Single DC Source Research Articles

An Enhanced Cascaded Five-Level Inverter Based on Switched Capacitors and Single dc Source

An Enhanced Cascaded Five-Level Inverter Based on Switched Capacitors and Single dc Source

A novel artificial neural network based selection harmonic reduction technique for single source fed high gain switched capacitor coupled multilevel inverter for renewable energy applications

Multilevel inverters (MLIs) are commonly used in renewable energy systems for their high-quality output, low total harmonic distortion (THD), and reduced component count. This study presents a high-gain, single-source MLI designed for renewable applications like solar or wind power. It features a novel topology with twice the voltage-boosting factor, utilizing a single DC source. The inverter achieves thirteen voltage levels using just 10 power switches and three switched capacitors. The voltage gain is achieved without the need for bulky DC-DC converters or transformers. This is accomplished by configuring the switched capacitors in series and parallel arrangements to attain the desired voltage boost. Additionally, the self-balancing capacitors eliminate the need for extra sensors. Both symmetric and asymmetric variants of the extensible configuration are investigated. The suggested design lowers the total standing voltage (TSV) while achieving high gain. A selective harmonic removal technique using artificial neural networks (ANN) reduces THD by up to 6.07 %. An extensive review of recent literature reveals significant advancements and applications of ANNs in this field. The proposed system's benefits, such as gain factor, total standing voltage (TSV), and minimized device count, are assessed. Comparative analysis reveals that the proposed topology employs fewer components and features a more simplified design. Additionally, the inverter achieves an efficiency of 96.9 %. The design is validated through an experimental prototype after being confirmed with MATLAB/SIMULINK.© YEAR The Authors. Published by Elsevier Ltd.Peer-review under responsibility of the scientific committee of the Name of the Conference, Conference Organizer Name, Year or Edition of Conference.

A new single-source, single-phase, 9-L 4-B switched capacitor-based multilevel inverter

ABSTRACT All types of non-conventional energy sources (NCES) produce low voltage, but offer it to be converted into usable and essential form. Switched capacitor multilevel inverter (SC-MLIs) has played a vital role in extracting power from NCES to fulfill the requirements of today’s need. Researchers have shown a great interest in extracting this power which comes from solar PV, wind, fuel cells and other miniature sources which is often not significant at all. This research offers a topology that is very simple and easy to implement. The authors also demonstrate a novel SC-MLI with a single ground and four voltage boosting capabilities. This paper analyzes and reviews the suggested inverter can create nine levels along with four times the voltage from a single dc source. Three self-balanced switched capacitors in association with a pair of five switches and single diode are used to offer quadruple boosting. A level-shifted pulse width modulation technique helps to generate the output voltage. The execution of the SC-MLI and the capacitor architecture for the suggested topology are fully investigated. The availability of common neutral is advantageous in reducing leakage current, especially in green energy utilization. In the context of voltage gain, the number of components employed, and the presence of common neutral, the designed inverter is contrasted to several other previously revealed inverters.

PV system applied on the new PUC-NPC inverter

In this article, the authors present a new competitive Packed-U-cell and neutral point clamped (PUC-NPC) 9-level converter that utilizes a small number of power switches and passive components. Only seven switches are added to a single DC source. However, the proposed converter takes benefits of the neutral point clamped (NPC) converter’s capability to connect capacitors in series, all with a simple control that enables the algorithm associated to the proposed inverter operate correctly in an open loop operation. A technique of pulse width modulation (PWM) is employed to maintain capacitor voltage at desired values. The proposed inverter produces an almost sinusoidal waveform output voltage, as result, a perfectly sinusoidal charge current with minimal impact on the economy and energy consumption are optioned. The converter has been integrated with a photovoltaic system to minimize its impact on the electricity supply and enhance energy efficiency. In order to take a maximum power from the photovoltaic panel, authors employ a maximum power point tracking (MPPT) technique based on disturbance and observe (P and O). When combined with the proposed control technique, it offers a competitive system suitable for standalone use or as an energy source, eliminating the need for PI regulators or additional investments. The proposed 9-level converter has been validated through simulation, utilizing the MATLAB Simulink environment to model the proposed system. Dynamics of this later were verified by changing the load charge.

