Hybrid Multilevel Inverter Research Articles

Machine learning based fault detection technique for hybrid multi level inverter topology

AbstractMultilevel inverters (MLIs) have a significant contribution in many industrial sectors due to their improved power quality and lesser voltage stress, over the conventional three‐level inverters. However, the implementation of MLIs with an increased device count creates the scope of development in MLIs topologies. In this regard, a hybrid MLI topology is studied in this paper whose architecture is based on conventional two‐level inverters. This topology has lesser device count characteristics when compared to conventional and most of the recently presented configurations for nine‐level output voltage generation. The major issue of capacitor voltage balancing is resolved by employing an appropriate switching strategy. However, the semiconductor switches are the most vulnerable components and causes the open circuit faults frequently that creates issues in real time operation. Hence, it is important to detect the open circuit fault in switches in the least possible time. A new approach to open circuit fault detection technique based on the analysis of load voltage waveform is proposed in this paper. The wavelet transform technique has been implemented for feature extraction of load voltage. Later, the classification of the fault has been achieved by training an artificial neural network (ANN). The proposed work has been studied in MATLAB/simulation and the obtained results are verified experimentally.

Enhancing grid‐connected solar PV systems with a novel three‐phase hybrid multilevel inverter

SummaryThis paper presents a novel three‐phase hybrid multilevel inverter (TPHMLI) designed for grid‐connected solar photovoltaic (SPV) systems. The TPHMLI combines series‐connected bridge topologies of half and full circuits to generate 11 stages of line load voltages, reducing the need for DC sources. It also introduces an improved pulse width modulation (PWM) approach, addressing computational challenges and high‐frequency triggering issues. Practical validation in a laboratory setting demonstrates the MLI's functionality and effectiveness. Furthermore, the advanced MLI topology successfully addresses design issues in grid‐integrated SPV structures, including power quality, efficiency, and reliability. It excels in managing reactive power and fault obstructive capabilities. Extensive simulations using MATLAB/Simulink confirm its superior performance, making it a promising solution for power conditioning units in grid‐connected solar PV systems. This research contributes to clean and sustainable energy conversion technologies, enhancing power quality and cost‐effectiveness, with significant potential for practical applications in the renewable energy sector.

Generalized Switched-Capacitor-Based Hybrid Multilevel Inverter With Reduced Components Count and Inrush Current

Generalized Switched-Capacitor-Based Hybrid Multilevel Inverter With Reduced Components Count and Inrush Current

Modified SPWM technique for single phase variable voltage nine level inverter for PV system

<span lang="EN-US">Multilevel inverters are widely popular because they boost the overall staging of the network with low harmonic distortion, less strain, and simply create highest possible development in industrial and electrical vehicle applications. Here a hybrid multilevel inverter having few switches compare to traditional multi-level inverters has been implemented. It has the capability to operate as a 3-level, 5-level, 7-level and 9-level inverter with different magnitudes of output voltage by varying the modulation index without changing of circuit topology and switching sequences. A new variable amplitude phase opposition disposition sinusoidal pulse width modulation (VAPODPWM) technique is proposed to control the inverter. In this concept unsymmetrical carrier wave form, i.e. A single triangular wave is divided into three triangular waves of different magnitude was chosen. it reduces the volt-sec of output due to that it gives less total harmonic distortion (THD) compare to other conventional space pulse width modulation (SPWM) techniques and conventional space vector pulse width modulation (CSVPWM) control techniques. The ease of conversion capability with less count of switches and operation with less THD shows the effectiveness of the converter. The converter is simulated by using MATLAB/Simulink and results are discussed.</span>

Design and Implementation of Modified Multilevel Inverter FED BLDC Motor for Electric Vehicle Application

In this work a modified hybrid multilevel inverter with reduced device is proposed. The system considerably reduces the quantity of power electronic power switches to twenty-one so as to create fifteen level three phase output, whereas conventional structures require higher number of power devices. Higher number of power switches leads to increased distortion, losses and cost. The recommended circuit gives better response, higher efficiency, reduced cost, high reliability and fault tolerance. Decrease in number of power switches, intensely diminishes the convolution of the switching circuitry.

