A bridgeless CUK PFC converter with positive output voltage

The output voltage of the traditional CUK PFC converter is negative, and an additional inverting amplifier circuit is needed, which increases the volume and cost of the converter. A new type of bridgeless CUK PFC converter topology is proposed in this paper, which makes the converter have a positive output voltage without the need of an additional inverting amplifier circuit, and has the advantages of simple control, high efficiency, and low cost. Through topology optimization, one input capacitor is reduced, and the two diodes are converted from the high-current working state of high frequency to low-current working state of power frequency, ordinary rectifier diodes can be selected instead of fast recovery diodes, thereby reducing the volume and cost of the converter. The converter works in DCM, so no current control loop is required, which simplifies the control circuit. In addition, the main switch is turned on under ZVS condition, and the output diode is turned off under ZCS condition, which reduces the switching loss and improves the efficiency of the converter. A simulation model was built in PSIM, and a prototype with a rated power of 150 W was fabricated to verify the effectiveness and superiority of the proposed converter. Experimental results show that the PF of the proposed converter is 0.995 7, and the input current THD is 3.78% under rated input conditions.

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High Efficiency Buck-Boost Converter with Three Modes Selection for HV Applications using 0.18 μm Technology

ECTI Transactions on Electrical Engineering, Electronics, and Communications ◽

10.37936/ecti-eec.2020182.222580 ◽

2020 ◽

Vol 18 (2) ◽

pp. 137-144

Author(s):

Fouad Farah ◽

Mustapha El Alaoui ◽

Abdelali El Boutahiri ◽

Mounir Ouremchi ◽

Karim El Khadiri ◽

...

Keyword(s):

Power Conversion Efficiency ◽

Conversion Efficiency ◽

Output Voltage ◽

High Efficiency ◽

Power Conversion ◽

Boost Converter ◽

Current Control ◽

Voltage Range ◽

Operating Modes ◽

Soft Start

In this paper, we aim to make a detailed study on the evaluation and the characteristics of the non-inverting buck–boost converter. In order to improve the behaviour of the buck-boost converter for the three operating modes, we propose an architecture based on peak current-control. Using a three modes selection circuit and a soft start circuit, this converter is able to expand the power conversion efficiency and reduce inrush current at the feedback loop. The proposed converter is designed to operate with a variable output voltage. In addition, we use LDMOS transistors with low on-resistance, which are adequate for HV applications. The obtained results show that the proposed buck-boost converter perform perfectly compared to others architecture and it is successfully implemented using 0.18 μm CMOS TSMC technology, with an output voltage regulated to 12V and input voltage range of 4-20 V. The power conversion efficiency for the three operating modes buck, boost and buck-boost are 97.6%, 96.3% and 95.5% respectively at load current of 4A.

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New Type of Distributed Biomass Combustion Device Necessity and Feasibility in China

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.4013 ◽

2011 ◽

Vol 383-390 ◽

pp. 4013-4016

Author(s):

Chang Le Pang ◽

Li Chen ◽

Ren Jie Dong

Keyword(s):

Rural Areas ◽

High Efficiency ◽

Low Cost ◽

Biomass Combustion ◽

Combustion System ◽

Human Beings ◽

New Type ◽

Energy Products ◽

The Ideal ◽

Commercial Energy

Worldwide changes in climate and environment forced us human beings to seek for alternatives to replace commercial energy products like coal and petroleum. However, there have some difficulties to promote commercial energy products in China’s rural areas and newly urbanized areas. Biomass combustion system will become one of the ideal devices for such areas in a period of time. It is necessary to develop new types of biomass combustion system consisting of gasification or Semi-Gasification and combustion units so that it can provide high efficiency and low cost for household purposes.

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Design of 500W Safety Photovoltaic Off-Grid Inverter for Family

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.651-653.1019 ◽

2014 ◽

Vol 651-653 ◽

pp. 1019-1023

Author(s):

You Huan Wang ◽

Ning Liu ◽

Dong Wei Xia

Keyword(s):

High Performance ◽

High Efficiency ◽

Low Cost ◽

Maximum Power Point ◽

Point Tracking ◽

Pv Inverter ◽

Power Point Tracking ◽

Converter Topology ◽

Power Point ◽

Digital Processor

In order to address and meet the needs of people in these regions without electricity, we designed a small 500W off-grid PV-inverter. The main circuit includes battery charge and discharge circuit, and two-stage converter topology isolated. The digital processor TMS320F28023, high-performance and low-cost, is used to achieve maximum power point tracking (MPPT) of PV modules and charge control for battery. The experimental results of the prototype show that this design with high-precision and high-efficiency, meets the design requirements.

