Voltage Conversion Research Articles

High Efficiency Bidirectional Dual Active Bridge DC/DC Converter for Level 3 Electric Vehicle Charging

In the current scenario, slowly but surely we are getting familiar with the concept of “electric vehicles” or “charging stations”. It’s only been a brief period of time since the notion of “electric vehicles” or EVs has been taken up in society. Many different types of “electric vehicles” are there like hybrid, plug-in hybrid, or battery-powered “electric vehicle”, one thing is clear that “electric vehicles” are intended to stay. Advancement in battery technology has allowed for lighter vehicles, longer battery “efficiency”, and cost “efficiency” as well. With these developments, the public's acceptance of an alternative fueled vehicle has also grown. In this review paper design of “Dual Active Bridge (DAB) bidirectional DC/DC converter” for level 3 “electric vehicle (EV) charging” application is presented. To support battery charging and discharging applications, DAB topology is preferred due to its modular and symmetrical structure which facilitates high power throughput and bidirectional mode of operation. Simulation done using PLECS (Piecewise Linear Electrical Circuit Simulation) and MATLAB software. We have : “Single Phase Shift Control (SPS)” and “Extended Phase Shift Control (EPS)”, 97% peak “efficiency” and 96% full load “efficiency”, secondary “voltage”: “700V-800V DC” and primary voltage: 300 V-500V DC. This design is preferred where power density, cost, weight, “galvanic isolation”, high voltage conversion ratio, and reliability are critical factors.

Highly efficient (31%) of rubidium-based halide perovskite solar cell using SCAPS-1D simulation

Perovskite solar cells (PSCs) have emerged as potential substitutes to conventional photovoltaic devices due to their outstanding performance, affordability, and simplicity of construction. This study focuses on optimizing rubidium-based halide perovskite solar cells using numerical simulation tools, specifically SCAPS-1D (Solar Cell Capacitance Simulator), with rubidium germanium bromide (RbGeBr3) as the absorber material. The aim is to improve both efficiency and durability, addressing challenges in creating sustainable and cost-effective photovoltaic technologies. The performance of the proposed solar cell configuration was evaluated by examining various parameters such as the thickness of the absorber, the thickness of the electron transport layer and hole transport layer (HTL), defect densities, temperature, etc. Various hole transport layer materials, including Copper Barium Tin Sulfide (CBTS), Copper Iodide (CuI), PEDOT: PSS, and Spiro-MeOTAD, were analyzed to evaluate their impact on open-circuit voltage, short-circuit current, fill factor, and power conversion efficiency. The findings indicate significant potential for RbGeBr3-based solar cells, with the CBTS HTL yielding the highest efficiency. Among the structures, the ITO/WS2/RbGeBr3/CBTS/Au structure was found to be optimal, achieving a power conversion efficiency of 31.48%, a current density of 26.27 mA/cm2, a voltage of 1.39 V, and a fill factor of 85.76%. This research provides valuable insights for designing and optimizing future perovskite solar cells, contributing to the advancement of renewable and sustainable energy technologies.

Intelligence Based Controlling Models for Effective Power Tracking and Voltage Enhancement in Grid-PV Systems

The underlying research work is focused on enhancement in the efficiency and voltage gain for solar PV systems with the help of designing a novel regulating framework that includes advanced converter topologies integrated with intelligent control techniques. Optimization in extracting energy from the solar panel at different climatic conditions, voltage gain with minimum losses, and enhancing overall system efficiency and power quality are major tasks to be undertaken. The proposed control architecture presents a new Fractional Order Proportional-Integral-Derivative Control (FOPTC) technique and its adaptation mechanism for correct MPPT under dynamic variations of meteorological conditions. Consequently, it offers improved energy harvesting because it is able to identify the global maximum power point with higher speed and precision than traditional control techniques that apply hybrid approaches. The improved topological structure will ensure a substantial rise in voltage gain and efficiency with reduced voltage and current stresses upon the circuit components. In addition, the idea of a Neuro Feed Quadratic Controller (NFQC) is introduced to generate the regulating pulses for switching components of the converter for optimizing the voltage conversion process. Simulation and analytical studies confirm the higher efficiency, improved voltage gain, and reduced total harmonic distortion in the proposed framework over conventional systems. Doi: 10.28991/ESJ-2025-09-01-015 Full Text: PDF

Development and laboratory assessment of a subsea particle image velocimetry system for bubble and turbulence measurements in marine seeps

