High-efficiency DC-DC Converter Research Articles

A High-Efficiency DC-DC Converter Based on Series/Parallel Switched Inductor Capacitors for Ultra-High Voltage Gains

A high-efficiency DC-DC converter employing a modified architecture called the hybrid switched inductor–capacitor series (MHSLCS) is proposed in this paper. The primary goal is to achieve a notably ultra-high voltage gain for renewable energy systems (RESs). Furthermore, the use of only one input capacitor in the MHSLCS eliminates pulsations in the input current at both low and high duty ratios. The proposed converter integrates the MHSLCS with a modified switched capacitor (MSC) that interleaves with the main MOSFET, effectively doubling the voltage transfer gain. Additionally, a modified hybrid switched inductor–capacitor parallel (MHSLCP) is incorporated in parallel with an interleaved auxiliary MOSFET. Both MOSFETs, combined with the MSC, contribute to achieving an ultra-high voltage gain. In addition, the inductors of the MHSLCP operate in a discontinuous conduction mode (DCM), which results in significant stress reductions in the power diodes and switches at high output voltages. The advantages of the proposed converter are multifaceted, demonstrating a high efficiency while minimizing the voltage in power device diodes and MOSFETs. The use of low inductance and capacitance values at high switching frequencies further enhances the performance. Wide-bandgap (WBG) power devices are employed to achieve the desired high voltage gain and efficiency. The proposed converter was designed with a PCB and underwent experimental testing to validate laboratory results. The proposed converter boosted the input voltage from 30 V to a variable output voltage between 325 V and 500 V, with a power output of 325 watts and an efficiency of 95.5%.

Modified SEPIC DC-DC Converter with Wide Step-up/Step-down Range for Fuel Cell Vehicles

The high efficient buck-boost DC-DC converter with wide step-up/step-down range is the way to solve the issue of voltage matching for commercial fuel cell vehicles with a strong hydrogen-electric hybrid. Based on the conventional SEPIC converter, the negative of one of the capacitors is connected with the negative of the power source to get more energy. A modified SEPIC buck-boost DC-DC converter with the advantages of wide voltage conversion range, continuous input current, common ground, and high conversion efficiency is proposed in this paper, meeting all the requirements of DC-DC converters for commercial fuel cell vehicles. On the basis of the steady-state analysis and comparison, the controller is designed based on the small-signal model. To verify the efficiency of the proposed converter, experimental prototypes are built using Si-based and SiC-based devices respectively. The experimental results show that the proposed buck-boost converter can effectively realize 2/3 times step-down and 5 times step-up. When disturbance and voltage dip occur, the adjust time of the control system is less than 200ms. The controller is verified to be robust and have fast responses. The maximum calculation, simulation and experimental efficiencies all exceed 96%, and the maximum efficiency of the SiC prototype under rated power is 96.1%.

Design and development of modified high efficient high gain DC-DC converter for SPV standalone systems

<p class="MDPI17abstract"><span lang="EN-US">A conventional DC-DC converter is not viable for power conditioning in standalone solar photovoltaic applications. Switching losses are the primary reason for the poor performance of conventional DC-DC converters. To mitigate the issues in conventional DC-DC converters, a high efficient high gain (HEHG) DC-DC converter is designed and developed in this research work. Modified HEHG converter utilizes the passive components switched capacitors, coupled inductor, and resistor capacitor (RC) snubber circuit for minimizing the switching losses and improving the overall power conversion efficiency of the solar photovoltaic (SPV) system. In addition, a modified <br /> D-sweep maximum power point tracking (MPPT) algorithm is in-corporate into this system to improve the tracking efficiency of the SPV system. HEHG for a standalone system is designed using MATLAB/Simulink environment and developed the hard-ware prototype. As a part of the validation, real-time testing is carried out and compares the performance of the HEHG converter with a traditional DC-DC converter. The theoretical efficiency of the HEHG converter is 96.01%, and the real-time efficiency is 95.62%. Found that theoretical and practical values of performance parameters are closely tallying.</span></p>

Research on High-Performance Multiphase DC–DC Converter Applied to Distributed Electric Propulsion Aircraft

