Pandav Kiran Maroti

Hextuple-inverter configuration for multilevel nine-phase symmetrical open-winding converter

Hextuple-inverter configuration for multilevel nine-phase symmetrical open-winding DC converter is articulated in this work. Power modular unit consists of six classical three-phase voltage source inverters (VSI). Each VSI includes one bi-directional device (MOSFET/IGBT) per each phase and link to two capacitors for neutral connection. A modified single carrier five-level modulation (MSCFM) algorithm is developed and modulates each 2-level VSI as 5-level multilevel inverter (MLI). A set of test results is presented, which are observed from the model based developments in numerical simulation softwares (Matlab/PLECS). The results always showed good conformity with the developed theoretical background under working conditions. The proposed converter found suited for (low-voltage/high current) electric vehicles, DC tractions and ‘More-Electric Aircraft’ applications.

Single-phase seven-level stack multicell converter using level shifting SPWM technique

This paper presents a single-phase seven-level stack multicell converter (SMC) which provides a viable solution for multilevel converter. Conventional cascaded multilevel inverter (MLI) removes the drawbacks of clamping diodes and clamping capacitors topologies. However, in a cascaded MLI number of voltage source and power switches increases as the number of level increases. The main advantage of single-phase SMC converter is only two DC sources are needed for any number of levels. Level shifting SPWM technique has been incorporated to achieve gate pulses, in which carrier wave of 20kHz is compared with 50Hz sinusoidal reference wave at a modulation index of 1 and 0.9. Total harmonic distortion (THD) for SMC converter is achieved at 1.55% and 5.26% with and without filter respectively. The seven-level SMC topology is simulated in MATLAB/SIMULINK and simulation results are provided to verify the performance.

A new multilevel inverter with fewer number of control switches

Multilevel inverters (MLI) plays a vital role in high voltage and high power applications due to its capability of converting DC to AC with reduced total harmonics distortion (THD). In this paper, a new multilevel inverter (MLI) with fewer number of control switches is proposed. The proposed topology requires a fewer number of control switches compared to conventional and recently derived topologies, thereby reducing complexity and the total cost of circuit. The topology operation is discussed for a seven-level and it can be easily extended to N-level by adding (N-3)/4 repeating stages. N-level proposed topology requires (N+3)/2 unidirectional power switches and 2N-2 diodes. The proposed topology is simulated for 100W; seven levels with level shifting SPWM technique in MATLAB/SIMULINK and results shows the validity of topology.