异步电机定子系统磁固耦合振动机理研究

发布时间：2018-07-15 18:41

【摘要】：电机作为机械能和电能之间转换的电磁装置,在民用和国防工业领域中都有广泛的应用。大型电机运行过程中,定子系统的电磁振动是其噪声的主要来源之一,直接影响着电机的噪声水平。而在复杂电磁场作用下的定子系统的磁固耦合振动是导致电磁噪声的主要来源。随着电机向大型化和超大型化发展,对电机定子系统中的磁固耦合作用的研究不容忽视。本文即在民用和国防工业领域减振降噪应用需求的牵引下,以某大型推进电机为实际工程背景,通过对其定子结构的建模和磁固耦合振动的理论研究工作,力求给出准确的计算模型、电磁力的计算方法及其作用下的定子系统磁固耦合振动的机理,为大型电机的电磁设计提供理论依据。本文的主要研究成果与创新点为:1.基于大型推进电机的原理样机,建立了定子系统内、外壳不等长的双壳物理模型,使双壳模型的适用范围得到了推广。该模型可以通过解析表达式描述系统的振动形态,并可以分别考虑内、外壳不同的边界条件,同时,可以计算不同长度比的双壳定子系统的固有特性。2.通过对气隙磁场电磁力组成成分的分析,得到了考虑定子径向变形与气隙磁场相互耦合时的电磁力表达式,指出作用于定子铁芯内圆表面的由偏心气隙磁场产生的电磁力,不仅包含电磁力波项,还包含线性电磁刚度项、非线性电磁刚度项和参数激励项,以及与转子转动情况相关的项。3.将机电耦联系统的非线性振动研究方法应用于异步电机,利用多尺度法对双壳定子系统在偏心气隙磁场作用下的参数共振、参-强联合共振及双重共振问题进行了求解,得到了幅频响应方程,并对定常解的稳定性和分岔方程的奇异性等问题进行了分析,讨论了电磁参数和机械参数对异步电机定子系统产生磁固耦合振动时的解的多值性、跳跃现象,以及系统的周期运动等非线性动力学行为的影响,得到了一些新的规律。4.给出了偏心气隙磁拉力和铁芯内有质动力共同作用下,双壳定子系统磁固耦合振动微分方程。为了对定子铁芯内有质动力做进一步的分析,从Maxwell方程组和电磁本构关系出发,通过对定子铁芯内涡流方程的求解,给出了定子铁芯内有质动力的解析表达式,讨论了电磁场和电磁力随几何参数的变化规律,并分析了铁芯内电磁力对磁固耦合振动的影响。对铁芯内有质动力的分析改进了定子系统的磁固耦合振动的激励形式,为定、转子耦合振动的研究打下了基础。
[Abstract]:As an electromagnetic device to convert mechanical energy to electric energy, motor has been widely used in civil and national defense industries. The electromagnetic vibration of the stator system is one of the main sources of the noise in the running process of the large motor, which directly affects the noise level of the motor. The magneto-solid coupling vibration of stator system under complex electromagnetic field is the main source of electromagnetic noise. With the development of large and super large motor, the study of magneto-solid coupling in motor stator system can not be ignored. In this paper, based on the practical engineering background of a large propulsion motor, the modeling of stator structure and the theoretical study of magneto-solid coupling vibration are carried out under the traction of the application of vibration and noise reduction in civil and national defense industries. The accurate calculation model, the calculation method of the electromagnetic force and the mechanism of magneto-solid coupling vibration of the fixed subsystem under the action are given, which provides the theoretical basis for the electromagnetic design of the large motor. The main research results and innovations of this paper are as follows: 1. Based on the prototype of large propulsion motor, a two-shell physical model with unequal shell length in the stator system is established, which extends the application range of the double-shell model. The model can describe the vibration form of the system by analytical expression, and consider the boundary conditions of the inner and outer shell separately. At the same time, it can calculate the inherent characteristics of the two-shell stator system with different length ratio. By analyzing the composition of electromagnetic force of air-gap magnetic field, the expression of electromagnetic force when considering the interaction between stator radial deformation and air-gap magnetic field is obtained, and the electromagnetic force produced by eccentric air-gap magnetic field acting on the inner circular surface of stator core is pointed out. It includes not only the electromagnetic force wave term, but also the linear electromagnetic stiffness term, the nonlinear electromagnetic stiffness term and the parameter excitation term, as well as the term .3related to the rotor rotation. The nonlinear vibration research method of electromechanical coupling system is applied to asynchronous motor. The parametric resonance, parameter-strong joint resonance and double resonance of two-shell stator system under the action of eccentric air-gap magnetic field are solved by multi-scale method. The amplitude-frequency response equation is obtained, and the stability of the steady solution and the singularity of the bifurcation equation are analyzed. Some new laws, such as jump phenomenon and the influence of nonlinear dynamical behavior such as periodic motion of the system, are obtained. The differential equation of magneto-solid coupling vibration of the two-shell fixed subsystem under the action of the eccentric air-gap magnetic pull force and the mass force in the iron core is presented. In order to further analyze the mass force in the stator core, starting from the Maxwell equations and the electromagnetic constitutive relation, the analytical expression of the mass force in the stator core is given by solving the eddy current equation in the stator core. The variation law of electromagnetic field and electromagnetic force with geometric parameters is discussed, and the influence of electromagnetic force in core on magneto-solid coupling vibration is analyzed. The analysis of the mass force in the iron core improves the excitation form of the magneto-solid coupling vibration of the stator system, which lays a foundation for the study of the stator and rotor coupling vibration.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM343

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