Estratégia generalizada de modulação por largura de pulso para inversores multiníveis.

Abstract

This work proposes a generalized pulse width modulation method for multilevel inverters. The strategy takes advantage of the fact that the Space Vector PWM switching sequences are the same as those created by the Carrier Based PWM, when an adequate zero sequence component is injected into the carrier system references. This work introduces a generalized equation for the zero sequence component, which is a function of a "broad sense" distribution ratio of zero voltage vectors and the number of levels of the inverter. The method dispenses with the complicated derivation of similar relations for inverters with more than three levels. It can also be applied to determine the switching pattern that minimizes the switching losses. The topology of the three level voltage inverter with clamped diodes was set up to test the proposed technique. A digital signal processor was used to generate the command signals for the inverter. In addition, a structure of three level inverter with a reduced number of components is analyzed. The objective is reduce the conduction losses. Experimental results that demonstrate the efficiency and the quality of the multilevel strategy are presented.