Asymmetrical Multilevel Inverter Research Articles

Reduced Power Components Based Asymmetric Multilevel Inverter With Elimination of Lower Order Harmonics

Reduced Power Components Based Asymmetric Multilevel Inverter With Elimination of Lower Order Harmonics

Asymmetric Multilevel DC Link inverter for Reducing THD using a Meta-Heuristic Algorithm

Multilevel inverters are essential for increasing power quality, boosting efficiency, and lowering harmonic distortion in the field of power electronics. This research presents a new method using the Pelican optimization algorithm (POA) to create pulse patterns in multilevel inverters. The work focuses on deploying a 125-level asymmetric multi-level inverter that is powered by solar panels through a Dc-Dc converter in order to address power quality difficulties. In order to get better performance in multilevel inverter systems, the Pelican optimization algorithm is used to create pulse patterns that are modeled after the hunting strategies of pelicans. The Distributed Static Synchronous Compensator, is a leading device that uses power electronic components to control power flow and improve power quality in power grids. It is one of the many specialized power devices available. The primary objective is to enhance reactive power to ensure the stability of voltage within the power system and the aim of this research is to maintain voltage stability. Using the pelican optimization algorithm, the method entails creating and deploying a DSTATCOM based on a 125-level asymmetric multi-level inverter.

Design and performance evaluation of a novel modular asymmetrical multilevel inverter with minimal switches

In the present scenario, emerging topologies in the area of Asymmetrical Multilevel Inverter (AMLI) with fewer power switches and voltage sources have been received greater attention to achieve higher levels with low THD and voltage stress. The present work proposes a novel modular AMLI topology to generate 7-level and 15-level in the output voltage. This topology needs minimal components in comparison of topologies reported in literature. Simulation of the 7-level and 15-level AMLI is performed using MATLAB to generate all the desired levels in the output voltage for different operating frequencies and different modulation indexes. Further, a comparison of the suggested topology with other similar multilevel inverter (MLI) topologies has also been performed on the basis of number of drivers, number of DC sources, levels in the output voltage and power switches. Furthermore, efficiency, losses and total harmonic analysis of 7-level and 15-level AMLI have been calculated and compared with other studies. Finally, simulation results are validated on a hardware set up of the proposed inverter using Opal-RT 4510 controller.

Novel MLI-based DVR and DSTATCOM with ANFIS control for enhanced power quality improvement

This paper proposed a novel multi-level inverter and a hybrid renewable energy source integrated dynamic voltage restorer and static synchronous compensator to reduce grid power quality issues. The 51-level asymmetrical multi-level inverter is proposed in this work with less number of switches and DC sources. Hybrid renewable energy sources like solar and wind are used to feed input power to multi-level inverters. In addition, the battery is connected to the hybrid renewable energy sources to store the excess energy and deliver. After that, the 51-level asymmetrical multi-level inverter is connected to improve the power quality. The switching pulses for the proposed multi-level inverter are generated by including the pelican optimization algorithm optimized adaptive neuro-fuzzy interference system controller. This proposed method is implemented in the Matlab/Simulink tool to validate the proposed method. The results show that the proposed inverter optimally achieved 51 levels, and the proposed method improved the power quality. The results confirmed that the proposed inverter had a total harmonic distortion of 1.41 % and 1.23 % with dynamic voltage restorer and distributed static synchronous compensator connection, which is lower than the existing 51-level inverter topologies.

