Motor-Converter Synchronization Phenomena in a Subsynchronous Cascade Drive

In the past, subsynchronous cascade drive behavior at slips that are a multiple of 1/6 has caused controversy among researchers. A new approach for predicting and interpreting drive behavior at these slips is presented in this paper. With the help of the space vector theory, an analytical investigation that shows a specific synchronization of the induction motor with the diode rectifier is carried out. The method of analysis presented can also be generally applied when a specific symmetry of the space vectors of the motor electromagnetic quantities is imposed by a power electronic converter or other sources.