Efficiency Of Converter Research Articles

Non-Isolated Bidirectional DC-DC Converter Design And Low Power Application for EV Charging Station

Today, the negative impact of charging on the grid is becoming a major concern as the number of electric vehicles increases. The charging topologies such as V2G, V2H and V2V are being studied to solve this problem. The most critical issue in this context is the design and use of appropriate infrastructure and equipment. In this study, firstly a low-cost and high-efficiency non-isolated bidirectional DC-DC converter suitable for DC charging stations is designed. The designed converter was analysed both by analytical methods and by operating at low powers. Secondly, a real-world implementation of V2V and V2H topologies has been performed using these designed converters. In the application study, a DC charging station model was created by using 4 of these converters as charging units. The 90-minute operation of the designed charging station was realised according to a rule-based algorithm. Accordingly, it has been shown that the efficiency of the non-isolated bidirectional DC-DC converter designed is 95%. It is also proved that 54.16% of the EVs load can be shifted to off-peak time period using V2V topology in real world application. According to the results, it is understood that the isolated and high-power version of the designed converter is suitable for charging stations.

A Novel Predictive Voltage Control Technique for a Grid Connected Five Phase Permanent Magnet Synchronous Generator

This study focuses on developing an effective control strategy to enhance the dynamics of a wind turbine grid-connected five-phase permanent magnet synchronous generator (PMSG). To visualize the superior performance of the newly proposed controller, the generator's performance is evaluated with another traditional predictive control scheme: predictive torque control (PTC). However, the vector control principle is applied to the GSC converter. The PTC has limitations such as significant ripple, substantial load commutation, and the inclusion of a weighting element in its cost functions. The proposed predictive methodology aims to overcome limitations, uses a simple cost function, and doesn't require weighting elements to address concerns about stability errors. Comparing the proposed predictive voltage controller (PVC) to the PTC, the findings show that the suggested PVC has many benefits, including faster dynamic response, a simpler control structure, fewer ripples, reduced current harmonics, low computation burdens, and robustness, so the generated power affects system efficiency, leading to improved power quality and reduced switching losses, enhancing power converters efficiency and their switches lifespan, this fact is verified mathematically as the total harmonic distortion (THD) has reduced to 1.346% average percentage for the proposed controller. However, the THD of the PTC is 3.05%. In addition, the study examines the incorporation of pitch angle control (PAC) and maximum power point tracking (MPPT). These controls restrict the consumption of wind energy when the generator speed surpasses its rated speed and optimize the extraction of wind energy during periods of low wind availability. In summary, the proposed PVC-enhanced control system reveals superior performance in dynamic response, control simplicity, current quality, and computational efficiency compared to other methods.

A reconfigurable Buck-Boost Cross-Coupled charge Pump

This paper presents a reconfigurable buck-boost Charge Pump (CP) based on the cross-coupled topology. The proposed CP is a switched capacitor (SC) converter merging different ratios and operation modes in one topology. The converter is able to step-up or step-down the input voltage at the output only by controlling the external connections of the circuit. By achieving various conversion ratios and operation modes, higher efficiency levels are performed maximizing the power that is delivered to the load. The reconfigurable buck-boost CP has been designed in 65 nm TSMC CMOS technology and covers an input voltage range from 1.6 V to 3.2 V and an output voltage range also from 1.6 V to 3.2 V in the boost mode and an input voltage range from 2.6 V to 3.6 V and an output voltage range from 1.4 to 1.8 V in the buck mode. In addition, efficiency estimation analysis is presented and proves how parasitic capacitances of flying capacitors affect the overall efficiency of a multi-ratio converter. The converter indicates peak efficiency equal to 77 % and delivers up to 4 mA load current.

High Power Density Buck Boost DC/DC Converter Using SIC MOSFET

Abstract High power density is an advance in power electronics. Third generation wide-bandgap semiconductor devices (WBG SICs) offer significantly improved performance compared to standard silicon devices. SIC MOSFET is commonly used in power electronic equipment such as converters due to its low resistance, excellent thermal stability, and rapid switching speed. Increasing the switching frequency effectively reduces the circuit size. This article uses SIC MOSFET and STM32 single-chip MCU to design a high power density and higher frequency buck boost converter and establish a simulation model in LTspice. The driving circuit designed for SIC MOSFET is intended to maximize the converter’s reliability. Synchronous rectification applies to enhance the converter efficiency. Compared to other types of converters, the size of the converter is reduced, achieving the goals of lightweight and high power density of DC/DC converters.

