We report on measurements of capacitors with about 1 pF of capacitance, which have unmeasurably small leakage at very low frequencies, placing a lower bound of about 1019[2 on the parallel resistance at an effective frequency of 1 mHz. These measurements are made possible by two themes: the use of vacuum-gap capacitors (i.e., no dielectric material, operated in vacuum), and detection of leakage...

A remaining useful life prediction algorithm and degradation model for electrolytic capacitors is presented. Electrolytic capacitors are used in several applications ranging from power supplies on critical avionics equipment to power drivers for electro-mechanical actuators. These devices are known for their low reliability and given their criticality in electronics subsystems they are a good c...

Ultrathin, transparent and flexible capacitors using graphene as the bottom electrodes were directly fabricated on polyethylene naphthalate (PEN) substrates. ZrO₂ dielectric films were deposited on the treated surface of graphene by atomic layer deposition (ALD). The deposition process did not introduce any detectible defects in the graphene, as indicated by Raman measurements, guaranteeing the...

In this paper optimum size and location of capacitors and distributed generations (DGs) are determined simultaneously in a radial distribution network. The objective function includes power losses reduction and voltage profile improvement using ant colony algorithm. Allocation capacitors and of DGs should be carefully determined with the consideration of different planning incentives. It shows ...

DC-link capacitors are an important part in the majority of power electronic converters which contribute to cost, size and failure rate on a considerable scale. From capacitor users’ viewpoint, this paper presents a review on the improvement of reliability of dc link in power electronic converters from two aspects: 1) reliability-oriented dc-link design solutions; 2) conditioning monitoring of ...

In this work, two high-voltage charge pumps are introduced. In order to minimize the area of the pumping capacitors, which dominates the overall area of the charge pump, high density capacitors have been utilized. Nonetheless, these high density capacitors suffer from low breakdown voltage which is not compatible with the targeted high voltage application. To circumvent the breakdown limitation...

Stress-induced changes in the imprint and switching behavior of ~111!-oriented Pb(Zr,Ti)O3 ~PZT!-based capacitors have been studied using piezoresponse force microscopy. Visualization of polarization distribution and d33-loop measurements in individual 131.5-mm 2 capacitors before and after stress application, generated by substrate bending, provided direct experimental evidence of stress-induc...

Polypropylene metallized capacitors are of general use in power electronics because of their reliability, their self healing capabilities, and their low price. Though the behavior of metallized coiled capacitors has been discussed, no work was done about stacked and flattened metallized capacitors. The purpose of this article is to propose a simple analytical low frequency model of stacked capa...

CONTENTS Introduction ........................................................................................................................................................................ 1 Part types ............................................................................................................................................................................ 3 Leakage currents ....

The mathematical description of the charging process time-varying capacitors is reviewed and a new formulation proposed. For it, suitable fractional derivatives are described. case that follow Curie–von Schweidler law considered. Through substitutions, similar scheme for inductors obtained. Formulae voltage/current input/output presented. Backward coherence with classic results established gene...