scholarly journals High Efficient Resonant DC-DC Converter for Automotive LED Driver Applications using Phase Shift Control Strategy

2021 ◽  
Vol 7 (10) ◽  
pp. 1-7
Author(s):  
Syed Simran.K, Md.Anwar, Dr.Sharan Reddy and Santosh.B.M
Keyword(s):  
Phase Shift ◽  
High Performance ◽  
High Efficiency ◽  
Switching Frequency ◽  
Led Driver ◽  
Load Current ◽  
Shift Control ◽  
Wide Range ◽  
High Efficient ◽  
Overall Performance

A high frequency DC-DC converter operating in the MHz range is proposed, which can achieve unbiased load current even while maintaining high performance over a wide range of load voltages. Due to these functions, the provided transformer is suitable for LED driver applications, which require different types of LEDs to operate with controlled current. The proposed transformer satisfies the uncontrolled load current using the LCL-T resonance community and achieves high efficiency using a predetermined switching frequency. The LCL-T resonance transformer also works effectively in controlling its output to the required rating using phase shift control. The overall performance of the LCL-T Echo transducer was evaluated and compared with the LC3L controlled echo transducer. Simulation work is done using the MATLAB / Simulink program.

A high-power PCCM LED driver based on GaN eHEMT with hybrid dimming modes

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xixian Lin ◽  
Yuming Zhang ◽  
Yimeng Zhang ◽  
Guangjian Rong
Keyword(s):  
Printed Circuit Board ◽  
Pulse Width Modulation ◽  
Circuit Board ◽  
Switching Frequency ◽  
Led Driver ◽  
Power Circuit ◽  
Content Type ◽  
Wide Range ◽  
Circuit Function ◽  
Pwm Dimming

Purpose The purpose of this study is to design a more flexible and larger range of the dimming circuit that achieves the independence of multiple LED strings drive and can time-multiplex the power circuit. Design/methodology/approach The state-space method is used to model the BUCK circuit working in Pseudo continuous conduction mode, analyze the frequency characteristics of the system transfer function and design the compensation network. Build a simulation platform on the Orcad PSPICE platform and verify the function of the designed circuit through the simulation results. Use Altium Designer 16 to draw the printed circuit board, complete the welding of various components and use the oscilloscope, direct current (DC) power supply and a signal generator to verify the circuit function. Findings A prototype of the proposed LED driver is fabricated and tested. The measurement results show that the switching frequency can be increased to 1 MHz, Power inductance is 2.2 µH, which is smaller than current research. The dimming ratio can be set from 10% to 100%. The proposed LED driver can output more than 48 W and achieve a peak conversion efficiency of 91%. Originality/value The proposed LED driver adopts pulse width modulation (PWM) dimming at a lower dimming ratio and adopts DC dimming at a larger dimming ratio to realize switching PWM dimming to analog dimming. The control strategy can be more precise and have a wide range of dimming.

scholarly journals Development of the PGT 25 High Efficiency Gas Turbine: Part 2 — Aerodynamic Design and Performance

1984 ◽  
Author(s):  
E. Benvenuti ◽  
B. Innocenti ◽  
R. Modi
Keyword(s):  
Gas Turbine ◽  
High Efficiency ◽  
Performance Testing ◽  
Operating Conditions ◽  
Aerodynamic Design ◽  
Direct Drive ◽  
Gas Generator ◽  
Full Load ◽  
Wide Range ◽  
Overall Performance

This paper outlines parameter selection criteria and major procedures used in the PGT 25 gas turbine power spool aerodynamic design; significant results of the shop full-load tests are also illustrated with reference to both overall performance and internal flow-field measurements. A major aero-design objective was established as that of achieving the highest overall performance levels possible with the matching to latest generation aero-derivative gas generators; therefore, high efficiencies were set as a target both for the design point and for a wide range of operating conditions, to optimize the turbine’s uses in mechanical drive applications. Furthermore, the design was developed to reach the performance targets in conjunction with the availability of a nominal shaft speed optimized for the direct drive of pipeline booster centrifugal compressors. The results of the full-load performance testing of the first unit, equipped with a General Electric LM 2500/30 gas generator, showed full attainment of the design objectives; a maximum overall thermal efficiency exceeding 37% at nominal rating and a wide operating flexibility with regard to both efficiency and power were demonstrated.

A High Robustness and High Efficiency Single-Ended Wireless V2H System with a New Phase Shift Control.