A single DC source, seven-level switched capacitor tripple boost inverter with fewer switches for renewable energy applications

This article presents a new SSTB-MLI with 3 times voltage boosting capability for medium voltage applications with optimal efficiency. Single DC source MLI topologies are more appropriate for many applications, including grid applications and renewable energy (RE) conversion systems than multiple DC source MLI topologies. The ability of switched-capacitor multi-level inverters (SCMLIs) to raise voltage has made them more and more popular in recent years. LS-PWM technique is used for the switching scheme. Two capacitors are employed in SSTB topology to operate alternatively in charging and discharging states at the carrier frequency of this LS-PWM algorithm for making the levels of output voltage. Comparing this innovative topology to those documented in the literature. It can also minimise the number of switches and capacitors needed, their voltage stresses, and switching loss. Since the suggested topology includes built-in capacitor voltage balancing, no additional voltage balancing circuit is required. Applications requiring industrial drives as well as grid-connected and R, RL loads can employ the suggested architecture. Based on less TSV (total standing voltage), MSV (Maximum standing voltage), the number of components used, optimum efficiency 98.43%, and other factors, a comparative analysis is done between the existing topology and the proposed topology. Experimental data and thorough simulation are used to verify the suggested switched capacitor multilevel topology.

A modified T-type multilevel inverter for renewable energy applications

The primary challenge in integrating renewable resources into grids using multilevel inverters (MLI) is the need for many separate DC sources and switching device counts. Transformer-based multilevel inverters (TMIs) have emerged to address this issue, aiming to minimize system components and boost source voltage with a single DC source. This research article introduces a novel TMI topology that utilizes only a single DC source and incorporates ten switches to produce good-quality load voltage with high magnitude. The proposed TMI offers several structural advantages, including self-galvanic isolation, reduced switching devices and uniform voltage levels across all turn ratios. Additionally, the TMI operates a switching method called pulse width modulation, which provides the gating pulses to all the power semiconductor devices in the proposed TMI. An experimental model has been created in a laboratory environment, and simulations are performed using the MATLAB/Simulink platform to assess the effectiveness of the suggested TMI. Furthermore, a comparison between the suggested TMI circuit and other recent TMI designs with similar characteristics is performed. This comparison is carried out to assess and validate the superior features of the proposed TMI over the alternative designs.

A seven‐level switched‐capacitor based transformerless inverter with modified PWM strategy to enhance the performance of grid‐connected PV systems

AbstractAmong different types of transformerless photovoltaic inverters, multi‐level inverters based on switched‐capacitors (SC) are the burning topic of recent decades due to their potential advantages, such as, single source requirement, voltage boosting capability, and high power density. However, for a seven level output voltage, a conventional SC based inverter architecture uses more than two units of SC, a large amount of power switches, which then lead to capacitor voltage balancing problems. This paper presents a seven‐level switched‐capacitor transformerless inverter (SCTI), which is structured with only two SC units, ten power switches, and a single DC source. The proposed SCTI ensures voltage boosting capability, self‐voltage balancing, and low power semiconductor losses. Apart from these, a modified sinusoidal pulse width modulation (MSPWM) is also proposed in this work, which guarantees better thermal performance and low inverter output voltage THD for the proposed SCTI. The proposed SCTI along with the MSPWM is simulated in MATLAB/Simulink and PLECS computer simulation environments. A reduced scale laboratory prototype is also built and tested to ensure the feasibility of the proposed SCTI.

An FPGA-based balancing of capacitor voltage for multi-level inverter

ABSTRACT This paper introduces a novel cascaded multilevel inverter circuit configuration aimed at generating a five-level load voltage using a single DC source and a capacitor. In this inverter configuration, an additional switch is added to the charging circuit which helps to charge the capacitor from the DC source. Additionally, an inductor is incorporated to mitigate the substantial charging current during capacitor charging operation. A level-shifted pulse width modulation (LS-PWM) technique is implemented to generate gate pulses for both inverter and charging switches. The capacitor gets charged when an extra switch is enabled and discharged when it is connected to a load. Analysis of charging and discharging of capacitor is described thoroughly in this paper. Each operational mode of the inverter is thoroughly analysed. Furthermore, the proposed five-level inverter setup is designed, and its control logic is implemented using FPGA platform. Subsequently, simulation and experimental investigations are conducted under varied loads and different modulation indices to evaluate the efficacy of the proposed inverter configuration and the respective results are presented.

