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Introduction. This paper delves into the practical application of multilevel technology, particularly focusing on the capacitor-clamped converter as a promising solution for medium-to-high voltage power conversion, with specific emphasis on direct AC-AC switching conditions. Problem. The limitations of conventional single-cell matrix converters (MC) in efficiency and performance for medium-to-high voltage power conversion applications are well-recognized. Goal. The primary objective is to investigate the performance of the 3 phase modular multilevel matrix converter (3MC) with three flying capacitors (FCs) modeling. This investigation utilizes the Venturini method for gate pulse generation, aiming to compare the performance of the 3MC with standard converter designs. Methodology. To achieve the research goal, the Venturini method is adopted for generating gate pulses for the 3MC, representing a departure from conventional approaches. Detailed simulations employing MATLAB/Simulink are conducted to comprehensively evaluate the performance of the 3MC in comparison to conventional converter designs. Results. The simulation outcomes reveal a significant reduction of 73 % in total harmonic distortion (THD) achieved by the 3MC. This reduction in THD indicates improved robustness and suitability for medium-to-high voltage power conversion systems necessitating direct AC-AC conversion. These results highlight the efficacy of the 3MC in enhancing power conversion efficiency and overall performance. Originality. This paper contributes novel insights into the practical implementation of multilevel technology, particularly within the realm of capacitor-clamped converters. Furthermore, the utilization of the Venturini method for gate pulse generation in the 3MC represents an original approach to enhancing converter performance. Practical value. The research findings present significant advancements in multilevel transformer technology, offering valuable guidance for optimizing transformer design in various industrial and renewable energy applications. These contributions serve to enhance the development of reliable and efficient power systems, addressing critical needs in the energy sector. [ABSTRACT FROM AUTHOR]

This paper presents a non‐isolated DC‐DC converter designed to validate ultra‐high voltage gain using a modified double boost mode. The objective is to achieve exceptionally high voltage gain by integrating a modified triple boost technique (MTBT), interleaved with second main and auxiliary third MOSFETs, and a modified switched inductor‐capacitor (MSLC), effectively doubling the voltage transfer gain. Furthermore, MSLC is combined with the auxiliary third and double main MOSFET to double the voltage gain while concurrently mitigating voltage stress on the auxiliary MOSFET and diodes in the proposed converter (the PC). Additionally, all diodes in the MTBT operate under zero current switching (ZCS) and the double main and auxiliary third MOSFET face very low current stress at ultra‐high voltage gain. The input current of the PC remains steady without pulsating at a low duty ratio, making the PC more suitable for renewable energy systems. The PC offers numerous advantages, exhibiting high efficiency and ensuring minimal voltage stress on power devices with low current stress on the power switches. Notably, PC aims to elevate input voltages from 30 V to a variable output range of 335 to 600 V, delivering 440 watts at 96.1% efficiency. [ABSTRACT FROM AUTHOR]

The country's first on-site hydrogen refueling station (HRS) is installed at the Hydrogen Energy Laboratory, Bangladesh Council of Scientific and Industrial Research (BCSIR), and its performance is studied to penetrate and prepare the hydrogen refueling network for the future. The study fills the power conditioning and integration information gap to HRS and refueling performances of on-site HRS in the particular conditions of the country. Strategic integration of grid power to the HRS is materialized and its adaptation with on-site HRS. Low-cost frequency & voltage conversion (conversion of 50 Hz, 420 V, or 220 V to stable 60 Hz, 220 V, or 110 V) and its stabilization are successfully made. An initial pressure of 5 MPa and 10 MPa of the vehicle tank (two-time refueling conditions) at 25 °C fills with the hydrogen at the APRR of 5.07 & 6.39 by 5.91& 7.5 min accordingly whereas the target pressure is 35 MPa. Hydrogen transfer to the vehicle tank at the pressure established by SAE J2799 according to the APRR during refueling time. The system consumes 52.71 kW and 3.73 kW of power to produce and compress 1 kg of hydrogen. The temperature profile shows that at the maximum hydrogen flow rate of 20 g/s, the temperature rose to 56 °C maintaining the fueling protocol. The levelized cost of hydrogen (LCOH P) of on-site hydrogen production is $6.68 and the LCOH S&D of storage & dispensing of hydrogen is $1.07 using the grid electricity whereas it gets down to $3.74 and $0.76 for the case of solar PV. Hydrogen vehicles reduce 43% fuel cost (using grid power) as compared to diesel engines. The study also depicts that a solar-powered hydrogen fleet is a better option for replacing fossil fuels and in shaping a sustainable transport system. The economic analyses provide the net present value (NPV 20) and benefit and cost ratio (BCR) of the on-site HRS are 0.09 million and 1.18 at the discount rate of 9.5% which corresponds to the investment to the on-site HRS is feasible and free of risk. • Strategic conversion and integration of power with on-site hydrogen refueling station. • LCOH of hydrogen at on-site HRS $7.5 & $3.50 using grid and Solar PV accordingly. • SAE J2799 nozzle and slow filling are used to refuel the vehicle without precooling. • Hydrogen vehicle reduces 43% of fuel cost as compared to gasoline-burned vehicles. [ABSTRACT FROM AUTHOR]

This paper proposes a new soft‐switching bidirectional multiport DC/DC converter for PV/EV applications. The proposed topology is capable of using several different sources simultaneously. Also, it has some benefits including high voltage gain, bidirectional, soft‐switching technique, and multi‐input multi‐output (MIMO) topology. In addition, all inputs of the proposed converter are separate from each other and it causes control of the outputs to be simple in the wake of the common ground of the inputs and outputs. The proposed converter can work on zero current switching (ZCS) conditions on some power semiconductors (power diode/switch) and decreases the switching and conduction losses. It also makes use of semiconductors with lower resistance on‐state (Rds‐on). Using coupled inductor techniques and working of semiconductors under ZCS conditions eliminates the total loss affected by reverse recovery of the power diodes, and a passive clamp circuit can recover the leakage energy released by the leakage inductance of the used coupled inductor. The proposed topology is built and tested in the laboratory. To confirm the accurate operation of the proposed topology, it is tested by Typhoon HIL‐404 emulator at 12 V–12 V–12 V inputs/270 W with 50 kHz switching frequency. [ABSTRACT FROM AUTHOR]

