The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

Hosein Farzanehfard - One of the best experts on this subject based on the ideXlab platform.

  • single switch soft switched isolated dc dc converter
    IEEE Transactions on Power Electronics, 2012
    Co-Authors: Amin Emrani, Ehsan Adib, Hosein Farzanehfard
    Abstract:

    In this paper, a new single-switch soft-switching isolated converter is introduced. In the proposed converter, the transformer parasitic elements are used as resonant elements to transfer energy and to attain soft-switching condition. The proposed converter does not require output inductor just like the flyback converter, and the transformer core does not store energy just like the forward converter. The proposed converter is analyzed and its advantages over conventional converters are discussed. Also, experimental results are presented to justify the validity of theoretical analysis.

K I Hwu - One of the best experts on this subject based on the ideXlab platform.

  • study and simulation on control to output transfer function of ky boost converter
    Conference of the Industrial Electronics Society, 2015
    Co-Authors: K I Hwu, W Z Jiang, Jennjong Shieh
    Abstract:

    The KY boost converter, which combines the KY converter and the traditional synchronously rectified (SR) boost converter, is a novel step-up converter to overcome the disadvantages of the KY converter, which has a quite low voltage gain. Compared with the KY converter, the KY boost converter has one additional inductor and one additional capacitor. Therefore, the dynamic characterization of the KY boost converter is a more important issue in designing the converter. In this paper, based on the averaging method, a more precise control-to-output transfer function is established. The transfer function contains parameters of input voltage, two energy-transferring capacitors, input and output inductors, duty cycle, output load, input and output currents, and switching frequency. Finally the two Bode plots of the open loop KY boost converter from theoretical analysis and from PSIM are compared.

  • IECON - Study and simulation on control-to-output transfer function of KY boost converter
    IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 2015
    Co-Authors: K I Hwu, W Z Jiang, Jennjong Shieh
    Abstract:

    The KY boost converter, which combines the KY converter and the traditional synchronously rectified (SR) boost converter, is a novel step-up converter to overcome the disadvantages of the KY converter, which has a quite low voltage gain. Compared with the KY converter, the KY boost converter has one additional inductor and one additional capacitor. Therefore, the dynamic characterization of the KY boost converter is a more important issue in designing the converter. In this paper, based on the averaging method, a more precise control-to-output transfer function is established. The transfer function contains parameters of input voltage, two energy-transferring capacitors, input and output inductors, duty cycle, output load, input and output currents, and switching frequency. Finally the two Bode plots of the open loop KY boost converter from theoretical analysis and from PSIM are compared.

  • A novel buck-boost converter combining KY and buck converters
    IEEE Transactions on Power Electronics, 2012
    Co-Authors: K I Hwu, T. J. Peng
    Abstract:

    In this letter, a buck-boost converter, i.e., 2D converter with a positive output voltage, is presented, which combines the KY converter and the traditional synchronously rectified (SR) buck converter. By doing so, the problem in voltage bucking of the KY converter can be solved, thereby increasing the application capability of the KY converter. Since such a converter operates in continuous conduction mode inherently, it possesses the nonpulsating output current, thereby not only decreasing the current stress on the output capacitor but also reducing the output voltage ripple. Above all, both the KY converter and the SR buck converter, combined into a buck-boost converter with no right-half plane zero, use the same power switches, thereby causing the required circuit to be compact and the corresponding cost to be down. Furthermore, during the magnetization period, the input voltage of the KY converter comes from the input voltage source, whereas during the demagnetization period, the input voltage of the KY converter comes from the output voltage of the SR buck converter.

Jeffrey G. Schreiber - One of the best experts on this subject based on the ideXlab platform.

  • Summary of Stirling Convertor Testing at GRC
    4th International Energy Conversion Engineering Conference and Exhibit (IECEC), 2006
    Co-Authors: Jeffrey G. Schreiber
    Abstract:

