Performance and efficiency enhancement of induction machine drives: Duality-based approach to VSI and CSI control

Duality between the two-level voltage sourced inverter (VSI) and the current sourced inverter (CSI) is examined for performance and efficiency enhancement of induction motor drives over wide operating conditions. A loss minimization algorithm is developed using a comprehensive loss model to achieve optimum flux for minimizing system-level drive losses. The total losses obtained are lower for the proposed system-based minimization than for previously reported machine-based minimization algorithms. A minimum-inverter-dc-bus-current technique is devised using the output filter capacitor. Although higher performance is reported in the literature for VSI drives than for CSI drives, the comparisons are not based on identical standards. Since high-frequency pulse-width modulation methods are adopted for VSI and more basic quasi-square pulse or selective harmonic elimination methods for CSI, CSI drives show poor power factor and harmonic distortions in the output. This work adopts comparable standards using space vector pulse width modulation control with a combinational logic map to translate switching pulses from VSI to CSI. Simulations and experimental implementation are carried out to validate the proposed scheme.