BENCH TESTS OF A CATALYTIC CONVERTER UNIT WITH A CATALYST LAYER ON THE SURFACE OF GLASS-CRYSTAL MEDIATORS

The article examines the problems of industrial gas emissions and vehicle emissions as the main sources of environmental pollution. The article focuses on the importance of catalytic conversion as a modern method of cleaning gas emissions, but points to the need for further improvement of catalytic converter designs. The authors point out the shortcomings in the production of mechanically strong and thermally stable catalysts and their carriers, as well as the limitations of existing calculation and design methods. The article experimentally shows approaches to increasing the efficiency of catalytic conversion of gas emissions, and also provides a comparative analysis of the efficiency of the developed catalytic converter and its industrial analogue. The article presents experimental research on the motor stand using the VAZ-21081i engine, presents technical characteristics and tools of control and measurement equipment. The developed catalytic converter, its design and characteristics are considered. Key attention in the article is given to the program and methodology of testing catalytic converters and processing the results: including the system for measuring temperatures, velocity and composition of the outgoing gases. In experimental studies, the influence of the load on the internal combustion engine on the temperature and speed of the flow of exhaust gases is analyzed. The analysis of the results of the experiments shows that an increase in the load on the engine leads to an increase in the temperature and speed of the flow of exhaust gases. The authors use the mathematical model of the conversion of gas emissions, developed in previous works, and experimentally prove that increasing the load on the engine contributes to more efficient purification of gases from carbon (II) oxide and hydrocarbons. The extremum of the dependence of the degree of conversion of carbon (II) oxide and hydrocarbons on engine power was revealed, where an increase in load leads to a decrease in the degree of gas purification. Comparative tests show the high efficiency of the experimental catalytic converter compared to the industrial analogue.

Investigation and implementation of a common ground DC‐DC buck converter with a novel control method for loss reduction in the converter

AbstractThis paper proposes a new control method for loss reduction of two series buck converters. The proposed method can be applied to each series of buck converters with two power switches. To enhance the efficiency of the converter compared to other structures, a method based on determining operating cycles for loss reduction is employed, leading to increased output efficiency of the converter. Additionally, to demonstrate the efficiency improvement using the proposed method compared to the conventional approach, the efficiency of converter is calculated through theoretical computations under real conditions, and the output results are compared for both losses and efficiency. In addition, the proposed high‐buck converter in this paper benefits from a common ground advantage and exhibits a suitable conversion ratio. The high‐buck converters are used in numerous applications for situations with low voltage and low power. The most important applications for these converters are the power supply for mobile phones, tablets, and other portable electronic devices, battery chargers, and LED drivers. Here, in order to demonstrate the validity of the proposed method, the MATLAB‐Simulink results are provided. Moreover, in order to show the feasibility of the high‐buck converter, a 100‐W prototype has been implemented and the experimental results are provided.

An efficient buck-boost converter for fast active balancing of lithium-ion battery packs in electric vehicle applications

This article proposes a fast active cell balancing circuit for lithium-ion battery packs. The proposed architecture incorporates a modified non-inverting buck-boost converter to improve balancing efficiency, an equivalent circuit model technique for battery designing, and an extended Kalman Bucy filter for accurate SOC estimation. The proposed balancing technique analyses a six-series and one parallel (6S1P) battery pack combination in static, charging, and discharging modes. With fewer components, the proposed architecture reduces the losses and improves the balancing performance. The design limitations, balancing principle, loss analysis, and control strategies are thoroughly investigated. The proposed topology is modelled in the MATLAB/Simulink platform to perform energy transformation analysis between stronger and weaker cells. The FPGA-based real-time simulator OPAL-RT (OP5700) validates the balancing performance of the proposed topology. For the 22V, 2200mAh battery pack the proposed topology had an overall balancing efficiency of 97.05% and a balancing speed of 1328s. The proposed topology has a 1.3% deviation in balancing efficiency and a 57s deviation in balancing speed compared to MATLAB and real-time simulation. The proposed active cell balancing architecture considerably increases balancing speed and efficiency.

