Study of Multi-Level Inverter Staircase Modulation Technology

2013 ◽  
Vol 347-350 ◽  
pp. 1540-1543
Author(s):  
Man Yuan Ye ◽  
Song Li ◽  
Wen Hua Hu

With the rapid development of high-voltage large-capacity converters, multi-level inverter has been more widely used. Cascaded H-bridge multi-level inverter topology and using the trapezoidal modulation technique are described in this paper. The trapezoidal modulation of the H-bridge cascaded inverter is simulation studied with Matlab simulation software. This paper analyzes trapezoidal modulation techniques, how to establish the elimination of specific harmonics of nonlinear equations and the equations of Runge-Kutta algorithm to solve the problem, given in the different modulation to eliminate the 5th and 7th harmonic of the switching angle data. Finally, simulation results show the feasibility and correctness of the trapezoidal modulation of selective harmonic elimination technique.

2014 ◽  
Vol 63 (2) ◽  
pp. 187-196
Author(s):  
R. Kavitha ◽  
Rani Thottungal

Abstract Harmonic minimisation in hybrid cascaded multilevel inverter involves complex nonlinear transcendental equation with multiple solutions. Hybrid cascaded multilevel can be implemented using reduced switch count when compared to traditional cascaded multilevel inverter topology. In this paper Biogeographical Based Optimisation (BBO) technique is applied to Hybrid multilevel inverter to determine the optimum switching angles with weighted total harmonic distortion (WTHD) as the objective function. Optimisation based on WTHD combines the advantage of both OMTHD (Optimal Minimisation of Total Harmonic Distortion) and SHE (Selective Harmonic Elimination) PWM. WTHD optimisation has the benefit of eliminating the specific lower order harmonics as in SHEPWM and minimisation of THD as in OMTHD. The simulation and experimental results for a 7 level multilevel inverter were presented. The results indicate that WTHD optimization provides both elimination of lower order harmonics and minimisation of Total Harmonic Distortion when compared to conventional OMTHD and SHE PWM. Experimental prototype of a seven level hybrid cascaded multilevel inverter is implemented to verify the simulation results.


2017 ◽  
Vol 117 ◽  
pp. 855-861
Author(s):  
N. Vinoth kumar ◽  
V. Kumar Chinnaiyan ◽  
M Pradish ◽  
S. Prabhakar Karthikeyan

In the couple of years, the demand of multilevel inverter has expeditiously increased in the field of utilization of electrical energy. Because the multilevel inverter is a key technology to integrate the different renewable energy sources (wind, solar etc) with the grid. In this research work, authors have configured a novel topology of nine level multilevel inverter has less number of switches with dc voltage sources. The presented approach has been designed to 9-level inverter with seven unidirectional switches with voltage sources. It comprises of an H-bridge which synthesize to ac voltage by utilizing almost all possible additive and subtractive cases of the voltage sources with its combinational power switches and generated optimal firing angles using selective harmonic elimination method with Genetic Algorithm to decrease the lower order harmonic present in the output voltage of the, which supplied by the presented nine-level inverter. It has been concluded that presented approach use a less number of power switches in drive circuit and the number of dc voltage sources also make a simple circuit and enhance the efficiency of the complete system


Author(s):  
Tao Jing ◽  
Alexander Maklakov ◽  
Andrey Radionov ◽  
Sergei Baskov ◽  
Aleksandra Kulmukhametova

<span>This paper presents a hybrid pulse width modulation (HPWM) strategy based on different switching patterns of selective harmonic elimination pulse width modulation (SHEPWM) for the three-level neutral point clamped (3L-NPC) converter. Specific low-order harmonics can be eliminated by SHEPWM at low switching frequency, while the remaining high-order harmonics can be selected to be simply filtered by additional hardware. Large oscillation waveform usually occurs in the transition instant between two diverse modulation situations, therefore switching between distinct switching patterns can be problematic if no effective means is taken, especially when the effect of smooth and fast transition at any time is considerable. A universal and valid control strategy, which maintains the high-quality output voltage and current, is proposed and implemented in this paper to address this issue. Simulation results obtained from MATLAB/SIMULINK are presented to analyze the performance and validate the feasibility and effectiveness of this control scheme.</span>


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