The electrification of vehicles has emerged as a pivotal technique for addressing environmental concerns and reducing reliance on conventional fuel sources. Conversely, the best way to incorporate renewable energy into electric vehicles (EVs) is still a challenging task, particularly in enhancing the performance of EVs through efficient energy management. The transition to EVs has gained momentum as part of global efforts to mitigate environmental impacts and reduce dependence on fossil fuels. This paper proposes a hybrid method for enhancing EV performance through buck‐boost converters with renewable energy integration. The proposed technique is the joined execution of Flying Foxes Optimization (FFO) and Viscoelastic Constitutive Artificial Neural Networks (vCANNs) techniques. The proposed method's goal is to enhance the energy efficiency, minimize EV charging cost, and mitigating environmental impacts. The renewable energy sources: solar panels, fuel cells, and wind turbines, are integrated into the EV power system through buck‐boost converters. The buck‐boost converter's control signal is optimized through the FFO method. vCANNs are used to predict these control parameters. The proposed strategy is executed in MATLAB software and is compared with existing strategies. In comparison with other current approaches like particle swarm optimization, heap based optimizer, and wild horse optimize, the proposed method achieves a high efficiency of 99% and low cost of 0.05 €/KWh. [ABSTRACT FROM AUTHOR]

Introduction. This paper delves into the practical application of multilevel technology, particularly focusing on the capacitor-clamped converter as a promising solution for medium-to-high voltage power conversion, with specific emphasis on direct AC-AC switching conditions. Problem. The limitations of conventional single-cell matrix converters (MC) in efficiency and performance for medium-to-high voltage power conversion applications are well-recognized. Goal. The primary objective is to investigate the performance of the 3 phase modular multilevel matrix converter (3MC) with three flying capacitors (FCs) modeling. This investigation utilizes the Venturini method for gate pulse generation, aiming to compare the performance of the 3MC with standard converter designs. Methodology. To achieve the research goal, the Venturini method is adopted for generating gate pulses for the 3MC, representing a departure from conventional approaches. Detailed simulations employing MATLAB/Simulink are conducted to comprehensively evaluate the performance of the 3MC in comparison to conventional converter designs. Results. The simulation outcomes reveal a significant reduction of 73 % in total harmonic distortion (THD) achieved by the 3MC. This reduction in THD indicates improved robustness and suitability for medium-to-high voltage power conversion systems necessitating direct AC-AC conversion. These results highlight the efficacy of the 3MC in enhancing power conversion efficiency and overall performance. Originality. This paper contributes novel insights into the practical implementation of multilevel technology, particularly within the realm of capacitor-clamped converters. Furthermore, the utilization of the Venturini method for gate pulse generation in the 3MC represents an original approach to enhancing converter performance. Practical value. The research findings present significant advancements in multilevel transformer technology, offering valuable guidance for optimizing transformer design in various industrial and renewable energy applications. These contributions serve to enhance the development of reliable and efficient power systems, addressing critical needs in the energy sector. References 54, tables 3, figures 4.

Abstract This paper presents a non‐isolated DC‐DC converter designed to validate ultra‐high voltage gain using a modified double boost mode. The objective is to achieve exceptionally high voltage gain by integrating a modified triple boost technique (MTBT), interleaved with second main and auxiliary third MOSFETs, and a modified switched inductor‐capacitor (MSLC), effectively doubling the voltage transfer gain. Furthermore, MSLC is combined with the auxiliary third and double main MOSFET to double the voltage gain while concurrently mitigating voltage stress on the auxiliary MOSFET and diodes in the proposed converter (the PC). Additionally, all diodes in the MTBT operate under zero current switching (ZCS) and the double main and auxiliary third MOSFET face very low current stress at ultra‐high voltage gain. The input current of the PC remains steady without pulsating at a low duty ratio, making the PC more suitable for renewable energy systems. The PC offers numerous advantages, exhibiting high efficiency and ensuring minimal voltage stress on power devices with low current stress on the power switches. Notably, PC aims to elevate input voltages from 30 V to a variable output range of 335 to 600 V, delivering 440 watts at 96.1% efficiency.

Abstract This paper proposes a new soft‐switching bidirectional multiport DC/DC converter for PV/EV applications. The proposed topology is capable of using several different sources simultaneously. Also, it has some benefits including high voltage gain, bidirectional, soft‐switching technique, and multi‐input multi‐output (MIMO) topology. In addition, all inputs of the proposed converter are separate from each other and it causes control of the outputs to be simple in the wake of the common ground of the inputs and outputs. The proposed converter can work on zero current switching (ZCS) conditions on some power semiconductors (power diode/switch) and decreases the switching and conduction losses. It also makes use of semiconductors with lower resistance on‐state (Rds‐on). Using coupled inductor techniques and working of semiconductors under ZCS conditions eliminates the total loss affected by reverse recovery of the power diodes, and a passive clamp circuit can recover the leakage energy released by the leakage inductance of the used coupled inductor. The proposed topology is built and tested in the laboratory. To confirm the accurate operation of the proposed topology, it is tested by Typhoon HIL‐404 emulator at 12 V–12 V–12 V inputs/270 W with 50 kHz switching frequency.