Performance evaluation of hybrid multilevel inverter with a high-frequency switching technique

This proposed work deals with the implementation of a single-phase topology with using hybrid for multilevel inverters. It is observed that the proposed structure improves the performance of the hybrid multilevel inverter with high-frequency switches for positive levels and reverse voltage with negative levels. This paper studies a novel construction for an asymmetrical hybrid single-phase multilevel inverter. This paper also studies the operation of multi level inverter under depreciating sources condition due to fluctuation in input. The PWM method, i.e. APOD and CO, has been incorporated into the simulation of single-phase 7-level, 9-level, and the 11-level hybrid inverter. These two methods are compared to one another and to standard methods in terms of THD for different values of the modulation index, and they are found to be superior. Overall loss of 50% of the THD is almost equal to rated output voltage, it is observed in cascaded multilevel inverters. The working and performance of the proposed model are simulated in MATLAB Simulink software and the results are discussed in detail.

Design of Hybrid multi-level inverter for photovoltaic(PV) application

Nowadays the demand and consumption of energy increase in the word. Due to high cost of fossil fuel it’s not able to meet the required power generation demand. But the developed and developing countries encourage to generate power from renewable energy sources. The developed countries manage their resources in such a manner that they will fulfill their needs today and in the future as well. Nevertheless, the developing countries have limited sources of fossil fuels, which may decrease day by day. For this problem, the alternate solution is required, which is renewable energy. The output of renewable i.e. photovoltaic (PV) is DC. Now this is a challenging task for the researcher to integrate the renewable energy into the ac grid. For the reliable future of the power system, it is imperative for the modern era to integrate non-conventional sources into the AC power grid.The use of photovoltaic cells is increasing dramatically in all areas of life because of their small environmental impact, pollution-free, minimal maintenance, and zero noise. The real work focuses on the integration of PV systems with the proposed new topology called Multi-level inverters based on switch dc sources for low, medium and high power applications. An inverter is a power electronics device that converts DC input to AC output voltage. Input DC voltage is obtains from PV cell array, fuel cell or any other source.The output of PV panels is use as DC input voltage source for the proposed inverter. Single-phase multi level inverter is use to convert dc power receiving form PV array to AC power. First single phase two level inverter introduce which have many problems like those that high value capacitor required at output and high total harmonics distortion’s (THD). Nevertheless, as the number of level increased in inverter output the number of electronic switches also increased which may increase the losses.Multi-level inverters are gave more attention for high power applications. In recent years, lower order harmonic components has been developed to operate at higher switching frequencies.On the other side as the number of level increased the output waveform approach to sinusoidal waveform and the harmonics decreased. Output voltage and current waveforms are obtains and THDs are analyze. The multi-level inverter used in un-interrupted power supply (UPS), variable frequency drives (VFD), pumps etc. The performance of single-phase multi-level inverter will be analyzed in MATLAB / Simulink software.

A Three-Phase Hybrid Multilevel Inverter With Enhanced Pulse-Width Modulation Strategy

This paper presents a three-phase hybrid multilevel inverter (MLI) with enhanced pulse-width modulation (PWM) strategy. The proposed hybrid MLI is developed based on the series connection of half-bridge and full-bridge for its level generation together with the T-type inverter for its polarity generation. The level and polarity generation circuits operate at high and fundamental frequencies respectively. An enhanced PWM strategy has been proposed to reduce the computational complexity and solve the high-frequency switching transitions issue in the existing hybrid MLI modulation method. The proposed MLI can produce 11 levels of line output voltage with reduced dc sources requirement. The detailed analyses which have been performed include the circuit configuration, operating principles and modeling, PWM signals generation, output voltage characteristics, dynamic response, harmonics content, power loss analysis and voltage stress of power switches. The results obtained from simulation and experiments verified the operating principle and functionality of the proposed hybrid MLI.