Single Source Switched Capacitor Based Multilevel Inverter With Reduced Number of Components

Multilevel inverters find extensive use across various applications owing to their capability to generate voltage waveforms of superior quality. thereby minimizing harmonic distortion. Traditional multilevel inverters require a substantial number of power semiconductor devices and passive components, resulting in heightened costs, intricacy, and physical dimensions. These multilevel inverters play a pivotal role in the electric vehicle sector, serving as a critical component in EV power trains for converting Convert DC power from batteries into AC power to operate electric motors.. The research methodology involves the following steps: Design and configuration of a multilevel inverter utilizing switched capacitor technology from a single source.. Design proposed topologies for multilevel inverter design. Design a circuit according topologies in MATLAB. Comparative analysis with existing multilevel inverter designs. Evaluation of the inverter's performance in terms of harmonic distortion, output voltage quality, and efficiency. Rather than employing a multilevel inverter with fewer switches that operates from a single source the highest possible levels are preferred. This paper introduces an innovative 9-level multilevel inverter based on a single source and switched capacitors, which significantly reduces the number of switches required, utilizing only three capacitors and a single DC source. This design approach serves to streamline the inverter's intricacy, decrease costs, and minimize its physical footprint. Furthermore, it elevates the voltage levels by up to 96%, enhancing the overall performance and efficiency of the inverter. Additionally, this technology can be applied in electric vehicles, integrated with renewable energy sources, and utilized in industrial settings. The novelty of this research lies in the utilization of a single-source switched capacitor configuration to achieve multilevel inverter functionality. This approach reduces the number of components required, leading to potential cost savings and improved system reliability. The novel features of this study include: Integration of switched capacitors in a single-source multilevel inverter design. Achieving multilevel inverter functionality with fewer components. Improved performance and efficiency compared to traditional multilevel inverter designs.

A new single DC source five-level buck-boost inverter for single phase application

Recent decades have seen an amazingly fast development of inverter topology, including multilevel inverters. This kind of inverter typically functions as a buck converter; a boost converter is the reverse of this kind of inverter. The two inverters limitation to operating in either buck mode or boost mode is a negative. In this study, a five-level inverter that can operate in both buck and boost modes and only requires a single DC source input voltage is proposed. The suggested inverter will therefore have a large operational area. This new inverter's possible conduction modes are examined in order to determine the control system that will be used. A test based on computational modeling and hardware implementation is then conducted in the lab after the new control structure based on sinusoidal pulse width modulation is established. This new inverter can operate in five-level in a buck and/or boost converter in terms of the output voltage to the input voltage, according to the results of simulation and testing. The proposed new inverter outperforms traditional inverters that solely run on buck or boost.

Isolation‐based bidirectional generalized step‐up multilevel converter with optimized device count

SummaryThis article describes a generalized single‐phase multiwinding step‐up transformer‐based multilevel converter with optimized device count. The proposed topology comprises of a single dc source, eight switches (four unidirectional and four bidirectional) and a single high‐frequency multiwinding transformer. Phase disposition pulse width modulation (PDPWM) is used for the level creation. The proposed converter is examined qualitatively and quantitatively using the total number of transformers, PWM control method, switch count, voltage stress, and the number of gate drivers, all of which are favorable. All elements of transformer selection, winding requirements, and comparative study have been thoroughly examined. A thorough Lagrange multiplier method has been applied to minimize the copper losses and optimize the multiwinding transformer (MWT) winding. The proposed converter simulations are performed using the MATLAB/SIMULINK environment. Further, the validation of the result is confirmed by a hardware setup of 0.9 kW.