Abstract Three‐coil inductive power transfer (IPT) charging system can not only achieve inherent constant current (CC) to constant voltage (CV) transition but also tolerate load open‐circuit. However, due to the cross‐coupling between the auxiliary coil and the receiver coil, the output voltage in CV mode may deviate from the CV voltage significantly, which makes the design freedom of the three‐coil coupler low. By replacing the auxiliary coil with a transformer, an improved auxiliary circuit is proposed in this paper to address the cross‐coupling issue and to increase the design freedom of the loosely coupled transformer (LCT). The improved auxiliary circuit can achieve load short‐circuit and open‐circuit protection. Besides, the optimization design of LCT is easy to achieve by load impedance matching. The operating principle and parameters design of the improved auxiliary circuit are discussed. A 1 kW experimental prototype is built to verify the feasibility of the proposed method.

Abstract This study provides a comparative analysis of feasible architectures of Power Pulsating Buffer (PPB) as an actively controlled energy storage solution alternative to the electrolytic capacitors in a single‐stage isolated, single‐phase 120 V AC 60Hz grid‐connected photovoltaic (PV) microinverter for a 400 W rated system with 20–40 V input range. The comparison encompasses key factors including energy density, volume reduction, efficiency, frequency operation, and system stability. The findings shed light on the primary advantages and disadvantages of the buck‐ and boost‐derived PPB under study. The results indicate that the boost PPB exhibits enhanced stability, a more compact design, and higher power efficiency compared to the buck PPB. However, for low switching frequency operations, the buck PPB proves to be more effective in mitigating DC port voltage ripple and ensuring controller over microinverter load variation.

Abstract Most coupled inductor‐based step‐up DC–DC converters encounter a significant voltage overshoot on their power switch due to the leakage inductance of the coupled inductor. So, they need additional bulky snubber circuits or a sophisticated procedure for coupled inductor design to reduce that effect. This paper proposes an improved coupled inductor‐based DC–DC converter, which provides a high quadratic voltage conversion ratio without excessive voltage stresses on the power switch. An active clamp circuit that operates with the zero‐voltage switching (ZVS) feature has been utilized for this aim. This feature allows the main power switch to be selected from low voltage ratings and low on‐resistance MOSFETs, which reduces conduction loss. The topology also benefits from continuous input current, high gain, high efficiency, and an appropriate number of components compared with the produced gain. In this article, the theory and operation of this converter are described by proposing the dc and small‐signal models, loss model, and continuous and discontinuous current modes (CCM and DCM) relations. Experimental results are represented to evaluate the performance of the proposed topology. For this purpose, a 240 V/240 W prototype has been designed and fabricated. Results confirm the above claims.

Abstract This paper introduces a new direct step‐up ac‐ac converter designed based on the SEPIC. It provides a higher step‐up conversion ratio than other counterparts with valuable features like high efficiency, reasonable input and output total harmonic distortions (THD), continuous input current waveform, common ground, few components, and single‐stage conversion without snubber and LC filters. Unlike most counterparts, the duty cycle can be varied between zero and one in boost operation and is not limited to any value below one. The voltage stress on one switch is reduced by increasing the winding coefficient of the utilized coupled inductor, and current stress on another is independent of this coefficient. It reduces the switches' losses and improves the converter efficiency. Thanks to the above attributes, the proposed converter is suitable for inductive power transfer from low‐voltage ac sources, operating as an ac voltage regulator for sensitive ac loads, and any applications that require a boost converter with few components. This article shows the converter's operation principle and evaluates its performance through experiments on a 225 W prototype. Accordingly, the maximum obtained efficiency is 95.4%. The input and output current THDs for the nominal inductive load equal 4.5 and 2.8%, respectively. Results confirm the claims.

Abstract Here, a high gain DC–DC converter which is based on switched capacitor (SC) and switched LCL (SLCL) cells is presented. The diode employed in the classical passive switched inductor (SI) cell is replaced by a capacitor in the proposed SLCL cell to achieve higher voltage gain. Two switches—one each in the positive and negative DC rails of the supply are employed to charge and discharge the inductors of SLCL cells. A generic structure comprising of N and M number of SLCL cells in the positive and negative DC rails respectively along with K number of SC cells is presented. To validate the proposed gain extension concept, a two‐switch based converter comprising of 2 SLCL and 1 SC cells is synthesized and its operation is described in detail. The voltage gain expression of the proposed SLCL‐SC converter is derived. Experimental results are obtained from a 25 to 380 V prototype converter which operates at a full‐load efficiency of 94.22% at 200 W. Since the switches employed in the proposed converter are operated at a moderate and safe duty ratio of D = 0.51, the voltage stress on the switches is about 25% of the output voltage while the diodes are subjected to even lesser voltage stress levels of only one‐fifth of the output voltage. The main salient features of the proposed topology are its (i) modular structure, (ii) ability to provide higher voltage gain values at lower duty ratios (iii) reduced voltage stress on the semiconductor devices and (iv) reduced conduction losses due to the replacement of diodes with capacitors in SLCL cells.

Abstract The IPT system has been studied for underwater applications such as autonomous underwater vehicles (AUVs) and subsea sensors. However, it rarely comparatively shows the performance of the IPT system in air, freshwater, and seawater. Based on the fore‐mentioned research background, this paper presents a survey of the properties of the IPT system in different mediums. Here, a 100 W power‐level experimental IPT prototype is built and tested. The resonant frequency is set at 300 kHz with a gap range from 10 to 190 mm. The comparison is focused on the efficiency, mutual inductance, coupling coefficient, coil resistance, and quality factor of the IPT system. The IPT system is placed in air, freshwater, and seawater with the same settings. What's more, the magnetic fields of coupling coils in air, freshwater, and seawater are presented in this paper. This paper could be acted as a reference to optimize the IPT system and facilitate future IPT research for underwater applications by analysing the performance of the IPT system in different mediums. The 3D Ansys Maxwell simulation of the IPT system is also given here to study the magnetic fields.

