High-performance Converters Research Articles

P‐68: Distinquished Student Poster Paper: Dye‐Bridged Hybrid Materials for Robust and High‐Performance Wavelength Converter of White LEDs

AbstractRed and green dye‐bridged hybrid materials (DBHs) are synthesized as organic wavelength converter to increase color rendering index and color temperature tunability of phosphor based white light‐emitting diodes (LEDs). DBH based white LEDs show high performance and it is ensured to have long term thermal stability for solid‐state lighting application.

Influence of High-Frequency Leakage Current on Motor Position Control in PWM Inverter-Fed Servo Drives

Summary Advances in power semiconductor devices have contributed to the realization of high-performance power converters and high-precision motor positioning. However, high-speed switching of power devices leads to a high-frequency leakage current and/or electromagnetic interference (EMI). On the other hand, it has been considered that the leakage current has no relation to motor position control in servo drive systems. This paper analyzes the influence of high-frequency leakage current on motor positioning and describes its mechanism. Experimental and simulation results show that high-frequency leakage current may cause variations in the motor position with a frequency that is twice the line frequency. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 185(4): 33–43, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22479

Molecular-beam epitaxy of GaAs/Si(001) structures for high-performance tandem A III B V/Si-solar energy converters on an active silicon substrate

In the present study, a method of low-temperature atomic layer epitaxy of GaAs at the initial stage of formation of a GaAs/Si heterojunction is used for growing GaAs films with a low density of threading defects. It was shown that growth of GaAs films can take place bypassing the stage of formation of islands, provided the first monolayer of GaAs is formed by atomic layer epitaxy at low temperature (200–350°C). A regime was found for growing the GaAs/Si films with a density of threading dislocations less than 106 cm–2, which corresponds to the best world achievements. In this mode, the GaAs/Si and Al0.2Ga0.8As/Si structures were grown for solar-energy converters, the devices were produced, and their characteristics were measured. It is shown that during the growth of the GaAs/Si heterojunction, a p–n-junction is formed in the near-surface layer of silicon. This allows one to produce high-performance cascade converters of solar energy based on the A III B V compounds on the active Si substrate in a single growth cycle.

Design of High-Performance CMOS Level Converters Considering PVT Variations

CMOS SoCs can reduce power consumption while maintaining performance by adopting voltage scaling (VS) technologies. The operating speed of the level converter (LC) strongly affects the effectiveness of VS technologies. However, PVT variations can cause serious problems to the LC, because the state-of-the-art LC designs do not give enough attention to this issue. In this work, we proposed to analyze the impact of PVT variations on the performance of the LC using a previously developed heuristic sizing methodology. Based on the evaluation results from different operating corners with different offset voltages and temperatures, we proposed a variation-tolerant LC that achieves both high performance and low energy with a high tolerability for PVT variations.

High-Performance Rust Converter with a Formula Based on Polyphosphoric Acid and Tannic Acid

This paper presents a high-performance rust converter whose formulation is based on polyphosphoric acid and tannic acid. In order to improve the performance of the product, active agent, catalytic agent, corrosion inhibitor, penetrating agent and wetting agent, etc., are added. Some results of accelerating experiment such as the A. C. impedance experiment are also presented, which demonstrate the high performance of the product. All ingredients in the product are cheap, easily accessible, and environment-friendly.

Heuristic Sizing Methodology for Designing High-Performance CMOS Level Converters with Balanced Rise and Fall Delays

Heuristic Sizing Methodology for Designing High-Performance CMOS Level Converters with Balanced Rise and Fall Delays

Non-Inverted Buck-Boost Converters with Dual Delta Sigma Modulators

This paper presents a new control circuit to create high-performance non-inverted Buck-Boost converter with dual ⊿∑ modulations. Experimental load regulation, corresponding to load current steps of ±0.5A, is within 45mVpp, and the efficiency without synchronized rectifier is 83% at input voltage 2.5V and load current 0.8A.

On the Spectral Tones in a Digital-Analog Converter Due to Mismatch and Flicker Noise

Spurious-free dynamic range (SFDR) is one of the most important design metrics for a high-performance digital-analog converter (DAC). SFDR is limited by both dynamic (switching) and static (mismatch) nonlinearities. A good design needs to ensure that the spurious spectral tones caused by the static mismatches do not limit the performance. Aggressively scaling device sizes have also aggravated the problem of flicker noise, which gets modulated by the signal and presents itself as spectral tones. Typically, time domain statistical simulations are needed to guarantee system performance in presence of these nonidealities. In this work, we present a theoretical approach to compute these spectral tones.

