Output Voltage Levels Research Articles

Z source based switched capacitor nine level boost inverter with a modified modulation strategy

This article presents a Z source (ZS) based switched capacitor multilevel inverter (SC-MLI) with low capacitors charging inrush currents utilizing a modified modulation strategy. The topology generates nine output voltage levels with quadruple voltage gain utilizing eight power switches, five capacitors, two inductors, four discrete diodes, and a single DC source. The voltage gain can be further increased by applying shoot through (ST) states to the frontend ZS-network. Owing to its high voltage gain, the topology is suitable for low voltage renewable energy sources such as photovoltaics (PV), and fuel cells (FC). A modified modulation strategy is presented based on the conventional level shifted sinusoidal pulse width modulation (LS-SPWM). The proposed modulation strategy improves the dc-link utilization at higher modulation index. A detailed mathematical analysis is provided for the gain calculation based on the modified modulation strategy. A comparative study is implemented to verify the merits of the proposed topology. A simulation model is implemented utilizing MATLAB / Simulink to verify the topology characteristics. The power losses and efficiency calculations are presented using Altair PSIM. Furthermore, an experimental prototype is constructed to verify the simulation findings. The topology is tested with different loading conditions at numerous modulation index values and ST duty ratios. Furthermore, step change conditions are implemented to test the topology response. The effect of the ZS network on the switched capacitors charging inrush currents is validated. The proposed topology shows an overall advantage in terms of the output characteristics as well as the hardware requirements.

Energy-efficient power summator of hydrogen fuel cell

The most important task after the end of the COVID-18 pandemic is to solve the problem of preserving the planet's climate and improving the environment in populated areas (metropolises, cities, towns). The most important principles contributing to the solution of this problem were set out in the Centenary Memorandum (A.L. Gusev, T.N. Veziroglu, J. Sheffield and other scientists, 2006). The most important element of hydrogen energy is the fuel cell. Fuel cells are produced in different modifications, they can be different in principle of operation, and different in size and DC generation power. Large consumers, both stationary and autonomous, at different times consume different amounts of power from the minimum value to the average and maximum. Obviously, if an object consumes minimal power over a given period of time, then there is no point in generating maximum power. Typically, fuel cells are designed for a specific power range. In connection with the above, in practice situations arise when it is necessary, depending on energy consumption, to connect hydrogen fuel cells of various powers.A new principle for constructing energy-efficient and small-sized summing step-up capacitor DC-DC converters (SSCC) capable of not only converting the level of output voltages, but also summing the powers of several sources in a common load is proposed. The sources are hydrogen fuel cells converted into constant voltage sources, different in output parameters and having a common grounded bus. The principle of multi-cycle construction of SSСС is proposed, which provides additional improvement of their weight and size characteristics under conditions of increased source power. It is shown that the effect is achieved by a multiple increase in the conversion frequency of individual SSСС modules and the practical elimination of a bulky output capacitor due to a sharp decrease and multiple increase in the frequency of the first harmonic of the total output current. Analytical expressions have been obtained that make it possible to calculate the parameters of the reactive elements of the SSСС, to analyze and quantify their efficiency.

An extendable switched‐capacitor based three‐phase multilevel inverter with boosting capability

AbstractThe increasing demand for integrating renewable energy sources necessitates inverter topologies with boosting capabilities. Using inverters with boosting capability and a low number of components to integrate renewable energy sources can reduce costs. This study describes a three‐phase multilevel inverter based on extendable switching capacitors. The use of voltage‐doubling modules permits the development of the inverter's capability. By increasing the number of doubling modules, the number of output voltage levels and boost factor are increased. Furthermore, the study introduces and implements a line voltage‐based pulse width modulation approach developed for the proposed inverter. The operation of the proposed multilevel inverter, along with the pulse width modulation scheme, common mode voltage, and power loss analysis are thoroughly discussed. Additionally, a comparative analysis is provided; highlighting the advantage of reducing the number of power switches in the proposed three‐phase inverter compared to other existing topologies. Finally, a laboratory prototype is developed, operating at a 4 kHz switching frequency and with a 120 V DC‐link voltage. The experimental results corroborate the efficiency and performance of the proposed multilevel inverter, thereby validating its practical applicability.

