THD Analysis of Reduced Switch Five Level Inverter Using Multicarrier PWM Schemes

Abstract

Multilevel inverter has gained popularity in high power and voltage applications such as electrical power transmission and grid integration of renewable energy sources. Multilevel inverters are designed to achieve higher voltage levels with low harmonics and without requiring higher ratings of individual devices, transformers and series connected synchronized devices. Multilevel inverter has more advantages then the conventional two-level inverter but it also has some limitation, such as the switching losses and complexity increases with increasing the level of output voltage. To overcome these limitations reduced switched multilevel inverter are designed. These topologies require less number of switches and DC sources as compared to the conventional multilevel inverter topologies for the same level of the output voltage. In this paper the design and analysis of a five level reduced switch multilevel inverter topology is presented. The total harmonic distortion (THD) is analyzed by using multicarrier pulse width modulation control schemes such as phase disposition (PD), phase opposition disposition (POD), alternate phase opposition disposition (APOD), phase shifted (PS) and hybrid PWM. Inverter is modeled and analyzed in matlab simulink. Results shows that PDPWM outperforms its companions.