Low Voltage Stress Research Articles

Direct maximum power injection control of grid-connected PV micro-inverter systems connected to the grid

The increasing use of fossil fuels such as gas and oil has caused many environmental problems, including air pollution, depletion of underground resources, the destructive phenomenon of global warming, destruction of the ozone layer, and many other problems for the environment. Photovoltaic systems are one of the most promising solutions to overcome these problems. Due to the low voltage of solar panels and the higher controllability of photovoltaic systems against changes in sunlight intensity during the day, DC-DC power converters are required. In this project, the aim is to design and build a DC-DC converter with the ability to provide high voltage gain at a suitable efficiency for a 1-string photovoltaic system with the ability to track the maximum power point 2. The designed converter is designed and analyzed with the ability to provide a voltage gain of 5/6 at the critical operating point, a minimum efficiency of 94%, and a power of 500 watts. This converter uses classical soft switching, so the switching losses are reduced, which in turn increases the efficiency of the converter. This converter has a lower voltage stress on the switch (4/0) than the existing techniques. On the other hand, while new converters use a large number of switches and magnetic cores in the cell to provide high gain, this converter uses the least number of switches and magnetic cores to achieve high gain. Also, the passive elements of this converter, such as inductor and capacitor, are in the order of a few microhenries and farads, and therefore the size of these components is also reduced. In addition, due to the high gain provided in lower duty cycles, the efficiency of the switch is increased, and therefore cheaper switches can be used. Also, due to the reduction in the size of passive elements, the size of the magnetic core is also reduced, which in turn optimizes the converter economically.

A new class of active impedance source inverter with low voltage stress on semiconductors

SummaryIn this paper, a new group of active impedance source inverters, along with a suitable control method based on the pulse width modulation (PWM) technique, is presented. The purpose of these inverters is to reduce the voltage stress on capacitors, diodes, and switches compared to other topologies. Using the proposed control method to produce the gate pulse of the switches, all operating modes of one of the proposed inverters, in two different operations (synchrony and asynchrony), to calculate boost factor and critical inductance in the boundary condition, are analyzed. Furthermore, all equations of voltage and current of components to design the suitable amounts of capacitors and inductors are calculated. Then, the comparative analysis from different points of view, such as boost factor, total voltage blocked by diodes and switches, and voltage stresses on capacitors between the proposed topology and conventional structures to examine the advantages and disadvantages, is done. Also, the losses and efficiency of the proposed topology at different loads are fully given. Finally, a prototype of the proposed topology is designed, and its experimental results are provided to check the performance and correctness of the obtained equations in different operating modes.

Stacked bidirectional DC‐DC converter based on classical boost/buck converter for uninterruptible power supply applications

SummaryIn this paper, a new stacked bidirectional non‐isolated DC‐DC converter for uninterruptible power supply applications is presented. It is a stacked adaptation of the classical bidirectional boost/buck converter and presents improvements such as low number of components; low voltage and current stress on components; high efficiency; and simplicity of operation. In addition, in this paper, the modeling and control of the proposed converter are done, and a comparative evaluation among proposed converter with similar topologies is evaluated. A prototype of 1 kW, 144 to 400 V, is developed in laboratory to validate the theoretical evaluations of proposed converter. Besides that, the proposed converter is also evaluated under different dynamic condition, which illustrates the effectiveness of the converter. Finally, the maximum efficiency obtained is 96.38% in step‐up mode and 95.7% in step‐down mode.

Non-Isolated High Gain Interleaved DC–DC Converter with Voltage Multiplier and Switched Capacitor for Renewable Energy Systems

A novel non-isolated high-gain DC–DC converter for green energy employment is presented and analyzed. The proposed converter comprises a switched capacitor cell, passive clamp circuit, coupled inductors, and voltage multiplier unit. An interleaved boost converter (IBC) is placed on the input side of the proposed design. The voltage multiplier unit (VMU) with the secondary windings of the coupled inductors is located on the load side. It is used to accomplish interleaved power storage. The leakage energy of coupled inductor is recirculated to the load side, and the reverse recovery problem of diodes is effectively suppressed. As a result, a low-on-state resistance power switch with a low voltage rating is employed and minimizing conduction losses. The presented topology is suitable for sustainable energy applications due to its low operating duty cycle, high voltage conversion ratio, and higher efficiency. The output voltage causes substantially low voltage stress on semiconductor switches and passive elements. This proposed paper deals with simulation, parameter selection, experimental design, results and discussion. The simulation is verified using MATLAB/Simulink with a DC voltage of 30–517[Formula: see text]V. To validate the design analysis, a 1.5-kW experimental prototype is designed with a switching frequency of 10[Formula: see text]kHz and attained an efficiency of 96.07%.