Low-power ternary inverter using vertical tunnel field-effect transistor with pocket

ABSTRACT This paper proposes a vertical tunnel FET with pocket (VP-TFET)-based standard ternary inverter (T-inverter) model for low-power applications. Using TCAD Sentaurus tool and mixed-mode simulations, it is verified that the device can exhibit T-inverter voltage transfer characteristics (VTCs) with three steady output voltage levels when the doping length and concentration of the pocket are optimized The device’s T-inverter characteristics are achieved by employing channel-channel and source-channel tunnelling mechanisms. Current matching is crucial for n-/p–type devices to produce a steady third output voltage state. The proposed ternary inverter’s static noise margin (SNM) and static and dynamic power dissipations are computed to be 220 mV, 4.8 × 10−12 W, and 4 × 10−12 W, respectively, which assures better noise immunity and low power consumption compared to other models.

Comprehensive assessment of voltage and current source PV‐based modular multilevel converters

AbstractRecently, modular multilevel converters (MMCs) gained popularity for the grid integration of photovoltaic (PV), due to their many advantages, including low total harmonic distortion, high control flexibility, and distributed maximum power point (MPP) tracking capability. Two distinguished families of MMCs exist: voltage source and current source. Voltage source MMCs are mostly studied, but current source MMCs offer advantages under certain operating conditions. This article compares voltage and current source MMCs, for PV integration. To this aim, several key indicators are identified: number of components, energy stored in passive elements, semiconductor power rating, and the number of MPP trackers. The results of the analysis, performed in MATLAB©, show that for a fixed number of output voltage levels, power rating, and switching frequency, voltage source MMCs have simpler control and higher number of MPP trackers. In contrast, current source MMCs minimize the semiconductor power rating, the number of components and the energy stored in passive elements. Regarding efficiency, in the analyzed case study, voltage source MMCs perform better under both homogeneous and non‐homogenous irradiance conditions. This article provides a tool to select the optimal solution based on the required target (e.g. efficiency, energy storage etc.), given the specific characteristics of the application.

A New Cascaded Multilevel Inverter for Modular Structure and Reduced Passive Components

In high-power applications, achieving adequate power quality in power converter design is accomplished by utilizing multilevel inverters instead of using two-level and three-level inverters. The device generates a sinusoidal output voltage, which results in reduced total harmonic distortion and lower voltage stress on the switches and leads to lower electromagnetic interference, making it suitable for use in renewable energy applications. However, to illustrate the advantages mentioned above, a significant number of switching devices and DC sources are necessary while raising the voltage levels. This article proposes an asymmetrical voltage generation method, which operates in a ratio of 1:5 and generates 25 levels using 11 power switches. The topology is modular in structure, and each module has a lower component count, which significantly reduces the overall cost. The proposed topology is capable of generating negative output voltage levels without the use of an H-bridge configuration, where only three switches are used to generate any voltage levels. The functionality of the developed module is amended by fixing different voltage values in DC sources. This article also presents a comprehensive examination of the circuit and the functioning of various voltage levels. The advantages of the proposed inverter have been demonstrated by comparative research with the currently existing MLI topologies. Ultimately, both the simulation and experimental findings validated the practical capabilities.

A wide dynamic range front-end electronics for SiPMs using high-speed operational and integration amplifiers

Silicon photomultipliers (SiPM) have gained popularity in particle physics due to their inherent advantages in terms of compactness, low power consumption, and high photon detection efficiency. Moreover, we have to deal with signals ranging from a few photoelectrons (PE), where we need to reconstruct the exact shape, up to thousands of PEs in short time intervals.The design of this amplifier was conceived to handle the SiPMs signal in both cases, combining together a high-speed amplifier for precisely reconstruct the shape of the signals of a few PEs and an integrated one in which the output voltage level is directly proportional to the number of the input PEs.