The performance of power converter of electric propulsion aircraft (EPA), which should have high efficiency, high power density and high reliability, affects the volume, weight and efficiency of the whole electric aircraft (EA). This paper proposes a novel DC-DC converter with gallium nitride (GaN) transistors. Firstly, the working modes and main operation waveforms of the converter are analyzed. The new converter can achieve ZVS and ZCS through auxiliary soft switch branches. Compared with the traditional Buck-Boost converter, the soft switching capability of the proposed converter allows operation at very high frequency and has a higher efficiency. The multiphase interleaving magnetic integration technology is adopted to realize the modular design, which not only meets the requirements of high power and low ripple, but also eliminates right half-plane zero in boost mode, achieves high dynamic response and improves the power density. A novel parallel multiphase inverse coupled inductor (ICI) and a symmetrical array ICI are proposed, to allow a high-density and high-efficiency bidirectional DC-DC converter design for hybrid energy storage system of EPA. Finally, the proposed ICI prototype was compared with the state-of-the-art commercial ICI product, and the comprehensive performance of the converter was verified through steady-state, transient, efficiency and thermal experiments.

The Design of 24V DC to 400V DC Converter with Pure Sine Wave Inverter

The demand for high-efficiency DC-DC converters is growing rapidly, especially for use in batteryoperated. To increase the supply DC input from power sources such as batteries, solar panels, and output from rectifiers, DC supplies, or DC generators, boost converters are used. This research designed a 24 VDC to 400 VDC voltage booster, tested using a 220 Vac amplification inverter system with an output of 220 Vac. The EGS-002 inverter used in this research was equipped with a Sinusoidal Pulse Width Modulation (SPWM) driver, a method that produces an output signal in the form of a pure sinusoidal wave. The test was carried out by connecting the inverter circuit directly with a voltage booster circuit in the form of a 400VAC step-up transformer to produce 24 VDC input and 50-400VDC output voltages. The length, width and height of the voltage booster are 55 cm x 35 cm x 15 cm, equipped with a cooling fan consisting of a 24V battery charger, and 4 VDC output terminals.

A High-Step-Up Low-Ripple and High-Efficiency DC-DC Converter for Fuel-Cell Vehicles

A high efficiency dual active bridge with coupled inductor (DABCI) for fuel cell vehicles is proposed in this article and its operation principle is analyzed to reveal the optimal operation modes of this converter, which provides the basis for circuit parameters design. Compared with dual active bridge, the DABCI is more suitable for high voltage gain applications because its low voltage bridge works like interleaved boost circuit and it is easy to get high voltage gain by adjusting the duty cycle D. In order to reveal the best operation mode of the DABCI, an optimal current stress modulation strategy is proposed, which can realize zero voltage switching operation in wide load range for all switches. Furthermore, the input current ripple is suppressed by interleaving two boost circuits in low voltage bridge, which can extend the life span of fuel cell vehicles. In addition, advanced magnetic integration technology is adopted to improve the system power density. Finally, a 4-kW rated prototype is made and experimental results are presented to verify the previous analysis.

High Efficiency and Voltage Conversion Ratio Bidirectional Isolated DC-DC Converter for Energy Storage System

This paper proposes a high efficiency and conversion ratio bidirectional isolated DC-DC converter with three-winding coupled inductor, which can fulfil storage system charging and discharging. The proposed topology is improved from traditional Buck-Boost converter. By integrating coupled inductor and switched-capacitor into power stage, the proposed converter can achieve the merits of isolation and bidirectional power flow. The proposed topology has only four switches and a common core coupled inductor, which greatly reduces design costs and achieves high step-up/step-down voltage gain without excessive duty cycles or high turns ratios. In addition, the proposed also has the function of leakage inductance energy recovery, which can recover all the energy stored in the leakage inductance to improve efficiency, and the main switches has a zero voltage switching (ZVS) feature. This paper implements a 500 W converter to verify the feasibility of the proposed topology through software simulation and experiment results, and conducts theoretical analysis, formula derivation, operation principle analysis, and non-ideal analysis. Finally, the experimental results show that the highest efficiency of the step-up and step-down modes are 96.8% and 96.4%, respectively.