AbstractWe present the development and laboratory evaluation of RPiPIV, an underwater particle image velocimetry (PIV) system controlled by a Raspberry Pi. Designed specifically to measure bubble characteristics and bubble‐induced flow in natural hydrocarbon seeps, RPiPIV comprises three primary pressure enclosures, housing a consumer‐grade laser for particle illumination, a Gig‐E camera for image capture, a Raspberry Pi for system control, and essential supporting electronics for voltage conversion, battery management, and remote connection. Operating on 24–36 V DC power, the RPiPIV system can be deployed tethered onto a remotely operated vehicle or self‐contained for extended duration measurements. Comparing the RPiPIV and a laboratory high‐speed camera system, we conducted assessments of bubble imaging in a bubble stream and PIV measurements in a water jet, bubble‐chain flow, and single‐orifice bubble plume. Laboratory assessments revealed that bubble diameter estimates differed by approximately 5%. In PIV measurements, mean axial velocities exhibited differences of approximately 5%, while turbulent normal and shear stresses showed variances within 10–30%. Dissipation rates of turbulence kinetic energy differed by approximately 60%. These findings underscore the system's potential for reliably quantifying complex multiphase flow characteristics in deep‐sea environments.

Comparative evaluation of voltage conversion and encoder pulse detection methods for controlling a model high-bay warehouse

This study evaluates five control methods for the Fischertechnik Training Factory Industry 4.0–24 V system, focusing on accuracy, efficiency, and performance in managing voltage differences and encoder pulse detection. The proposed method introduces a novel approach by integrating a dedicated pulse-counting Arduino with the TBD62783APG chip, enhancing precision and reliability beyond traditional methods. Despite requiring additional hardware, this method demonstrated exceptional control and dependable operation, showcasing the efficacy of specialized integrated circuits in industrial automation applications. The presented evaluation enhances control strategies for industrial automation, emphasizing efficient voltage conversion and precise encoder pulse detection to enhance system performance and reliability, laying the groundwork for future advancements in remote control capabilities and complex manufacturing systems.

Predicting Perovskite Photovoltaics Performance.

Wide band gap FA0.8Cs0.2Pb(I0.6Br0.4)3 perovskite photovoltaic (PV) devices are measured by spectroscopic ellipsometry in the through-the-glass configuration and analyzed to determine the complex optical property spectra of the perovskite absorber as well as the structural properties of all constituent layers. This information is used to simulate external quantum efficiency (EQE) spectra, to calculate PV device performance parameters such as short circuit current density, open circuit voltage, fill factor, and power conversion efficiency, and to develop strategies for increasing the accuracy of predictions. Simulations and calculations tend to overestimate PV device performance parameters, undermining the accuracy and usefulness of those simulations. Mapping spectroscopic ellipsometry measurements of an incomplete device are also collected from the perovskite film side to obtain layer thicknesses, perovskite band gap energies, and Urbach energies at each mapping point. The incomplete device stacks feature the perovskite absorber as the final deposited layer, while the complete devices add electron transport layers and silverback electrical contacts. When simulations are based on structural and optical properties obtained from spectroscopic ellipsometry measurements of incomplete PV device stacks, further inaccuracies arise as characteristics of the exposed perovskite film are not necessarily the same as those of an absorber in a complete, protected PV device. Predictions for PV performance parameters fall within 5% of the experiment for three of four baseline devices. The usefulness of this is apparent in situations where experimentally measuring PV device performance is unfeasible or overly tedious, as well as during intermediate steps during production.

Dimensional Regulation of Organic n-Type Dopants for Highly Efficient Perovskite Solar Cells and Modules.

A strong n-type perovskite layer is crucial in achieving high open-circuit voltage (VOC) and power conversion efficiency (PCE) in the p-i-n solar cells, as the weak n-type perovskites result in a loss of VOC, and the p-type perovskites contain numerous electron traps that cause the severe carrier recombination. Here, three types of perylene diimide (PDI) based small molecule dopants with different dimensions, including 1D-PDI, 2D-PDI, and 3D-PDI are designed, to produce heavier n-type perovskites. The PDI-based molecules with Selenium atoms have a strong electron-donating ability, effectively enlarging the quasi-Fermi level splitting within the perovskites. Besides, the PDI molecules can coat the surface of the perovskite crystal to form the lattice cage through their conjugate skeletons, which passivates the trap states and improves the n-doping efficiency, as well as the stabilities of perovskites and related devices. With the addition of the 2D-PDI, the small-area solar cells achieved a PCE of 26.06% (25.44% certified) with a high VOC of 1.18V and a remarkable fill factor of 87.23%. Furthermore, the rigid and flexible perovskite solar modules yielded high PCEs of 21.48% and 20.71%, respectively. This dimensional regulation strategy provides useful guidance for effective n-type doping and high-performance p-i-n solar cells.

