Topic
Nyquist plot
About: Nyquist plot is a research topic. Over the lifetime, 1078 publications have been published within this topic receiving 20314 citations. The topic is also known as: Nyquist diagram.
Papers published on a yearly basis
1 / 2
Papers
TL;DR: In this paper, the results obtained on the electrochemical behavior of electrochemical capacitors assembled in nonaqueous electrolyte are presented and the impedance of the supercapacitors is discussed in terms of complex capacitance and complex power.
Abstract: This paper presents the results obtained on the electrochemical behavior of electrochemical capacitors assembled in nonaqueous electrolyte. The first part is devoted to the electrochemical characterization of carbon-carbon 4 cm2 cells systems in terms of capacitance, resistance, and cyclability. The second part is focused on the electrochemical impedance spectroscopy study of the cells. Nyquist plots are presented and the impedance of the supercapacitors is discussed in terms of complex capacitance and complex power. This allows the determination of a relaxation time constant of the systems, and the real and the imaginary part of the complex power vs. the frequency plots give information on the supercapacitor cells frequency behavior. The complex impedance plots for both a supercapacitor and a tantalum dielectric capacitor cells are compared. © 2003 The Electrochemical Society. All rights reserved.
1,920 citations
TL;DR: In this paper, a physicochemical transport model was used for numerically reproducing Nyquist plots accounting for electric double layer (EDL) formation at the electrode/electrolyte interface, charge transport in the electrode, and ion electrodiffusion in binary and symmetric electrolytes.
Abstract: Electrochemical impedance spectroscopy (EIS) consists of plotting so-called Nyquist plots representing negative of the imaginary versus the real parts of the complex impedance of individual electrodes or electrochemical cells. To date, interpretations of Nyquist plots have been based on physical intuition and/or on the use of equivalent RC circuits. However, the resulting interpretations are not unique and have often been inconsistent in the literature. This study aims to provide unequivocal physical interpretations of electrochemical impedance spectroscopy (EIS) results for electric double layer capacitor (EDLC) electrodes and devices. To do so, a physicochemical transport model was used for numerically reproducing Nyquist plots accounting for (i) electric double layer (EDL) formation at the electrode/electrolyte interface, (ii) charge transport in the electrode, and (iii) ion electrodiffusion in binary and symmetric electrolytes. Typical Nyquist plots of EDLC electrodes were reproduced numerically for d...
1,146 citations
TL;DR: A systematic method is proposed to obtain the highest stability and avoidance of closed-loop anomalous peaks: it is achieved by the minimization of the inverse of the Nyquist trajectory distance to the critical point, i.e., the sensitivity function.
Abstract: The following two types of resonant controllers are mainly employed to obtain high performance in voltage-source converters: 1) proportional + resonant (PR) and 2) vector proportional + integral (VPI). The analysis and design of PR controllers is usually performed by Bode diagrams and phase-margin criterion. However, this approach presents some limitations when resonant frequencies are higher than the crossover frequency defined by the proportional gain. This condition occurs in selective harmonic control and applications with high reference frequency with respect to the switching frequency, e.g., high-power converters with a low switching frequency. In such cases, additional 0-dB crossings (phase margins) appear; therefore, the usual methods for simple systems are no longer valid. In addition, VPI controllers always present multiple 0-dB crossings in their frequency response. In this paper, the proximity to the instability of PR and VPI controllers is evaluated and optimized through Nyquist diagrams. A systematic method is proposed to obtain the highest stability and avoidance of closed-loop anomalous peaks: it is achieved by the minimization of the inverse of the Nyquist trajectory distance to the critical point, i.e., the sensitivity function. Finally, several experimental tests, including an active power filter that operates at a low switching frequency and compensates harmonics up to the Nyquist frequency, validate the theoretical approach.
413 citations
TL;DR: The transmission line model with pore size distribution (TLM-PSD) developed for blocking electrodes without faradaic reactions in this article was reformulated on the basis of the distribution of the penetrability coefficient α 0, which is a more generalized concept than the distribution for pore sizes.
302 citations
TL;DR: In this article, a two-step procedure is proposed to fit impedance data to an equivalent electric circuit model (EECM) using complex nonlinear least square (CNLS) to extract physical parameters from impedance data.
281 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 6 |
| 2024 | 38 |
| 2023 | 80 |
| 2022 | 148 |
| 2021 | 66 |
| 2020 | 88 |