Minimizing switching losses in cascaded multilevel inverters by proper switching array selection

Author(s):  
Amirhosein Gohari ◽  
Ebrahim Afjei ◽  
Hossein Torkaman ◽  
Ali Mosallanejad
2017 ◽  
Vol 7 (1.5) ◽  
pp. 209
Author(s):  
B.Vijaya Krishna ◽  
B. Venkata Prashanth ◽  
P. Sujatha

Multilevel Inverters (MLI) have very good features when compared to Inverters. But using more switches in the conventional configuration will reduce its application in a wider range. For that reason a modified 7-level MLI Topology is presented. This new topology consists of less number of switches that can be reduced to the maximum extent and a separate gate trigger circuit. This will reduce the switching losses, reduce the size of the multilevel inverter, and cost of installation. This new topology can be used in Electrical drives and renewable energy applications. Performance of the new MLI is tested via. Total harmonic distortion. This construction structure of this multilevel inverter topology can also be increased for 9-level, 11-level and so on and simulated by the use of MATLAB/SIMULINK. A separate Carrier Based PWM Technique is used for the pulse generation in this configuration.


2013 ◽  
Vol 768 ◽  
pp. 231-237
Author(s):  
R. Seyezhai ◽  
K. Radha Sree ◽  
K. Sivapathi ◽  
V. Vardhaman

Multilevel inverters have been gaining immense popularity in high power applications such as Electric vehicles, Flexible AC Transmission Systems etc. This paper focuses on an asymmetric cascaded multilevel inverter employing the variable frequency carrier phase shifted PWM technique. The major advantage of this strategy is that it aids in balancing the switch utilization. The proposed strategy was found to have lower THD and switching losses when compared to the conventional strategies. The simulation was performed using MATLAB/Simulink and the results were verified experimentally.


As the demand for electrical energy increases continuously, we cannot rely on the existing conventional source for continuous power supply, as they are diminishing fast. The renewable energy sources are the best alternative for this energy crisis. We have different types of renewable energy sources and choice of source depends on location and load requirement. The most prominent source is the solar energy because of its own advantages. The nature of supply from this source is DC and it is to be converted into AC for supply to consumers. However, inverters are used for this conversion but produces harmonics. The Multilevel inverters are the alternate choice over conventional inverters due to the advantages of Low dv/dt and lower switching losses. Out of various multilevel inverters, cascaded H bridge (CHB) MLI topology is a well known solution for reducing the harmonics, which needs more number of switches and isolation power supplies which further increases the cost. This paper describes a proposed hybrid H-bridge topology with reduced switches. The proposed topology is implemented in Matlab/Simulink and results for 5, 7, 9 and 11 level are analyzed with their THD in output voltage. Hardware model for 5-level inverter is developed using 8051 micro-controller and results are presented


Author(s):  
CH. Sajan

Multilevel inverters are widely used because of its increased power rating with reduced harmonics and electromagnetic interference. The proposed 7-level cascaded H-Bridge inverter is symmetrical in nature and uses equal sources of DC voltage. Whereas 31-level cascaded H-Bridge inverter is asymmetrical in nature and uses unequal sources of DC voltage. The PD-PWM modulation technique was used here to achieve switching sequence. The proposed idea was validated through simulation and the results provide better efficiency, fewer low order harmonics and lower switching losses. The proposed topology is simulated using MATLAB / SIMULINK.


Author(s):  
F.X. Edwin Deepak ◽  
V. Rajasekaran

Purpose The purpose of this paper is to present the three phase seven-level Z-source neutral point clamped (NPC) inverter with multicarrier pulse-width modulation (PWM) technique. Despite numerous topologies and modulation methods, there is a dire need of developing PWM techniques that can be deployed in multilevel inverters. These inverters decrease the total harmonic distortion and it has a good performance for various electrical power system applications. The proposed inverter is investigated for its performance by executing it in shoot through and non-shoot through modes. Design/methodology/approach The purpose is validated through MATLAB/Simulink software platform for implementing the proposed seven-level Z-source NPC inverter outlined with multicarrier based phase disposition technique. The experimental results are verified using SPARTAN 3E FPGA controller with the same control strategy. Findings The efficiency of the proposed inverter is confirmed in terms of increased and faster conversion in the shoot-through mode. By using PDPWM technique the maximum boost gain is achieved with lower modulation index. High control of DC voltage is obtained with only one DC voltage source and one Z network. Originality/value Three phase multilevel inverters are widely used in improving the output voltage quality and reducing the encountered electromagnetic interference in electronic device or circuitry. They are employed in medium and high –power applications to attain increased power ratings while decreasing the switching losses. The performance results shown in this paper will satisfy the above needs of usage in certain applications and less switching losses.


