Post-Fault Demagnetization of a PMSG Under Field Oriented Control Operation

To assess demagnetization, a line-to-line short-circuit fault study is carried out with constant input torque and field-oriented control (FOC) for the speed of a permanent magnet synchronous generator (PMSG). For the study, a cosimulation between finite element analysis (FEA), power electronics simulation (Simplorer) and model-based control design software (Matlab Simulink) is used. The analyzed system was previously validated in the experimental set-up with DS1103 card. The initial short circuit currents, although higher than nominal, did not present a risk of demagnetization for the generator in the analyzed working conditions, namely magnets temperature and speed. Nevertheless, the acceleration during the fault, due to constant input torque, and the control scheme with a constant speed reference, provided a greater demagnetizing current while breaking the machine speed back to the pre-fault reference. The cosimulation results bring higher fidelity to the modeling and analysis of the behavior of the PMSG under FOC.