Direct calculation of the stability domains of three-phase ferroresonance in isolated neutral networks with grounded neutral voltage transformers

An easy recyclable and interesting Ag3PO4@Pt@TiO2 (APTP) three-phase heterocrystal chains were self-assembled by the cohesive action and chemical construction of polyvinylpyrrolidone (PVP). We found that a new electron–hole transmission path has been built via the rematch of the band structure of Ag3PO4, Pt and TiO2 which extends the light absorption and promoted the electron–hole separation to treat the antibiotic residues in the water. Based on the thorough investigations, a new catalytic material was provided for antibiotics degradation. The catalytic activity of APTP toward the degradation of tetracycline solution was enhanced by 166.67% and the stability increased remarkably compared with pure Ag3PO4 through the integration of different functional components.

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The Impact of Three-phase Impedances on the Stability of DER Systems

10.1109/naps52732.2021.9654621 ◽

2021 ◽

Author(s):

Jaimie Swartz ◽

Alexandra Von Meier

Keyword(s):

Three Phase ◽

The Stability ◽

The Impact

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Optimization and comparative analysis of PID and FOPID controller for BLDC motor

IAES International Journal of Robotics and Automation (IJRA) ◽

10.11591/ijra.v8i3.pp174-183 ◽

2019 ◽

Vol 8 (3) ◽

pp. 174

Author(s):

P. Vimala ◽

C. R. Balamurugan ◽

A. Subramanian ◽

T. Vishwanath

Keyword(s):

Genetic Algorithm ◽

Comparative Analysis ◽

Input Signal ◽

Pid Controller ◽

Input Voltage ◽

Bldc Motor ◽

Phase Inverter ◽

Three Phase ◽

The Stability ◽

Three Phase Inverter

The FOPID and PID controller are designed to control the speed of <br /> the BLDC motor. The parameters , , , λ and µ of these controller are optimized based on genetic algorithm. The optimized coefficients keep in track with zero error signals. The output of the controller is given to the variable dc source which varies the input voltage to the three phase inverter depending on the input signal. The three phase inverter gives the voltage to the BLDC motor which enhances the stability of the system. <br /> The effectiveness of the controller is demonstrated by simulation.

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Coupling Influence on the dq Impedance Stability Analysis for the Three-Phase Grid-Connected Inverter

Energies ◽

10.3390/en12193676 ◽

2019 ◽

Vol 12 (19) ◽

pp. 3676

Author(s):

Chuanyue Li ◽

Taoufik Qoria ◽

Frederic Colas ◽

Jun Liang ◽

Wenlong Ming ◽

...

Keyword(s):

Stability Analysis ◽

Nyquist Plot ◽

Current Control ◽

Impedance Ratio ◽

Three Phase ◽

Grid Impedance ◽

Nyquist Criterion ◽

Grid Connected Inverter ◽

The Stability ◽

The Right

The dq impedance stability analysis for a grid-connected current-control inverter is based on the impedance ratio matrix. However, the coupled matrix brings difficulties in deriving its eigenvalues for the analysis based on the general Nyquist criterion. If the couplings are ignored for simplification, unacceptable errors will be present in the analysis. In this paper, the influence of the couplings on the dq impedance stability analysis is studied. To take the couplings into account simply, the determinant-based impedance stability analysis is used. The mechanism between the determinant of the impedance-ratio matrix and the inverter stability is unveiled. Compared to the eigenvalues-based analysis, only one determinant rather than two eigenvalue s-function is required for the stability analysis. One Nyquist plot or pole map can be applied to the determinant to check the right-half-plane poles. The accuracy of the determinant-based stability analysis is also checked by comparing with the state-space stability analysis method. For the stability analysis, the coupling influence on the current control, the phase-locked loop, and the grid impedance are studied. The errors can be 10% in the stability analysis if the couplings are ignored.

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Impedance Modeling and Stability Analysis for Cascade System of Three-Phase PWM Rectifier and LLC Resonant Converter

Energies ◽

10.3390/en11113050 ◽

2018 ◽

Vol 11 (11) ◽

pp. 3050 ◽

Cited By ~ 5

Author(s):

Rutian Wang ◽

Yuyang Wu ◽

Guoqing He ◽

Ying Lv ◽

Jiaxing Du ◽

...

