维温度场有限元模型进行了分析与计算。结果表明,在合理增大阻尼绕组节距的基础上,结合斜槽措施,既能明显地优化空载电压波形,又能有效地防止阻尼条过热故障的发生。计算结果与实测数据相符合。该研究结果对提高发电机的设计水平并改善发电机与电网的运行稳定性具有参考价值。 相似文献
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众所周知,当同步发电机定子表面光滑时,励磁磁势所生的气隙磁场并非正弦分布,因此空载电势波形也是非正弦的,含有一系列高次谐波分量。当电机定子开槽后,由于气隙比磁导分布更不均匀,又增添了一个与定子齿数相对应的附加周期性分量,于是气隙磁场波形更加畸变,而使空载电势中 相似文献
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This paper presents a combined analytical and finite-element (FE) method for computation of the no-load voltage waveform of laminated salient-pole synchronous generators. The described method takes into account saturation effects as well as the damper bar currents due to the slot pulsation field. The method calculates first the damper bar currents and then includes them in the calculation of the no-load voltage. The combination of magnetostatic two-dimensional (2-D) FE simulations for calculating the magnetic coupling between the machine windings and of an analytical resolution results in a very precise prediction of the no-load voltage. At the same time, simulation time is drastically reduced compared with transient magnetic 2-D FE simulations. The method was verified on several examples, comparing the obtained results (damper bar currents and no-load voltage) with results obtained from transient magnetic FE simulations and, in one case, with the measured no-load voltage. 相似文献
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同步发电机空载电压波形的齿磁通计算 总被引:13,自引:1,他引:13
为了快速准确计算谐波励磁同步发电机和普通同步发电机的空载谐波电压,提出一种齿磁通法计算谐波电压。利用有限元法,仅计算转子在一个齿距内移动时不同位置处的定子各个齿的磁通,通过绕组与齿的关联关系得到定子绕组感应电动势。该方法考虑了磁路、凸极效应、饱和、绕组布置、齿槽效应以及斜槽的影响。谐波励磁同步发电机上的实验结果与计算结果的比较说明了方法的正确性。该方法计算准确,计算量小,计算速度快。 相似文献
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采用不对称磁极优化水轮发电机空载电压波形 总被引:1,自引:0,他引:1
改善空载电压波形是发电机优化设计、保证电能质量的重要问题。采用极靴偏心与阻尼条偏心等不对称磁极结构设计方案,对一台45 MW的大型水轮发电机空载电压波形进行优化设计,并利用二维运动电磁场场路耦合时步有限元模型,进行分析与计算。结果表明,合理偏移极靴和阻尼条位置,可以明显削弱齿谐波,改善气隙磁场分布和空载电压波形。计算结果与实测数据相吻合。研究成果已在3个电站的大型水轮发电机上得到工程实际应用。 相似文献
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With the recent development of power electronics technology, thyristor-controlled equipment has largely been introduced to the electric power system. These devices generate harmonics that cause voltage distortion and undesirable effects on the power system components. On the other hand, the damper windings of synchronous generators basically are designed to reduce harmonics as well as to damp out system oscillations. However, up to now, the effects of damper windings on harmonics have not been clarified fully in a quantitative way. In this paper, the results of experimental study on the harmonics reduction effect of damper windings have been presented. A specially designed 6-kVA generator was connected to an infinite-bus system to investigate the characteristics of damper windings. A new method to measure induced voltages between damper bars, damper bar currents and air-gap flux densities in the tested generator was established. By comparing these measurements with and without the presence of damper windings, the effect of damper windings was quantified. Thus the reduction effects of the damper windings on slot ripples and harmonics caused by armature current mmf were investigated and were made clearer than before by the proposed method. 相似文献
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Design Principles of a New Generator Stator Ground Relay for 100% Coverage of the Stator Winding 总被引:1,自引:0,他引:1
The design principles of a new relay for detection of grounds on the stator windings of generators is discussed. The relay provides 100% coverage of the stator windings with measurement of the fundamental and third harmonic components of the residual voltage at the terminals of the generator and the voltage across the grounding resistor at the neutral of the generator. The design concepts of the detectors utilizing the third harmonic components of the above signals are based on measurements of these signals on a number of Ontario Hydro thermal units. 相似文献