    The NASA Glenn Research Center (GRC) has been testing free-piston Stirling Convertors for potential use in radioisotope power systems. These Convertors tend to be in the 35 to 80 watt electric power output range. Tests at GRC have accumulated over 80,000 hours of operation. Test articles have been received from Infinia Corporation of Kennewick, WA and from Sunpower of Athens, OH. Infinia designed and built the developmental Stirling Technology Demonstration Convertors (TDC) in addition to the more advanced Test Bed and Engineering Unit Convertors. GRC has eight of the TDC's under test including two that operate in a thermal vacuum environment. Sunpower designed and developed the EE- 35 and the Advanced Stirling Convertor (ASC). GRC has six of the EE-35's and is preparing for testing multiple ASC's. Free-piston Stirling Convertors for radioisotope power systems make use of non-contacting operation that eliminates wear and is suited for longterm operation. Space missions with radioisotope power systems are often considered that extend from three to 14 years. One of the key capabilities of the GRC test facility is the ability to support continuous, unattended operation. Hardware, software, and procedures for preparing the test articles were developed to support these tests. These included the processing of the Convertors for minimizing the contaminants in the working fluid, developing a helium charging system for filling and for gas sample analysis, and the development of new control software and a high-speed protection circuit to insure safe, round-the-clock operation. Performance data of Stirling Convertors over time is required to demonstrate that a radioisotope power system is capable of providing reliable power for multi-year missions. This paper will discuss the status of Stirling Convertor testing at GRC.

  • Assessment of the free-piston Stirling Convertor as a long life power Convertor for space
    Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022), 1
    Co-Authors: Jeffrey G. Schreiber
    Abstract:

    There is currently a renewed interest in the use of free-piston Stirling power Convertors for space power applications. More specifically, the Stirling Convertor is being developed to be part of the Stirling Radioisotope Power System to supply electric power to spacecraft for NASA deep space science missions. The current development effort involves the Department of Energy, Germantown, MD, the NASA Glenn Research Center, Cleveland, OH, and the Stirling Technology Company, Kennewick, WA. The Stirling Convertor will absorb heat supplied from the decay of plutonium dioxide contained in the General Purpose Heat Source modules and convert it into electricity to power the spacecraft. For many years the "potentials" of the free-piston Stirling Convertor have been publicized by its developers. Among these "potentials" were long life and high reliability. This paper presents an overview of the critical areas that enable long life of the free-piston Stirling power Convertor, and present some of the techniques that have been used when long life has been achieved.

Amrad Arridha - One of the best experts on this subject based on the ideXlab platform.

  • Design and Implementation of Series Resonant DC-DC Converter
    'Perpustakaan Universitas Andalas', 2020
    Co-Authors: Budiman, Firmansyah Nur, Amrad Arridha
    Abstract:

    The resonant DC-DC converter is known as advantageous over conventional DC-DC converter in terms of efficiency. This is primarily because the resonant converter operates at soft switching mode. In this paper, we report our work on the design and implementation of a series resonant DC-DC converter with full-bridge switching. The developed converter consisted of two main parts, namely the PWM signal-generating circuit as the driver for MOSFET and converter primary circuit. The first part was implemented by using Arduino UNO R3, whose output was amplified with IR2110 optocoupler. The latter was made up of full-bridge inverter, which employs MOSFET as the electronic switches, resonance circuit, and full-bridge uncontrolled rectifier. Performance of the developed converter was tested by supplying input voltage ranging from 20 to 30 V. It was shown that the converter functioned as a step-down “DC” transformer, i.e. voltage reducer. The maximum output voltage level obtained was half of the input, which was achieved at switching frequency of 40 kHz and efficiency of 50%. The converter was also tested to supply practical electrical load. In this case, a 12-V electric drill was put in place. The drill worked well, and a converter efficiency of 43% could be calculated during this operation.Keywords : DC-DC Converter, Series Resonance and Switchin

R B Ridley - One of the best experts on this subject based on the ideXlab platform.

  • a new continuous time model for current mode control power Convertors
    IEEE Transactions on Power Electronics, 1991
    Co-Authors: R B Ridley
    Abstract:

    A current-mode control power Convertor model that is accurate at frequencies from DC to half the switching frequency is described for constant-frequency operation. Using a simple pole-zero transfer function, the model is able to predict subharmonic oscillation without the need for discrete-time z-transform models. The accuracy of sampled-data modeling is incorporated into the model by a second-order representation of the sampled-data transfer function which is valid up to half the switching frequency. Predictions of current loop gain; control-to-output; output impedance; and audio susceptibility transfer functions were confirmed with measurements on a buck converter. The audio susceptibility of the buck converter can be nulled with the appropriate value of external ramp. The modeling concentrates on constant-frequency pulse-width modulation (PWM) converters, but the methods can be applied to variable-frequency control and discontinuous conduction mode. >