Magneto-solid coupling nonlinear vibration of generator set stator system

Magneto-Solid Coupling Nonlinear Vibration of Stator System of Generator Set 1 Qiu Jiajun, Li Wenlan, School of Mechanical Engineering, Tianjin University, Tianjin Addition 0072. The numerical calculation of the obtained amplitude-frequency response equation shows that the maximum amplitude of each mode in the two-phase short-circuit is smaller than that in the steady-state operation. This is different from the vibration law of the generator rotor shaft.

Two-phase short-circuit is the more common species in the asymmetrical operation state of the generator set. At this time, a large inrush current will be generated. When the two phases are short-circuited, the vibration of the hydro-generating unit's shafting system is significantly more severe than the rated normal operating state. In this paper, according to the actual situation of the Luxia Project, the magnetic-solid coupled nonlinear vibration of the stator system with two-phase short-circuit is analyzed with the physical model of the double-shelf system as the stator system for the Qianxi 24 hydro-generator unit.

1 Mathematical model of magnetic-solid coupling nonlinear vibration of stator and stator The electromagnetic force of the inner surface of the stator core in the event of two-phase short-circuit is: The stator-double-shell model magneto-solid coupling nonlinear vibration equation is the manufacturer's, and is the stator vibration of the double-shell model. The heart is the inner diameter of the stator core. From, right, to the general mass of the inner shell of the stator, it is the first mode of the radial vibration of the stator core.

2 Magnetic-Solid Coupling Double Resonance of the Stator System When considering the mutual influence between the radial vibration displacement of the stator core and the air gap magnetic field, the electromagnetic force acting on the inner surface of the stator iron core contains the nonlinear component of the vibration displacement. Equation 1 is the nonlinear vibration. equation. As long as the electromagnetic force acting on the inner surface of the stator iron core is given, the magneto-solid coupling nonlinear vibration equation of the stator system in the corresponding operating state is obtained. The multi-scale method was used to analyze the magnetic-solid coupling double resonance of the stator system under the action of combined excitation and excitation, and its steady state equation was obtained. Through analysis, the steady-state equation has two solutions, namely the amplitude of the 4th-order mode and the 8th-order mode. Either zero or none. When 6 is zero at the same time, only the 8th-order mode is excited, and the solution of the steady-state equation 3 is caused by the strong-joint resonance, which has been discussed in detail in article 3. When both of them are not zero, the modal modality is stimulated at the same time. The solution of the amplitude-frequency response equation is 1 national 973 key basic research project, and 99802039 special fund is used to support it. 2 is the coefficient of the equation, which is generated by The electromagnetic parameters of the machine and the structural parameters of the double-shell system are determined. 3 Analysis of calculation results To solve the equation numerically, the frequency response curve of each mode participating in double resonance under the corresponding operating state is obtained.

1 is the frequency response curve of each mode in the steady state operation. 2 is the frequency response curve of each mode when the positive and negative sequence currents are maximum when the two phases are short-circuited. The resonance amplitude of the two-phase short-circuit and the maximum amplitude of each mode are reduced compared to the steady-state operating state, which is related to the vibration of the rotor shaft of the hydro-generator set given in the literature 1. Different laws.

4 Conclusions There are two solutions to the double resonance of the stator system in the case of two-phase short circuit, and the maximum amplitude of the resonance range and the modes participating in the resonance are reduced compared with the relative steady-state operation state, and the power generation is reduced. The rotor shaft system of the machine has different vibration laws.

1 Chen Guiqing, Qiu Jiajun. Intensity and Joint Resonance During Large-scale Hydrogenerator Units' Asymmetric Operation. Huang Huai Xuebao, 1999, 522 Qiu Jiajun, Li Wenlan. The Influence of Boundary Constraints on the Solid and Frequency of the Hydrogenerator Stator System . Motor Technology, 998, 13725