An extendable voltage boosting gain unit with a self‐balanced switched‐capacitors multilevel inverter using a single DC source

SummaryThis paper suggests an extendable voltage boosting gain unit (EVBGU) using switched‐capacitors SC with a single DC source. The proposed unit can be extended by a modular pattern to increase the output voltage levels and voltage‐boosting gain of the inverter. The main feature of this work is presenting a unit topology that utilizes multiple and modular subcells to achieve (double, quadruple, hexapole, octapule, etc.) voltage gain at the output by increasing the number of the subcells. All the subcells are connected only with one DC source. A positive feedback technique has been used to charge the capacitors of the unit using the accumulative charging voltage (ACV) method. Furthermore, all the capacitors are self‐balanced, so there is no need for any additional and complex control circuit. Moreover, to decrease the cost factor of the inverter, a low IGBT switch count is taken into consideration and no passive elements such as diodes are used in the proposed structure. The H‐bridge is connected to the unit to achieve bipolar voltage at the output. The operational analysis of the inverter is delineated in detail. A comparative study, with state‐of‐the‐art MLIs in different terms such as the number of components, the total standing voltage, and the gain, shows the particularity of the proposed EVBGU. The simulation of the proposed MLI is performed using PSCAD‐EMTDC software. The simulation results are validated experimentally.

Investigation of PWM methods for a 9 level boost inverter using CD-type carriers

The article suggests a new boost inverter topology that uses two switching capacitors and a single dc source to produce an output voltage waveform with nine levels. There are no sensors or other electronics required because the capacitor voltages balance themselves. An input dc boost converter is not necessary when using an inverter because its output voltage is frequently two times greater than its input voltage, especially when the inverter is powered by a natural source. The new modulation techniques that have been proposed for CD-type carrier waves have better efficiency, higher RMS voltage, and less harmonic distortion (THD).The efficacy of the suggested carriers has been confirmed by phase disposition (PD), alternate phase opposition disposition (APOD), and phase opposition disposition (POD) investigations. The effectiveness of each technique described under 9LBI has been evaluated using a MATLAB/Simulink configuration. The operation and dynamic performance of the suggested architecture have been modelled using MATLAB/ SIMULINK.

A New Five-Level Switched-Capacitor-Based Transformer-less Common-Grounded Grid-Tied Inverter

This paper proposes a new switched-capacitor grid-tied inverter. The proposed topology can eliminate leakage current using a common-grounded strategy. Also, the proposed topology generates a five-level output voltage waveform using a single input dc source with a voltage boosting factor of 2. This structure uses six power switches, two diodes, and two self-balanced capacitors. The proposed inverter has some advantages such as a common-grounded feature, eliminated leakage current, and voltage boosting feature with single-stage energy conversion operation. Also, the proposed topology can support both active and reactive powers and generate a perfect sinusoidal output current injected into the grid. Also, to control both active and reactive powers an efficient control strategy is applied. To generate the precise gate pulses for the power switches, the introduced efficient control strategy is applied. Also, comprehensive discussions on the operating modes of the proposed inverter, Capacitor charging current analysis, the control technique, and design considerations are presented. To show the advantages and differences of the proposed inverter with some other recently presented switched-capacitor-based grid-tied inverters a comparison study is considered. Finally, to validate the performance and feasibility of the proposed inverter, various experimental results based on a 620 W experimental prototype are presented.

A Single DC Source Multilevel Inverter with Extended Linear Modulation Range to the Full Base Speed and Predictive Capacitor Control for Induction Machine Drives

A Single DC Source Multilevel Inverter with Extended Linear Modulation Range to the Full Base Speed and Predictive Capacitor Control for Induction Machine Drives

A Single DC Source Gradient Driver Circuit With Boosting Output Capability for MRI Applications

Magnetic resonance imaging (MRI) systems gradient driver (GD) circuits, which drive current through gradient coils, have essential roles in imaging quality and speed. They drive large current values, higher than 1000 A, with high fidelity to the commands, low current ripples, and fast transient responses, which lead to high voltage values, larger than 2 kV, to properly drive the coils. Till now, some solutions with parallel and stacked structures have been reported to fulfill such requirements, which need several independent isolated voltages to deliver the necessary output current. Thus, other parts are generally needed to generate these voltages, separately. Here, a new GD circuit with only a single independent voltage source and output voltage boosting capability is proposed to drive such gradient coils. It reduces the semiconductor and magnetic element counts, in the MRI gradient driver power chain. It also reduces the pulsed power demand from the facility, by storing energy. The proposed circuit has been mathematically analyzed, here. A 2.34 MVA,1300A/1800 V GD circuit has been designed and simulated based on the proposed topology to verify its performance. Finally, a laboratory 700 V, 10 A scaled-down prototype converter has been implemented, based on the proposed topology to verify the given analyses and simulation results.

