Performance of 3-phase induction motor fed from improved delta PWM voltage source inverter

The proposed improved delta modulator with PI controller (DMPI) generates a switching pattern that can handle the inverter switching requirements with minimum complexity. It can provide constant voltage over frequency (v/f) control up to the motor base speed and smooth transition to constant voltage mode of operation beyond the base speed. DMPI also optimizes the slope of the feedback signal, window width and magnitude of the DM reference signal. It has been found that a proper selection of these parameters play a vital role on the design of a 3-phase IGBT based VSI for superior induction motor performance. Analytical and simulated results are confirmed with those obtained from an experimental laboratory setup. The experimental results confirm the improved performances of the delta VSI-fed induction motor over a wide speed range