A switched-inductor switched-capacitor based ultra-gain boost converter: analysis and design

A feature known as high-voltage gain conversion is necessary for a number of applications, including photovoltaic (PV) connected systems, UPS, SMPS, and some inverter applications, specifically for the power processing of low-voltage renewable sources. This article makes a suggestion for an ultra-gain boost converter based on a switched-inductor switched-capacitor (SISC) network. Ultra-voltage gain (> 15) and lower voltage stresses across the switches are the main benefits of the proposed converter. Additionally, compared with other high-gain topologies, the number of components decreases. This paper presents a systematic analysis of the proposed ultra-gain boost DC–DC converter along with a comparison to other topologies that have been previously published in the literature. The simulation model confirmed that the efficiency of the proposed topology is 95.23%.

A single switch high gain multilevel boost converter with switched inductor topology for photovoltaic applications

This paper proposes a new transformer-less single-switch high-gain dc-dc converter for solar power systems. The suggested converter is created by supplementing the conventional boost converter with a switched inductor cell plus a voltage multiplier stage. The converter has several benefits, including a high voltage conversion ratio, reduced voltage stress on semiconducting switches and diodes, a reduction in the need for gate drivers because only one switch is used, as well as constant input current to prolong the lifespan of the photovoltaic cell. The analytical waveforms of the recommended converter can be seen in the continuous conduction mode (CCM). The analysis of voltage stress is done. In the presence of parasitic components, increased voltage gain and efficiency were also obtained.The proposed high-gain converter topology is compared to recently published high-gain converter topologies in terms of performance. Using PSIM, a high-gain dc-dc converter's performance is studied and analysed with regard to its low switching voltage stress. The suggested converter is successful in stepping up 20V to 400V at 160W power capacity, while offering a continuous input source current at 95% efficiency.

SWISS rectifier structure sector boundary current distortion suppression based on multi‐step predictive control

AbstractThe SWISS rectifier is a three‐phase BUCK type Power Factor Correction rectifier with the advantages of adjustable output full voltage range, low voltage stress in the back stage devices, and high efficiency. However, because the voltage ripple of the input filter capacitor will cause the input current deviation, the input current of the SWISS rectifier will produce distortion at the sector boundary, which will affect the system performance. To this end, a multi‐stage predictive model method based on the spherical algorithm is presented. By predicting the grid‐side capacitor voltage and the input current state of the rectifier, the harmonic injection network switching tube is controlled in advance to supplement the grid‐side capacitor voltage, so that the grid‐side capacitor voltage approximately tracks the input voltage. Meanwhile, considering the current step that may be generated after the current distortion returns to normal, which leads to the resonance problem with the pre‐stage filter, this problem is incorporated into the value function and damping is optimized according to the feedback value. Finally, a 10‐kW SWISS rectifier on the SIMULINK platform is used to verify the feasibility of the new control method.

Development of a new mixed 5-level inverter for 3 kW household photovoltaic applications

Multilevel inverters are well used in high power electronic applications (about 10 kW) because of their ability to generate a very good quality of waveforms, reducing switching frequency, and their low voltage stress across the power devices. However, inverter architecture must be modified in order to take into account the different photovoltaic (PV) problems in conventional installation. This paper presents a comparative study of 5-level Neutral Point Clamped (NPC) and a new mixed 5-level inverter. The theoretical study is validated using simulation with the LTspice environment. The output voltage and total harmonic distortion are particularly compared. An experimental 5-level inverter was realized in order to validate analytical results.

A quad DC source switched three-phase multilevel DC-link inverter topology

The concept of an isolated DC source cascaded multilevel inverter finds good solutions for generating quality output voltage for low-medium power applications. It shapes the output voltage from three levels into a number of steps closer to a sinusoidal shape using small DC sources or batteries. Several advantages have been sighted like lower voltage stress and bearing noise, and lesser THD. However, a common issue in the MLIs is the total components required which increase with the rise in voltage levels. This paper proposes a three-phase MLI design having several isolated quad voltage source modules including an H-Bridge inverter. The design suggested claims reduced switching components for current conduction paths showing improved output quality. The operational features of the suggested MLI have been analyzed using Matlab/Simulink software, furthermore, an experimental module is constructed for demonstrating the effectiveness of the simulated results.