Keyword(s):

Resonant Converter ◽

Pwm Rectifier ◽

Output Impedance ◽

Cascade System ◽

Signal Model ◽

Impedance Model ◽

Small Signal Model ◽

Three Phase ◽

Llc Resonant Converter ◽

The Stability

In this paper; the impedance model of PWM rectifier and LLC resonant converter are deduced, and the stability analysis of cascade system is studied. The principle of three-phase PWM rectifier is introduced; and the small signal model in d-q coordinate system is deduced. The expression of dc side output impedance model for PWM rectifier is derived. The LLC resonant converter is operated in a fixed-frequency state, and the LLC resonant converter is modeled as a small signal model. On this basis, the input impedance model expression of the LLC resonant converter is derived. According to the impedance stability criterion, it can seen that the amplitude of input impedance is greater than the amplitude of output impedance in a certain frequency domain. In addition, the Nyquist curve is not around the point (−1,0), which can judge that the cascade system is stable. In simulation software, a cascade system simulation is built and corresponding simulation curves are obtained, which verifies the stability of the cascade system.

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An Edge Dislocation in a Three-Phase Composite Cylinder Model

Journal of Applied Mechanics ◽

10.1115/1.2897182 ◽

1991 ◽

Vol 58 (1) ◽

pp. 75-86 ◽

Cited By ~ 64

Author(s):

H. A. Luo ◽

Y. Chen

Keyword(s):

Edge Dislocation ◽

Stable Equilibrium ◽

Phase Model ◽

Composite Cylinder ◽

Two Phase ◽

Trapping Mechanism ◽

Three Phase ◽

Cylinder Model ◽

Stable Equilibrium Position ◽

The Stability

An exact solution is given for the stress field due to an edge dislocation embedded in a three-phase composite cylinder. The force on the dislocation is then derived, from which a set of simple approximate formulae is also suggested. It is shown that, in comparison with the two-phase model adopted by Dundurs and Mura (1964), the three-phase model allows the dislocation to have a stable equilibrium position under much less stringent combinations of the material constants. As a result, the so-called trapping mechanism of dislocations is more likely to take place in the three-phase model. Also, the analysis and calculation show that in the three-phase model the orientation of Burgers vector has only limited influence on the stability of dislocation. This behavior is pronouncedly different from that predicted by the two-phase model.

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Divided DQ Small-Signal Model: A New Perspective for the Stability Analysis of Three-Phase Grid-Tied Inverters

IEEE Transactions on Industrial Electronics ◽

10.1109/tie.2018.2868271 ◽

2019 ◽

Vol 66 (8) ◽

pp. 6493-6504 ◽

Cited By ~ 11

Author(s):

Zhikang Shuai ◽

Yang Li ◽

Weimin Wu ◽

Chunming Tu ◽

An Luo ◽

...

Keyword(s):

Stability Analysis ◽

Small Signal ◽

Signal Model ◽

Small Signal Model ◽

Three Phase ◽

New Perspective ◽

The Stability

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Impedance-Based Interactions in Grid-Tied Three-Phase Inverters in Renewable Energy Applications

Energies ◽

10.3390/en12030464 ◽

2019 ◽

Vol 12 (3) ◽

pp. 464 ◽

Cited By ~ 12

Author(s):

Teuvo Suntio ◽

Tuomas Messo ◽

Matias Berg ◽

Henrik Alenius ◽

Tommi Reinikka ◽

...

Keyword(s):

Renewable Energy ◽

Experimental Measurements ◽

Stability Assessment ◽

Transient Performance ◽

Energy Applications ◽

Impedance Ratio ◽

Three Phase ◽

The Cross ◽

And Performance ◽

The Stability

Impedance-ratio-based interaction analyses in terms of stability and performance of DC-DC converters is well established. Similar methods are applied to grid-connected three-phase converters as well, but the multivariable nature of the converters and the grid makes these analyses very complex. This paper surveys the state of the interaction analyses in the grid-connected three-phase converters, which are used in renewable-energy applications. The surveys show clearly that the impedance-ratio-based stability assessment are usually performed neglecting the cross-couplings between the impedance elements for reducing the complexity of the analyses. In addition, the interactions, which affect the transient performance, are not treated usually at all due to the missing of the corresponding analytic formulations. This paper introduces the missing formulations as well as explicitly showing that the cross-couplings of the impedance elements have to be taken into account for the stability assessment to be valid. In addition, this paper shows that the most accurate stability information can be obtained by means of the determinant related to the associated multivariable impedance ratio. The theoretical findings are also validated by extensive experimental measurements.

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