电磁阻尼对低速电机转子横向非线性振动的影响

对交流电机转子横振时电磁阻尼及考虑电磁阻尼时转子横振进行了研究.首先应用磁场理论求得了电机三相不对称运行时电磁阻尼力,并对三相对称时的电磁阻尼进行了计算.接着用拉格朗日-麦克斯韦方程求得了转子横向振动的方程,画出了三相对称时转子强迫振动的幅频曲线,并与实验进行了对照,实验结果与理论结果吻合的很好.

The effect of electromagnetic damping to lateral nonlinear vibration of low-speed electric motor rotors

Now electric power has more and more become the heart of native economics.So,modern industry requirs electric motors running safely.But with motor units developed larger and larger,vibration problem is getting outstanding.The vibration can not only influence stability of motors,but also cause fatigue of some parts of the system,cause noise and destroy.If the lateral vibration of a rotor responded to the nature frenquency of the system itself,a large damege would occure.People before chiefly concentralized their study on mechanical action,seldom on electromagnetic action.Therefore the research on this respect has become a urgent demond. Studies of coupled mechanical and electric dynamics system are seldom abroad.In our country,the studies on the system have been researched detailedly,especially on combination of parameter and forced resonances excited by electromagnetic forces and multiple resonance.The studies all concern electromagnetic damping,but directly quote the results of experiments.No one has studied it theoretically.For this reason,this paper studys the electromagnetic damping and lateral vibration of a rotor when considering electromagnetic dapming.This paper emphasises on the situation of pole's number being eight.In other situation,the same result can be acquired. At first in this paper,the electromagnetic damping force when a electric motor ran unsymmetrically is obtained by using electromagnetic field theory.The electromagnetic damping of three phases symmetry is calculated,and the curve of electromagnetic damping voltage is drawn due to the result.Then,the rotor vibratory differential equation is obtained by using Lagrange Maxwell's equation,the analytical solution of the equation is acquired by using asymptotic method of non linear vibratory theory,and amplitude equation is obtained through stable solution.The resonance curve of rotor's vibration is drawn.All the curves are contrasted with experimental curves.The results of theoretical analysis are shown to be in agreetment with experimental results.