This work deals with the simulation of a perovskite solar cell with structure, ITO/SnO2/MAPbI 3 − x Clx/Spiro-MeOTAD/Ag using SCAPS-1D software. The optimization of absorber thickness and carriers' lifetime results in PCE = 1 9. 7 0 % ( V oc = 1. 1 4 V, J sc = 2 4. 3 1 mA/cm2 and FF = 7 0. 8 8 %). The same structures are also analyzed without ETL and HTL for making cost-effective solar cell. The efficiencies for both ETL and HTL free structures are found to be 17.42% and 9.98%, respectively. Further, the optimization of gradient doping shows a significant increment in performance parameters i.e. PCE = 2 4. 4 2 % ( V oc = 1. 1 9 V, J sc = 2 3. 9 8 mA/cm2 and FF = 8 4. 8 4 %). Moreover, the analysis of various factors like average doping concentration, number of absorber sublayers, recombination velocities and temperature on the cell performance are performed to examine device stability. Present observations suggest that by considering only two sublayers, one can achieve the highest cell performance by using the gradient doping method. We have also validated the cell performance by comparing it with the experimental results and found a good agreement in both. Our findings may provide an effective route to fabricate highly efficient solar cell devices. [ABSTRACT FROM AUTHOR]

In this article, a multipurpose embedded system for testing organic photovoltaic modules is presented. It is designed to include all the features for real-time monitoring, data acquisition, and power conversion based on a Ćuk converter, providing useful data for scientific investigation of the outdoor operation of organic photovoltaic modules. The embedded system allows both the scan of the I–V curve and the continuous operation of the organic photovoltaic module, such as at its maximum power. Voltage and current at the terminals of the organic photovoltaic module under test and up to four temperatures are continuously measured and stored on a Secure Digital card. The communication interface allows the embedded system to connect with other instruments, such as irradiance sensors, with digital serial output. The embedded system is designed both for laboratory and in-the-field use: it can be powered either by the AC electrical grid or a battery, which can also operate as a backup battery. Galvanic isolation divides the embedded system into the field-side and the logic-side functional sections, providing improved noise immunity and safe operation. The main power distribution system within the embedded system is a +9 V bus; ultra-low-noise linear low dropout regulators provide the +3.3 V and +5 V regulated voltages to supply the analog and digital circuits within the logic-side section, and a flyback converter supplies the field-side section of the board. The proposed embedded solution is validated using an experimental setup built at SolarTechLab, Politecnico di Milano. The experimental results report the feasibility of the proposed embedded system. [ABSTRACT FROM AUTHOR]

This study provides a comparative analysis of feasible architectures of Power Pulsating Buffer (PPB) as an actively controlled energy storage solution alternative to the electrolytic capacitors in a single‐stage isolated, single‐phase 120 V AC 60Hz grid‐connected photovoltaic (PV) microinverter for a 400 W rated system with 20–40 V input range. The comparison encompasses key factors including energy density, volume reduction, efficiency, frequency operation, and system stability. The findings shed light on the primary advantages and disadvantages of the buck‐ and boost‐derived PPB under study. The results indicate that the boost PPB exhibits enhanced stability, a more compact design, and higher power efficiency compared to the buck PPB. However, for low switching frequency operations, the buck PPB proves to be more effective in mitigating DC port voltage ripple and ensuring controller over microinverter load variation. [ABSTRACT FROM AUTHOR]

Three‐coil inductive power transfer (IPT) charging system can not only achieve inherent constant current (CC) to constant voltage (CV) transition but also tolerate load open‐circuit. However, due to the cross‐coupling between the auxiliary coil and the receiver coil, the output voltage in CV mode may deviate from the CV voltage significantly, which makes the design freedom of the three‐coil coupler low. By replacing the auxiliary coil with a transformer, an improved auxiliary circuit is proposed in this paper to address the cross‐coupling issue and to increase the design freedom of the loosely coupled transformer (LCT). The improved auxiliary circuit can achieve load short‐circuit and open‐circuit protection. Besides, the optimization design of LCT is easy to achieve by load impedance matching. The operating principle and parameters design of the improved auxiliary circuit are discussed. A 1 kW experimental prototype is built to verify the feasibility of the proposed method. [ABSTRACT FROM AUTHOR]

This paper introduces a new direct step‐up ac‐ac converter designed based on the SEPIC. It provides a higher step‐up conversion ratio than other counterparts with valuable features like high efficiency, reasonable input and output total harmonic distortions (THD), continuous input current waveform, common ground, few components, and single‐stage conversion without snubber and LC filters. Unlike most counterparts, the duty cycle can be varied between zero and one in boost operation and is not limited to any value below one. The voltage stress on one switch is reduced by increasing the winding coefficient of the utilized coupled inductor, and current stress on another is independent of this coefficient. It reduces the switches' losses and improves the converter efficiency. Thanks to the above attributes, the proposed converter is suitable for inductive power transfer from low‐voltage ac sources, operating as an ac voltage regulator for sensitive ac loads, and any applications that require a boost converter with few components. This article shows the converter's operation principle and evaluates its performance through experiments on a 225 W prototype. Accordingly, the maximum obtained efficiency is 95.4%. The input and output current THDs for the nominal inductive load equal 4.5 and 2.8%, respectively. Results confirm the claims. [ABSTRACT FROM AUTHOR]

Most coupled inductor‐based step‐up DC–DC converters encounter a significant voltage overshoot on their power switch due to the leakage inductance of the coupled inductor. So, they need additional bulky snubber circuits or a sophisticated procedure for coupled inductor design to reduce that effect. This paper proposes an improved coupled inductor‐based DC–DC converter, which provides a high quadratic voltage conversion ratio without excessive voltage stresses on the power switch. An active clamp circuit that operates with the zero‐voltage switching (ZVS) feature has been utilized for this aim. This feature allows the main power switch to be selected from low voltage ratings and low on‐resistance MOSFETs, which reduces conduction loss. The topology also benefits from continuous input current, high gain, high efficiency, and an appropriate number of components compared with the produced gain. In this article, the theory and operation of this converter are described by proposing the dc and small‐signal models, loss model, and continuous and discontinuous current modes (CCM and DCM) relations. Experimental results are represented to evaluate the performance of the proposed topology. For this purpose, a 240 V/240 W prototype has been designed and fabricated. Results confirm the above claims. [ABSTRACT FROM AUTHOR]

