Step-down Voltage Research Articles

New single-switch buck–boost converter with continuous input/output currents and a wide conversion range

The main aim of this paper is to introduce a new high step-up/down buck-boost converter with a minimum number of switches which provides the benefit of having the continuity of the input/output current. This single-switch semi-quadratic converter is suitable for high step-up applications while being able to provide step-down voltage gains. Also, by applying some minor changes to the circuit elements, another single-switch buck-boost converter is suggested which has two operative outputs with different voltage gains. One of the outputs of this topology has quadratic buck-boost converter voltage gain which is appropriate for high step-up/step-down applications. The other output could vary from input voltage to minus infinity, ideally. After studying the steady-state operation of the proposed converters in Continuous Conduction Mode (C.C.M), the simulation results are presented. In addition, a comparison among related converters proposed in the literature is made. Finally, experimental results are evaluated by implementing a laboratory prototype of the proposed converter in both step-down and step-up modes. Theoretical, simulation, and experimental results are compatible with each other.

A new high step-down soft-switched DC–DC converter based on coupled inductor

ABSTRACT This study introduces a new non-isolated DC–DC converter capable of achieving a high step-down conversion ratio. The design reduces switching losses through soft-switching, allowing switches to operate under Zero Voltage Switching (ZVS), which enhances efficiency. The converter employs a single coupled inductor without additional inductors in the power path, achieving low voltage gain and an extended duty cycle, resulting in reduced losses, lower costs, and optimal efficiency compared to similar topologies. Voltage stress on semiconductors is minimised by recycling leakage inductance energy to the output. The proposed converter achieves a greater step-down voltage gain per component compared to similar designs. Different operational modes and design aspects are examined. A prototype was constructed, and experimental results confirmed the theoretical analysis.

Switched capacitor and coupled inductor based high power factor charger for E-2/E-3 wheelers

This paper introduces a modified Zeta converter topology designed specifically for charging low voltage electric vehicles (LVEVs), enhancing performance for electric two (E-2) and electric three (E-3) wheelers. Unlike traditional Zeta converter, which offers buck-boost gain, an AC-DC converter in this study, utilizes a switched capacitor configuration to efficiently step-down voltage in a single phase, bridging the gap between the AC grid and low potential battery assemblies. This design incorporates a coupled inductor structure and operates in discontinuous inductor current mode (DICM), reducing the size of magnetic components and overall dimensions of converter and power factor correction (PFC) rectifier. DICM operation provides intrinsic PFC and minimizes switching losses, ensuring exceptional grid-side performance with unity power factor and minimal input current harmonic distortions, while maintaining an optimal battery charging profile. The meticulously developed hardware prototype, rated at 450 W, features precise component selection and carefully designed modes of operation. Performance analysis reveals a converter peak efficiency of 94.7 %, total harmonics distortion (THD) in input current at 2.7 % under rated conditions, and near unity power factor with zero phase displacement between input voltage and current.

A Power Self-Balanced High Step-Down Medium Voltage DC Converter With Expandable Soft-Switching Range

This paper proposed a power self-balanced high step-down medium voltage dc converter with expandable soft-switching range. The proposed one features the input voltage self-balance of each submodule and the current self-balance of each MOSFET, due to the sub-modules transmitting the same power through LC-coupled branches. The LC-coupled branch provides multiple direct AC power paths from medium voltage input to load, eliminating the losses caused by conventional multi-stage transmission. Each submodule of the proposed converter is a soft-switching unit that uses an auxiliary inductor to achieve soft switching, which reduces the resonant current and facilitates the expansion of the number of modules, without redesigning the transformer, instead of the conventional resonant converter that reduces the transformer magnetizing inductance to achieve soft-switching. Moreover, an auxiliary power supply scheme for the proposed converter is provided, which is used to solve the problem of difficult startup of the medium voltage DC converter, where the negative impedance characteristics of the series-connected auxiliary power supply are suppressed without the need for lossy voltage sharing resistors. A prototype with 1kV dc input and 100V/1kW output is built to verify the feasibility of the proposed topology.