A new method for selecting optimum levels in asymmetric Cascaded H‐Bridge‐Multilevel Inveter with variable DC sources

SummaryIn general, cascaded H‐bridge multilevel inverters (CHB‐MLI) are typically operated with either symmetrical or asymmetrical input DC sources, set at predefined specific ratios such as binary (1:2) or trinary (1:3) in the case of asymmetry, to achieve the desired output voltage waveform. However, if any DC source fails to provide the predefined voltage magnitude, or CHB‐MLIs with unspecified DC source ratios are utilized, the output voltage waveform may exhibit unequal magnitudes between consecutive levels, thereby causing a significant increase in total harmonic distortion (THD). Conventionally, to mitigate this effect, the corresponding H‐bridge is bypassed through zero voltage switching, which leads to an additional burden on the remaining H‐bridges to serve the same load. To reduce the burden on the remaining cells and improve the THD profile of the inverter, this article proposes a novel method for CHB‐MLI with varying DC magnitudes. It aims to enhance the quality of the output voltage waveform by strategically selecting optimum voltage levels rather than utilizing all available levels when CHB‐MLI has unspecified or variable DC sources. This approach can achieve a more balanced distribution of voltage magnitudes across successive levels by eliminating redundant states. Moreover, the proposed technique can reduce switch losses and enhance the converter's efficiency. The proposed method is validated through MATLAB/Simulink software simulations, followed by experimental verification.

Low-noise short-wavelength pumped frequency downconversion for quantum frequency converters

We present a highly efficient low-noise quantum frequency converter from the visible range to telecom wavelengths, combining a pump laser at intermediate frequency resonantly enhanced in an actively stabilized cavity with a monocrystalline bulk crystal. A demonstrator for photons emitted by nitrogen-vacancy-center qubits achieves 43% external efficiency with a noise photon rate per wavelength (frequency) band of 2 s−1/pm(17 s−1/GHz) – reducing the noise by two orders of magnitude compared with current devices based on periodically poled crystals with waveguides. With its tunable output wavelength, this device enables the generation of indistinguishable telecom photons from different network nodes and is, as such, a crucial component for a future quantum internet based on optical fiber.

Double wavefront reversal during six-wave interaction on Kerr nonlinearity in a waveguide with infinitely conducting surfaces

Background. Generation of a wave with a double reversed wavefront in multimode waveguides increases the efficiency of six-wave radiation converters and expands the possibilities of its use in adaptive optics problems and the conversion of complex spatially inhomogeneous waves. Aim. The quality of double wavefront reversal during six-wave interaction in a waveguide with infinitely conducting surfaces with Kerr nonlinearity is analyzed for the ratio of the wave numbers of the pump waves equal to 2 and 0,5, and the condition that one of the pump waves excites the zero mode of the waveguide, and the amplitude distribution of the other pump wave excites the edges of the waveguide are described by a Gaussian function. Methods. The influence of pump wave parameters on the half-width and contrast of the amplitude modulus of the object wave was studied using numerical methods. A wave from a point source located on the front face of the waveguide was used as a signal wave. Results. The dependences of the half-width and contrast of the amplitude modulus of the object wave on the ratio between the width of the waveguide and the width of the Gaussian pump wave are obtained. Conclusion. It is shown that the maximum change in the characteristics of a wave with a double reversed wavefront is observed when the width of the Gaussian pump waves changes in the range from 0,3 to 2 half-widths of the waveguide.

Power converters analyzed in energy storage systems to enhance the performance of the smart grid application

This paper implements and compares the existing power supply converters for an energy storage system to determine the best suited for the smart grid application. A survey of different DC-DC converters is carried out to analyze the battery's overall performance. The main objective is to identify this application's most appropriate energy storage device. The advantages of this technology have high efficiency and reliability, which can connect various energy sources and reduce conduction losses in the power converters. Through the converter control, reference currents are imposed to charge the battery. The battery nominal voltage needs to change to see which type of converter is the most suitable and robust. Simulation results show that the operating ranges of boost-buck, buck-boost, and buck-boost converters with negative output voltage enhance the efficiency of battery and renewable energy sources and compared the DC converters to know the functional voltage for the energy storage system. The power converter's efficiency and control facility will allow us to link the energy storage system with the power grid. The overall installation is established using MATLAB/Simulink software.