Here, a high gain DC–DC converter which is based on switched capacitor (SC) and switched LCL (SLCL) cells is presented. The diode employed in the classical passive switched inductor (SI) cell is replaced by a capacitor in the proposed SLCL cell to achieve higher voltage gain. Two switches—one each in the positive and negative DC rails of the supply are employed to charge and discharge the inductors of SLCL cells. A generic structure comprising of N and M number of SLCL cells in the positive and negative DC rails respectively along with K number of SC cells is presented. To validate the proposed gain extension concept, a two‐switch based converter comprising of 2 SLCL and 1 SC cells is synthesized and its operation is described in detail. The voltage gain expression of the proposed SLCL‐SC converter is derived. Experimental results are obtained from a 25 to 380 V prototype converter which operates at a full‐load efficiency of 94.22% at 200 W. Since the switches employed in the proposed converter are operated at a moderate and safe duty ratio of D = 0.51, the voltage stress on the switches is about 25% of the output voltage while the diodes are subjected to even lesser voltage stress levels of only one‐fifth of the output voltage. The main salient features of the proposed topology are its (i) modular structure, (ii) ability to provide higher voltage gain values at lower duty ratios (iii) reduced voltage stress on the semiconductor devices and (iv) reduced conduction losses due to the replacement of diodes with capacitors in SLCL cells. [ABSTRACT FROM AUTHOR]

The IPT system has been studied for underwater applications such as autonomous underwater vehicles (AUVs) and subsea sensors. However, it rarely comparatively shows the performance of the IPT system in air, freshwater, and seawater. Based on the fore‐mentioned research background, this paper presents a survey of the properties of the IPT system in different mediums. Here, a 100 W power‐level experimental IPT prototype is built and tested. The resonant frequency is set at 300 kHz with a gap range from 10 to 190 mm. The comparison is focused on the efficiency, mutual inductance, coupling coefficient, coil resistance, and quality factor of the IPT system. The IPT system is placed in air, freshwater, and seawater with the same settings. What's more, the magnetic fields of coupling coils in air, freshwater, and seawater are presented in this paper. This paper could be acted as a reference to optimize the IPT system and facilitate future IPT research for underwater applications by analysing the performance of the IPT system in different mediums. The 3D Ansys Maxwell simulation of the IPT system is also given here to study the magnetic fields. [ABSTRACT FROM AUTHOR]

Significant advancements in the field of power electronics have created an ideal opportunity to introduce various topologies of multilevel inverters. These multilevel inverter topologies comprise different notable characteristics, such as staircase sinusoidal output voltage with high quality, a lowered number of power switches, no filter requirement, etc. In this literature, a new asymmetrical MLI topology is proposed to reduce the number of components of the inverter with admirable voltage-step creation. The proposed topology provides a 17-level, staircase-type, nearly sinusoidal output voltage waveform. The number of switches required for the proposed multilevel inverter topology is fewer compared to the existing topology for the same level. A carrier-based sinusoidal pulse-width modulation technique is used for the proposed topology at a switching frequency of 3 kHz. The functioning of the proposed inverter topology is thoroughly examined. A 17-level asymmetrical inverter is executed; both the MATLAB/SIMULINK as well as the experimental results using dSPACE-1103 controller. The simulation results are verified using the experimental results for the proposed 17-level multilevel inverter for modulation indexes of 1 and 0.6. [ABSTRACT FROM AUTHOR]

Abstract This paper proposes, a novel soft‐switching bidirectional direct current to direct current (DC–DC) converter based on switched‐capacitor and coupled‐inductor. The proposed converter has a simple structure and utilizes four switches and a three‐winding coupled inductor and can achieve a high voltage conversion ratio in both step‐up/step‐down operations. By employing the switched‐capacitor technique, voltage stress across the power switches is low and therefore low voltage rating switches can be adopted to reduce the losses of their conduction. Soft‐switching characteristic of the proposed converter reduces the switching loss of active power switches and raises the conversion efficiency. This paper presents theoretical analysis for all operating modes of the converter, voltage conversion ratio, voltage and current stresses of all power switches. Finally, to test the validity of theoretical results and demonstrate the performance of the converter, experimental results are provided.

Abstract Silicon carbide (SiC) power metal‐oxide‐semiconductor field‐effect transistors (MOSFETs) switch at an unprecedented speed, even at high currents. For accurate dynamic characterization, current sensors must measure high currents at a high bandwidth. Moreover, at high switching speeds, parasitic impedances in the commutation loop become critical. To ensure high‐accuracy measurements, the current sensor insertion impedance must be minimal. Here, a two‐step current sensor evaluation method is proposed. This method serves the characterization and suitability assessment of high‐power, high‐bandwidth current sensors for fast‐switching applications using SiC power MOSFETs. Conducting a small‐ and a large‐signal transmission behaviour analysis separately results in holistic information about the current sensor behaviour in both time and frequency domain. The proposed method is validated using four commercially available current sensors that are widely used for SiC power MOSFET characterization. The work concludes transferring the knowledge derived in the conducted experiments to a practical, application‐oriented sensor selection guide.

