| Since the 90s of last century, our country pumping energy storage power plant developed rapidly, a large number of generator-motors has been put into operation, pumped storage energy power station plays an improtant roal in the power system for reducing peak load, filling load valley, frequency and phase modulation. Compared with the conventional hydro generator, the pumped storage generator has the characteristics of high speed, large capacity, complex operating conditions and frequent start-up. Because of its operation in bad condition, unit operation time of growth and, pumped storage generator motor rotor faults occur frequently, mainly for the rear of the magnetic yoke t appear crack, T tail breaks caused pole skewed swept bore accident, caused by rupture of main shaft and other. The cause of the accident is that the design of the early generation motor does not consider the fatigue of the material.Multi physical field coupling analysis method is often used to study the coupling mechanism of electromagnetic thermal structure, and to explore the main factors affecting the safe operation of the unit. In this paper a pumped storage power plant in service of motor generator as the research object, focusing on motor normal operation, mode conversion, rejection of load and the runaway operating condition of electromagnetic temperature field structure interaction process, explore unit fault mechanism. In multi physics field coupling analysis based on, combined with the fatigue properties of the material, by using the theory of fatigue strength of motor generator rotor fatigue life prediction, and guide the generator motor condition assessment and maintenance methods are formulated.Firstly, the transient electromagnetic field of the motor is analyzed by using the time stepping finite element method, the electromagnetic force, heat loss and other parameters are obtained, and the excitation source input is provided for the temperature field and structure field calculation. Then, on motor generator temperature distribution and thermal stress were calculated, the temperature field and thermal should force calculation can not only know the hot region, but also the thermal stress is considered in fatigue assessment in. In the electromagnetic field and temperature field calculation is done using the kinetic calculation method of rotor motion is analyzed, and the several typical operation situation generation motor rotor parts have been should stress/strain fatigue analysis of load spectrum for monitoring sensors as well as the limitations of static analysis cannot consider characteristics of dynamic process, laid the foundation for the fatigue analysis of the generator motor rotor. For multi physics coupling calculation relates to the data transfer problem, put forward a by mesh mapping method achieve shaped grid method of data transmission to be addressed.It is an important research content of this topic to reasonably evaluate the fatigue performance and remaining life of pumped storage power generation motor rotor. In the multi physics field coupling analysis based on, first explore generator motor rotor material fatigue failure mechanism, the fatigue life characteristics of the rotor components of material obtained by fatigue test; secondly, according to the strain life assessment method under the various conditions alone rotor fatigue life was calculated. Finally, the fatigue cumulative damage theory combined with the analysis of the fatigue life of the generator motor rotor, in order to provide a theoretical basis for the power generation motor repair, the improvement and the design and manufacture. |
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