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Equivalent series resistance

About: Equivalent series resistance is a research topic. Over the lifetime, 5335 publications have been published within this topic receiving 83362 citations. The topic is also known as: ESR.


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Journal ArticleDOI
TL;DR: In this paper, a simple on-line fault detection technique that is able to prevent structural failures in aluminium electrolytic capacitors used in the output filter of step-down DC-DC converters is presented.
Abstract: The aim of this study is to present a simple on-line fault detection technique that is able to prevent structural failures in aluminium electrolytic capacitors used in the output filter of step-down DC–DC converters. The aluminium electrolytic capacitors equivalent circuit consists of an ideal resistance in series with an ideal capacitor and an ideal inductor. The first two elements change with frequency, temperature and aging. Most manufacturers define the end of life limit of these capacitors when their internal resistance (equivalent series resistance (ESR)) doubles or their capacitance (C) reduces by 20%, when compared with the initial values. The proposed on-line fault detection technique is able to estimate the capacitor ESR value during converter operation. For that purpose, a simple relationship between the input current and the output voltage ripple is used. The measurement system is composed of a digital oscilloscope that is connected to a microcomputer with ‘Matlab’ software. Several simulation and experimental results are presented to validate the proposed fault detection technique.

107 citations

Journal ArticleDOI
TL;DR: In this paper, a method of calculating the series resistance as a function of grid geometry is presented with the following assumptions: (1) current generation is uniform over the area of the cell; (2) the thickness of the upper semiconductor layer is very much smaller than the lateral dimensions of a cell; and (3) the resistance of the grid electrode is much less than the sheet resistance of a layer.
Abstract: Most photovoltaic solar cells use some type of light-transmitting grid electrode on the upper surface to reduce series resistance losses as the current is collected. The geometry of this grid is chosen through consideration of optical transparency and series resistance. A method of calculating the series resistance as a function of grid geometry is presented here with the following assumptions: (1) current generation is uniform over the area of the cell; (2) the thickness of the upper semiconductor layer is very much smaller than the lateral dimensions of the cell; (3) the resistance of the grid electrode is much less than the sheet resistance of the upper semiconductor layer, and (4) the current flow in the layer is ohmic. These assumptions will be satisfied for most solar cells of interest. The method is then applied to several representative grid geometries and the results are compared with previous calculations in the literature.

107 citations

Journal ArticleDOI
TL;DR: A novel noninvasive technique for capacitor diagnostic in Boost converters is presented that can easily be applied online and even in real time, and it is suitable for the operation in both continuous current mode (CCM) and discontinuousCurrent mode (DCM).
Abstract: Capacitors usually determine the overall lifetime of power converters since they are mainly responsible for breakdowns. Their failure results from the deterioration of their dielectric, the production of gases, and, eventually, their explosion. This process leads to an increase in the capacitor equivalent series resistance (ESR) and a decrease in its capacitance value for both electrolytic and metalized polypropylene film (MPPF) capacitors. In this paper, a novel noninvasive technique for capacitor diagnostic in Boost converters is presented. It can easily be applied online and even in real time, and it is suitable for the operation in both continuous current mode (CCM) and discontinuous current mode (DCM). The technique is based on the double estimations of the ESR and the capacitance, improving the diagnostic reliability. This way, predictive maintenance is provided, and it is possible to alarm for capacitor replacement, avoiding downtime. As the method is intended for railway high-power applications, it has been conceived neither to add any additional hardware in the power stage nor to even slightly modify it. To demonstrate and validate the effectiveness and accuracy of the proposed technique, several simulations and experimental results are discussed in a small prototype. In this prototype, the software for real-time estimation is programmed in a low-cost digital signal processor (DSP).

107 citations

Journal ArticleDOI
TL;DR: In this article, a continuous grading of the heterointerfaces in the Bragg reflectors eliminated the energy-band discontinuities, thus improving carrier transport and resulting in a substantial reduction in the series resistance and threshold voltage of the laser diodes.
Abstract: GaAs/AlGaAs vertical-cavity top-surface-emitting lasers (VCSELs) with a continuously graded mirror composition have been grown by MOCVD, and planar devices with proton-implant current confinement have been characterized. Continuous grading of the heterointerfaces in the Bragg reflectors eliminated the energy-band discontinuities, thus improving carrier transport and resulting in a substantial reduction in the series resistance and threshold voltage of the laser diodes. These VCSELs have excellent room-temperature CW electrical characteristics, including some of the lowest series resistances, highest power efficiencies and lowest operating voltages ever reported. >

106 citations

Journal ArticleDOI
01 Jan 1962
TL;DR: In this paper, the design theory for a new range of p-n junction applications is presented, including pulse generation, wave shaping, and harmonic generation, where the diodes are characterized by a very abrupt interruption of reverse current in the turn-off transient.
Abstract: The design theory for a new range of p-n junction applications is presented. The applications include pulse generation, wave shaping, and harmonic generation. The diodes are characterized by a very abrupt interruption of reverse current in the turn-off transient and are approximately ideal nonlinear capacitors. The abrupt interruption of current in the reverse transient is related to the impurity profile in the junction. An estimate is given of the duration of the abrupt phase. In addition, the role of parasitic elements such as inductance, capacitance, and series resistance is discussed in relation to a particular representative circuit. In typical cases, the abrupt turn-off phase lasts for a time of the order of 10-9 sec. Transitions in excess of 100 v or an ampere are readily obtained.

106 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023121
2022235
2021126
2020170
2019171
2018206