Nonlinear vibration characteristics of bulb tubular unit under influence of faulty oil receiver
ZHANG Leike1*, WU Jing1, WANG Xueni1, MA Zhenyue2, ZHANG Jinjian1, TANG Hualin1
1. College of Water Resources Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China; 2. School of Hydraulic Engineering, Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian, Liaoning 116023, China
Abstract：Accident of bulb tubular unit caused by fault oil receiver components occasionally, which directly affects the safety and stability of unit operation. Based on constructing unbalanced magnetic pull model under the influence of compound eccentricities, the shaft model of bulb tubular unit with fault oil receiver and corresponding differential equation are established. Nonlinear vibration characte-ristics of rotor system in the process of excitation current, static eccentricity of air gap and dynamic eccentricity are studied by numerical analysis. The results show that, on one side, the unsteady motion range and the adverse vibration of rotor is increased due to fault oil receiver, on the other side, the failure part plays a positive role in suppressing system amplitude and weakening harmonic component to certain extent. Furthermore, compared with the constant static eccentricity, the dynamic eccentricity, which is continually changing with the unit operation, makes the system produce more abundant responses such as quasi-periodic and periodic-2 motions, meanwhile, the stable operating range is reduced, which needs to be paid enough attention to. The results can provide useful references for the safe operation and stability analysis of bulb tubular hydropower units.
