A New Structure of Quasi Z-Source-Based Cascaded Multilevel Inverter

2017 ◽  
Vol 26 (12) ◽  
pp. 1750203 ◽  
Author(s):  
Ebrahim Babaei ◽  
Mohammad Shadnam Zarbil ◽  
Mehran Sabahi

In this paper, a new topology for cascaded multilevel inverters based on quasi Z-source converter is proposed. In the proposed topology, the magnitude of output voltage is not limited to dc voltage source, while the magnitude of output voltage of conventional cascaded multilevel inverters is limited to dc voltage source. In the proposed topology, the magnitude of output voltage can be increased by controlling the duty cycle of shoot-through (ST) state, transformer turn ratio, and the number of switched inductors in the Z-source network. As a result, there is no need for extra dc–dc converter. In the proposed topology, the total harmonic distortion (THD) is decreased in comparison with the conventional Z-source inverters. The proposed topology directly delivers power from a power source to load. In addition, in the proposed basic unit, higher voltage gain is achieved in higher modulation index which is an advantage for the proposed base unit. The performance of the proposed topology is verified by the experimental results of five-level single-phase inverter.

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 154
Author(s):  
Wei Yao ◽  
Jiamin Cui ◽  
Wenxi Yao

This paper presents a novel digital control scheme for the regulation of single-phase voltage source pulse width modulation (PWM) inverters used in AC power sources. The proposed scheme adopts two deadbeat controllers to regulate the inner current loop and the outer voltage loop of the PWM inverter. For the overhead of digital processing, the change of duty of PWM lags one carrier period behind the sampling signal, which is modeled as a first-order lag unit in a discrete domain. Based on this precise modeling, the deadbeat controllers make the inverter get a fast dynamic response, so that the inverter’s output voltage is obtained with a very low total harmonic distortion (THD), even when the load is fluctuating. The parameter sensitivity of the deadbeat control was analyzed, which shows that the proposed deadbeat control system can operate stably when the LC filter’s parameters vary within the range allowed. The experimental results of a 2kW inverter prototype show that the THD of the output voltage is less than 3% under resistive and rectifier loads, which verifies the feasibility of the proposed scheme. An additional advantage of the proposed scheme is that the parameter design of the controller can be fully programmed without the experience of a designer.


2018 ◽  
Vol 7 (2.24) ◽  
pp. 55
Author(s):  
Anuja Prashant Diwan ◽  
N Booma Nagarajan ◽  
T Murugan ◽  
S Ashrafudeen ◽  
G J. Jenito Paul

In this paper, single phase nine level cascaded multilevel inverter using trinary voltage source is described. Normally for getting nine level MLI output, four H-Bridges are required. But in proposed method, nine level output is achieved by using two H-Bridges only. Performance of Multilevel inverter is improved by using modular switching pattern. This method reduces the number of switches to the half and thus reduces switching losses. Since the number of levels at the output voltage is increased, Total Harmonic Distortion (THD) gets reduced significantly. This presents simple configuration is simple and can be controlled easily. MATLAB-SIMULINK is used to validate the results of proposed technic, simulation is carried out using. The proposed method has been exhaustively compared with classical cascaded H-Bridge topology. 


2021 ◽  
Vol 10 (6) ◽  
pp. 2921-2928
Author(s):  
Adil Hasan Mahmood ◽  
Mustafa F. Mohammed ◽  
Mohammed Omar ◽  
Ali H. Ahmad

In power electronics, it is necessary to select the best converter circuit topology that has good performance among different converters. The single-ended primary inductor converter (SEPIC) has good performance and is advantageous among different direct current/direct current (DC/DC) converters. In this paper, a design of a SEPIC converter is made by selecting the values of its components according to the required output voltage and power. The design is made by an assumption that both of its inductors have the same value. The converter is tested by using MATLAB Simulink successfully. Later, its output voltage is regulated by using a proportional integral (PI-controller) through tuning its proportional and integral gains. Finally, the SEPIC converter is connected to a single-phase full-bridge inverter to supply its required DC voltage. The role of the SEPIC converter is to regulate the dc-link voltage between its output side and the inverter. The results showed the success of this connection to supply alternating current (AC) loads with low total harmonic distortion (THD).


Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 268 ◽  
Author(s):  
Ali Shojaei ◽  
Bahram Najafi ◽  
Hani Vahedi

In this paper the standalone operation of the modified seven-level Packed U-Cell (MPUC) inverter is presented and analyzed. The MPUC inverter has two DC sources and six switches, which generate seven voltage levels at the output. Compared to cascaded H-bridge and neutral point clamp multilevel inverters, the MPUC inverter generates a higher number of voltage levels using fewer components. The experimental results of the MPUC prototype validate the appropriate operation of the multilevel inverter dealing with various load types including motor, linear, and nonlinear ones. The design considerations, including output AC voltage RMS value, switching frequency, and switch voltage rating, as well as the harmonic analysis of the output voltage waveform, are taken into account to prove the advantages of the introduced multilevel inverter.