SEPIC-Boost-Based Unidirectional PFC Rectifier with Wide Output Voltage Range

A novel unidirectional hybrid PFC rectifier topology based on SEPIC and boost converters is proposed, which is applicable to various industrial applications such as electric vehicle charging stations, variable speed AC drives, and energy storage systems. Compared to other rectifiers, the proposed SEPIC-boost-based rectifier exhibits continuous current on the AC side, lower voltage stress on the active switches, a wider range of DC output voltage, no auxiliary DC-DC converters, and a high step-up static voltage gain operating with low input voltage and a low step-up static gain for the high-input-voltage operation. These traits allow the SEPIC-boost-based rectifier to utilize smaller input-side harmonic filtering inductors and adopt active switches with lower voltage ratings, resulting in reduced conduction losses. Additionally, the proposed rectifier features power factor correction and high boost/buck voltage-gain capabilities, simplifying control for electric vehicle charging and expanding its range of applications. In this paper, the operating principle of the novel topology is presented first, and then the mathematical model of the proposed rectifier is built. Based on this, the comparison between the proposed topology and conventional boost and SEPIC converters is given. Furthermore, the control strategy, including the high-power-factor control and the balancing control to the DC capacitor voltages, is discussed. Finally, to validate the accuracy of the proposed rectifier’s theoretical research, a 500-W SEPIC-boost rectifier system has been constructed in the laboratory, generating a 200/120 Vdc output voltage from a 155 Vpk/50 Hz power source.

An asymmetrical multilevel inverter with minimum voltage stress and fewer components for photovoltaic renewable-energy system

Abstract The enhanced power quality provided by multilevel inverters (MLIs) has made them more appropriate for medium- and high-power applications, including photovoltaic systems. Nevertheless, a prevalent limitation involves the necessity for numerous switches and increased voltage stress across these switches, consequently increasing the overall system cost. To address these challenges, a new 17-level asymmetrical MLI with fewer components and low voltage stress is proposed for the photovoltaic system. This innovative MLI configuration has four direct current (DC) sources and 10 switches. Based on the trinary sequence, the proposed topology uses photovoltaics with boost converters and fuzzy logic controllers as its DC sources. Mathematical equations are used to calculate crucial parameters for this proposed design, including total standing voltage per unit (TSVPU), cost function per level (CF/L), component count per level (CC/L) and voltage stress across the switches. The comparison is conducted by considering switches, DC sources, TSVPU, CF/L, gate driver circuits and CC/L with other existing MLI topologies. The analysis is carried out under various conditions, encompassing different levels of irradiance, variable loads and modulation indices. To reduce the total harmonic distortion of the suggested topology, the phase opposition disposition approach has been incorporated. The suggested framework is simulated in MATLAB®/Simulink®. The results indicate that the proposed topology achieves a well-distributed stress profile across the switches and has CC/L of 1.23, TSVPU of 5 and CF/L of 4.58 and 5.76 with weight coefficients of 0.5 and 1.5, respectively. These values are notably superior to those of existing MLI topologies. Simulation results demonstrate that the proposed topology maintains a consistent output at varying irradiance levels with FLCs and exhibits robust performance under variable loads and diverse modulation indices. Furthermore, the total harmonic distortion achieved with phase opposition disposition is 7.78%, outperforming alternative pulse width modulation techniques. In summary, it provides enhanced performance. Considering this, it is suitable for the photovoltaic system.

An Isolated DC-DC Converter for 800 V Electric Vehicle With Wide Soft-Switching Range and Low Voltage Stress on Power Switches

An Isolated DC-DC Converter for 800 V Electric Vehicle With Wide Soft-Switching Range and Low Voltage Stress on Power Switches

Novel Scalable Topologies of High Power Density Quadratic Converters With Low Voltage Stress on Power Diode

Novel Scalable Topologies of High Power Density Quadratic Converters With Low Voltage Stress on Power Diode

Two-Switch Ultrahigh Step-Up DC–DC Converterer With Low Input Current Ripple and Low Switch Voltage Stress

Two-Switch Ultrahigh Step-Up DC–DC Converterer With Low Input Current Ripple and Low Switch Voltage Stress

