Modeling, Analysis, and Identification of Armature Winding Interturn Fault in Multiphase Brushless Exciters

As the core of large-capacity nuclear power generation system, the multiphase annular brushless exciter (MPABE) may cause a serious catastrophe to the nuclear power plant if it fails. In order to effectively protect the armature winding of MPABE, a rapid simulation model and a sensitive diagnosis method of armature winding short-circuit (AWSC) fault are studied systematically in this article. First, this article proposes a general and rapid simulation model of MPABE with AWSC fault. To verify the correctness of this model, corresponding simulations and experiments of AWSC faults are carried out, respectively, through which the fault characteristics are obtained. Then, a detailed mechanism analysis is presented, which explains the induction process of the related harmonics in the stator and rotor currents. The variation law of the characteristics value when the number of short-circuited coils changes is also analyzed. Finally, a new method to diagnose AWSC fault of the MPABE is proposed and then optimized. The test results on the prototype show that this method can sensitively diagnose even the slightest AWSC fault. Therefore, it can provide a reliable basis for the monitoring and protection of MPABE in nuclear power plants.