2015 ◽  
Vol 793 ◽  
pp. 167-171
Author(s):  
Mohd Aizuddin Yusof ◽  
Yee Chyan Tan ◽  
M. Othman ◽  
S.S. Lee ◽  
M.A. Roslan ◽  
...  

Multilevel inverters are one of the preferred inverter choices for solar photovoltaic (PV) applications. While these inverters are capable of producing AC staircase output voltage waveform, the total harmonic distortion (THD) of the output voltage waveform can become worse if the switching angle of each voltage level is not carefully chosen. In this paper, four switching angle arrangement techniques are presented and the switching angles generated by these techniques are applied to a new single-phase boost multilevel (SPBM) inverter. The performance of 3-, 5-, 7-, 9-and 11-level SPBM inverter having four different sets of switching angles derived using the aforementioned techniques have been evaluated and compared using PSIM software. Simulation results show that one of the techniques is able to produce an output voltage waveform with the lowest THD, whilst the other generates an output voltage waveform with the highest fundamental voltage component.


2019 ◽  
Vol 8 (3) ◽  
pp. 6584-6591

In recent days, multilevel inverter has widely been used for high power application. This may be due to the reduction of total harmonic distortion (THD) of the output voltage level and having low blocking voltages of switches. In the existing system, DC voltage source which is maintained constant is given as the input to the inverters which contains the series connection of fundamental block and is analyzed in symmetric and asymmetric mode of operation to produce various voltage levels. The proposed approach replaces the DC voltage source to the Photovoltaic (PV) cell has been used which has variations in the output voltage side depends on the solar irradiation level. This Photovoltaic cell uses Maximum Power Point Tracking (MPPT) algorithm to produce required voltage. As the input to the multilevel inverter (MLI) has to be maintained constant a fly back forward converter has been used in between the Photovoltaic cell and the multilevel inverter, so that the required multiple constant output voltage has been obtained on the output of the converter. Using the output of the converter 13 output voltage levels can be obtained from the multilevel inverter. The performance of the proposed system is verified by simulation through MATLAB/Simulink environment


Author(s):  
Nik Fasdi Nik Ismail ◽  
Norazlan Hashim ◽  
Dalina Johari

This paper presents the analysis study between multilevel inverters that are often classified into multilevel voltage source and multilevel current source inverters.  For multilevel voltage source inverter (MVSI), the specific topology studied for this work is the Cascaded H-Bridge MVSI.  Whereas, the multilevel current source inverter (MCSI) is based on Paralleled Inductor Configuration MCSI.  For this study, the analysis between these converters are done with respect to the number of components, the advantages and disadvantages of each converters during performing inverter operation. In term of output voltage and current quality, the percentage of the Total Harmonic Distortion (THD) are measured and compared for both topologies.  MATLAB/Simulink software has been used in this research to design and simulate in order to study the performances of both inverters.


2019 ◽  
Vol 5 (6) ◽  
pp. 9
Author(s):  
Deepa Raghuwanshi ◽  
Santosh Kumar

Multilevel inverters with a large number of steps can generate high quality voltage waveforms, good enough to be considered as suitable voltage source generators. An advanced multilevel inverter topology is proposed to optimize number of bidirectional switches. In this work the an five-level cascade H-bridge Inverter, which uses multicarrier based control structure and two capacitor with 10 switching MOSFETs topology is being presented. Analysis is done for RL and pure resistive load. The PWM strategy reduces the THD and this strategy enhances the fundamental output voltage. The experimental and simulated results show that total harmonic distortion of output voltage and current waveform shapes are 5.16 % and 5.77% respectively for RL load which are within the acceptable limits.


Author(s):  
Hassan Salman Hamad

<span>Researchers<strong> </strong>have found interest in the multilevel inverters (MLI) owing to the low total harmonic distortion (THD) associated with their output voltage, as well as their low electromagnetic interference (EMI). The MLI represents an effective and feasible solution for enhancing power demand and minimizing AC waveforms’ harmonics as they generate a preferred level of output voltage as inputs from varying levels of DC voltages. In this paper, the performance of a seven-level cascaded H-bridge MLI with an asymmetrical number of power switches was evaluated. The simulation performance is shown to validate the operating principle of the single-phase cascaded H-bridge inverter. To control the MLI, a pulse width modulation approach was utilized. The operating principle of the MLI was verified via simulation using PSIM software.</span>


Sign in / Sign up

Export Citation Format

Share Document