共查询到20条相似文献,搜索用时 234 毫秒
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针对某大型电站混流式水电机组自投产来一直存在顶盖垂直振动异常问题,采用真机振动试验方式,获取了该水电机组于不同运行工况下的顶盖垂直振动峰值及对应的频谱曲线。基于有限元法构建了机组顶盖的高精度动力学仿真模型,获取了该机组顶盖的固有频率及其对应振型,并同步采用真机模态实测方法对顶盖的固有频率进行验证。在此基础上,通迆顶盖振动频谱曲线与其固有频率的对比分析,捕获了机组顶盖垂直振动异常的根本原因,设计并实施了顶盖补强方案,改变了顶盖的刚强度与固有频谱。经真机试验验证,顶盖补强有效地降低了顶盖垂直振动幅值,降低了机组的运行风险。 相似文献
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本文建立了国产300MW汽轮发电机组轴系扭转振动的分析模型。用有限单元法分析和计算机组轴系扭转振动的固有频率和振型,并得到了一定的结论。 相似文献
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针对大型汽轮发电机定子端部线圈引出线由于受到电磁力的作用而振动 ,导致其绝缘磨损而引发的发电机短路事故 ,提出通过测量其引出线固有频率的方法是抑制发电机定子端部线圈引出线振动的必要检测手段。详细阐述了引出线固有频率测试的基本原理、测试仪器、测试方法 ,并用内蒙古达拉特发电厂 330MW发电机的端部线圈引出线进行实测分析。在测试分析中提出了引出线的振动幅值在评判中的重要作用 ,并认为采取引出线加配重降低其固有频率的方法要优于加强引出线强度提高其固有频率的方法。 相似文献
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适用于扭振测试的调频解调电路 总被引:2,自引:0,他引:2
本讨论了适用于汽轮发电机组轴系扭转振动测试的调频解调电路,该电路由频率电压转换电路和低通滤波器组成,试验与实测表明,该电路具有足够的灵敏度和跟踪范围,满足了扭振测试的需要。 相似文献
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This paper considers a generator system using variable energy such as wind power. The variable energy influences the voltage and frequency of a generator system. However, the load requires constant voltage and frequency. Therefore, this paper proposed that a generator system have the following good points:
- (1) This generator is a brushless system which makes use of the multifield induction machine;
- (2) Frequency converter of small capacity which is used for constant voltage and frequency in load at variable speed;
- (3) The PWM inverter can supply reactive power to the self-excited generator; and
- (4) Voltage wave of load is sine wave by LC filter of the frequency converter.
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基于转子凸极跟踪的永磁同步电机转子位置的自检测方法 总被引:10,自引:0,他引:10
提出了一种永磁同步电机转子位置估算的自检测方法。文中讨论了利用旋转矢量载波高频信号注入、外差法及跟踪观测器检测转子位置的原理。同时给出了针对内埋式永磁同步电机的实验系统及实验结果。 相似文献
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高速电机的转速高、转子细长,与常速电机相比接近临界转速的可能性大大增加,当电机额定转速接近临界转速时,电机会发生剧烈的振动,甚至使转子损坏。大功率高速电机的转子长度远远大于转子直径,很难设计为刚性转子,需要穿越1阶临界转速,工作在1阶临界转速和2阶临界转速中间的安全区域,而这个安全区域的范围却很小,这对大功率高速电机转子系统的动力学设计带来了极大的困难。基于一台1.12MW、18 000r/min的高速永磁电机,对转子系统的动力学特性进行理论分析,对有叶轮和无叶轮状态下的转子模态和临界转速进行计算,分析轴承支承刚度、陀螺效应以及转子主要尺寸对临界转速的影响,并通过样机进行了实验验证,总结了相应的规律,为大功率高速电机挠性转子的设计提供了参考。 相似文献
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Károly Veszprémi 《Electrical Engineering (Archiv fur Elektrotechnik)》2009,90(8):559-567
Brushless excitation of a synchronous machine has a significant advantage: no slip-rings are necessary. The rotating transformer
method is investigated: the excitation machine is a wound rotor induction machine with controllable voltage supply on the
stator side. The synchronous machine is excited by a diode bridge, connected to the rotor of the excitation machine. The operation
of the system is essentially determined by the commutation of the rotating diode bridge. It has different rectifier modes
in such a configuration (possibly long commutation process caused by the variable, possibly lower voltage; larger commutation
inductance). With justified simplifications, a model is derived to investigate the operation. The classical converter theory
is applicable for the variable voltage, variable frequency supply of the diode bridge. Optimal operation considering the utilization
of the excitation machine is introduced, developed and extended to all rectifier modes. The result is a matching rule for
the parameters of the system, which can be satisfied by complex design of the system elements. 相似文献
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Analytical approach of the stator current frequency harmonics computation for detection of induction machine rotor faults 总被引:1,自引:0,他引:1
The aim of this paper is to analyze theoretically and experimentally the stator current of a three-phase squirrel-cage induction machine in order to show how it is influenced by electrical rotor faults. The approach used for this study analyzes the modification introduced by n broken rotor bars in the rotor cage magnetomotive force and then estimates the resulting frequency spectrum in the stator current. This approach is validated in a 3-kW 230-V/400-V 50-Hz 2850-r/min two-pole three-phase induction machine, showing the sensitive frequency components to rotor fault condition. 相似文献
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为了方便和准确地计算双馈风电机组(DFIG)接入系统的短路电流分布,提出了投撬棒后DFIG的工频和转频序网等值电路,并给出了利用该等值电路计算系统短路电流的方法。通过求解投撬棒后DFIG磁链的状态微分方程,得到其工频分量和转频分量的解析表达式。在此基础上,将DFIG的电压空间矢量方程按转频和工频分量进行分解,并根据空间矢量与相量间的关系,分别形成了转频和工频序网等值电路。其中,转频正序、负序等值电路分别为带内阻抗的电势和无源阻抗,而工频正序、负序等值电路均为无源阻抗。利用该等值电路只需已知DFIG的电机参数和故障初值条件而无需仿真即可求得DFIG接入系统各处的短路电流。以某DFIG接入系统为例,通过PSCAD仿真验证了该等值电路和短路计算方法在不同故障条件下的有效性。 相似文献
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