ASYMMETRICAL 7 LEVEL MULTILEVEL INVERTER FOR DYNAMIC LOADS

Asymmetric multilevel inverters (AMLIs) have received great attention in the power industry due to their ability to solve problems caused by power supply in various applications. This report explores the design, analysis and performance of AMLI's heavy-duty equipment. Dynamic loads are characterized by rapid and unpredictable changes in power demand, causing significant outages due to the limitations of traditional inverters in providing efficient power delivery and stability. The AMLI concept takes advantage of the ability to produce multiple voltage levels, providing greater flexibility to adapt to the needs of the load. This study investigates the optimization of modulation techniques to improve the efficiency and response time of the inverter in dynamically changing scenarios. In addition, factors such as harmonic distortion and power quality were also taken into account in the study, and the effect of asymmetric voltage levels on the overall system performance was examined. Simulation results and experimental results show that the effectiveness of AMLI in dynamic switching is good. The results of this study provide great insights into the use of AMLI with electronic devices, showing promise in improving power conversion and safety in real-world applications. Keywords: Asymmetric multilevel inverters (AMLIs), Power industry, Design, Analysis, Performance, Heavy-duty equipment.

Meta Heuristic Algorithm Based Novel Dstatcom Architecture for Power Quality Improvement

Electric utility systems are increasingly favoured as local energy systems due to their ability to integrate renewable energy, improve energy efficiency, and enhance the resilience of the power grid. However, while these benefits are significant, they also present certain complexities related to control and power quality (PQ). PQ is crucial within utility systems to ensure the proper functioning of connected devices and the overall health of the system. Therefore, both voltage quality and current quality are of utmost importance. Control strategies combined with advanced power electronics devices (PED) provide a robust framework to address PQ challenges. This paper introduces a novel approach for constructing a distributed Static Synchronous Compensator (DSTATCOM) utilizing innovative 125-level asymmetric multilevel DC link inverters to enable multilevel operation. A modified 125-level multilevel inverter aimed at enhancing power quality is proposed herein. By employing a minimal number of components, this inverter can generate 125-level voltages per phase, serving as a DSTATCOM to address power quality issues such as sag, swell, and harmonics. Bidirectional DC-DC converters are employed for purposes other than just providing power to the inverter's DC connections replacing DC sources. Additionally, the Coati Optimization Algorithm (COA), a newly introduced metaheuristic approach inspired by observed behavioural patterns in coatis in their natural habitat, is presented. COA is designed to emulate two primary behaviours of coatis: (i) their hunting strategy when pursuing iguanas and (ii) their evasion tactics when confronted by predators. To validate the effectiveness of the Coati Optimization algorithm, simulation is carried out with Matlab Simulink, and the outcomes of the simulation for the proposed scheme are provided in this paper. The efficacy of Solar-PV integrated 125-level asymmetric multilevel DC link inverter in enhancing power quality by adhering to the IEEE-519 Standards is demonstrated.

A new single modulating and single carrier signal based control technique for symmetrical and asymmetrical multilevel inverter topology

Abstract In literature, to generate gate pulses for any inverter topology, most of the authors are using a single modulating signal with (level-1) or (level-1)/2 carrier-based pulse width modulation (PWM) techniques and single carrier (SC) signal with (level-1)/2 modulating signal based PWM techniques. Then, while going to higher-level inverter topologies, the complexity of the PWM control approach in both cases can increase. To reduce the control complexity, few authors have reported a single modulating signal with single carrier-based PWM techniques. However, these techniques need more mathematical equations and if-else loops. This article proposes a new single-modulating and single-carrier signal-based generalized PWM control approach using floor function (FF). This technique has been verified by considering one of the single-phase conventional symmetrical and asymmetrical multilevel inverter (MLI) topologies. Generally, FF rounds the value to the nearest integer towards the negative infinity. The proposed PWM control implementation process is very simple and suitable for both high switching frequency (HSF) and low switching frequency (LSF) operations. The proposed control technique (PCT) has been experimentally verified with different steady-state and transient-state studies of results under standalone operation.

