Analysis On Core Temperature In Generator Coupling Faults Composed By Static Air-Gap Eccentricity & Rotor Short Circuit

The temperature on stator and rotor in turbo-generator under normal,static air-gap eccentricity(SAGE),rotor inter-turn short circuit(RISC)and composite fault were studied in this paper.The detailed formulas of magnetic flux density(MFD),hysteresis loss(HL)and eddy current loss(ECL)under different conditions were firstly obtained.Then,taking MJF-30-6 generator as the simulation research object,the temperature on stator and rotor under different conditions were obtained by means of 3D finite element software Maxwell-ANSYS workbench.Combined with theoretical analysis and simulation: the temperature on stator and rotor will increase compared to room temperature 22°C due to stator and rotor produce HL and ECL with the existence of odd harmonic components of MFD under normal condition.SAGE and forced excitation due to RISC will increase the stator and rotor loss and temperature,and was higher than normal condition.The greater the degree of failure is,the more obvious this trend will be.Under composite faults,when the SAGE is constant,the HL,ECL,temperature of stator and rotor gradually increases as the increment of RISC degree under intensified excitation condition.When the RISC is constant,the HL,ECL,temperature of stator and rotor increases as the increment of SAGE degree.The overall temperature of stator and rotor is higher than normal condition and the equal degree of single failure.When the degree of SAGE and RISC were simultaneously increased,the HL,ECL,temperature of stator and rotor will increase.Finally,the experiment was taken on a CS-5 non-salient synchronous simulating generator to measure stator temperature under four operating conditions.The experimental results were basically consistent with the theoretical simulation analysis.The accuracy of the research method in this paper was verified.