水力作用对水电机组主轴稳定性影响研究

发布时间：2018-04-26 10:31

本文选题：水电机组主轴 + 水力影响　；参考：《河北联合大学》2014年硕士论文

【摘要】：随着社会经济的高速发展，社会对电力能源的需求量越来越大，水力发电逐渐引起了我们高度的关注。但是水电机组主轴稳定性问题一直困扰着人们。尤其是在大水力冲击和高强度磁场的作用下，其规律还有待探索。因此，对水电机组主轴系统稳定性研究是十分必要的。运用有限元法和传递矩阵法分别计算固有频率，，验证结果可靠性。探究了附加水质量、电磁刚度和陀螺效应对固有频率的影响。结果表明：陀螺效应是主要影响因素、电磁刚度次之、附加水质量影响最小。各因素均值得引起重视。探究了水力影响、磁力影响以及不同初始条件的影响。结果表明：附加水质量对振动的影响并不十分显著，振动基本稳定时发电机转子和水轮机转轮的振幅相近，而且水轮机转轮的振幅略大，下机架的振幅远小于二者，三者振动速度极值相近；抬机现象和b10（电磁影响因素中位移三次项的系数）是主要影响因素，它们的增大会加速下机架振动速度的下降；下机架的振动速度变化最快，水轮机次之，转子最慢，但是三者的包络线的变化趋势基本一致。在分别单独给予三部分相同振动初速度时，作用在发电机转子上的瞬时冲击引起振动的最大，作用在水轮机转轮上次之，作用在下机架上振动最小。与给予系统振动初位移时不同的是振动基本稳定时，水轮机的速度极值是另两部分的数倍。阻尼11（位移阻尼）的提高会引起振幅的明显下降；阻尼21（速度阻尼）同样会引起振幅的下降，但是效果没有阻尼11明显。另外阻尼21的提高在时域图中会增加曲线单调下降前的振动次数，在幅频曲线中会减小共振区的宽度；幅频曲线中，共振区的振幅极值随着f1（抬机现象振幅）的减小而成比例降低，f1的减小还会缩小共振区的宽度。
[Abstract]:With the high - speed development of the social economy , the demand for power energy is increasing and the hydroelectric power generation has caused our attention . However , the problem of the stability of the main shaft of the hydro - hydro unit has been beset by people , especially under the influence of large hydraulic shock and high intensity magnetic field . Therefore , it is necessary to study the stability of the main shaft system of hydro - hydro unit .

The effects of additional water quality , electromagnetic stiffness and gyroscopic effect on natural frequency were studied by means of finite element method and transfer matrix method .

The effects of hydraulic influence , magnetic force and different initial conditions are studied . The results show that the influence of the additional water quality on the vibration is not very significant , the amplitude of the generator rotor and the turbine runner is similar when the vibration is basically stable , the amplitude of the rotating wheel of the turbine is slightly larger , and the amplitude of the lower frame is much smaller than that of both .
The lifting phenomenon and the b10 ( the coefficient of displacement three items in the electromagnetic influence factors ) are the main influencing factors , and their increase can accelerate the decrease of the vibration speed of the lower frame ;
The vibration velocity of the lower frame is the fastest , the second of the turbine and the slowest of the rotor , but the change trend of the envelope of the three is basically the same . When three parts of the same vibration initial speed are given separately , the maximum vibration caused by the transient impact on the rotor of the generator is the least of the vibration . When the vibration is basically stable with the initial displacement of the given system , the speed extreme value of the water turbine is multiple of the other two parts .
The damping 21 ( velocity damping ) also causes a decrease in amplitude , but the effect is not damped 11 . In addition , the increase of damping 21 increases the number of oscillations before the curve monotonically decreases in the time domain diagram , and the width of the resonance region is reduced in the amplitude frequency curve ;
In the amplitude - frequency curve , the amplitude extreme of the resonance region decreases in proportion with the decrease of f1 ( the amplitude of the lift phenomenon ) , and the reduction of f1 also reduces the width of the resonance region .

【学位授予单位】：河北联合大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV734

【参考文献】