Harmonics mitigation technique for asymmetrical multilevel inverter fed by photovoltaic sources

A multilevel inverter is an electrical device that converts a DC voltage into a higher AC voltage by generating a stepped waveform with several voltage levels. Unlike traditional inverters that produce a square wave or a pulse-width modulated (PWM) waveform with only two voltage levels, multilevel inverters can generate waveforms with three or more levels, resulting in reduced harmonic distortion, improved efficiency, and decreased electromagnetic interference. The design and control of multilevel inverters are active research areas that aim to enhance their performance, reliability, and scalability. In this research, a 31-level asymmetric cascaded multilevel inverter is suggested. The proposed multilevel inverter (MLI) system employs four photovoltaic cells as dc sources with structure of (1:2:4:8) Vdc. The system is modeled by MATLAB/Simulink and total harmonic distortion (THD) values of the output voltage and current are 1.106% for resistive load, and 1.35% and 0.403% for inductive load. These outcomes demonstrate the recommended circuit's efficacy and demonstrate its suitability for medium- and high-power applications.

Simulation and FPGA based Implementation of PI and Fuzzy Controllers for Cascaded Asymmetric Multilevel Inverter

The main objective of this work is to improve the performance of Multilevel Inverter by using the novel LS-PD- PWM and controlling technique instead of the existing approach. The proposed work focus on closed loop controller such as existing PI and Fuzzy Logic Controller for resistive load with Multilevel Inverter. The proposed Asymmetric fifteen level Inverter offers less THD and high frequency than the Asymmetric nine level inverter. Asymmetric multilevel inverter is used to reduce the switching losses and THD. In this work is the generation and implementation of Pulse Width Modulation (PWM) techniques using Field Programmable Gate Array (FPGA) for Multilevel Inverter. PWM can be generated via Microprocessors, Microcontroller, FPGA and DSP Processors. Higher density Programmable Logic Devices (PLD) such as FPGAs can be used to amalgamate large amounts of logic into a single Integrated. Pulse width modulation (PWM) is generally used in power converter control. To generate LS-PD- PWM by using FPGA, this occupies less memory capacity and accurate than conventional one. An efficient PWM generation technique is performed using FPGA for lower frequency applications. Simulation and synthesis is done by ModelSim6.3c and Xilinx10.1. Further, the Implementation is carried out by FPGA Spartan3 Xc3s50. Key Word: PWM, FPGA, PLD (Programmable Logic Devices), LS-PD-PWM

An asymmetrical multilevel inverter with minimum voltage stress and fewer components for photovoltaic renewable-energy system

Abstract The enhanced power quality provided by multilevel inverters (MLIs) has made them more appropriate for medium- and high-power applications, including photovoltaic systems. Nevertheless, a prevalent limitation involves the necessity for numerous switches and increased voltage stress across these switches, consequently increasing the overall system cost. To address these challenges, a new 17-level asymmetrical MLI with fewer components and low voltage stress is proposed for the photovoltaic system. This innovative MLI configuration has four direct current (DC) sources and 10 switches. Based on the trinary sequence, the proposed topology uses photovoltaics with boost converters and fuzzy logic controllers as its DC sources. Mathematical equations are used to calculate crucial parameters for this proposed design, including total standing voltage per unit (TSVPU), cost function per level (CF/L), component count per level (CC/L) and voltage stress across the switches. The comparison is conducted by considering switches, DC sources, TSVPU, CF/L, gate driver circuits and CC/L with other existing MLI topologies. The analysis is carried out under various conditions, encompassing different levels of irradiance, variable loads and modulation indices. To reduce the total harmonic distortion of the suggested topology, the phase opposition disposition approach has been incorporated. The suggested framework is simulated in MATLAB®/Simulink®. The results indicate that the proposed topology achieves a well-distributed stress profile across the switches and has CC/L of 1.23, TSVPU of 5 and CF/L of 4.58 and 5.76 with weight coefficients of 0.5 and 1.5, respectively. These values are notably superior to those of existing MLI topologies. Simulation results demonstrate that the proposed topology maintains a consistent output at varying irradiance levels with FLCs and exhibits robust performance under variable loads and diverse modulation indices. Furthermore, the total harmonic distortion achieved with phase opposition disposition is 7.78%, outperforming alternative pulse width modulation techniques. In summary, it provides enhanced performance. Considering this, it is suitable for the photovoltaic system.