STUDY BY MODELING THE ELECTRICAL PROPERTIES OF SEMICONDUCTOR MATERIALS

This article discusses the process of developing a device for producing semiconductor elements operating on the basis of the thermoelectric phenomenon. The focus is on methods and technologies that improve the efficiency of thermoelectric converters. The article describes the main stages of device design, as well as an analysis of its functional characteristics. The results of experimental studies are presented, confirming the high efficiency and reliability of the developed device.

Design and Implementation of an Interleaved High Efficiency and High Voltage Gain Converter With Minimum Switch Count for Renewable Energy Integration

Design and Implementation of an Interleaved High Efficiency and High Voltage Gain Converter With Minimum Switch Count for Renewable Energy Integration

Fabrication of Erbium-Doped Upconversion Nanoparticles and Carbon Quantum Dots for Efficient Perovskite Solar Cells.

Upconversion nanoparticles (UCNPs) and carbon quantum dots (CQDs) have emerged as promising candidates for enhancing both the stability and efficiency of perovskite solar cells (PSCs). Their rising prominence is attributed to their dual capabilities: they effectively passivate the surfaces of perovskite-sensitive materials while simultaneously serving as efficient spectrum converters for sunlight. In this work, we synthesized UCNPs doped with erbium ions as down/upconverting ions for ultraviolet (UV) and near-infrared (NIR) light harvesting. Various percentages of the synthesized UCNPs were integrated into the mesoporous layers of PSCs. The best photovoltaic performance was achieved by a PSC device with 30% UCNPs doped in the mesoporous layer, with PCE = 16.22% and a fill factor (FF) of 74%. In addition, the champion PSCs doped with 30% UCNPs were then passivated with carbon quantum dots at different spin coating speeds to improve their photovoltaic performance. When compared to the pristine PSCs, a fabricated PSC device with 30% UCNPs passivated with CQDs at a spin coating speed of 3000 rpm showed improved power conversion efficiency (PCE), from 16.65% to 18.15%; a higher photocurrent, from 20.44 mA/cm2 to 22.25 mA/cm2; and a superior fill factor (FF) of 76%. Furthermore, the PSCs integrated with UCNPs and CQDs showed better stability than the pristine devices. These findings clear the way for the development of effective PSCs for use in renewable energy applications.

Sustainability evaluation of C3MR natural gas liquefaction process: Integrating life cycle analysis with Energy, Exergy, and economic aspects

In a transition towards a clean energy future, natural gas serves as an interim fuel due to its lower emissions whereas the C3MR (propane pre-cooled mixed refrigerant process) is widely recognized for high efficiency and commercial scale application converting natural gas to LNG. Previously, numerous studies have been conducted to optimize the energy efficiency and performance of C3MR process but very little contribution has been made towards its sustainability analysis. To address this, a life cycle analysis approach is established to evaluate the carbon footprint of C3MR process. In order to showcase its link with energy consumption and put forward the groundwork of analyses, the research focuses on using simulation – assisted optimization to reduce the specific energy consumption (SEC) of C3MR process by optimizing design variables. The study highlights the use of mixed refrigerant (MR) as a process variable and validates that its optimal implementation has decreased SEC to 0.2195 kWh/kg LNG, while achieving a minimum inlet temperature approach (MITA) of main cryogenic heat exchanger (MCHX), less than 3 °C. The knowledge − based optimization approach applied in this research, developed comparative case studies on which multiple analyses are performed to verify scientific findings. Energy and exergy analyses are conducted to determine thermal efficiency of the process where the optimized case exhibits a reduced difference in its composite curves and an 8.65 % improvement in exergetic performance compared to the base case. The economic indicators assessment reveals that optimized case demonstrates lower capital and operating costs, establishing economic viability. Furthermore, the energy consumption parameters are utilized for evaluation of ecological impact ofLNGsupply chain through life cycle assessment (LCA) which reflects reduced greenhouse gas (GHG) emissions for optimized case. Hence, the current study fills existing research knowledge gaps in terms of providing a comprehensive process system engineering by evaluating energy synergistic point, thermodynamic irreversibility, process viability and sustainability using life cycle assessment.