A Reduced Switch Count Multilevel Inverter for PV Standalone System using Modified JAYA Algorithm

ABSTRACT This paper introduces a hybrid multilevel inverter (MLI) with reduced switch count, which can generate higher output voltage level with minimum number of DC input sources. The operation of this proposed MLI is carried out with unequal DC sources to achieve the desired output voltage level. The reduced MLI output voltage is set to minimal total harmonic distortion (THD) with the help of modified JAYA (MJAYA) algorithm. A JAYA algorithm with improved steps by adopting an accelerating parameter has been proposed in this research work to obtain a faster convergence of the objective function. The MJAYA algorithm has provided the suitable switching angles for the proposed three-phase 15-level MLI and reduced the output voltage THD to 2.23%, which satisfies the standard set by IEEE-519. To prove the efficiency of this proposed modified algorithm, the comparative analysis is carried out through MATLAB program and Simulink tool using common JAYA and modified particle swarm optimisation algorithms. The performance and productivity of the proposed MLI have been investigated through simulation and experimental setups.

Symmetric and Asymmetric Multilevel Inverter Topologies With Reduced Device Count

In this work, two new topologies of single-phase hybrid multilevel inverters for symmetrical and asymmetrical configurations are presented for use in drives and control of electrical machines and the connection of renewable energy sources. The proposed topology uses 2 dc sources, 12 switches, 1 flying capacitor, and 3 diodes to generate boosted 13-levels and 17-levels for symmetric and asymmetric configuration, respectively. Self-voltage balancing of its capacitor voltage regardless of load type, load dynamics, or modulation index is a key advantage of the suggested design. The higher performance of proposed topologies in terms of the total number of switches, TSV, THD, switch stress, and dc sources are demonstrated by comparing those with recently published topologies. In addition, a widely employed nearest level control modulation approach is used to provide output voltage levels with low THD. Finally, experiments were undertaken to validate the performance of the suggested topology.

ASO-Based SHE Method on Hybrid Multilevel Inverter for PV Application Under Dynamic Operating Conditions

ASO-Based SHE Method on Hybrid Multilevel Inverter for PV Application Under Dynamic Operating Conditions

Selective harmonic elimination pulse width modulation based hybrid multilevel inverter topology with reduced components

AbstractIn this paper, a reduced switch count single‐phase hybrid multilevel inverter (MLI) is presented. Level generation unit (LGU) and polarity changing unit (PCU) are the two parts of the presented topology which are connected in series. Other advantages of the proposed topology include the reduced switch count, higher level generation with reduced sources and the possibility of higher‐level generation with lower component counts. A single unit produces an output voltage of 13 levels with the modulation techniques as selective harmonic elimination pulse width modulation (SHEPWM) to improve harmonics. The use of selective harmonic elimination (SHM) is made to improve harmonics. The logical generation unit carries a series connection of multiple switched dc voltage sources with half and full‐bridge configurations. The proposed topology is verified by a hardware bench setup as well as in simulations which are developed in Simulink/MATLAB® environment.

Hybrid Multi-Level Source Inverter Design and Validation in Solar Photo-voltaic Renewable Energy System

This paper proposes the hybrid multi-level source inverter in light of staggered coordinated framework for boosting photo voltaic power. Hybrid multi-level inverter (MLI) proposed to design less number of switches compare with other MLIs of diode clamped multi-level inverter, the smallest number of switches are required to accomplish the highest steps in staircase AC output voltage. HMLIs additionally include variable info voltage and carries out load guideline to keep up with consistent result voltage. The HMLIS intends to operate in multiple stages during shoot through stage exchanging beat width (PWM) adjustment keeps up with to work in buck and lift mode. The activity of proposed work implemented in MATLAB and discuss effectiveness with diminished sounds took care of inverter operation. Model of converter is planned and accomplished the most extreme effectiveness of 95.4% as information voltage goes from 10-60 volts and result of half breed staggered source inverter keeps up with steady of 230v dc. Trial results approve the exhibition of proposed half and half staggered source inverter for exchanged mode power supplies utilized in PC.