A CMOS SoC for Wireless Ultrasonic Power/Data Transfer and SHM Measurements on Structures

This paper describes a highly-integrated CMOS system-on-chip (SoC) for active structural health monitoring (SHM). The chip integrates ultrasonic power and bidirectional half-duplex data transfer, a power management unit (PMU), and an ultrasound transceiver to enable wireless ultrasonically-coupled sensor SHM networks on structures. The PMU includes an active bias-flip rectifier with off-delay compensation, a high-efficiency dual-path DC-DC converter with inductor time-sharing, and five switched-capacitor DC-DC converters to generate multi-level spectrally band-limited pulses for guided-wave SHM. The chip was fabricated in a standard 180 nm process and has a die area of 2 × 2 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Test results show power conversion efficiency (PCE) > 85% for the active rectifier, > 70% for the inductive DC-DC converter, and > 60% for the switched-capacitor DC-DC converters. Output pulses have a peak-to-sidelobe ratio (PSL) > 30 dB and worst-case out-of-band emissions < -30 dB, respectively. The SoC was integrated with a low-power microcontroller and passive components to realize miniaturized (15 mm × 30 mm) wireless SHM nodes. A set of nodes was deployed on an SHM test-bed (carbon fiber reinforced polymer sheet) representing an airframe panel. Tests on this wireless network confirm both long-range ultrasound power/data transfer and the ability to detect structural damage.

Analysis and Design of High-Efficiency Modular Multilevel Resonant DC-DC Converter

This paper demonstrates a high-efficiency modular multilevel resonant DC-DC converter (MMRC) with zero-voltage switching (ZVS) capability. In order to minimize the conduction loss in the converter, optimizing the root-mean-square (RMS) current flowing through switching devices is considered an effective approach. The analysis of circuit configuration and operating principle show that the RMS value of the current flowing through switching devices is closely related to the factors such as the resonant tank parameters, switching frequency, converter output voltage and current, etc. A quantitative analysis that considers all these factors has been performed to evaluate the RMS current of all the components in the circuit. When the circuit parameters are carefully designed, the switch current waveform can be close to the square waveform, which has a low RMS value and results in low conduction loss. And a design example based on the theoretical analysis is presented to show the design procedures of the presented converter. A 600 W 48 V-to-12 V prototype is built with the parameters obtained from the design example section. Simulation and experiments have been performed to verify the high-efficiency feature of the designed converter. The measured converter peak efficiency reaches 99.55% when it operates at 200 kHz. And its power density can be as high as 795 W/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> .

Variable switching frequency control for efficient DC-DC converter

A load adaptive high efficiency dc-dc converter with optimized switching control is proposed in this paper. The converter is controlled through the switching frequency auto-tuning over a full range of load changes. It presents the latest algorithm to adapt the loading condition while keeping the output voltage constant. The algorithm is employed with a low-cost microcontroller having the capability to maintain dynamic performance through DPWM operation. In different operational conditions and with varying parameters, the converter continually retains the higher switching frequency. This proposed AFO (Adaptive frequency Optimization) controller performance is presented through simulation and results are also verified on a 100 W DC-DC converter.

Efficient Non-Isolated DC-DC Converter Using Variable Switching Frequency Control

A load adaptive high efficiency dc-dc converter with optimized switching control is proposed in this paper. The converter is controlled through the switching frequency auto-tuning over a full range of load changes. The load current tracking using a single current sensor is implemented with real-time computation of the desired switching frequency. It presents the latest algorithm to adopt the loading condition while keeping the output voltage constant. The algorithm is employed with a low-cost microcontroller having the capability to maintain dynamic performance through DPWM operation. In different operational conditions and with varying parameters, the converter continually retains the higher switching frequency. This proposed AFO (Adaptive frequency Optimization) controller performance is presented through simulation using MATLAB/SIMULINK and results are verified on a 100W DC-DC converter.

A Multistage Resonant DC–DC Converter for Step-Up Applications

Resonant switched capacitor converters are a viable option for high-efficiency dc-dc converters. This article proposes a generic multistage resonant switched capacitor converter (MSR-SCC) for step-up applications. This article studies the performance of the MSR-SCC using a systematic approach both above and below the resonant frequency, which results in zero-voltage switching and zero-current switching, respectively. It also proposes a control algorithm to regulate the output voltage of the converter in both operating conditions. To validate the proposed analysis and control algorithms, an MSR-SCC is simulated and experimentally implemented with GaN switching devices, which enable converter operation at lower conduction losses and higher switching frequencies.