Synthesis of a Discontinuous Control Law for a Step-Down Voltage Converter

Synthesis of a Discontinuous Control Law for a Step-Down Voltage Converter

Wide voltage range and low current ripple bidirectional DC/DC converter

ABSTRACT Along with the prosperous growth of battery energy storage system being applied in renewable energy system, wide voltage range regulation and low current ripple bidirectional DC/DC converters attract much attention of researchers. Based on a basic boost–buck converter and voltage multiplying unit (VMU), this article proposes a two-stage DC/DC converter. The front stage is an input parallel output serial connected boost–buck converter and the back stage contains a dual-coupled inductors VMU. The storage inductors of the front stage aremagnetically coupled with those in back stage. Employing dual coupled inductors VMU can increase voltage gain while not increasing main switch voltage stress during step-up mode, which can widen the application scenarios. During step-down mode, a fully controlled method can obtain a greater step-down voltage ratio. Due to the interleaving control mode of the main switches, the current ripple of the battery side is lower when the converter works bidirectionally. The proposed converter has the advantages of widening voltage range regulation and lowering current ripple while avoiding extreme switch duty cycle. This article discusses theoretical step-up and step-down work mode of the proposed converter. Experimental results sampled from a 12 V/115 V prototype are presented to verify the analysis of the proposed converter.

Synthesis of a Discontinuous Control Law for a Step-Down Voltage Converter

This paper presents a nonlinear discontinuous control law that allows stabilizing the output voltage of a step-down voltage converter in conditions when the input voltage and load current are unknown. The main idea is based on the use of the so-called vortex algorithms, which ensure invariance with respect to external unmatched disturbances. The efficiency of the developed algorithms is shown by numerical simulation.

An Extendable Bidirectional High-Gain DC–DC Converter for Electric Vehicle Applications Equipped With IOFL Controller

High gain bidirectional dc-dc converters are so popular in many applications such as drives, photovoltaic systems, Electric Vehicles (EV) and etc. This paper proposes an extendable bidirectional common-ground dc-dc converter suitable for high gain applications such as EVs. The proposed converter uses fewer number of switches to provide high step-up and high step-down voltage converting capabilities in both power flow directions. Since the input and output of this converter share the same ground, the electromagnetic interface (EMI) is alleviated. In order to assess the versatility of the proposed dc-dc converter and to achieve a fast response, by equipping this converter with an Input-Output Feedback Linearization (IOFL) controller, its performance is analyzed in EV applications. To this end, the steady state calculations are worked out for both charge and discharge directions, then dynamic analysis and control design is presented based on nonlinear controller by IOFL. Simulation and experimental results are provided to prove the feasibility of the proposed converter.

A Coupled-Inductor-Based Nonisolated DC-DC Converter With High Step-Down and Wide Input Voltage

In the data center applications, the bus converter not only needs to achieve high step-down gain but also can keep stable output for data back-up when the bus voltage drops dramatically due to fault. Thus, a coupled-inductor-based nonisolated DC-DC converter with high step-down and wide input range is proposed in this paper. The proposed converter utilizes the coupled inductor to obtain the high step-down capability and the series-capacitor to achieve zero voltage switching and zero magnetizing currents, which can help reduce switching loss and core loss. Thanks to the feature of the voltage gain, lower conduction loss at low input voltage and wider input voltage can be ensured. The feasibility of the converter is verified by detailed theoretical analysis and a prototype with the 36∼60V input voltage, 3.3V output voltage, and the 1∼10A output current. The efficiency of the prototype can be maintained above 90% under all conditions, and the peak efficiency is 95.8%.

