A Multi-Pulse AC-DC Converter Fed Multi-Level Inverter for Power Quality Improvement in VCIMD

This work presents a variable frequency induction motor drive (VFIMD) for medium power application. A fifty-four pulse AC-DC converter is utilized on grid end of proposed IMD and a 27-level cascaded multi-level inverter (MLI) is utilized on the motor end. A fifty-four pulse converter makes the grid current nearly sinusoidal and reduces total harmonics distortion (THD) to a very low value. A ternary principle is utilized to select the DC-link voltages of a cascaded MLI in order to get a 27-levels in phase voltage. Proposed IMD has good power quality performances at both grid and motor end. Apart from this, proposed drive enhanced the performances of IMD. An area equalization modulation technique (AEMT) is proposed in this work for a 27-level cascaded MLI to switch this inverter at fundament frequency, which ensures the very low switching losses in the proposed VCIMD. A Simulink/MATLAB platform is utilized for modelling and design of proposed IMD and extensive simulation results from this model are presented here, to show the usefulness of proposed IMD for medium power application.