Analysis of Power Losses in a Three-Phase Inverter 3L-NPC. Comparison with different PWM Modulation Techniques

Abstract

This paper presents the basic operation of a three-phase NPC (Neutral-Point Clamped Converter) three-level converter, together with the different modulation strategies and control techniques most used in the academic literature. The objective was to develop a comparison between the conduction and switching losses in semiconductor devices depending on the modulation technique (SPWM, SVM, THIPWM or DPWM) used. The purpose is to analyze graphically and visually the most influential parameters on power losses, as well as to determine the set of techniques that minimize these losses on the devices. This document discusses the main fields of application and presents some associated technological problems. The heating on semiconductors according to their manufacturing technology (Si, SiC) has also been presented. The analysis has been developed using the free simulation tool Loss Simulation Software by Fuji-Electric. The application uses the specific characteristics of the devices in order to improve the accuracy in the calculation of losses. The purpose is that students can assimilate more quickly the concepts presented in the classroom. The power losses associated with the semiconductors that constitute the 3L-NPC topology have been compared. In this way it is easier to determine and observe the influence of different parameters such as switching frequency, modulation index, output current, power factor, gate resistance, etc. about the proposed structure. At the same time users can learn to use the IGBT application Losses Simulation software