Synchronization Angle determination in DVCSFO of DFIM naval propulsion

This paper presents the Dual Vector Control with Stator Flux Orientation (DVCSFO) of Doubly Fed Induction Machine (DFIM). This DFIM operates in motor mode and is intended for naval propulsion. This machine, without permanent magnets, is fed by two identical PWM VSIs. It has been specially designed to share its power equally between the stator and the rotor. The previous studies have discussed the cooling of all system carried out by the water, for the stator and rotating rotor of DFIM and also for two IGBT VSIs. The stator and rotor fluxes are controlled in rotating «d,q» reference frame and must be maintained at their nominal value. Therefore, the DVCSFO strategy requires precise knowledge of all transformation angles and especially the Synchronization Angle when an incremental encoder is used as a speed sensor. Unlike the squirrel cage asynchronous machine, this DFIM actuator can be blocked if the synchronization angle is neglected in Park transformations.