Abstract

With the increasing popularity of multi-level inverters, the room for improvement of the performance of voltage source inverters has continuously been tested for various applications. The present project highlights the comparison of the conventional two-level inverter and the three-level Neutral-Point Clamped inverters for the application in automotive industry. The two inverters are compared for different conditions for losses, efficiency and the permissible temperature limit of operation for the non-ideal inverters that have been chosen for the application. The allowable limits of the switching frequencies for both the inverters have been discussed. The project highlights the DC-link balancing control which is the most commonly faced problem in case of a three-level Neutral-Point Clamped Inverter, with no additional circuit. Modifications of the modulation techniques for the realization of the DC-link balancing control have been proposed. Comparison of the total harmonic distortion of the line-to-line voltages at the outputs of the two and three-level inverters has been presented for both modulation techniques. The project also deals with the control of the Permanent Magnet Synchronous Motor drive using Field-Oriented Control Technique. From the detailed comparison, three-level Neutral-Point Clamped inverter has stood out as a better candidate when compared to the conventional, two-level inverter.