Design and Performance of an All-Optical Wavelength Converter Based on a Semiconductor Optical Amplifier and Delay Interferometer

The design and performance of an all-optical wavelength converter based on a semiconductor optical amplifier (SOA) and a delay interferometer (DI) are presented for 10-Gb/s return-to-zero (RZ) transmission systems with pulsewidths of 25-45 ps. The performance of the wavelength converter is investigated in terms of the operating conditions for the SOA and DI, and the properties of the input signal. The regenerative characteristics of the wavelength converter are also examined for input signals degraded by amplified spontaneous emission noise and residual dispersion. With proper design, the SOA-DI structure provides a high-performance all-optical wavelength converter for 10-Gb/s RZ transmission with practical pulsewidths.

A broadband 10-GHz track-and-hold in Si/SiGe HBT technology

High-performance multistage data converters and sub-sampling frequency downconverters typically require track and hold amplifiers (THAs) with high sampling rates and high linearity. This paper presents a THA for sub-sampling communications applications based on a diode bridge design with high-speed Schottky diodes and an improved current source approach for enhanced linearity. Implemented in a 45-GHz BiCMOS Si/SiGe process, this IC has an input bandwidth in excess of 10 GHz, consumes approximately 550 mW, and can accommodate input voltages up to 600 mV. With an input frequency of 8.05 GHz and a sampling frequency of 4 GHz, the THA has an IIP3 of 26 dBm and a spurious free dynamic range of 30 dB.

Low-distortion variable-level PWM technique

A multicarrier disposition pulse width modulation (PWM) technique that results in low harmonic distortion for a three-phase PWM inverter with a 5-level line-to-line output voltage waveform is discussed in the paper. Comparison with the conventional 5-level unipolar PWM technique for three-phase inverters reveals that the proposed strategy results in a high performance converter with minimised filter requirements since the amplitude of all harmonics is reduced. The resulting line-to-line voltage waveform has five levels at high and three levels at low amplitude modulation indexes (variable-level). Harmonic analysis is presented, along with simulated and experimental results to support the theoretical considerations.

Analyse dimensionnelle des sources d'excitation dans les convertisseurs électromagnétiques linéaires à aimants permanents

Considering the unceasing progress in characterization of new magnetic alloys, the authors analyze the foreseeable growth in high-power, high-performance electromagnetic converters. They consider, in particular, linear structures excited by permanent magnets and study the principal aspects of magnetic fields generated by such exciting systems. The morphology of the produced field is examined according to the outer permeance influence and to the geometric shape of sources. A dimensional analysis of technical-economical importance defines the optimal choices. Some results of practical interest are proposed.

THE CONNECTION OF CONVERTERS INSTEAD OF SEMICONDUCTOR POWER DEVICES — A HIGH PERFORMANCE SOLUTION FOR THE MVA RANGE OF POWER COMVERTERS

Recently, there is an increased demand for high power, high performance converters for power system applications, motor drives, etc. The low switching frequency of the existing semiconductor power devices poses a severe limitation that can be overcome by the use of interconnected smaller power converters (multiconverter) with appropriate control. This paper gives an overview of the state of the art of multiconverters, followed by a comparison based on analytically calculated values of the spectra, RMS and peak values of their ripple currents, and the peak values of the transformer's flux. Special attention has been given to show that the transformerless parallel connection of converters is feasible and offers features such as simplicity, gracefully degrading operating, high reliability, easy expandability and easy maintenance.

High-performance soft-commutated converter for solar energy conversion

In this paper, the authors present a detailed study and analysis of a series resonant converter topology operating in quasi-resonant mode. The dc-to-ac converter is used to convert the solar energy obtained from a photovoltaic field into an ac current. Theoretical study based on the state-plane method is completed and sets of static characteristics curves for all operating modes are obtained. A general design methodology is elaborated which permits the determination of the constraints on the semiconductors and reactive components. Finally, a performance analysis of the converter feeding different types of loads (utility, linear and nonlinear loads), and a harmonic analysis of different waveforms based on simulation and experimental results are presented.

Evaluation of Freon modules for power electronics designed for a locomotive traction drive

A technological trend of using freon-cooled power electronics for traction application has developed. The unique advantages offered by the Freon immersion technique, especially for diesel-electric locomotives applications, are described. Experimental data pertaining to recently developed Freon modules used for cooling high-power semiconductors are presented. A procedure based on a well-known caloric method is used to determine the component losses for the high-performance power converter and inverter designs with calculated efficiency values higher than 98%. >

A Standard Digital Control Module for Two-Transistor Pulsewidth Modulated Converters

Two-transistor pulsewidth modulated converters do not find widespread application since they are usually expensive, bulky, and difficult to design. To resolve these difficulties, a circuit is presented in which the pulsewidth control mechanism is separate from the power-handling stages. This permits the use of a standard integrated digital control module, which simplifies the overall design of two-transistor pulsewidth modulated converters. The module is small and inexpensive, and results in efficient, high-performance converters.