This work examines the transient dynamics of synchronous machines under sudden fault conditions, with emphasis on short-circuit events. The study begins with a single-phase synchronous machine operating in open-circuit mode, where short-circuit current expressions are systematically derived and numerically evaluated using advanced integration algorithms. The transient evolution of stator and field currents is analyzed, highlighting their dependency on rotor position, machine parameters, and electromagnetic interactions. A SIMULINK-based model is implemented to simulate the time-domain responses and visualize the effects of parameter variations. The investigation is then extended to a three-phase synchronous machine with damper windings subjected to line-to-line faults. Generalized voltage equations in the d-q reference frame are formulated, leveraging Park’s transformation to enable detailed modeling of transient behavior. Numerical simulations confirm the analytical predictions, revealing the significant influence of rotor angle, leakage inductances, and damper circuits on fault current dynamics. The results provide valuable insights for fault analysis, power system stability assessment, and the design of synchronous machines under transient operating conditions.
Stoica et al. (Wed,) studied this question.