A Fully-Integrated Micro-Display System With Hybrid Voltage Regulator

A fully-integrated active matrix light-emitting diode (AMLED) micro-display system is demonstrated in this paper. The system consists of a 36 × 64 AMLED array chip based on GaN-on-Silicon epilayers and a silicon driving chip integrating an on-chip hybrid voltage regulator, pixel drivers, and peripheral circuits. Then two chips are bonded with low-cost Au-free flip-chip bonding technology. As such, this system is able to directly operate with a battery without any external passive components. Multiple techniques were proposed to achieve the system integration: (1) A fully-integrated hybrid voltage regulator consisting of a step-up switched-capacitor (SC) converter cascaded by a step-down linear voltage regulator was fabricated in a 0.18 μm CMOS technology. It achieved only 1.38% output voltage ripple without external capacitors, and be able to deliver a maximum power of 216mW with peak efficiencies of 91% in the linear mode and 78% in the SC mode; (2) Micro-LEDs are fabricated on GaN-on-Silicon substrate that significantly suppresses the light crosstalk between pixels and reduces the cost; (3) An Au-free flip-chip bonding technique is developed to reduce the bonding cost and achieved reliable connections between AMLED array chip and silicon driving chip. The whole system achieved 635 pixel/in (PPI) pixel density. Images and videos with 4-bit grayscale could be rendered. This prototype achieved a high integration level and demonstrates the tremendous potential of the highly efficient, low cost fully integrated AMLED micro-display system.

Design and Construction of a Modified SMS-Based Electronic Notice Board

This research aims to design and construct an electronic notice as an alternative to the traditional signpost parting on walls and billboards by providing practical, reliable and proper information dissemination. They consist of the following units, the power supply, voltage regulators, GSM modules, microcontroller, LED dot matrix display board, counter and subscriber identity module (SIM). The power supply comprises a 240/9 v ac 50 Hz step-down transformer rectifier filter and voltage regulations. AT89852, a low-power, high-performance CM05 8-bit microcontroller with 8 k bytes in-system programmable flash memory, is used in this design. A constant five v de is required to power microcontrollers and their associated input/output channel. GSM Modern is a wireless device that works with a GSM wireless network. The counter circuit of the device used to achieve this type of counting is the 5-stage Johnson decade counter. It is a typical chip in the 74HC555, with ten decoded outputs that go high one at a time. The assembler used for this research is MLAB version 5.7, downloaded from the microchip website. This window-based integrated development environment (IDE) software supports the PIC and other microcontrollers. The project constitutes both the software and hardware section for successful implementation. Operation more focus was given to the contribution of the system hardware. For verification of proper functionality of the message board, variation tests carry out and their results. Each component was carefully tested, and hardware troubleshooting and software debugging were carried out. The message was sent, and it appeared and started moving from left to right. In conclusion, by introducing the concept of wireless technology in communication, we can make our communication more efficient and faster with excellent efficiency, and the message can be displayed with less error and maintenance. This model can be used efficiently in establishments like colleges where in-order and special discounts can be displayed simultaneously at all branches. It is therefore recommended as a conventional model can say more than one message at a time LEDS have a limitation on size and a good number of characteristics. These can be replaced with large LED display boards, which not only catch bulb display attributes in a moving position one after another.

The Design of 2S2L-Based Buck-Boost Converter with a Wide Conversion Range

This manuscript proposes a novel nonisolated negative output buck-boost converter topology for wide voltage conversion applications. To design this converter, a typical buck-boost converter configuration is used. In conventional buck-boost converter, the active switches designed are replaced by two switches-two inductors (2S2L) cells. The proposed converter operates in the continuous conduction mode (CCM) operation under steady-state conditions. This converter has a lower component count and low voltage stress on the switches and diodes. Moreover, the major advantage of this buck-boost converter topology is that a wide range of step-down and step-up voltage conversions can be achieved. The performance of the proposed system is designed in MATLAB/SIMULINK. A few other comparisons are also presented to demonstrate the competitiveness of the proposed buck-boost converter.

