Comparative evaluation of modulation algorithms for three-phase neutral-point-clamped (NPC) multilevel inverter

Ho , Shun Ten (2014) Comparative evaluation of modulation algorithms for three-phase neutral-point-clamped (NPC) multilevel inverter. Project Report. UTeM. (Submitted)

Text COMPARATIVE EVALUATION OF MODULATION ALGORITHMS FOR THREE-PHASE NEUTRAL POINT CLAMPED (NPC) MULTILEVEL INVERTER 24pages.pdf Download (402kB)

Abstract

This project gives a comparative evaluation of modulation algorithms for neutral point clamped (NPC), which is a multilevel inverter topology which converted DC sources to AC sources. Neutral point clamped topology is progressively applied in motor drive applications due to their low harmonic output and low switching losses. Nevertheless, higher number levels of NPC multilevel inverter topology and increasing number of semiconductor devices promotes the difficulty to balance capacitors’ potential and raise the complexity of switching techniques involved. The important parameters of inverter such as total harmonic distortion (THD) measurements and voltage balancing are controlled by the adopted switching technique. Two switching modulation techniques have been proposed in this study, which are sinusoidal pulse-width modulation (SPWM) and space vector pulse-width modulation (SVPWM), but the selection of switching technique is based on several key properties which are simple, flexible, and produce low harmonic output. Besides that, this project also presents comparisons between two-level conventional inverter, three-level NPC and five-level NPC. The simulation will done using MATLAB/Simulink. Maintaining the THD level as low as possible is very crucial, because it would cost less effort on filtering. The percentages of voltage THD can be lessened by increasing the modulation index. Besides that, the implementation of SPWM is easier but the THD level is higher, than SVPWM.

Actions (login required)

View Item