Enhancing Buck-Boost Converter Efficiency and Dynamic Responses with Sliding Mode Control Technique

Enhancing Buck-Boost Converter Efficiency and Dynamic Responses with Sliding Mode Control Technique

A Single-Output-Filter Double Dual Ćuk Converter

This study introduces an innovative version of a recently studied converter. A Double Dual Ćuk Converter was recently studied with advantages like the possibility of designing it for achieving a low-input current ripple. The proposed converter, called the Improved Double Dual Ćuk Converter, maintains the advantages of the former one, and it is characterized by requiring one less capacitor and inductor than its predecessor. This allows addressing the challenge of optimizing the topology to reduce component count without compromising the operation; this work proposes an efficient design methodology based on theoretical analysis and experimental validation. Results demonstrate that the improved topology not only retains the advantages of the previous version, including high efficiency and robustness, but also enhances power density by reducing the number of components. These advancements open new possibilities for applications requiring compact and efficient power converters, such as renewable energy systems, electric vehicles, and portable power supply systems. This work underscores the importance of continuous innovation in power converter design and lays the groundwork for future research aimed at optimizing converter topologies. A detailed discussion of the operating principles and modeling of the converter is provided. Furthermore, simulation outcomes highlighting differences in steady-state duration, output voltage, input current ripple, and operational efficiency are shared. The results from an experimental test bench are also presented to corroborate the efficacy of the improved converter.

Nutritional value of meat from selected neotropical reptiles

This is the second part of a two-part review. The first part focused on the nutritive value of meat and meat products of selected neo-tropical mammals with the potential for domestication. The objective of this current review was to investigate the nutritional qualities and carcass traits of selected neotropical reptiles compared to domestic species, focusing on the spectacled caiman, iguana, tegu, and yellow anaconda. Carcass weight analysis revealed that the spectacled caiman and male iguana were efficient converters of live weight to edible carcass weight, with higher yields than other reptiles. Among domestic species, pigs and chickens showed higher carcass yields compared to cattle and lamb. Moisture content in reptile meat was generally higher than in domestic animals, impacting texture and juiciness. Protein content was lower in reptiles but still contributed to daily requirements, while fat content, though generally lower in reptiles, could impact flavor and tenderness. Cholesterol levels were lower in reptiles, particularly the yellow anaconda, making them potentially healthier options for those with cardiovascular concerns. Fatty acid composition analysis indicated varying levels of saturated, monounsaturated, and polyunsaturated fatty acids, with potential cardiovascular health benefits in reptile meats. Amino acid content, though lower in reptiles compared to domestic species, provided essential building blocks for various physiological functions. Overall, the study highlighted the nutritional value and potential health benefits of including neotropical reptile meat in the human diet, especially as alternative protein sources.

Triple-Level Single-Ended Main Inductor Converter (SeMLC) with regard to Wind-Solar Hybrid Energies

An output from a DC-to-DC converter that can be more or less than its input is called a Single-Ended Main Inductor Converter (SeMLC). Nevertheless, there is more switching stress in this dual-level SEMIC, which raises switching losses. This rise in switching loss causes the power converter's efficiency to drop. This research suggests a Triple stage SeMIC with lower switching losses to get over this drawback. Using a lower rated switch, Triple level SEMIC increases power efficiency. There is a description of a control method that balances the voltage of the capacitor to avoid damaging the power switch. The suggested converter also lessens the ripple in inductor current in the output inductor. Triple level SeMIC uses a hybrid wind-solar energy system as a source. The benefits of the suggested converter are emphasized by discussing the simulation results of both dual- and Triple-level SeMIC.

A Novel SVM Strategy to Reduce Current Stress of High-Frequency Link Matrix Converter

High-frequency link matrix converter (HFLMC) can directly realize DC/AC conversion without intermediate energy storage components, reduce the power conversion stage, and improve efficiency and power density. With the conventional space vector modulation strategy, the secondary side voltage of the high-frequency transformer presents an asymmetric trapezoidal wave, which leads to the DC magnetic bias phenomenon and increases the current stress in secondary side switches. This paper proposes a novel SVM strategy for HFLMC. It optimizes the space vector distribution, makes secondary side voltage periodic and symmetric, and reduces the switching actions. The current stress is reduced, and the converter's efficiency is improved. Simulation and experiment results verify the advantages of the proposed modulation strategy.