An Enhanced Second-Order Terminal Sliding Mode Control Based on the Super-Twisting Algorithm Applied to a Five-Phase Permanent Magnet Synchronous Generator for a Grid-Connected Wind Energy Conversion System

This paper presents the application of a proposed hybrid control strategy that is designed to enhance the performance and robustness of a grid-connected wind energy conversion system (WECS) using a Five-Phase Permanent Magnet Synchronous Generator (FP-PMSG). The proposed approach combines the second-order terminal sliding mode control technique (SO-STA) with the super-twisting algorithm (STA), with the main goal of benefitting from both their advantages while addressing their limitations. Indeed, the sole application of the SO-STA ensures rapid convergence and robust performances in nonlinear systems, but it leads to chattering and reduces the whole system’s efficiency. Therefore, by incorporating the STA, the obtained hybrid control can mitigate this issue by ensuring smoother control actions and a superior dynamic response. This designed hybrid control strategy improves the adaptability of the control system to wind fluctuations and enhances the system’s robustness against external disturbances and uncertainties, leading to higher reliability and efficiency in the wind energy conversion system. Furthermore, the proposed hybrid control allows optimizing the power extraction and boosting the WECS’s efficiency. It is worth clarifying that, besides this proposed control, a sliding mode controller is used for the grid side converter (GSC) and DC link voltage to ensure stable power transfer to the grid. The obtained simulation results demonstrate the effectiveness of the proposed strategy in improving the stability, robustness, and efficiency of the studied WECS under dynamic conditions, creating a promising solution for control in renewable energy systems operating under severe conditions.

A Three‐Port Quadratic Step‐Up DC–DC Converter With High Gain and Continuous Input Current

ABSTRACTThis article presents a new three‐port step‐up DC–DC converter with two input ports and one output terminal. This converter structure achieves a higher voltage conversion ratio and better switching device power (SDP) than its multi‐input counterpart circuits. Using the “quadratic” approach to reach high voltage gains and discarding coupled inductors from the topology have avoided voltage spikes on power switches, resulting in higher efficiency compared to other hard‐switched multi‐input counterparts. In addition, the proposed converter can transmit power from one or both inputs to the output, from the output to the inputs, or between the inputs. Besides, common ground and continuous input current for all input ports are two distinct features of the suggested topology that most multi‐input converter structures lack. This paper thoroughly explains the converter operation and confirms its performance using laboratory experiments on a 200‐W hardware prototype. This new topology has been compared with existing competitors, considering several indicators. Comparative studies show that the proposed topology outperforms in terms of gain and SDP. Laboratory results validate the above achievements and exhibit that the maximum achievable efficiency by this method is 94.1%. This converter is suggested for electric vehicles and microgrid applications.

Pass-Transistor-Enabled Split Input Voltage Level Shifter for Ultra-Low-Power Applications.

In modern ICs, sub-threshold voltage management plays a significant role due to its perspective on energy efficiency and speed performance. Level shifters (LSs) play a critical role in signal exchange among multiple voltage domains by ensuring signal integrity and the reliable operation of ICs. In this article, a Pass-Transistor-Enabled Split Input Voltage Level Shifter (PVLS) is designed for area, delay, and power-efficient applications with a wide voltage conversion range. The represented low-power LS structure is a general blend of both pull-up and pull-down networks that perform level-up or level-down shifts. The proposed PVLS is incorporated with the multi-threshold CMOS technique and a load-balancing driving split inverter to limit high static current, leakage power, and performance degradation. The schematic structure could be able to convert voltages from low to high as well as high to low. The architecture design has the lowest silicon area. The implementation of the proposed design was taken under 55 nm CMOS technology. The represented LS could be able to convert voltage ranges between 0.3 V and 1.3 V, which has a dynamic power of 2.00 nW. The overall propagation delay of the LS is 90 ps and an area of 7.66 µm2 for an input frequency of 1 MHz.