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CVD Diamond Film Polishing Based on Accelerant Theory

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.497.185 ◽

2012 ◽

Vol 497 ◽

pp. 185-189

Author(s):

Li Zhang ◽

Shao Jie Ding ◽

Dong Hui Wen ◽

Zhen Hao Xu ◽

Shi Ming Ji

Keyword(s):

Diamond Film ◽

High Efficiency ◽

Low Cost ◽

Cvd Diamond ◽

Reaction Rates ◽

Precision Machining ◽

Key Technologies ◽

Ultra Precision ◽

New Type ◽

Cvd Diamond Film

CVD diamond has become the mainstream trend for the development of diamond. Its ultra precision machining is one of the key technologies for expanding the application of CVD diamond film. The efficient polishing method is studied, called accelerant polishing technology, which can lower the activation energy needed in diamond graphitization by the accelerant action of transition metal. It accelerates reaction rates of graphitization and promotes the implementation of diamond’s removal mechanism. Experimentation results indicate that the polishing method is one new type of precision polishing technology with low cost and high efficiency.

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Efficiency Optimization Design of L-LLC Resonant Bidirectional DC-DC Converter

Energies ◽

10.3390/en14113123 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3123

Author(s):

Jing Lu ◽

Xiangqian Tong ◽

Jianwu Zeng ◽

Ming Shen ◽

Jun Yin

Keyword(s):

Parameter Optimization ◽

Optimization Design ◽

High Efficiency ◽

Design Method ◽

Optimization Method ◽

Switching Loss ◽

Intrinsic Mechanism ◽

Parasitic Parameters ◽

New Type ◽

Parameter Optimization Design

The new type of L-LLC resonant bidirectional DC-DC converter (L-LLC-BDC) has merits of high efficiency, high-power density and wide gain and power ranges, and it is suitable for energy interface between energy storage systems and DC micro grid. However, the resonances are sensitive to the parasitic parameters, which will deteriorate the efficiency. This paper investigates the intrinsic mechanism of parasitic parameters on the L-LLC-BDC operating principle and working characteristics based on the analysis of working modes and resonance tank. By taking the oscillation of parasitic parameters produced in the stage for the freewheeling stage into consideration, a parameter optimization method is proposed to reduce the resonant current oscillation while maintaining the characteristic of the natural soft switching. The experiment results not only validated the proposed parameter optimization design method, but also testified to the improvement of the efficiency through the minimization of the conduction and switching loss.

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Effect of Stator Structure and Field Analysis of a New Type Single-Phase Induction Motor

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.229-231.907 ◽

2012 ◽

Vol 229-231 ◽

pp. 907-910

Author(s):

Hui Zhong ◽

Xiu He Wang ◽

Cheng Zhang ◽

Ming Yin

Keyword(s):

Induction Motor ◽

Single Phase ◽

High Efficiency ◽

Low Cost ◽

Field Analysis ◽

Stator Windings ◽

Magnetic Field Analysis ◽

Dimensional Finite Element ◽

New Type ◽

Type Motor

The new type single-phase induction motors with three stator windings are brought forward for there high efficiency and low cost. However, the unbalance current density in the stator windings is still a problem to the design of this type motor. This paper presents the asymmetrical stator windings and slots structure in the motor design to get the currents density balance. A magnetic field analysis of the new type tri-winding induction motor is preformed using a two-dimensional finite element method. The Maxwell stress method is used to compute the air gap torque that is required for solving the equation of motion. The perfomance of the motor with different structure stator are compared and analysised.