2022 ◽  
Vol 18 (1) ◽  
pp. 48-57
Author(s):  
Aws Al-Jrew ◽  
Jawad Mahmood ◽  
Ramzy Ali

In this article, a comparison of innovative multilevel inverter topology with standard topologies has been conducted. The proposed single phase five level inverter topology has been used for induction heating system. This suggested design generates five voltage levels with a fewer number of power switches. This reduction in number of switches decreases the switching losses and the number of driving circuits and reduce the complexity of control circuit. It also reduces the cost and size for the filter used. Analysis and comparison has been done among the conventional topologies (neutral clamped and cascade H-bridge multilevel inverters) with the proposed inverter topology. The analysis includes the total harmonic distortion THD, efficiency and overall performance of the inverter systems. The simulation and analysis have been done using MATLAB/ SIMULINK. The results show good performance for the proposed topology in comparison with the conventional topologies.


Author(s):  
A. Ramesh ◽  
O. Chandra Sekhar ◽  
M. Siva Kumar

All industrial drives need a controlled output and it can be achieved by controlling the input supply. In this regard, the inverter circuit plays an important role in the applications of industrial drives. The industrial drives are operated at high rated power and the conventional inverters cannot be applicable for high power demands because of the large dV/dt (rate of change of voltage) and more switching losses. Therefore, multilevel inverters are introduced for high power-medium voltage applications. For all AC drives the MLIs are reliable in operation. This MLI topology also reduces the harmonics and bearings stress of a motor with low dV/dt. In most applications multilevel inverters are used because we can get more number of voltage levels. To increase the number of voltage levels, circuit needs to have more switches. But, we have to optimize the switch count and switching operations. The power level of the inverter is limited due to high currents and stress. In this paper, we proposed a new circuit topology which enables the switches to be active at different voltage levels, causes reduction of the switching losses and also increases the efficiency of the inverter. In this we have presented two configurations for an eleven level MLI for three phase induction motor drive application. In this an individual DC source is connected for each bridge circuit of each phase in one configuration and only one common DC link is used for three phases in another configuration. With this the size, cost and complexity could be decreased. In both the configurations the controlled output of the inverter is connected to the induction motor drive. The circuits are modeled using Matlab/simulink software and corresponding output waveforms are analyzed for both configurations.


2018 ◽  
Vol 69 (3) ◽  
pp. 233-238
Author(s):  
Cajethan M. Nwosu ◽  
Cosmas U. Ogbuka ◽  
Stephen E. Oti

Abstract An analysis, design and simulation of digital controlled symmetrical seven levels inverter is presented in this paper. Against the contemporary use of two asymmetrical DC sources with two H-bridge cells to generate seven levels inverter two DC sources of equal voltage ratings are used through digital control strategy to realize seven levels output voltage. By utilizing limited number of active switching components and avoiding the usual complex PWM control techniques for multilevel inverters by way of digital control strategy, high efficiency multilevel inverter systems due to reduction in total harmonic distortion and switching losses is guaranteed. Owing to symmetry of the H-bridge cells, a simple and single programmed counter built around J-K flip is required irrespective of number of cascades. The analyzed and designed system has been simulated in MATLAB/SIMULINK environment. With an R-L load of 200 Ω and 200 mH, improved total harmonic distortions (THDs) for the inverter current and voltage are 7.59% and 16.89% respectively. The obtained results show that the control-circuit-based multilevel inverter topology is most suited for applications in solar powered inverter systems.


Author(s):  
Arun V. ◽  
Prabaharan N.

This paper presents the Asymmetrical multilevel inverter with 1:3 voltage propagation. Switching pulse for Asymmetrical multilevel inverter are generated using embedded controller in m-file using MATLAB. The Asymmetrical multilevel inverter with 1:3 voltage propagation can produce high quality output voltage with less number of switches and voltage sources compare to conventional multilevel inverters. Contrasting other switching schemes, the proposed Switching scheme significantly reduces the Total Harmonic Distortion (THD) and minimize switching losses and reduces the complexity. To evaluate the developed scheme, simulations are carried out through MATLAB and real time implementations are done through microcontroller ARM Cortex™-M0 Core. The simulation and hardware results are presented.


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