A new concept in regulation of dc sources in cascaded multi-level inverters to improve output voltage total harmonic distortion

2012 ◽  
Vol 4 (4) ◽  
pp. 043122 ◽  
Author(s):  
M. G. Hosseini Aghdam
2018 ◽  
Vol 7 (3) ◽  
pp. 1059
Author(s):  
Mustafa Fawzi Mohammed ◽  
Ali Husain Ahmad ◽  
AbdulRahim Thiab Humod

The most concerns in the inverter's design are about, how to make the output voltage of the inverter sinusoidal at the desired fundamental frequency with low total harmonic distortion (THD). This paper presents a design and implementation of single-phase five-level inverter which is powered by single dc source and based on T-type multi-level inverters construction. The proposed inverter is built mainly by six IGBTs and two diodes. The used modulation technique is based on using two triangular carriers at 2000 Hz frequency and shifted by phase opposition disposition (POD) method. The carriers are made slightly unbalanced with their amplitudes. The over-modulation method is also introduced in the design to get the lowest possible THD effect without using filters. The inverter is simulated by MATLAB SIMULINK, implemented practically, and tested with the help of LabVIEW software.  


Author(s):  
Hatef Firouzkouhi

A new concept in control of cascaded H-Bridge multi-level inverters is proposed in this paper. According to this concept, switching angles are considered to be independent from the fundamental voltage. A polynomial term is presented to show the relation between switching angles and DC voltages. Based on this concept, Total Harmonic Distortion (THD) calculations are updated and proved to be independent from the fundamental voltage. Thus, once calculated for minimum THD, the switching pattern can be used for any required level of output voltage. To examine the effectiveness of the proposed method, it is applied in control of an eleven level inverter. The simulation results are demonstrated and verified through experiments with a setup controlled by Xilinx SPARTAN3 family FPGA (XC3S400-PQG208).


Author(s):  
Trong-Thang Nguyen

<p>In this study, the author analyzes the advantages and disadvantages of multi-level inverter compared to the traditional two-level inverter and then chose the suitable inverter. Specifically, the author analyzes and designs the three-level inverter, including the power circuit design and control circuit design. All designs are verified through the numerical simulation on Matlab. The results show that even though the three-level inverter has a low number of switches (only 12 switches), but the quality is very good: the total harmonic distortion is small; the output voltage always follows the reference voltage.</p>


2019 ◽  
Vol 8 (2S8) ◽  
pp. 1149-1154

A inverter is basically a device that usually converts DC to AC voltage without causing any power loss, applicable to only low to medium voltage applications. But in case of medium to high power applications, it has demerits like high switching losses, reduced cost and low efficiency. To overcome these demerits a Multilevel inverter applicable to high voltage and high-power applications which have low total harmonic distortion (THD) is introduced. This paper is mainly focused on seven-level inverter with five switches and four dc sources. with low total harmonic distortion, less switching loss without adding any complexity to the circuit. The switching topology is integrated with various SPWM techniques like Phase Disposition (PD), Phase Opposition Disposition (POD) and Anti Phase Opposition Disposition (APOD). For better performance of the inverter above three PWM techniques will be compared and analyzed to find the low THD configuration. The simulation of switching topology is done by MATLAB/Simulink.


2022 ◽  
Vol 4 (1) ◽  
pp. 1-13
Author(s):  
Madhu Andela ◽  
Ahmmadhussain Shaik ◽  
Saicharan Beemagoni ◽  
Vishal Kurimilla ◽  
Rajagopal Veramalla ◽  
...  

This paper deals with a reduced switch multi-level inverter for the solar photovoltaic system-based 127-level multi-level inverter. The proposed technique uses the minimum number of switches to achieve the maximum steps in staircase AC output voltage when compared to the flying capacitor multi-level inverter, cascaded type multilevel inverter and diode clamped multi-level inverter. The use of a minimum number of switches decreases the cost of the system. To eliminate the switching losses, in this topology a square wave switch is used instead of pulse width modulation. Thereby the total harmonic distortion (THD) and harmonics have been reduced in the pulsating AC output voltage waveform. The performance of 127-level MLI is compared with 15 level, 31-level and 63-level multilevel inverters. The outcomes of the solar photovoltaic system-based 127-level multi-level inverter have been simulated in a MATLAB R2009b environment.


Multilevel inverters are widely used for high power and high voltage applications. The performance of multilevel inverters are superior to conventional two level inverters in terms of reduced total harmonic distortion, higher dc link voltages, lower electromagnetic interference and increased quality in the output voltage waveform. This paper presents a single phase hybrid eleven level multilevel inverter topology with reduced switch count to compensate the above mentioned disadvantages. This paper also presents various high switching frequency based multi carrier pulse width modulation strategies such as Phase Disposition PWM Strategy (PDPWM), Phase Opposition and Disposition PWM Strategy (PODPWM), Alternate Phase opposition Disposition PWM (APODPWM), Carrier Overlapping PWM (COPWM), Variable frequency carrier PWM (VFPWM), Third Harmonic Injection PWM (TFIPWM) applied to the proposed eleven level multilevel inverter and is analyzed for RL load. FFT analysis is carried out and total harmonic distortion, fundamental output voltage are calculated. Simulation is carried out in MATLAB/SMULINK.


Sign in / Sign up

Export Citation Format

Share Document