A Wide Conversion Ratio Bidirectional Modified SEPIC Converter with Non dissipative Current Snubber

This article presents a wide conversion ratio bidirectional dc-dc converter based on a bidirectional modified Single-ended primary-inductor converter (SEPIC converter). A key feature of this modified SEPIC converter is the non-dissipative current snubber circuit, which is used to achieve zero current switching and to suppress voltage spikes that occur during MOSFET switching. The snubber is made up of a capacitor, an inductor, and a diode that work together to form a resonant circuit that absorbs the voltage spike and returns it to the circuit without dissipating it. Even with conventional MOSFETs, high efficiency is achieved. The SEPIC converter differs from other bi-directional DC-DC converters in that it provides continuous output current, has fewer components, and can provide high conversion ratios of step-up and step-down voltage without exceedingly low or high duty-cycle. This paper presents a theoretical analysis with stages of operation in both step-up and step-down modes, theoretical waveforms, and the design procedure, as well as a comparison with other bidirectional dc-dc converter topologies. The experimental results are presented to validate the performance of the proposed converter using a 500-W prototype with Voltage Source V1 = 48 V and Voltage SourceV2 = 300 V.

A High Frequency Multiphase Modular Hybrid Transformerless DC/DC Converter for High-Voltage-Gain High-Current Applications

In order to meet the demands of desirable efficiency, transformerless DC/DC equipment with great voltage step-down are inevitable needed. This research offers a unique type of high-frequency, high-voltage-gain DC/DC converter, which comprises a switched capacitor (SC) converter and a buck converter. Thanks to the transformation of a two-stage converter to a single-stage converter, it has a considerable ratio of step-down voltage transformation and a reasonable duty cycle. In addition, it can permit low voltage stress on the switches. The simple control method and easy driving circuit implementation makes it scalable for high-power-level devices. Low cost can be realized as fewer components are needed. Under all operational circumstances, total soft-charging and low equipment voltage stresses are accomplished. Compared to those classic high-voltage-gain converters, the proposed converter exhibits merits of higher efficiency, higher flexibility, lower ripples, and lower costs. A comprehensive analysis is carried out for the converter’s steady-state operations. With a 1 MHz switching frequency, a 900 W prototype of a 20-time converter is constructed, with a peak efficiency of 92.5%. Simulations and experiments verify the effectiveness of the theoretical investigation of the converter’s operation.

A New Tapped Inductor Buck Converter with Large Step-Down Voltage Conversion

This paper presents a new DC(DC converter with large step-down voltage conversion. The proposed converter is obtained by cascading an input circuit of a Quadratic Buck Converter (QBC) to a Tapped Inductor Buck Converter (TIBC). It uses only one active switch and provides a wider voltage conversion range than other well-known step-down converters. In the paper, the operation of the proposed converter is described. Circuit analysis is performed to derive the voltage gain and key current and voltage equations. The prototype circuit operating with the input voltage of 150 V, the output voltage of 5 V, the load current of 10 A and the switching frequency of 100 kHz is implemented. Experimental results show that the prototype converter exhibits good output voltage regulation and achieves the 30-to-1 voltage step-down operation with a maximum efficiency of 82%. In addition, measurement results confirm that the converter operation is consistent with the theoretical analysis.

Fully Soft-Switched Non-Isolated High Step-Down DC–DC Converter With Reduced Voltage Stress and Expanding Capability

In this article, a fully soft-switched expandable high step-down dc–dc converter is presented. In order to achieve a high step-down voltage conversion ratio and low component count, the synchronous buck and Cuk converters are integrated. Lower switches’ voltage stress is realized by splitting the input voltage, which can considerably decrease the switches’ conduction loss. Moreover, switching losses along with the reverse recovery problems are mitigated due to the soft-switching operation of all semiconductor devices. The switch utilized for soft-switching operation is also used to replace the output diode as a synchronous rectifier, which reduces the conduction loss. The mentioned features have considerably contributed to the converter efficiency. Furthermore, the converter shares a common ground between the input and the output, which is desirable in many applications, while the converter output current is continuous without adding current ripple cancellation methods. Finally, the number of converter cells can be expanded or reduced; therefore, the converter can be applied to a wide range of loads. The operating principles and analysis of the proposed converter are presented, and the results from the implemented prototype are provided to verify the converter operation and performance.

