A Load Commutated Multilevel Current Source Inverter Fed Open-End Winding Induction Motor Drive With Regeneration Capability

This paper presents a load commutated silicon controlled rectifier (SCR) based multilevel current source inverter (CSI) fed open-end winding induction motor (IM) drive with regeneration capability. Multilevel current waveform is realized using two isolated load commutated SCR-based CSIs connected in shunt configuration, but operated with a phase shift of 30° thereby attaining significant reduction in harmonic distortion of the motor current. The multilevel CSI connected to one side of the stator windings supplies real power to the motor. The other end of the stator winding is directly interfaced with a capacitor-fed voltage source inverter (VSI). The control scheme of the VSI facilitates load commutation of the multilevel CSI under all conditions of operation, including regenerative braking. The proposed scheme is experimentally verified on an IM with open-end stator winding, with the help of a digital signal processor TMS320F28335.