Study on transient characteristic of large hydro-generator based on field-circuit coupled time-stepping finite element method

This paper presents a Field-circuit Coupled Time-stepping Finite Element (FE) model of a 1000MW hydro-generator, in which the saturation of iron core, running of rotor, impedance of winding ends, distribution of stator windings and end rings of damper bars are taken into account. The 2-D moving electromagnetic finite element model is coupled with the external circuit elements in this model. Using this model, various transient processes are simulated including three-phase sudden short-circuit with and without damper bars. Furthermore, computed values of steady-state, transient and subtransient reactances, as well as, time constants are compared with those designed values, and the results show that the model established in this paper is more valuable.