High frequency and high efficiency DC-DC converter with sensorless adaptive-sizing technique

High frequency and high efficiency DC-DC converter with sensorless adaptive-sizing technique

Research on Digital Synchronous Rectification for a High-Efficiency DC-DC Converter in an Auxiliary Power Supply System of Magnetic Levitation

In this paper, a new auxiliary power supply system of magnetic levitation based on the LLC DC-DC converter is proposed. The switches of the DC-DC converter are SiC MOSFET, which enables high frequency, high temperature, and high power density. For further improving the efficiency of the system and realizing the stability of the output voltage under different load conditions, the digital synchronous rectification (DSR) based on the phase shift control strategy is proposed. The prototype of the LLC DC-DC converter based on SiC MOSFET is implemented, which can realize zero voltage switching (ZVS) and zero current switching (ZCS). Then, the thermal image of DSR is presented, which proves that the power loss of SiC MOSFET with DSR is relatively low. Additionally, the system efficiency among the Si IGBT, SiC MOSFET, and SiC MOSFET with DSR is analyzed and the prototype demonstrates 98% peak efficiency. Finally, simulations, experiments, and data analysis prove the superiority of the proposed DSR strategy for the new auxiliary power supply system of magnetic levitation.

High Efficient DC-DC Converter with Low-Input Ripple

The depletion of fossil fuel reserves and increased energy demand led to search of renewable energy resources. There are various renewable sources are available. Among these, the solar PV is most commonly used. In this paper a high efficient converter has been deliberated. There are two stages of conversion. In first stage, large conversion ratio with low potential stress on converter switch is accomplished. In second stage, the conversion rate of the converter is further improved with reduced conduction losses. A cuk regulator integrated through Boost and SEPIC converter based topology has been presented. The design parameters of proposed switched mode regulator topology has discussed and results are verified with MATLAB simulation

High‐efficiency soft‐switching step‐up DC–DC converter derived from a synchronous boost converter

This study presents a high-efficiency soft-switching step-up DC-DC converter. The proposed converter achieves zero-voltage switching of power switches and zero-current switching of the output diode. Also, it has improved the voltage conversion ratio. Moreover, the switch voltage stress can be lowered than the output voltage. Hence, improved efficiency, especially at full load, is achieved. The operational principle and detailed analysis of the proposed converter are given. The performance of the proposed converter is verified by testing a prototype converter implemented in the laboratory on an output 200 V-200 W.

Performance Measures of Positive Output Superlift Luo Converter Using Multitudinous Controller

In order to meet the increase in energy demand globally it is necessary to harness renewable energy at its maximum potential for the purpose of electric power generation. For the achievement of high output voltage and efficiency DC-DC converters plays a vital role in low voltage PV array and fuel cells. LUO converters are gaining importance because of geometric progression output. . LUO converters find its application because of high transient performance of the system, high power transfer gain, efficiency and reduced ripple .Because of load and line disturbances the output voltage of DC-DC converter must be operated in closed loop mode. This paper interpolates multitudinous controller for positive output elementary super lift LUO converter (POESLL). The pursuance of the converter under manifold such as variation in input, load are developed and compared for current mode controller and SMC.

A high-efficient and fast-transient buck-boost converter using adaptive direct path skipping and on-duty modulation

This paper proposes a high-efficient and fast-transient buck-boost DC-DC converter for battery-powered mobile devices. The proposed converter employs an adaptive direct path skipping to minimize the switching losses caused by power transistors, and thus enhances the power efficiency and extends the usage time of the mobile device. It also adopts an on-duty modulation to achieve a fast line transient response, thereby rapidly regulating its output voltage. The proposed buck-boost converter was fabricated using 0.18-μm CMOS process technology with 1.8 V and 6.0 V CMOS devices. The measurement results show that the maximum power efficiency is achieved up to 97.6% at a load current of 100 mA. In addition, the measured line transient response is 155 μs/V.

High Efficiency Dc-Dc Converter for Renewable Energy Applications and High Voltage Gain with Less Losses

High Efficiency Dc-Dc Converter for Renewable Energy Applications and High Voltage Gain with Less Losses

A high-efficiency DC-DC converter with LC resonant in the load-side of HFT and voltage doubler for solar PV systems

This paper presents the implementation of a prototype phase-shift soft-switching full-bridge PWM DC-DC power converter isolated by a high-frequency transformer (HFT). This circuit topology is based on a new concept of series resonant principle in the secondary side. The step-up HFT and the voltage doubler rectifier make this circuit suitable for low-voltage renewable sources such as fuel cell or PV applications. Meanwhile, all semiconductor switches can achieve zero-voltage soft-switching (ZVS) with the assistance of transformer leakage inductances and lossless capacitive snubbers. The new contribution of this work is that the passive semiconductor switches (diodes) on the secondary side can also perform ZVS and zero-current switching (ZCS) transitions with the assistance of voltage doubler capacitance. The theory of operation and the experimental setup of the proposed circuit with a rated output of 5 kW are presented and discussed. A comparison between simulation and experimental results is explored and illustrated.