| Generator-motor is the key equipment of pump storage power station. It is very difficult to design and analyze the generator-motor because generator-motor often changes operating conditions among the generator, pump, phase modifier and standstill. Particularly, electromagnetic parameters and the end region magnetic field problem, which affect the operating performance and reliability of generator-motor, are hot topics among academia and engineering fields. In this dissertation, the generator-motor is treated as the object of study, and calculation method, change rule, influence factor and structure optimization problem of electromagnetic parameters and end region magnetic field of generator-motor operating in multiple steady-state operation conditions are studied.Aimed at multiple steady-state operation conditions of generator-motor, a new terminal iterative method, named the inscribed circle iterative method, is proposed. The new method is used to fast determine the steady-state load operation condition of generator-motor. The new method is validated by the experiment. The calculation method of electromagnetic parameters of generator-motor based on 3-D magnetic field analysis is proposed. The simplification method of solution domain is given. Saturated and unsaturated steady-state and transient electromagnetic parameters of the generator-motor operating in generator and pump conditions are obtained. The reason why the difference between the 3-D magnetic field method and the 2-D magnetic field method appears is comparatively analyzed. This work can provide the theory reference for the proper selection of the numerical calculation method of electromagnetic parameters.The change rule of steady-state electromagnetic parameters of generator-motor operating in generator and pump reactive power regulation conditions is studied. The influence of rotor pole structure on the steady-state and transient electromagnetic parameters is analyzed. The change rule of electromagnetic parameters are obtained, when the single arc, even air-gap three-section arc, and uneven air-gap three-section arc are respectively used. The influence of the damper winding structure on transient electromagnetic parameters of generator-motor is analyzed. The change rules of transient electromagnetic parameters varying with the number of damper bar, damper bar pitch and the connection type of damper end ring are obtained. The work provides the basis for the optimization design of generator-motor rotor structure.The 3-D finite element calculation model of transient eddy current field of the end region in generator-motor is established, which is suitable for multiple steady-state operation conditions. The distribution of end region magnetic field and end structure losses are compared when the generator-motor operates in rated condition. The calculation results of end structure losses are treated as the heat source of calculating the end region thermal field. The calculation model of the end region magnetic field and the calculation method of end structure losses are indirectly verified by comparing the test and calculation temperatures. The change rule of the end region magnetic field and end structure losses of generator-motor operating in generator condition with different leading power factors are studied. Aimed at the distribution and major cause of eddy current losses of end structures in the end region of generator-motor operating in steady-state operation condition, the arch-shaped stator clamping plate structure and current-breaking-ceramic stator clamping plate are respectively proposed to reduce the eddy current losses of stator clamping plate and stator support finger.The calculation models based on the field-circuit-machinery coupling used for simulating the asynchronous starting, electric braking and grid connection conditions are established. In the full-voltage and no-load asynchronous starting condition, electric braking condition with double no-load field current and grid connection condition with 95% rated frequency, the change rules of winding currents, revolving speed, and electromagnetic torque are calculated. The transient process of the end magnetic field of generator-motor and dynamic change rule of end structure losses are studied and compared with the steady-state operating condition. |
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