Abstract High‐gain converters play a vital role in all industrial applications such as automobiles, motor drives, renewable energy systems, and railway transportation sectors. The conventional converters have low gain owing to high‐voltage stress on active MOSFET, diode and low efficiency related with high operating pulse ratio. To overcome the limitations associated with the conventional converters, this study proposes a non‐isolated configuration of multiport quasi‐resonant converter (MP‐QRC) with high gain. The proposed MP‐QRC has the merits of high‐voltage gain, reduced number of components, minimum conduction losses, realization of soft switching in the devices and improved reliability. Moreover, the proposed converter is scalable and can serve as a good candidate in microgrid environment where the integration of more than one input is essential. In this paper, first a comprehensive analysis of various operation modes and design constraints are presented. Further, the study is supported with a reliability evaluation of proposed converter based on component failure. Also, the futuristic behaviour of MP‐QRC under continuous conduction mode as a function of operational and environmental variables is investigated to ascertain the reliability. The steady‐state operation of the converter is demonstrated for off‐board electric vehilce (EV) charging using MATLAB/SIMULINK and experiments performed on a 300‐W test rig.

Silicon carbide (SiC) power metal‐oxide‐semiconductor field‐effect transistors (MOSFETs) switch at an unprecedented speed, even at high currents. For accurate dynamic characterization, current sensors must measure high currents at a high bandwidth. Moreover, at high switching speeds, parasitic impedances in the commutation loop become critical. To ensure high‐accuracy measurements, the current sensor insertion impedance must be minimal. Here, a two‐step current sensor evaluation method is proposed. This method serves the characterization and suitability assessment of high‐power, high‐bandwidth current sensors for fast‐switching applications using SiC power MOSFETs. Conducting a small‐ and a large‐signal transmission behaviour analysis separately results in holistic information about the current sensor behaviour in both time and frequency domain. The proposed method is validated using four commercially available current sensors that are widely used for SiC power MOSFET characterization. The work concludes transferring the knowledge derived in the conducted experiments to a practical, application‐oriented sensor selection guide. [ABSTRACT FROM AUTHOR]

This paper proposes, a novel soft‐switching bidirectional direct current to direct current (DC–DC) converter based on switched‐capacitor and coupled‐inductor. The proposed converter has a simple structure and utilizes four switches and a three‐winding coupled inductor and can achieve a high voltage conversion ratio in both step‐up/step‐down operations. By employing the switched‐capacitor technique, voltage stress across the power switches is low and therefore low voltage rating switches can be adopted to reduce the losses of their conduction. Soft‐switching characteristic of the proposed converter reduces the switching loss of active power switches and raises the conversion efficiency. This paper presents theoretical analysis for all operating modes of the converter, voltage conversion ratio, voltage and current stresses of all power switches. Finally, to test the validity of theoretical results and demonstrate the performance of the converter, experimental results are provided. [ABSTRACT FROM AUTHOR]

High‐gain converters play a vital role in all industrial applications such as automobiles, motor drives, renewable energy systems, and railway transportation sectors. The conventional converters have low gain owing to high‐voltage stress on active MOSFET, diode and low efficiency related with high operating pulse ratio. To overcome the limitations associated with the conventional converters, this study proposes a non‐isolated configuration of multiport quasi‐resonant converter (MP‐QRC) with high gain. The proposed MP‐QRC has the merits of high‐voltage gain, reduced number of components, minimum conduction losses, realization of soft switching in the devices and improved reliability. Moreover, the proposed converter is scalable and can serve as a good candidate in microgrid environment where the integration of more than one input is essential. In this paper, first a comprehensive analysis of various operation modes and design constraints are presented. Further, the study is supported with a reliability evaluation of proposed converter based on component failure. Also, the futuristic behaviour of MP‐QRC under continuous conduction mode as a function of operational and environmental variables is investigated to ascertain the reliability. The steady‐state operation of the converter is demonstrated for off‐board electric vehilce (EV) charging using MATLAB/SIMULINK and experiments performed on a 300‐W test rig. [ABSTRACT FROM AUTHOR]

This article outlines the comprehensive design and control approach for a single-phase bidirectional rectifier (SPBR) used in bidirectional charging of electric vehicle batteries. The operational parameters of the inverter are determined through a thorough analysis of all switching sequences to accurately assess power losses, considering the type of switching device chosen in each case, enabling proper component sizing, and understanding converter efficiency. An exclusive electronic control circuit is examined, governing two converter operation modes: boost rectifier with power factor correction (PFC) and sine pulse inverter width modulation (SPWM) with a minimum number of adjustments made automatically. One problem that arises when addressing the design of an SPBR is determining the operating frequency. To address this issue, this study offers to conduct a comparative analysis of losses using various power devices and magnetic circuits to determine the optimal operating frequency for achieving maximum energy efficiency. To validate the design's feasibility, a prototype with 10 kW output power was constructed, achieving a peak efficiency of approximately 97.5% in both directions, unity power factor (PF), and total harmonic distortion (THD) of less than 7% during full power operation. [ABSTRACT FROM AUTHOR]

A novel voltage boost system using DC‐inputs direct electric‐power converter (D‐EPC) is proposed. D‐EPC is an inverter that can control the distribution of power from two sources. In this study, a voltage boost system without boost chopper was developed using the power distribution control of D‐EPC. The power distribution control can control the voltage of the smoothing capacitor in the D‐EPC. The effectiveness of the proposed voltage boost system was verified using a prototype of the D‐EPC circuit and controller. [ABSTRACT FROM AUTHOR]

Boost and boost-derived converters play an important role in interfacing the low voltage input from renewable energy sources like photovoltaic (PV) panels with the high voltage DC bus or DC load. Interleaved boost converters (IBC) are a separate class of converters which have been in practical use for more than a decade. In this paper, high gain interleaved boost DC-DC converters are reviewed. Some gain extension mechanisms which are usually embedded along with the IBC structure are discussed. Such high gain converters are categorized based on their adopted gain extension mechanism. Further, the performance of the converters which employ hybrid combinations of few gain extension cells are also reviewed. The voltage gain capability, advantages, disadvantages, number of components employed and other salient features of all such interleaved high gain DC-DC converters are reviewed in detail. The review outcomes are portrayed using tables and images. Based on the voltage gain requirements, power level and efficiency of the target applications, the user may choose to adopt more than one gain extension technique.

