Analysis and calculation of the 3D rotor temperature field of a generator-motor

Abstract

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.

Analysis and Treatment of an Overheated Ablated Fault on the Pole Shoe Surface of a Large Tubular Hydro-Generator

“…(1) where k is the order of the tooth harmonic, m is the number of phases, and q is the number of the slots per pole per phase. For this generator, m = 3, q = 2, and the first-and second-order tooth harmonics are (11,13) and (23, 25), respectively.…”

“…To date, although in area of the rotor loss and heat of hydro-generator, researchers have carried out some constructive study and made a number of significant achievements [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], including the analytical calculation and numerical analysis of damper winding current and loss [2][3][4],the electromagnetic-temperature field coupling analysis of damper winding loss and heat [5][6][7] ， the discussion of the influence of structural parameters on damper winding loss and heat [8][9],and the coupling analysis of fluid-temperature field of rotor pole heat [10][11][12][13][14][15][16]. However, none of above research work involves the analysis of the overheat fault of the hydro-generator rotor.…”