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Negative impedance converter

About: Negative impedance converter is a research topic. Over the lifetime, 5801 publications have been published within this topic receiving 87636 citations.


Papers
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Proceedings ArticleDOI
16 May 2008
TL;DR: In this article, the authors proposed a novel current-fed ZVS isolated boost converter for fuel cell applications, which can achieve ZVS at a lighter load condition with less leakage inductance.
Abstract: This paper proposes a novel current-fed ZVS isolated boost converter suitable for fuel cell applications. Preserving the advantages of the current-fed converter which include smaller input current ripple, lower diode voltage rating and lower transformer turns ratio, the proposed converter does not require any clamping and start-up circuits unlike the conventional current-fed converters. The voltage ratings of the primary switches and secondary diodes of the proposed converter are significantly reduced. The proposed converter can achieve ZVS at a lighter load condition with less leakage inductance. These characteristics of the proposed converter lead to a high overall efficiency over wider load range. Experimental results on a 1 kW prototype are provided to validate the proposed concept.

51 citations

Journal ArticleDOI
TL;DR: In this article, the design space of hysteresis-free negative capacitance FETs was investigated by performing a cross-architecture analysis using HfZrOx ferroelectric (FE-HZO) integrated on bulk MOSFET, fully depleted SOI-FETs, and sub-10-nm FinFET.
Abstract: In this letter, we investigate the design space of hysteresis-free negative capacitance FETs (NCFETs) by performing a cross-architecture analysis using HfZrOx ferroelectric (FE-HZO) integrated on bulk MOSFET, fully depleted SOI-FETs, and sub-10-nm FinFETs. Our simulation analysis shows that FDSOI and FinFET configurations greatly benefit the NCFET performance due to their undoped body and improved gate-control, which enables better capacitance matching with the ferroelectric. A low-voltage NC-FinFET operating down to 0.25 V is predicted using ultra-thin 3-nm FE-HZO.

51 citations

Patent
18 Feb 2011
TL;DR: In this paper, a method of controlling the grid-side current of a single-phase grid-connected converter having an LCL filter connected between the output of the converter and the grid includes measuring a grid voltage and at least one signal in a group of signals consisting of a grid side current, a converter side current and a capacitor voltage.
Abstract: A method of controlling the grid-side current of a single-phase grid-connected converter having an LCL filter connected between the output of the converter and the grid includes measuring a grid voltage and at least one signal in a group of signals consisting of a grid-side current, a converter-side current and a capacitor voltage, estimating the fundamental component of the grid voltage, forming a grid-side current reference, a converter-side current reference and a capacitor voltage reference for the grid-side current of the LCL filter, forming estimates for the non-measured signals in the group of signals, forming a grid-side current difference term, a converter-side current difference term and a capacitor voltage difference term, and controlling the output voltage of the converter based on the grid voltage, a formed injection term and a formed estimate of the harmonic distortion term to produce a grid side current corresponding to the current reference.

51 citations

Patent
07 Mar 2013
TL;DR: An impedance control resonant power converter (converter) operated at a fixed switching frequency includes an impedance control network (ICN) coupled between two or more inverters with a phase shift between them and one or more rectifiers as mentioned in this paper.
Abstract: An impedance control resonant power converter (converter) operated at a fixed switching frequency includes an impedance control network (ICN) coupled between two or more inverters operated at a fixed duty ratio with a phase shift between them and one or more rectifiers. The phase shift is used to control output power or compensate for variations in input or output voltage. The converter operates at fixed frequency yet achieves simultaneous zero voltage switching (ZVS) and zero or near zero current switching (ZCS) across a wide operating range. Output power may be controlled by: (1) changing phase shift between inverters; or (2) adjusting phase shift between inverters depending upon input and/or output voltages so that an admittance presented to the inverters is conductive and then turning the converter on and off at a frequency lower than the converter switching frequency to control output power below a value set by the phase shift.

51 citations

Journal ArticleDOI
TL;DR: In this paper, the apparent impedance is defined as the ratio between the voltage and current at the injection point of a power system, and the eigenvalues are obtained by applying system identification techniques to the measured set of apparent impedances.
Abstract: In this paper, a new method for power system stability analysis is introduced. The method is based on injection of a small voltage or current in an arbitrary point of a power system. The apparent impedance is then defined as the ratio between the voltage and current at the injection point. It is shown that the apparent impedance can be used to estimate the eigenvalues of the system that are observable from the injection point. The eigenvalues are obtained by applying system identification techniques to the measured set of apparent impedances. The method is similar to the well-established impedance-based stability analysis based on source and load impedance models. However, while the source/load impedance ratio is viewed as the minor-loop gain, the apparent impedance can be viewed as a closed-loop transfer function. It can also be expressed as the parallel connection of the source and load impedance. It is shown, in this paper, how the system eigenvalues can be extracted based on a set of apparent impedance values. The apparent impedance holds, therefore, complementary information compared with the existing impedance-based stability analysis. The method can also be used as a tool to validate analytically derived state-space models. In this paper, the method is presented as a simulation tool, while further work will extend it to include experimental setups. Two case studies are presented to illustrate the method: 1) a dc case with a buck converter feeding a constant power load and 2) a three-phase grid-connected voltage source converter with a current controller and a phase lock loop. The estimated (apparent) eigenvalues of the studied systems are equal to those obtained from the analytic state-space model.

51 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202330
2022104
2021120
2020131
2019134
2018155