Loss of synchronism process of a synchronous generator described by its internal flux and force distributions

The authors report on the loss of synchronism process of a synchronous generator in an electric power system. The process is described in terms of the magnetic flux and force distributions inside the machine. Data on the field and armature currents used as input to the flux and force calculation by the finite element method were obtained from experiments on a machine connected to an infinite-bus system. By examining the transition of flux and force distributions during the loss of synchronism process, a physical picture of the process is given