Biocompatibility Analysis of GelMa Hydrogel and Silastic RTV 9161 Elastomer for Encapsulation of Electronic Devices for Subdermal Implantable Devices

The natural differences between human-made electronics and biological tissues constitute a huge challenge in materials and the manufacturing of next-generation bioelectronics. As such, we performed a series of consecutive experiments for testing the biofunctionality and biocompatibility for device implantation, by changing the exterior chemical and physical properties of electronics coating it with silicone or hydrogels. In this article, we present a comparison of the main characteristics of an electronic device coated with either silicone or hydrogel (GelMa). The coating was performed with a bioprinter for accurate silicone and hydrogel deposition around different electronic chips (Step-Down Voltage Regulator U3V15F5 from Pololu Corporation). The results demonstrate that the hydrogel coating presents an augmented biomechanical and biochemical interface and superior biocompatibility, lowers foreign body response, and considerably extends the capabilities for bioelectronic applications.

An Ultrahigh Step-Down DC–DC Converter Based on Switched-Capacitor and Coupled Inductor Techniques

In this article, high step-down dc–dc converters are widely employed in data center applications. Due to the higher step-down conversion ratio in the new generation 48 V voltage regulator module, a conventional buck converter is not suitable for such applications. To conquer this problem, a novel dc–dc converter is proposed in this article to achieve an ultrahigh step-down voltage conversion ratio for data centers. The nonisolated topology can be optimally designed to integrate both the switched-capacitor and coupled inductor techniques, which allows zero-voltage-switching (ZVS) of all active switches to be achieved and improves high efficiency. In addition, the converter presents the advantages of lower voltage stress, ultrahigh voltage gain, common ground, and simple control strategy. A comprehensive analysis of the steady-state analysis, derivation of voltage gain, voltage stress, and ZVS condition is presented in detail. Finally, a 30 W, 48-to-1 V experimental prototype is built and tested, which validates the ultrahigh step-down voltage gain and soft-switching characteristic of the proposed converter. The maximum efficiency of the prototype is 89.1% and the efficiency is 81.4% in full-load condition.

Non-Isolated Power Factor Corrected AC/DC Converter with High Step-Down Voltage Ratio for Low-Power Applications

This paper proposes a high step-down ratio AC-DC converter employing a quadratic buck converter with power factor correction. Conventional active power factor correction topologies employ boost-based correction schemes for unity power factor operation. This will require a steeper step-down ratio and higher switch voltage stress apart from complexity in the control scheme with sensors. The structure of the proposed topology is developed by combining the power factor correction stage with a high step-down stage. The passive input filter is split up into two for the purpose of reducing the thermal heating apart from offering a higher power factor. A single switch operation reduces the complexity of the control scheme. In addition, the number of conducting devices during the current path is also the same as the conventional buck converter due to cascading and hence offers lower conduction losses. The need for the converter to operate at an extremely low duty cycle is reduced due to the quadratic stage structure. The proposed converter operates at a moderate duty cycle, offering higher step-down voltage apart from reducing filtering requirements. MATLAB R2020b is used for carrying out simulation studies. Xilinx FPGA-based controller using system generator is implemented for the generation of pulses of appropriate duty cycle. Simulation and experimental results for a 150 W prototype are presented. An investigation and comparative evaluation of the conventional bridgeless buck system with the quadratic buck converter are carried out. The proposed structure offers the benefit of a higher step-down voltage ratio incorporating an inherent power factor correction stage along with the AC/DC stage.

High Step-Down Bridgeless Sepic/Cuk PFC Rectifiers With Improved Efficiency and Reduced Current Stress

In this article, two high step-down bridgeless power factor correction rectifiers based on the switched inductor network (SIN) are introduced. The proposed rectifiers employ the SIN to provide high step-down voltage gain with a higher duty cycle than the competitors. They also offer higher efficiency, lower current stress, and total peak switching device powers. A thorough and straightforward design algorithm in the discontinuous conduction mode is provided that ensures a unity power factor and a low total harmonic distortion with a simple control scheme. As a demonstration of the superior performance of the proposed rectifiers, a 300-W high-gain sepic rectifier setup with 48V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc</sub> output voltage from a 230V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</sub> /50Hz source is built in the laboratory.