Postfault Degradation Analysis of IGBT Power Devices in Medium Voltage Converters

Postfault Degradation Analysis of IGBT Power Devices in Medium Voltage Converters

Design of High Performance Graphene Thin Films Perovskite Solar Cells by Numerical Modeling Based on Coupled Differential Equations

In this study, graphene a two dimensional nanomaterial was prepared by modified Hummer’s method and the optical properties were explored using UV-visible spectroscopy to determine absorption coefficients at different wavelengths based on Beer-Lambert’s law. Graphene based lead-free methyl ammonium germanium halide solar cell was designed in the second stage using graphene oxide (GO) as carrier absorbers and transporters. Numerical modelling of the device in solar capacitance stimulating (SCAPS 1D) program based on second order differential equation was done. A photovoltaic parameters of 0.6227 V, 38.58 mAcm-2, 83.07 %, 19.95 % were recorded as the open-circuit voltage, current density, fill factor and power conversion efficiency (PCE) for FTO/GO/Perovskite/Cu2O/Au. Using the same settings for the second design, the Au/spiro-ometad/FASnI3/TiO2/FTO, the current density increases sharply from 0.50 V and with valence and conduction band at -0.35 eV and 1.78 eV respectively. The light transmittance and heat distribution across the device determine by origin pro-version 9.8.0200 indicated uniform transmission and absorption. The study showed that the presence of graphene, improved the optical transparency and enhanced carrier generation and interaction between other layers which optimized the electrical conductivity and efficiency of the solar cells when compared to previous studies in the literature. The results emphasized a viable approach in the design of efficient and stable solar cells at a reduced cost and optical losses. If mass produced can be deployed commercially due to enhanced solar energy absorption potential ahead of the Si based PVCs.

Enhanced voltage conversion and reduced inductor size in a flying capacitor boost converter compared to conventional boost converter for photovoltaic systems

In photovoltaic (PV) systems, conventional boost converters (CBCs) face limitations at high-duty cycles, including low voltage conversion ratio (VCR), high voltage stress, and reduced efficiency. While magnetic coupling components can enhance VCR, they introduce drawbacks such as reduced power rating and leakage current. To overcome these challenges, this paper proposes the flying capacitor boost converter (FCBC) as an alternative for PV systems. We analyze the performance of CBCs, FCBCs, and multilevel boost converters through MATLAB/SIMULINK simulations. The results demonstrate that the FCBC achieves a significantly higher VCR, requiring a smaller inductor size and potentially exhibiting a smoother output voltage compared to the CBC. Furthermore, the paper explores the trade-offs in complexity and cost associated with the FCBC, highlighting its advantages for high-voltage applications. Future research will focus on a comprehensive analysis of efficiency, control complexity, and the scaling of FCBCs to higher levels.

Variable frequency buck-boost converter for high efficiency voltage stacked systems

Variable frequency buck-boost converter for high efficiency voltage stacked systems

Achieving >28% power conversion efficiency in a-Si:H/c-Si solar cells through emitter optimization

Heterojunction solar cell efficiency is crucial for performance and commercial viability. This study investigates hydrogenated microcrystalline silicon (μc-Si:H), hydrogenated nanocrystalline silicon (nc-Si:H), and hydrogenated amorphous silicon germanium (a-SiGe:H) as p-type emitter layers in a-Si:H/c-Si heterojunction solar cells, examining their influence on short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), and power conversion efficiency (PCE). Considering the reported effects of hydrogen dilution and substrate temperature on the optoelectronic properties of these materials [1, 2], we employed AMPS-1D simulations to model device performance with various emitter layers (a-Si:H(p), nc-Si:H(p), μc-Si:H(p), a-SiC:H(p), and a-SiGe:H(p)). A baseline (PCE) of 27.38% was achieved using a standard a-Si:H(p) emitter (1.8 eV bandgap). Alternative emitters yielded improved PCEs: nc-Si:H(p) (28.26% at 1.9 eV), μc-Si:H(p) (28.04% at 1.5 eV), and a-SiGe:H(p) (28.18% at 1.7 eV). These enhancements are attributed to the wider bandgaps, higher conductivity, and lower defect densities of these materials, resulting in reduced recombination losses and enhanced carrier collection. Our findings demonstrate the significant potential of emitter layer optimization for maximizing a-Si:H/c-Si heterojunction solar cell power conversion efficiency.

The Effect of Antisolvent Treatment on the Growth of 2D/3D Tin Perovskite Films for Solar Cells.