Controlling the output current of a SEPIC H-bridge inverter

The rapid depletion of fossil fuels and humanity's increasing dependence on electricity drive us to adopt renewable energy-based power generation. However, using renewable energy requires a system to maximize the results of converting renewable energy into electrical energy. An inverter is a DC-to-AC power conversion device. Inverters have two types: buck and boost. In closed-loop control, it can be controlled using current or voltage control. Current-controlled inverters sent to the grid have constraints, such as the inverter input voltage value must exceed the voltage on the grid. This study suggests using an H-bridge inverter and an AC-AC SEPIC to generate a voltage value more significant than the input voltage value. The proposed converter uses a single DC source and bases grid current injection on the regulated output current approach. The proposed converter satisfies the IEEE Std 519-2014 requirement of less than 5% and has a Total Harmonic Distortion (THD) of 4.6%.

Switched Capacitor Based Cascaded Half-Bridge Multilevel Inverter with Voltage Boosting Feature

Abstract: In many applications, cascading multilevel inverter (CMI) topologies are common. However, the biggest disadvantage of CMI is the need for many separate switches and DC sources. As a result, the CMI topology becomes more expensive, more complex, and larger, and its performance suffers. In the proposed SC-CHMI, only one DC source is used and the other DC sources are replaced by switched capacitor cells. Thanks to the self-balancing function, the capacitor charging process occurs naturally without the need for any auxiliary equipment. In the proposed SC-CHMI, the inrush current of the capacitor is attenuated using a load inductor or a front-end boost converter. To improve the performance of multi-level inverters, several types of techniques can be tested with existing multi-level inverters. Due to the modulation algorithm, modulation frequency, voltage drop on the switches and bus voltage modulation, the output voltage of the inverter has overall harmonic distortion, leading to overheating of the device and shortening the life of the device bag. In the proposed SC-CHMI, a level-shifted pulse width modulation technique is proposed to improve the output voltage quality and reduce the total harmonic distortion. This new control scheme is applicable to nine-level, eleven-level and fifteen-level SC-CHMI. The proposed topology can be used as a general-purpose inverter in renewable energy systems, due to its voltage gain characteristics, minimal number of switches, and single DC source. The effectiveness of the proposed inverter topology is confirmed by simulation results.

Switched capacitor based 7-level and 9-level multilevel inverters with single DC source and reduced voltage stress

This paper proposes two different switched capacitor based Multilevel Inverter topologies having single dc voltage source. One of the proposed MLIs is a seven-level structure whereas the other circuit successfully generates a nine-level output voltage. The special features of the seven-level topology consist of reduced number of circuit elements, lower voltage stress on switches, and boosted output voltage. The nine-level MLI having unity gain also possess the reduced switch count along with lower value of switch voltage stress. Fundamental frequency based Nearest Level Control modulation and Level-Shifted Pulse Width Modulation have been used for generating the required voltage levels. Successful implementation of the proposed MLI circuits has been done with the help of a laboratory prototype and its results are presented and explained in the paper to show its practical suitability. Other type of analysis include loss analysis which has been done in PLECS software. From this analysis, the efficiency has been estimated. A comparative analysis of both the proposed structures has been carried out with some other similar topologies on different performance parameters. From the analysis and comparison, it is evident that the proposed MLIs are better than some of the existing topologies and can be used for industrial applications.

An Open-Circuit Fault Detection Method of PMSM Fed by Dual Inverter With High Robustness

Power semiconductor is one of the most fragile components in the drive system of electric vehicles. In order to diagnose the failure timely, this paper proposes a diagnosis method of the open-circuit fault for open-end winding permanent magnet synchronous motor (OEW-PMSM) fed by dual inverter with a single dc source. The OEW- PMSM can improve the speed range and tolerance capacity of driving systems. However, the open-circuit fault diagnosis methods for Y-connected PMSMs cannot judge the faulty switch because of the symmetry of the dual inverter structure. The first step of the proposed method is to detect the faulty switch combinations by the error of normalized average value and average value of the zero-sequence reference voltage. The next step is to judge the faulty switch from a certain fault combination. The experimental results show that the open-circuit fault can be diagnosed accurately.