A novel multilevel inverter using single carrier PWM technique

Abstract

This paper focuses on a nine level multilevel inverter with DC link capacitors at the input side. The main disadvantage of cascaded multilevel inverter is the number of DC sources. So a nine level multilevel inverter with DC link switches, which requires less number of DC sources as compared to the conventional multilevel inverter is proposed. Single carrier method is the control strategy used here. A comprehensive literature survey on existing nine level multilevel inverter is carried out. The feasibility of the proposed nine level inverter is verified through simulation. Proposed nine level inverter is compared with the conventional H bridge multilevel inverter.

Comparative Analysis of Five Level Multilevel Current Source Inverter and Bridge Configured Current Source Inverter for Pv System

“…In this mode M 2 and M 3 receives gate pulses and starts conducting and current flows through the path M 3, D 3 ,load, M 4, D 4 and source. Hence at the output we get negative current in the form of square shape [3,15].…”

“… Mode-1 (+i l level): Fig.3 shows the equivalent circuit to this mode. Through this approach, the CSI is operated in positive half cycle of grid voltage to maintain the +i l level by turning ON the power switches (Sp l and Sp 2 ) and modulating the switches (S 11 , S 12 , S 22 and S 21 ) at high frequency [1,4]. In this we get +i 1 current at the output and which is termed as a first level.…”

“…But because of more advantages CSI are used in its place of VSI. The reason behind this is that CSI has natural enhancing and short circuit protection abilities, direct output current controllability and AC side simple filter structure [3,4,15].…”