Optimized Interleaved Ultra-High Gain DC-DC Power Converter With Low Ripple Input Current and Voltage Stress for Fuel Cell Systems

Optimized Interleaved Ultra-High Gain DC-DC Power Converter With Low Ripple Input Current and Voltage Stress for Fuel Cell Systems

A Dual-Layer Receiver With Low Interlayer Voltage Stress and High Power Density for EVs Wireless Charging System

A Dual-Layer Receiver With Low Interlayer Voltage Stress and High Power Density for EVs Wireless Charging System

A bidirectional high voltage ratio DC–DC topology for energy storage systems in microgrid

AbstractThis study proposes a bidirectional DC–DC converter with low voltage stress on its semiconductor elements and high voltage gain. Bidirectional DC–DC converters play a crucial role in DC microgrid systems, and they have been used for many applications such as power flow management, battery storage systems, voltage regulation, and electric vehicle (EV) charging systems. This paper proposes a novel non‐isolated, bidirectional DC–DC converter with an improved voltage gain conversion ratio. In the structure of the proposed converter, the coupled inductor provides high voltage gain and is employed to reduce the overall voltage stress across the main switches. Additionally, a filter inductor on the input‐low voltage side of the converter reduces current ripple. In addition, a single switch is used in boost mode, which simplifies control of the converter. Furthermore, two power switches receive simultaneous pulses for adjusting the buck stage voltage gain. Also, in the following, the mathematical calculations and the small signal analysis for the proposed converter are provided. Furthermore, a 200 W prototype is finally implemented, and its results are validated by the theoretical analysis.

A novel energy storage system for efficiency improvement of fuel cell electric vehicles based on a new high step-up DC-DC converter

Proton exchange membrane fuel cell systems have relatively low efficiency in low power applications and have many uncertainties. In this regard, the design of a high-efficiency battery charger for fuel cell electric vehicles has been an important issue for researchers and has attracted a lot of attention in recent years. For this purpose, in this article, in the first step, with the aim of developing a battery charger with high efficiency and low cost, a new high step-up DC-DC converter with unique features is proposed. The main advantages of the proposed converter are continuous input current, high efficiency, low voltage stress on components, less component count, and high voltage gain. To prove the advantages of the proposed converter, a peer-to-peer comparison with some existing converters has been made and results are presented. In addition, this study comprehensively presents the different operating modes for the proposed converter and provides the necessary analysis and relationships for circuit operation. In the second step, this study explains the small signal modelling for the proposed converter as well as the maximum power point tracking controller for this system. In order to validate the proposed system, the values of theoretical calculations, simulation results, as well as the experimental results of the 48V-input/220V-output prototype device are presented and the results are compared side by side.

A novel non-isolated step-down converter with low switch voltage stress

ABSTRACT This article is aimed at introducing a novel non-isolated step-down converter with superior advantages including reduced voltage stress on switching, enhanced efficiency as well as reduced number of required components. Improved distribution of voltage among several switches mitigates the stress exerted upon individual switches, thereby inflicting reduced voltage MOSFETS with smaller ON resistance. To show the superiority of the introduced converter over other converters of this kind through comparison, ON-OFF switching operations of two switches are performed under ZVS conditions, and as a result, a reduced switching loss is observed which is a proof for optimised efficiency. Finally, the design formula and simulations of the converter operating modes are discussed.

Hybrid interleaved DC‐DC step‐up converter based on coupled inductor

SummaryIn this paper, a high voltage gain hybrid interleaved DC‐DC converter (HIC) with quadratic voltage gain is proposed that is suitable for renewable energy systems. The hybrid technique is used in this converter to increase the output voltage. The proposed DC‐DC converter utilizes the interleaved boost converter on the input side, and the input current is shared with a low ripple that lengthens the lifetime of the renewable power source. In addition, the proposed converter has low voltage stress across the components that can be adopted to reduce conduction losses and the cost of the elements. In addition, the proposed converter share ground between the input and output and has high efficiency. The operation modes of the proposed converter are analyzed, and its equations are calculated. Then, the elements of the proposed converter are designed in continuous conduction mode. A comprehensive comparison of the proposed converter with other recently presented existing converters is discussed to show the advantages and disadvantages of the proposed structure. Finally, to verify the performance of the proposed converter and the obtained relations, a 400 W prototype is built to demonstrate the effectiveness of the proposed converter.