This paper builds the mathematical model for the rotor temperature field of a generator-motor. The solved region for the temperature field is simplified according to the symmetry in geometry. Based on the assumptions of the solved region and taken into account the difference between the rotor's windward side and leeward side, the rotor temperature fields are calculated by 3D Finite Element Method. The steady temperature distributions are obtained under three operating modes, and the transient temperature curves are plotted under the asymmetry operation and the double rated excitation operation. The results show that the rotor temperature is within the range of the permissible temperature of designed insulation and has enough tolerance. I. INTRODUCTIONThe pumped-storage power station has been drawing more attentions as a measure to meet the system demand due to its flexibility, generating the load during peak time using lowercost energy of base-load plants. Pumped-storage has the ability to start and stop at short notice and to vary load almost instantaneously. It is often taken as peak and valley regulation, frequency and phase modulation, and spinning reserve, which ensures the security and quality of supply needs of the power system. The pumped-storage units operate at a high speed and they start and stop frequently. And the operating conditions often change unpredictably. The operating conditions of generator-motor are very rigorous, and the temperature changes acutely in the electric machinery. The copper loss in the excitation windings and the extra loss distributed on the surface of poles or in damping windings will lead to the temperature rising in the poles, so it is necessary to calculate the rotor temperature fields under different operating modes for safe and reliable operation.Although there are many research works on calculation of electric machinery temperature field at present [1][2][3][4][5][6][7] , few are concerned with generator-motor. The paper builds the mathematical model for the rotor temperature field. Taken into account the difference between the rotor's windward side and leeward side, the temperature fields are calculated by 3D Finite Element Method. The temperature distributions are obtained under different operating modes.

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For wind turbine operating above the rated wind speed, the output power of the generator is maintained near the rated power through pitch control. Due to the non-linear relationship between the pitch angle and the wind speed, the traditional PI controller is not ideal for control above the rated wind speed. Therefore, the currently used PI controller generally incorporates gain scheduling technology. A wind turbine pitch controller based on BP neural network PI is proposed in this paper, which optimizes PI parameters and has better control effects. First, the PI control strategy with gain scheduling is briefly introduced, and then the principle and implementation steps of BP neural network PI are given. Finally, compared the control effects of the two control strategies of PI with gain scheduling and BP neural network PI, a new co-simulation between Simpack and MATLAB/Simulink is built, and it is proved that the BP neural network PI can improve the effect of pitch control.