Antisolvent treatment is used in the fabrication of perovskite films to control grain growth during spin coating. We study widely incorporated aromatic hydrocarbons and aprotic ethers, discussing the origin of their performance differences in 2D/3D Sn perovskite (PEA0.2FA0.8SnI3) solar cells. Among the antisolvents that we screen, diisopropyl ether yields the highest power conversion efficiency in solar cells. We use a combination of optical and structural characterization techniques to reveal that this improved performance originates from a higher concentration of 2D phase, distributed evenly throughout the 2D/3D Sn perovskite film, leading to better crystallinity. This redistribution of the 2D phase, as a result of diisopropyl ether antisolvent treatment, has the combined effect of decreasing the Sn4+ defect density and background hole density, leading to devices with improved open-circuit voltage, short-circuit current, and power conversion efficiency.

Fault Prediagnosis, Type Identification, and Degree Diagnosis Method of the Photovoltaic Array Based on the Current–Voltage Conversion

Fault Prediagnosis, Type Identification, and Degree Diagnosis Method of the Photovoltaic Array Based on the Current–Voltage Conversion

Isolated High-Gain DC-DC Converter with Nanocrystalline-Core Transformer: Achieving 1:16 Voltage Boost for Renewable Energy Applications

This paper presents an isolated DC-DC converter with high voltage gain that features an advanced inter-built nanocrystalline-core medium-frequency transformer (NC-MFT). The isolated DC-DC converter with an NC-MFT is specifically designed for applications such as interconnect photovoltaic (PV) systems, DC microgrids, DC loads, and DC buses, where voltage gain is one of the essential issues to consider. The NC-MFT inside the DC-DC converter is designed with a new approach that not only provides isolation but also contributes to achieving high efficiency and a higher step-up ratio. The high efficiency of the converters contributes to the integration of PV systems into DC microgrids. The converter yields a high voltage conversion ratio of 16.17. The experimental results obtained at 41.8 V/676 V and 275 W for the prototype revealed high efficiency (95.63% at full load). The experimental results validate the theoretical analysis and simulation, confirming that the converter achieves the main objective of high voltage conversion and high efficiency. These results will contribute to the interest in the use of this type of energy and its impact on the reduction in CO2 emissions.

(Invited) Vacuum-Processable Additive for Controlling Growth of Perovskite Crystals in All Vacuum Processed Perovskite Solar Cell

We present a novel method for controlling the growth of perovskite crystals in a vacuum thermal evaporation process by utilizing a vacuum-processable additive, propylene urea (PU). Co-evaporating of perovskite precursors and PU retards the direct reaction between the perovskite precursors. This facilitates larger domain size and reduced defect density. In this study, we present a novel method for controlling the growth of perovskite crystals in a vacuum thermal evaporation process by utilizing a vacuum-processable additive, propylene urea (PU). By co-evaporating perovskite precursors with PU to form the perovskite layer (Figure1), PU, acting as a Lewis base additive, retards the direct reaction between the perovskite precursors. This facilitates larger domain size and reduced defect density (Figure 2). Following the removal of the residual additive, the perovskite layer, exhibiting improved crystallinity, demonstrates reduced charge recombination, as confirmed by time-resolved microwave conductivity analysis. Consequently, there is a notable enhancement in open-circuit voltage and power conversion efficiency, increasing from 1.05 V to 1.15 V and from 17.17% to 18.31%, respectively. The incorporation of a vacuum-processable and removable Lewis’s base additive into the fabrication of vacuum-processed perovskite solar cells offers new avenues for optimizing these devices. Figure 1

A single switch high step-up DC-DC converter derived from coupled inductor and switched capacitor for a photovoltaic system

This study suggests a single switch high step-up DC-DC Converter derived from coupled inductor and switched capacitor used in Grid-Connected Photovoltaic systems. In the suggested converter, a part of the yield voltage is produced by parallel charging of the capacitors on the side of the secondary winding and their series discharge together with the secondary winding. The other part of the output voltage is obtained by simultaneously charging the boost and buck-boost capacitors and discharging them in series with the input voltage source. Finally, these two parts make the output voltage in series, so that high voltage gain with proper duty cycle is obtained. In addition, boost and buck-boost capacitors absorb leakage inductance energy leading to a reduction of the switch voltage stress. As a result, switching losses are reduced and by choosing a switch with lower RDS(ON), conduction losses are also reduced. Finally, a prototype with an output power of 200 Watts, and a voltage conversion of 24–400 Volts was made to confirm the performance in the laboratory, which has the highest efficiency of 95.89%.