A New Modified H-Bridge Multilevel Inverter with Multi Carrier PWM Technique for Speed Control of Induction Motor

Abstract

This research work introduces a new Modified H-Bridge Multi Level Inverter (MHBMLI) with reduced power switches when compared to existing diode clamped and cascaded multi level inverters. The proposed topology involves a low hardware complexity thereby reducing the overall cost of an inverter. The proposed inverter with Proportional integral (PI) controller is tested for closed loop speed control with an induction motor. The simulation has been carried out using MATLAB/SIMULINK. The performance of the induction motor with various multi carrier PWM techniques such as Phase disposition (PD), Phase opposition disposition (POD) and phase shifted (PS) have been compared on different performance measures with Total harmonic distortion (THD) of stator voltage, current and motor speed settling time. The results are verified by hardware fabrication using IGBT (Insulated Gate Bipolar Transistor) power switches for inverter and XILINX-SPARTAN-6E FPGA based embedded system as overall control system. It has been observed that the proposed inverter with PDPWM offers reduced THD of stator voltage, current and fast speed settling time, thereby making this new MHBMLI is a good choice for real time speed control of induction motor.