Wild horse optimization algorithm implementation in 7-level packed U-cell multilevel inverter to mitigate total harmonic distortion

Introduction. Multilevel inverters (MLIs) are a popular industrial and, more especially, renewable energy application solution. This is because of its appetite for filters, low distortion class, and capacity to provide a multilayer output voltage that resembles a pure sine waveform. The novelty is in applying the wild horse optimization algorithm (WHOA) to adjust the sinusoidal pulse width modulation (SPWM) technique by producing the optimal reference signal parameters in a new multilevel inverter architecture known as the packed U-cell multilevel inverter (PUC-MLI). Purpose. This study helps with the idea of new inverter architecture and a modified pulse width modulation (MPWM) method to make the multilevel inverter smaller, cheaper, and with less total harmonic distortion (THD). Methods. We use the proposed approach to control a 7-level, single-phase PUC-MLI. The WHOA is used to discover the optimal parameters of the additional reference sine signal after being compared with SPWM to evaluate its performance in harmonic reduction. The simulation’s outcome was validated by building a PUC-MLI prototype. Results. Experimental results and simulations validate the effectiveness of the suggested approach. The WHOA-improved MPWM approach achieves a significant reduction in THD on the PUC-MLI output voltage, as indicated by the results. Practical value. THD in MLI output voltage will be reduced without spending any cost. The suggested solution works with many MLI topologies with varying output voltage levels. References 20, tables 6, figures 12.

Missing-cell defects in QCA wires: The ground and excited electronic states perspectives

Quantum Cellular Automata (QCA) technology offers promising prospects for designing molecular electronic circuits that operate at high frequencies and with ultra-low power consumption. QCA wires serve as crucial conduits for digital data transmission between logic gates. A series of QCA cells arranged sequentially forms these wires, with data written or read using paired nanogap electrodes. In this study, employing a simplified full-basis quantum mechanical model, we investigate the impact of single and double missing cells on the response function and output voltage of wires implemented within the two-dot QCA architecture. The electronic coupling between the quantum dots within each QCA cell stands out as a critical structural parameter influencing both the nonlinearity of the response function and the level of output voltage. Ground state analyses of wires affected by missing-cell defects suggest that employing QCA cells with weak electronic coupling could potentially enhance fault tolerance. However, examination of excited states reveals that reducing electronic coupling may compromise the thermal robustness of such defective QCA wires.

A Study on Dual-Gate Dielectric Face Tunnel Field-Effect Transistor for Ternary Inverter.

In this article, we propose a dual-gate dielectric face tunnel field-effect transistor (DGDFTFET) that can exhibit three different output voltage states. Meanwhile, according to the requirements of the ternary operation in the ternary inverter, four related indicators representing the performance of the DGDFTFET are proposed, and we explain the impact of these indicators on the inverter and confirm that better indicators can be obtained by choosing appropriate design parameters for the device. Then, the ternary inverter implemented with this device can exhibit voltage transfer characteristics (VTCs) with three stable output voltage levels and bigger static noise margins (SNMs). In addition, by comparing the indicators of the DGDFTFET and a face tunnel field-effect transistor (FTFET), as well as the SNM of inverters, it is demonstrated that the performance of the DGDFTFET far surpasses the FTFET.