Optimal Switching-Sequence-Based Model Predictive Control for a Hybrid Multilevel STATCOM

In this article, we introduce a model predictive control with optimal switching sequence (OSS-MPC) for a multilevel static synchronous compensator (STATCOM). The studied STATCOM is based on a hybrid multilevel inverter named HC-FNPC formed by the cascaded connection of H-bridge cells with a full-bridge neutral point clamped cell (FNPC). In this article, the optimal switching sequences are derived for HC-FNPC STATCOM by considering the impact of each switching sequence on the voltage of capacitors. Then, the control objectives of hybrid multilevel STATCOM, i.e., ac current control and capacitors’ voltages balancing, are formulated in terms of OSS-MPC for the first time. In contrast to the conventional MPC, this method provides a fixed-switching frequency. Also, by a combination of optimal switching sequences in MPC, the regulation of capacitors’ voltages with unequal values is realized. The control system's performance is verified on a nine-level (9L) 2.4 Mvar/11 kV HC-FNPC STATCOM in MATLAB/Simulink. Also, the experimental results are provided on a 9L 1.25 kvar/220 V scaled-down hardware prototype.

Hybrid MLI Topology Using Open-End Windings for Active Power Filter Applications

Different multilevel converter topologies have been presented for achieving more output voltage steps, hence improving system performance and lowering costs. In this paper, a hybrid multilevel inverter (MLI) topology is proposed for active-power-filter applications. The proposed MLI is a combination of two standard topologies: the cascaded H-bridge and the three-phase cascaded voltage source inverter. This configuration enhances the voltage levels of the proposed MLI while using fewer switches than typical MLI topologies. The proposed MLI was developed in the MATLAB/Simulink environment, and a closed-loop control technique was used to achieve a unity power factor connection of the PV modules to the grid, as well as to compensate for harmonics caused by nonlinear loads. To demonstrate that the configuration was working correctly and that the control was precise, the proposed MLI was constructed in a laboratory. A MicroLabBox real-time controller handled data acquisition and switch gating. The proposed topology was experimentally connected to the grid and the MLI was experimentally used as an active power filter to compensate for the harmonics generated due to nonlinear loads. This control technique was able to generating a sinusoidal grid current that was in phase with the grid voltage, and the grid current’s total harmonic distortion was within acceptable limits. To validate the practicability of the proposed MLI, both simulation and experimental results are presented.

A Comprehensive Review on Multilevel Inverters for Grid-Tied System Applications

Multi-level inverters (MLIs) have been widely used in recent years due to their various advantages in industrial and grid-connected applications. Traditional MLI topologies are being hampered by the rapid surge of renewable energy systems (RES) as a result of performance difficulties such as poor power reliability, an economically unviable structure, and a lack of efficiency. These difficulties are due to the traditional MLI topologies’ inability to keep up with the increasing demand for RES. Because of concerns about performance and limitations posed by classic MLI topologies, researchers have found themselves driven to the idea of building innovative hybrid MLI topologies. This study provides a comprehensive analysis of multilevel inverter systems that are wired into the main power supply. Grid-connected inverter types and their configurations are discussed in depth in this review. Diverse multi-level inverter topologies, as well as the different approaches, are divided into various categories and discussed in depth. Additionally, a number of control reference frames for inverters were brought forward for discussion. Furthermore, different inverter control strategies were investigated, followed by a tabular summary of recent developments in the inverter-related literature for the convenience of the readers. Moreover, the recently proposed grid-connected multi-level inverter systems were discussed including their findings and innovations. In conclusion, a brief description of the study’s scope was offered and research directions for future studies were provided.