Development of Fundamental Modulation Technique Based Asymmetric Multi-Level Inverter and Multi-Pulse Converter to Prevent Medium Voltage Drive from Harmonic Component

Development of Fundamental Modulation Technique Based Asymmetric Multi-Level Inverter and Multi-Pulse Converter to Prevent Medium Voltage Drive from Harmonic Component

A Novel Hybrid PWM Technique for Asymmetric Inverter

Multi-Level Inverters (MLIs) are achieving broad popularity owing to the rapid development of power semiconductor devices. The capability of MLIs became recognized as a significant aspect of a system heavily reliant on Pulse Width Modulation(PWM) strategy. The conventional high frequency PWM techniques suffer from significant Total Harmonic Distortion (THD) along with power loss difficulties. This work recommends a hybrid PWM technique for lowering the THD and power loss of VSI adding the benefits of level-shift PWM and Phase-shift PWM. A novel form of carrier signals is employed in the proposed hybrid PWM technique. In contrast to existing PWM techniques, the proposed hybrid PWM technique minimizes switching and conduction power losses. In this work, the proposed PWM scheme is employed for asymmetric multilevel inverter. The proposed configuration is also examined using PLECS software to estimate losses and efficiency. The simulation work is done in the MATLAB/Simulink environment and the OPAL-RT(OP4510) test platform is employed to evaluate topology performance.

Optimal fractional order interval type-2 fuzzy controller for upside-down asymmetric multilevel inverter based dynamic voltage restorer to accurately compensate faulty network voltage

Optimal fractional order interval type-2 fuzzy controller for upside-down asymmetric multilevel inverter based dynamic voltage restorer to accurately compensate faulty network voltage

Improvement of Power Quality in Smart Grid Connected PV System Using Multilevel Inverter

This research proposed a cascaded multi-level inverter (CMLI) technique using Harris Hawk’s Optimisation (HHO) for grid-connected P.V. systems. The photovoltaic (P.V.) system is connected to CMLI-isolated DC connections based on the relevant D.C. to D.C. converters. The main goal of the suggested approach is to control power or boost solar system energy conversion while maintaining power quality. CMLI is integrated into fewer switches, diodes, and sources to produce the best control signal with the suggested controller. To provide the best control signal data set for the CMLI, the gain parameter under the source's current normal value is assessed using the HHO. The proposed control theory and keeping the power factor constant control the active power fed to the grid. The suggested approach of integrating solar electricity into the grid using DC-DC converters and an asymmetric multi-level inverter structure is supported by the reduction in THD and active power to the grid. The suggested model is developed using the MATLAB/SIMULINK programme, and the experimental setup is used to validate the results. On the grid side, lower THD was attained, which complies with IEEE standards. .

Analytical Approach to THD Formulation and Optimization in Sine-PWM-Based Single-Phase Multilevel Inverters With Variable DC Ratios

Asymmetric Multilevel Inverters (MLI) with Unequal Voltage Steps (UVS) are often combined with the Staircase Modulation (SCM) technique to improve both voltage and current THD - an approach known as Optimal Minimization of THD (OMTHD). This is usually achieved by varying both the Switching Angles (SA) and the DC source Ratios (DCR), to obtain the desired Modulation Index (MI) while THD is minimized. In this article, a novel Sine-PWM (SPWM) based OMTHD is considered as an alternative to SCM-based OMTHD. Because only the DCRs need to be optimized instead of both SAs and DCRs, the OMTHD process is simplified, while voltage THD, current THD, as well as power efficiency, are improved, especially for the medium-low MI range, compared to conventional SPWM. An analytical formulation of phase-voltage THD for UVS-based SPWM MLIs is derived and utilized for the novel SPWM-based OMTHD. Validation is carried out by theoretical analysis, digital simulations, and real-time C-HIL-based experiments.

