Stability improvement of a current source inverter-induction motor drive system (Q1820115)

The induction motor driven by a current source inverter (CSI) is useful for four quadrant operation by a bridge controlled rectifier. In this paper, the dynamics and steady-state characteristics of the series diode type CSI-induction motor drive system are analyzed, taking into account the effects of the smoothing reactor and commutating capacitor. The stability of this system is analyzed as a sampled data system. The stabilizing effect of adding the stator voltage feedback, the dc-link current feedback and their derivative feedback is investigated, and experimental results are shown. The use of derivative feedback to the inverter frequency is found to be satisfactory in range of positive slip, but is found not to be satisfactory in range of negative slip.