Self-Sensing Control of Open-End Winding PMSMs Fed by an Asymmetrical Hybrid Multilevel Inverter

The paper presents a self-sensing control technique for a special type of multilevel motor drive featuring an Open-end Winding Permanent-Magnet Synchronous Motor fed on one side by a main multilevel inverter (MLI) and on the other side by an auxiliary two-level inverter (TLI). In order to minimize the power losses, the MLI manages the machine active power operating at a low-switching frequency. The TLI instead acts as an active power filter and operates at a higher switching frequency and a lower DC-Bus voltage than the MLI. The current control task is shared between the two inverters, as a predictive action is exerted by the MLI, while a feedback action is accomplished by the TLI. Common sensorless rotor position estimation techniques cannot be straightforwardly applied on such a system, due to the particular drive structure. Therefore, a specific technique has been carried out, able to ensure satisfactory efficiency and control performance in all the operating speed ranges by optimally exploiting the different features of the two inverters. Simulation and experimental results confirm the effectiveness of the proposed approach.

Hybrid multilevel inverter using switched capacitor with boosting and self-balancing capability

Switched capacitor based multilevel inverters with boosting capability are emerging as single stage DC–AC conversion in utilizing low voltage DC sources such as solar PV and fuel cell. This paper proposes a single-phase hybrid multilevel inverter topology based on a switched capacitor that is capable of generating 9-levels along with a voltage gain of 2. The components required to construct the basic module of topology are 11 switches, 1 diode and 2 capacitors. The voltage balancing of the switched capacitors is achieved with the help of a modulation strategy, thereby eliminating the need of sensors. The theoretical loss analysis of the inverter is presented and the nearest level control based fundamental switching frequency modulation technique is employed to study the performance of the proposed inverter. The effectiveness of the suggested topology is validated with the help of a prototype built in the laboratory. The superiority of the proposed topology is assessed with the help of comparison with existing topologies.

A New Hybrid Multilevel Inverter Topology With Level Shifted Multicarrier PWM Technique for Harvesting Renewable Energy

This article presents a new hybrid three-phase cascaded modular multilevel inverter developed with a reduced switch count concept for harvesting renewable energy. The basic module of the proposed inverter consists of six switches, three asymmetric dc links, and two blocking diodes. The inverter can generate six positive voltage states, which are negatively polarized by the end-side H-bridge unit. As a result, a higher number of voltage levels are obtained with a minimum number of switches that ensure reduced total harmonic distortion in the grid current. Additionally, the proposed inverter can operate at a comparatively lower switching frequency, which decreases the switching losses. Most of the switches in each individual module conduct for a small period resulting in low conduction losses. The reduced switch count with the low switching and conduction losses increases the compactness and the efficiency of the proposed inverter. Multiple high-frequency magnetic links are utilized for the dc sources required for the proposed inverter to achieve inherent dc-link voltage balancing ability and galvanic isolation. The performance of the proposed inverter is validated by simulation and experimental investigations.

Field programmable gate array-based new fusion control for photovoltaic inverter

This paper proposes a new fusion of digital controls for Photovoltaic (PV) fed DC-DC-AC inverter. The proposed PV-DC-DC-AC design includes the control for voltage regulation of the closed-loop buck converter by combining two duty cycles of Digital Proportional Integral-Digital Pulse Width Modulation (DPI-DPWM) and Maximum Power Point Tracking (MPPT) for one of the DC supply (9V) of the 81-level Trinary Cascaded Hybrid Multi-Level Inverter (TCHMLI). The control for the DC-DC converter is provided by the DPWM techniques, and the TCHMLI requires 16 switching patterns that are to be controlled by the Half Height-Switching Angle Method (HH-SAM). The real-time implementation for the proposed fusion control is verified with a resolution of 28 and 210 bits and validated using Field Programmable Gate Array (FPGA). The hardware result of the proposed photovoltaic inverter is compared with the existing methods and proves to be feasible.