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Extra-High-Voltage DC-DC Boost Converters Topology with Simple Control Strategy

Modelling and Simulation in Engineering ◽

10.1155/2008/593042 ◽

2008 ◽

Vol 2008 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

P. Sanjeevikumar ◽

K. Rajambal

Keyword(s):

High Voltage ◽

Output Voltage ◽

Control Algorithm ◽

High Efficiency ◽

Low Cost ◽

Buck Converter ◽

Boost Converters ◽

Wide Range ◽

Power Transfer Efficiency ◽

Extra High Voltage

This paper presents the topology of operating DC-DC buck converter in boost mode for extra-high-voltage applications. Traditional DC-DC boost converters are used in high-voltage applications, but they are not economical due to the limited output voltage, efficiency and they require two sensors with complex control algorithm. Moreover, due to the effect of parasitic elements the output voltage and power transfer efficiency of DC-DC converters are limited. These limitations are overcome by using the voltage lift technique, opens a good way to improve the performance characteristics of DC-DC converter. The technique is applied to DC-DC converter and a simplified control algorithm in this paper. The performance of the controller is studied for both line and load disturbances. These converters perform positive DC-DC voltage increasing conversion with high power density, high efficiency, low cost in simple structure, small ripples, and wide range of control. Simulation results along theoretical analysis are provided to verify its performance.

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Neutral Point Clamped Transformer-Less Multilevel Converter for Grid-Connected Photovoltaic System

Electronics ◽

10.3390/electronics10080977 ◽

2021 ◽

Vol 10 (8) ◽

pp. 977

Author(s):

P. Madasamy ◽

Rajesh Verma ◽

A. Rameshbabu ◽

A. Murugesan ◽

R. Umamageswari ◽

...

Keyword(s):

High Efficiency ◽

Low Cost ◽

Current Control ◽

Neutral Point ◽

Photovoltaic System ◽

Special Treatment ◽

Switching Frequency ◽

Medium Voltage ◽

Hysteresis Current Control ◽

Field Programmable

Transformer-less (TL) inverter topologies have elicited further special treatment in photo-voltaic (PV) power system as they provide high efficiency and low cost. Neutral point clamped (NPC) multilevel-inverter (MLI) topologies-based transformer-less are being immensely used in grid-connected medium-voltage high-power claims. Unfortunately, these topologies such as NPC-MLI, full-bridge inverter with DC bypass (FB-DCBP) suffer from the shoot-through problem on the bridge legs, which affect the reliability of the implementation. Based on the previous above credits, a T type neutral point clamped (TNP)—MLI (TNP-MLI) with transformer-less topology called TL-TNP-MLI is presented to be an alternate which can be suitable in the grid-connected PV power generation systems. The suggested TL-TNP-MLI topologies free from inverter bridge legs shoot-through burden, switching frequency common-mode current (CMC), and leakage current. The control system of the grid interface with hysteresis current control (HCC) strategy is proposed. The effectiveness of the proposed PV connected transformer-less TNP-MLI topology with different grid and PV scenario has been verified through the MATLAB/Simulink simulation model and field-programmable gate area (FPGA)-based experimental results for a 1.5 kW system.

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A Single-Stage DC Uninterruptible Power Supply

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.764-765.466 ◽

2015 ◽

Vol 764-765 ◽

pp. 466-470

Author(s):

Maoh Chin Jiang ◽

Bing Jyun Shih

Keyword(s):

Power Factor ◽

Power Supply ◽

Output Voltage ◽

High Efficiency ◽

Low Cost ◽

Single Stage ◽

Normal Operation ◽

Uninterruptible Power Supply ◽

Sinusoidal Input ◽

Uninterruptible Power

A single-stage DC uninterruptible power supply (UPS) is proposed in this paper. Basically, the proposed converter is an integration result of a power factor correction circuit with a dc-to-dc converter to achieve simple hardware circuit, high efficiency, and low cost for extra UPS function. Under normal operation, a novel two-switch SEPIC converter operates as an ac to dc converter with sinusoidal input current, unity power factor, and low ripple dc output voltage, and as a battery charger if a battery is added. Since both the input boost supply and the output supply can be controlled independently, a fast transient response can be maintained at both the input for active current wave shaping and at the output for good output regulation. When the ac source is in an outage condition, the proposed converter functions as a dc-to-dc buck-boost converter; therefore, the desired dc output voltage can be provided. Finally, some experimental results are presented for verification.

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