Stability analysis of Cu−C6H9NaO7 and Ag−C6H9NaO7 nanofluids with effect of viscous dissipation over stretching and shrinking surfaces using a single phase model

This paper proposes an overall practical stability assessment for a multi-port single-phase solid-state transformer (MS3T) in the electromagnetic timescale. When multiple stable subsystems are combined into one MS3T, the newly formed MS3T has a certain possibility to be unstable. Thus, this paper discusses the stability assessment of the MS3T in detail. First and foremost, the structure of the MS3T and its three stage control strategies are proposed. Furthermore, the stability analysis of each of the MS3T’s subsystems is achieved through the closed loop transfer function of each subsystem, respectively, including an AC-DC front-end side converter, dual active bridge (DAB) with a high-frequency (HF) or medium-frequency (MF) transformer, and back-end side incorporating DC-AC and dc-dc converters. Furthermore, the practical impedance stability criterion in the electromagnetic timescale, which only requires two current sensors and one external high-bandwidth small-signal sinusoidal perturbation current source, is proposed by the Gershgorin theorem and Kirchhoff laws. Finally, the overall stability assessment, based on a modified impedance criterion for the MS3T is investigated. The overall practical stability assessment of the MS3T can be validated through extensive simulation and hardware results.

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Study of Steady, Two-Dimensional, Unicellular Convection in a Water-Copper Nanoliquid-Saturated Porous Enclosure Using Single-Phase Model

Trends in Mathematics - Applied Mathematics and Scientific Computing ◽

10.1007/978-3-030-01123-9_16 ◽

2019 ◽

pp. 147-155

Author(s):

P. G. Siddheshwar ◽

B. N. Veena

Keyword(s):

Single Phase ◽

Phase Model ◽

Two Dimensional ◽

Porous Enclosure

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Impedance Modeling and Stability Analysis of Weak-Grid Interfaced Single-Phase VSG

2019 22nd International Conference on Electrical Machines and Systems (ICEMS) ◽

10.1109/icems.2019.8921704 ◽

2019 ◽

Author(s):

Xinying Zhang ◽

Jie Chen ◽

Xin Chen

Keyword(s):

Stability Analysis ◽

Single Phase ◽

Weak Grid ◽

Impedance Modeling

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Dual similarity solutions of MHD stagnation point flow of Casson fluid with effect of thermal radiation and viscous dissipation: stability analysis

Scientific Reports ◽

10.1038/s41598-020-72266-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Liaquat Ali Lund ◽

Zurni Omar ◽

Ilyas Khan ◽

Dumitru Baleanu ◽

Kottakkaran Sooppy Nisar

Keyword(s):

Stability Analysis ◽

Differential Equations ◽

Thermal Radiation ◽

Stagnation Point ◽

Viscous Dissipation ◽

Shooting Method ◽

Casson Fluid ◽

Similarity Solutions ◽

Stagnation Point Flow ◽

Stretching Surfaces

Abstract In this paper, the rate of heat transfer of the steady MHD stagnation point flow of Casson fluid on the shrinking/stretching surface has been investigated with the effect of thermal radiation and viscous dissipation. The governing partial differential equations are first transformed into the ordinary (similarity) differential equations. The obtained system of equations is converted from boundary value problems (BVPs) to initial value problems (IVPs) with the help of the shooting method which then solved by the RK method with help of maple software. Furthermore, the three-stage Labatto III-A method is applied to perform stability analysis with the help of a bvp4c solver in MATLAB. Current outcomes contradict numerically with published results and found inastounding agreements. The results reveal that there exist dual solutions in both shrinking and stretching surfaces. Furthermore, the temperature increases when thermal radiation, Eckert number, and magnetic number are increased. Signs of the smallest eigenvalue reveal that only the first solution is stable and can be realizable physically.

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