DC-biased Suzuki stack circuit for Josephson-CMOS memory applications

Josephson-CMOS hybrid memory leverages the high speed and low power operation of single-flux quantum logic and the high integration densities of CMOS technology. One of the commonly used type of interface circuits in Josephson-CMOS memory is a Suzuki stack, which is a latching high-voltage driver circuit. Suzuki stack circuits are typically powered by an AC bias voltage that has several limitations such as synchronization and coupling effects. To address these issues, a novel DC-biased Suzuki stack circuit is proposed in this paper. As compared to a conventional AC-biased Suzuki stack circuit, the proposed DC-biased design can provide similar output voltage levels and parameter margins, approximately two times higher operating frequency, and three orders of magnitude lower heat load of bias cables.

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 Review on Various Voltage Boosting Topology in DC-DC Converter

Abstract: Step-up DC-DC converters are employed to raise the output voltage level from the input voltage level. Although the basic boost dc-dc converter has advantages like simplicity of implementation, it also has drawbacks like low boost ability and low power density. The literature has reported various topologies which have switched inductor/voltage lift, switched capacitor, voltage multiplier, magnetic coupling, and multistage types. Each converter topology possesses its own advantages and disadvantages with a focus on power density, cost, efficiency, reliability, and complexity depending upon the applications. Demands of such applications are being fulfilled by using new power conversion topologies. Various combinations of such boosting topologies with additional components are complex. This paper provides a simple glance to the basic law and context for the development of future DC/DC converters. This paper has surveyed and classified various topologies according to the voltage-boosting topology and characteristics. The banes and boons of these topologies are also discussed in the paper with the applications of each boosting topology.

Design and implementation of novel multilevel inverter with full DC-utilization

ABSTRACT This paper presents a novel single-source transformer-based nine-level (9 L) inverter configuration. The design incorporates a three-level neutral-point-clamped (3 L NPC) inverter, a 3-L full bridge, and a transformer to produce 9 L output voltage levels. In particular, one of the 2 L legs in the full bridge is common among the transformer and the load. The proposed structure minimises the components compared to existing transformer-based nine-level inverters. Thus, the suggested inverter volume, cost, and complexity are minimised. Furthermore, a pulse width modulation method has been developed to generate the necessary gating pulses for the proposed inverter. Additionally, a complete comparison study illustrates the enhanced performance of the suggested architecture. The validity of the suggested 9 L inverter is assessed by performing MATLAB simulations and using a scaled prototype. The results obtained from the simulations and experimental tests are then presented and analysed. A clear correlation was observed between the simulation and the hardware results.

A bidirectional power converter connecting electric vehicle battery and DC microgrid

One way to increase electric vehicle (EV) battery utilization is to connect it to a dc microgrid. The EV battery can assume the role of an energy storage from the grid point of view. A bidirectional DC-DC converter will be needed to transfer power between them back and forth. This paper proposes the converter design considering its functional objective, including interleaved phase number determination. Efficiency performance evaluation is presented by power loss analysis with the parasitic-parameters consideration of the components. Finding optimum switching frequency based on power loss analysis is performed independently between input and output sides of the converter. Finally, experiments using a scaled-down prototype are shown to verify the analytical analysis of the converter. The experimental results properly validate the power loss analytic analysis carried out in this paper with a maximum error of 2.04% at 1131-watt, 60 V battery voltage, and 140 V grid voltage. Maximum efficiency 96.97% is obtained at 301-watt, 130 V battery voltage, and 151 V grid voltage. Overall, the converter has a simple structure, capable to be operated in various levels of input and output voltages with a minimum battery side current ripple.

Development of a Closed-Loop Controller for an Arduino-Based DC Chopper using Proteus and LabVIEW

This research focuses on developing a DC-DC converter voltage regulation system using an Arduino microcontroller, addressing the instability inherent in renewable energy sources like solar panels and wind turbines. Utilizing Proteus and LabVIEW, the study employs a quantitative deductive approach to experimentally simulate and model the system over four months at the Control and Automation Laboratory of Politeknik ATI Makassar. Key challenges of conventional converters, including limited PWM flexibility, output stability, and ripple reduction, are addressed through a closed-loop control system with voltage feedback. The methodology involves extensive parameter calculations derived from literature review and expected testing scenarios to ensure precise component selection and system performance. Specific calculations guide the determination of minimum component values, facilitating the desired input and output voltage levels with minimal ripple. Simulation testing validates the system's effectiveness, demonstrating successful integration between LabVIEW and Proteus through additional library utilization. The resulting DC-DC converter voltage regulation system enables more robust control through Arduino microcontroller, enhancing stability and efficiency in renewable energy applications.