This research focuses on evaluating and comparing different DC-DC converter designs, specifically for low power applications. The study considers inductor-based, switching capacitor, and linear voltage regulator (LVR) DC-DC converters. While there has been critical investigation of DC-DC converters in the literature, there is a gap in assessing their performance based on a comprehensive set of conflicting parameters. Additionally, there is a lack of research on matching the most suitable DC-DC converter with specific low power applications. The chosen application for this study is a DC-DC converter on a glass substrate, specifically for smart glass in electric vehicles. The research presents a complete process that includes design, simulation, layout, fabrication, and measurement. Through simulations, a 4.8 V to 3.3 V buck converter is recommended, demonstrating an almost ideal response time and minimal output ripples. Experimental measurements also confirm a low output ripple of 0.3 %. By addressing this research gap and providing a comprehensive evaluation of DC-DC converters, this study contributes to the development of efficient and reliable power solutions for smart glass applications in electric vehicles.

Abstract This paper proposes a novel bidirectional DC–DC converter with high voltage conversion ratio and capability of cancelling input current ripple. The proposed converter uses two coupled inductors and switched‐capacitor circuit to increase the voltage conversion ratio. The input current ripple at low voltage side can be eliminated for a pre‐selected duty cycle by adjusting special values of magnetizing inductances of coupled inductors. The input current is divided into two paths of the primary winding of coupled inductors that causes the decrease in the current stresses of switches. The proposed converter has five switches that consist the internal diodes of switches to bring about bidirectional power flow and have boost and buck operations. Here, the proposed topology is analysed in all operating modes and the current and voltage stresses of switches, input current ripple cancelling condition and voltage conversion ratio are calculated. Finally, the accuracy performance of the proposed converter is reconfirmed through EMTDC/PSCAD simulation and experimental results for boost operations.

Abstract This paper introduces a dual‐input single‐output (DISO) non‐isolated DC–DC converter with the capability to accommodate multiple input ports. It supports both bidirectional and unidirectional power flows. The proposed converter employs the switched‐capacitors (SC) technique, resulting in a high‐ voltage transfer gain. Although the use of the SC technique leads to discontinuous input current, this issue has been addressed by incorporating an inductor at the input side. The DISO high‐voltage gain converter offers flexible control options, reduces current and voltage stress on semiconductors, and imposes no duty cycle limitations due to the proposed switching methods. Furthermore, when Port 2 fails, the proposed converter can transfer energy to the load by sources in Port 1 without interruption. The steady‐state model and small‐signal analysis (SSA) of the proposed converter are examined at continuous conduction mode (CCM). To evaluate accurately, the proposed converter is compared with the recently presented converters based on important characteristics. Additionally, a comprehensive power loss analysis is performed. Following the design specifications, an evaluation and testing of a prototype are conducted to verify the feasibility and performance of the converter.

A novel control scheme applicable to in-road inductive wireless charging pads in a dynamic system is presented. Primary inverter current sensing allows the primary pad to detect an approaching secondary pad. Zero-crossing detection of the same current allows the primary to synchronize to the secondary, functioning as a synchronous inverter with dual-active switching. Such primary synchronous inverters allow for independent primary pads. Necessary measures to ensure stable operation of the design are discussed. The control scheme only adds an analog filter to the bare-bones open-loop design. The design is validated through simulation and hardware experimentation, with a strong demonstration of robustness.

As power demand from electric vehicles and digital loads increases, the use of direct current power supplies is increasing. As a result, the application of microgrid utilizing various distributed power systems is expanding. As demand power and load capacity increase, parallel operation of multiple power converters is required to increase the capacity of power converters used in distributed power systems. Among parallel control methods, load sharing through communication has a significant effect on control performance due to communication speed and reliability. This paper proposes an instantaneous load-sharing parallel control method using a high-speed communication method that can transmit data necessary for load-sharing every control cycle. The proposed communication method uses enhanced PWM and capture communication using a DMA module to compensate for the shortcomings of the existing method using PWM and capture functions. Whenever the master voltage controller is executed, the data required for parallel operation is updated, and by transmitting this data to the slave, instantaneous load sharing control with high speed response is possible. We explain the communication and system architecture of the proposed method and present the communication protocol specifications and design. The performance and validity of the proposed instantaneous load sharing parallel control method were verified through simulation and experiments.

Power hardware in the loop (PHIL) is a modern experimental technique that allows the emulation of a full-scale converter (FSC) with the combination of a scaled-down converter (SDC), a power amplifier, and a real-time simulator, thus enabling the study of real-time interactions of power electronics with large power systems. However, assembling an accurate scaled-down replica of an FSC with off-the-shelf laboratory SDCs is practically impossible due to a mismatch in per unit losses, as well as in the impedance of the $L/LC/LCL$ filter. Consequently, the scaled-up power flow capability of SDCs differs from that of FSCs, restricting emulation to smaller regions of the four quadrants than those corresponding to the FSCs' nominal active and reactive capacity. These PHIL test beds cannot be used to emulate FSCs demanding bidirectional active and reactive power flow. Any scaling method on SDCs, emulating the entire operation of FSCs, demands underutilization of SDCs, reducing the advantages of PHIL tests. This article, therefore, proposes a physics-informed scaling method that exploits power capability curves to emulate FSCs in all four quadrants of operation. This method is independent of SDC topology, filter type, and interfacing methods. A visual identification of semiconductor device constraints bounding the emulation is also presented, utilizing the physics of converter control. A theoretical analysis of the proposed method is presented, followed by validation with MATLAB simulations and experimental tests using a 50-kVA SDC.