Reduced Device Count for Self Balancing Switched-Capacitor Multilevel Inverter Integration with Renewable Energy Source

In this study, a new switched-capacitor-based seven-level inverter topology with a photovoltaic system is presented. The proposed topology requires a smaller number of devices and has the ability to self-balance the voltage across the capacitor. The proposed topology configuration is simple and has the ability to extend to higher levels of voltage. This multilevel inverter topology is suitable for low- and medium-voltage applications with photovoltaic (PV) system integration. To improve the PV system efficiency as an input of a DC–DC boost converter, a Fuzzy logic-based maximum power point controller technique is used. A PV system with a DC–DC boost converter integrates with the proposed seven-level inverter topology. The anti-predatory particle swarm optimization (APSO) technique is used to solve the non-linear transduction equations of the seven-level PV switched-capacitor-based multilevel inverter (7L−PV−SCMLI) topology. The proposed APSO is described to minimize the harmonics in the multilevel inverter (MLIs), which is a complex optimization problem involving a non-linear transcendental equation. Furthermore, APSO can be applied in order to solve non-linear transcendental equations for all symmetrical and asymmetrical MLIs that have equal and non-equal DC sources. The APSO-based selected harmonic elimination (SHE) technique obtained the best switching angle value, and the optimized obtained switching angles reduced the total harmonic distortion (THD) of 7L−PV−SCMLI.

Experimental Design and Analysis of Symmetrical and Asymmetrical Multilevel Inverters

Experimental Design and Analysis of Symmetrical and Asymmetrical Multilevel Inverters

A Novel Multilevel Inverter With Self-Balancing Capability of Capacitors Voltage; Structure, Modulation, and Operation

This article presents a 17-level asymmetrical multilevel inverter (MLI) with a reduced number of components. This structure can also be used symmetrically to increase redundancy. It can be extended in a modular fashion to increase the number of output voltage levels. Moreover, the capacitor voltages are self-balanced and do not require a sensor to stabilize the voltage. Due to the application of a level-shifted modulation (LSM), most power switches are turned on and off at low and fundamental frequencies, which will significantly reduce losses. Other benefits of this topology are the inherent production of negative levels without H-bridge, reduced total standing voltage (TSV), and low total harmonic distortion (THD). Power loss analysis is also presented as well as calculation of capacitances. MATLAB simulation results and laboratory implementation are carried out to evaluate circuit performance in different operational conditions.

Modular three phase asymmetrical cascaded multilevel inverter with lower number of switches

ABSTRACT This paper introduces a modular circuit for three-phase asymmetrical multilevel inverter, which is composed of series basic unit cells. It requires fewer number of switches as compared to conventional MLI circuits. Carrier-based pulse width modulation scheme is used to generate switching pulses circuit switches. The proposed circuit is compared with conventional MLI circuit. In order to verify the superiority of proposed circuit, a single phase 4-level inverter and three phase 7-level inverter are simulated in MATLAB/Simulink environment and hardware porotype is also demonstrated using dSPACE 1104 real-time controller.

Design and performance analysis of asymmetric multilevel inverter with reduced switches based on SPWM

<span lang="EN-US">Multilevel inverters have the benefit of producing high output voltage values with little distortion. This paper deals with decreasing total harmonic distortion (THD) and providing an output voltage with various step levels switching devices. In this study, a 27-level inverter with three asymmetric H-Bridge was designed and simulated based on level shift sinusoidal pulse-width modulation and phase shift sinusoidal pulse-width modulation methods. MATLAB/Simulink has been used to create this model and test it at different types of loads. The results showed that a multilevel inverter with (PS-PWM) produces less (THD) than a multilevel with (LS-PWM), when the resistive load was used, the produced voltage and current THD in (PS-PWM) and (LS-PWM) are 3.02% and 4.30% respectively, that has resulted from the linearity between voltage and current in the resistive load. While in the case of applying an inductive load, the THD in the voltage is constant in both (PS-PWM) and (LS-PWM) methods and has the same values as the THD in a resistive load. However, the THD in the current with inductive load decreased to 2.79% in (PS-PWM) and 4.04% in (LS-PWM). Finally, these results show that the performance of the proposed power circuit with PS-PWM is better than (LS-PWM).</span>