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.

Dual‐input step‐up switched‐capacitor multilevel inverter with reduced voltage stress on devices

SummaryThis paper proposes a single‐phase dual‐input step‐up switched‐capacitor multilevel inverter that employs three capacitors, 15 switches, and two diodes to provide 13 voltage levels and triple‐voltage boosting factor in its symmetric form and 37 levels with voltage boosting factor of 3.6 in its asymmetric version. This high boosting factor is accomplished without utilizing any transformer. For each output voltage level, there exists flow paths for both the positive and negative load current directions, which makes the proposed inverter capable of supplying any load type with variety of power factors (zero to unity). The voltage balancing of the capacitors takes place naturally, which tackles the need to auxiliary charge‐balancing circuits or control mechanisms. The proposed inverter can generate negative levels without the end‐side H‐bridge. Moreover, the voltage stress on the semiconductor devices is less than the peak output voltage. The increased number of levels and sinusoidal‐like waveform of the output voltage waveform enhances the quality and lowers the harmonic content of the load voltage and current waveforms, even for resistive loads. As the result, the load‐side filter can be downsized or removed. This paper employs the fundamental frequency method (FFM) as the switching technique, which is simple to implement and also operates the switches at low frequencies, leading to lower switching losses. The ascendancy of proposed inverter over similar counterparts has been investigated through comprehensive comparative analysis. Moreover, the correct performance of the proposed inverter at different modulation indices, and load types as well as during dynamic load changes has been verified by simulation and experimental analysis.

Fuzzy Optimized Quadratic Boost Converter for Photovoltaic Application

To enhance the Inverter and Quadratic Boost Converter utilizing Fuzzy Logic Control for the Solar Panels. The quadratic boost converter is the intermediate stage between the solar panel and the Voltage Source Inverter. In normal boost converter produces a medium level of output voltage, but a quadratic boost converter produces double voltage gain for example if you give the supply voltage 20V and duty cycle 0.7 it will be output voltage 220V produced. Key Words: Quadratic boost converter, Single phase Voltage source inverter, Fuzzy logic control,

A Comparative Study of 9-Level Inverter and 15-Level Multi Inverter for a Grid Connected System

Abstract: Recently, the emergence of single phase multilevel inverter has been increased due to its advantages over traditional one. Multilevel Inverters [MLI] are the ones which can give out a stepwise output waveform with the use of power electronic switches, power diodes and some DC voltage source which might be a series/parallel connected PV cells, a renewable source or a battery. Multilevel inverters not only produce low harmonic distortion but also decrease the dv/dt stresses on the equipment Multilevel inverters is a good option as the output voltage of a Multilevel inverter is a stepped waveform which approaches a sinusoid providing lesser harmonic distortion. As the number of levels are increased the harmonic distortion reduces but at the same time the number of switching devices and the DC voltage sources required increases, thus increasing the complexity of the system design and control. Multilevel inverter proposed in this paper uses only 7 switches to provide 9 levels and 15 levels of output voltage. A symmetrical Cascaded H bridge Multi level inverter (SCHBMLI) and Asymmetrical Cascaded H bridge Multilevel Inverter (ASCHBMLI) using PD-PWM technique have been analysed in this paper for grid connection. The Asymmetric Cascade H Bridge [ASCHMLI] implemented in real time system using PIC16F877A microcontroller with RL load. This type of proposed system is used for high power applications in photovoltaic and it’s reduce overall cost as well as size of the system.