Abstract In this paper, an open‐circuit fault‐tolerant topology of LC‐coupling hybrid active power filter (LC‐HAPF) and its control strategy are proposed at the switch level, which can greatly improve the reliability of the system. The proposed structure has a contactor between the midpoint of each bridge arm and the negative bus of the dc‐link capacitor. When a single‐phase fault occurs, the proposed LC‐HAPF can be reconstructed into a three‐phase four‐switch system to compensate for the harmonic and reactive power, while the power quality compensation effect is hardly affected. When a two‐phase fault occurs, the operation of the normal bridge arm is not affected, and the two faulty bridge arms can suppress harmonic current and compensate for a fixed reactive power through the passive filters. When the bridge arms all fail, the whole device acts as a passive filter to suppress the harmonic current of the load and to compensate for reactive power as well. Finally, the effectiveness of the proposed topology and its control strategy is verified by simulation and experiment results.

Abstract For a sustainable system to be designed with the lowest possible cost, photovoltaic thermal (PV/T) system efficiency and heat transmission must be increased. The performance of each hybrid PV/T air system was examined using four air PV/T models with various geometric configurations. The examination of the various mathematical models revealed how each geometry configuration affected each system's performance. Air PV/T arrangements with expanded surfaces, like fins, enhance thermoelectric performance. According to the findings, the thermal efficiencies of finned absorber PV/T and finned Tedlar PV/T are, respectively, 80.3 and 77.54%. Additionally, the figures for electrical efficiencies are 11.88 and 11.93%, respectively. For these two types of PV/T systems, the annual energy output has increased and now stands at roughly 3242 and 3316 kWh/m2, respectively. Additionally, compared to other PV/T systems, the finned Tedlar PV/T system offers higher profitability in terms of cost and revenue according to an economic research.

Maintaining energy balance and economical operation is significant for energy hub (EH) which serves as the central component. Implementing real‐time regulation for heating and cooling equipment within the EH is challenging due to their slow response time in response to the stochastic fluctuation in renewable energy sources and demands while the opposite is true for electric energy storage equipment (EST), a conventional single timescale energy management strategy is no longer sufficient to take into account the operating characteristics of all equipment. With this motivation, this study proposes a deep reinforcement learning based two‐timescale energy management strategy for EH, which controls heating & cooling equipment on a long timescale of 1 h, and EST on a short timescale of 15 min. The actions of the EST are modelled as discrete to reduce the action spaces, and the discrete‐continuous hybrid action sequential TD3 model is proposed to address the problem of handling both discrete and continuous actions in long timescale policy. A joint training approach based on the centralized training framework is proposed to learn multiple levels of policies in parallel. The case studies demonstrate that the proposed strategy reduces the economic cost and carbon emissions by 1%, and 0.5% compared to the single time‐scale strategy respectively. [ABSTRACT FROM AUTHOR]

This paper proposes a novel bidirectional DC–DC converter with high voltage conversion ratio and capability of cancelling input current ripple. The proposed converter uses two coupled inductors and switched‐capacitor circuit to increase the voltage conversion ratio. The input current ripple at low voltage side can be eliminated for a pre‐selected duty cycle by adjusting special values of magnetizing inductances of coupled inductors. The input current is divided into two paths of the primary winding of coupled inductors that causes the decrease in the current stresses of switches. The proposed converter has five switches that consist the internal diodes of switches to bring about bidirectional power flow and have boost and buck operations. Here, the proposed topology is analysed in all operating modes and the current and voltage stresses of switches, input current ripple cancelling condition and voltage conversion ratio are calculated. Finally, the accuracy performance of the proposed converter is reconfirmed through EMTDC/PSCAD simulation and experimental results for boost operations. [ABSTRACT FROM AUTHOR]

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This paper introduces a dual‐input single‐output (DISO) non‐isolated DC–DC converter with the capability to accommodate multiple input ports. It supports both bidirectional and unidirectional power flows. The proposed converter employs the switched‐capacitors (SC) technique, resulting in a high‐ voltage transfer gain. Although the use of the SC technique leads to discontinuous input current, this issue has been addressed by incorporating an inductor at the input side. The DISO high‐voltage gain converter offers flexible control options, reduces current and voltage stress on semiconductors, and imposes no duty cycle limitations due to the proposed switching methods. Furthermore, when Port 2 fails, the proposed converter can transfer energy to the load by sources in Port 1 without interruption. The steady‐state model and small‐signal analysis (SSA) of the proposed converter are examined at continuous conduction mode (CCM). To evaluate accurately, the proposed converter is compared with the recently presented converters based on important characteristics. Additionally, a comprehensive power loss analysis is performed. Following the design specifications, an evaluation and testing of a prototype are conducted to verify the feasibility and performance of the converter. [ABSTRACT FROM AUTHOR]

High‐power applications with low‐voltage (LV) dc loads, for example, fast charging stations for electric vehicles (EVs), are typically supplied from the medium‐voltage (MV) grid. Aiming for low volume, MVac‐LVdc solid‐state transformers (SSTs) that provide galvanic separation with medium‐frequency transformers (MFTs) are thus considered, which are conventionally realized as two‐stage systems that consist of an ac‐dc power‐factor‐correction (PFC) rectifier and an isolated dc‐dc converter. This letter extends a new single‐stage isolated bidirectional PFC rectifier concept to MV levels, resulting in an SST that performs MVac‐LVdc conversion in a single converter stage and, unlike many modular SST concepts, employs only a single MFT. The SST's primary side operates modular‐multilevel‐converter (MMC) bridge legs, whose input voltages contain large ac components, in the quasi‐two‐level mode to minimize the cell capacitors. The secondary side employs a standard LV three‐phase rectifier, and a dual‐active‐bridge‐(DAB)‐like modulation strategy allows power flow regulation and ensures sinusoidal grid currents. The concept is explained and validated using detailed circuit simulations of an exemplary 1‐MW system operating between a 10‐kV three‐phase grid and an 800‐V dc output. The component stresses are evaluated, and an efficiency of 98.1% and a power density of up to 0.6 kW/dm3 are estimated. [ABSTRACT FROM AUTHOR]