2020 ◽  
Vol 46 (0) ◽  
pp. 59-67
Author(s):  
Junnosuke Nohara ◽  
Hideki Omori ◽  
Masahito Tsuno ◽  
Toshimitsu Morizane ◽  
Hidehito Matayoshi
Keyword(s):  
Phase Shift ◽  
High Efficiency ◽  
Shift Control ◽  
New Phase

A unique high-performance wide-range (10–1500 eV) spherical grating monochromator beamline

1998 ◽  
Vol 5 (3) ◽  
pp. 723-725 ◽  
Author(s):  
P.-C. Tseng ◽  
C.-C. Chen ◽  
T.-E. Dann ◽  
S.-C. Chung ◽  
C. T. Chen ◽  
...  
Keyword(s):  
High Performance ◽  
Low Energy ◽  
Resolving Power ◽  
Photon Flux ◽  
Wide Spectral Range ◽  
Experimental Station ◽  
Wide Range ◽  
Grating Monochromator ◽  
Overall Performance ◽  
Under Construction

A wide-spectral-range high-performance 6 m-spherical grating monochromator (6 m-SGM) beamline has been designed and is under construction at SRRC. Two different entrance slits, instead of additional mirrors, are used to optimize the overall performance. Six gratings are used to cover photon energies from 10 to 1500 eV. Movable entrance slits and bendable vertical focusing mirrors are used to enhance further the beamline performance. A bendable horizontal focusing mirror is used to improve the resolution and to focus the photon beam at the experimental station immediately after the exit slit. Several end-stations can be installed at the same time to utilize the beam time fully. The expected energy-resolving power, with both slit openings set at 10 µm, is up to 15 000 and 40 000 for the high- and low-energy branches, respectively. A photon flux of 1 × 1011 photons s−1 can be obtained with an energy-resolving power of 20 000.

scholarly journals Multi-Objective Unified Optimal Control Strategy for DAB Converters with Triple-Phase-Shift Control

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6444
Author(s):  
Jinhui Zeng ◽  
Yao Rao ◽  
Zheng Lan ◽  
Dong He ◽  
Fan Xiao ◽  
...  
Keyword(s):  
Optimal Control ◽  
Phase Shift ◽  
Dynamic Response ◽  
Control Strategy ◽  
High Efficiency ◽  
Soft Switching ◽  
Optimal Control Strategy ◽  
Current Stress ◽  
Multi Objective ◽  
Shift Control

To solve the problems of large current stress, difficult soft-switching of all switches, and slow dynamic response of dual active bridge converters, a multi-objective unified optimal control strategy based on triple-phase-shift control was proposed. The forward power flow global modes of triple-phase-shift control were analyzed, and three high-efficiency modes were selected to establish the analytical models of current stress and soft-switching. Combined with these models, the optimal solutions in different modes were derived by using the cost function-optimization equation to overcome the limitation of the Lagrange multiplier method, such that the DAB converter achieved the minimum current stress, and all switches operated in the soft-switching state over the entire power range. At the same time, the virtual power component was introduced in the phase-shift ratio combination, which improved the dynamic response of output voltage under the input voltage or load steps changed by power control. The theoretical analysis and experimental results show that the proposed control strategy can optimize the performance of the DAB converter from three aspects, such as current stress, soft-switching, and dynamic response, which achieves multi-objective optimization of the steady-state and dynamic performance of DAB converters.

scholarly journals Coiling-Up Space Metasurface for High-Efficient and Wide-angle Acoustic Wavefront Steering

2021 ◽  
Vol 8 ◽  
Author(s):  
Shuang Chen ◽  
Yuancheng Fan ◽  
Fan Yang ◽  
Kangyao Sun ◽  
Quanhong Fu ◽  
...  
Keyword(s):  
High Efficiency ◽  
Structural Parameters ◽  
Space Structures ◽  
Destructive Interference ◽  
Diffraction Mode ◽  
Anomalous Reflection ◽  
Wide Range ◽  
High Efficient ◽  
Scattering Field ◽  
3D Printed

The recent advent of acoustic metasurface displays tremendous potential with their unique and flexible capabilities of wavefront manipulations. In this paper, we propose an acoustic metagrating made of binary coiling-up space structures to coherently control the acoustic wavefront steering. The acoustic wave steering is based on the in-plane coherent modulation of waves in different diffraction channels. The acoustic metagrating structure with a subwavelength thickness is realized with 3D printed two coiling-up space metaunits. By adjusting structural parameters of the metaunits, the −1st-order diffraction mode can be retained, and the rest of the diffraction orders are eliminated as much as possible through destructive interference, forming a high-efficiency anomalous reflection in the scattering field. The anomalous reflection performance of the designed metagrating is achieved over a wide range of incident angles with high efficiency.

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