Research on electromagnetic characteristics of large hydro generators based on the finite element method

In this paper, a physical model is established for the finite element calculation of a 770 MVA large hydro generator, considering such complex factors as core saturation, rotor motion, damping winding, and eddy current loss of the damping winding. Through the simulation of three-phase (A, B, C) sudden short circuit and other transient processes with damping windings, the model verification shows that the error between the simulation results of no-load tests and the actual data is less than 5% (no-load maximum 3.87%, short-circuit maximum 4.89%); the deviation between the rated load torque simulation value of 54.29 MN•m and the theoretical value is only 6.8%, and the magnetic density of 0.946T meets the design expectation. The finite element physical calculation model significantly improves the accuracy and engineering applicability of electromagnetic characteristics analysis of large hydro generators.