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In this paper, the generalized (3+1)-dimensional nonlinear wave equation in fluid with gas bubbles is studied in soliton theory and produced by taking the Hirota bilinear operators. The first- to third rogue wave solutions through numerous rogue wave strategy by Maple typical estimations are recovered. The made conditions for the analyticity and positively of the gotten arrangements can be effectively accomplished by utilizing the specific determinations of the included values. The most merits of this plot are to recoup the Hirota bilinear models and their generalized equivalences. Also, the rational tan(Π(ξ)) technique on the generalized nonlinear wave equation is examined. The perturbed solution of the generalized nonlinear wave equation through the way of Modulational stability is studied. Finally, the graphical reenactments of the precise arrangements are portrayed. By selecting suitable values for the parameters involved in the solutions, 3D graphs, 2D contour graphs and line graphs are presented to provide graphical demonstration of the results. The reported results will be helpful to design new and better optical devices. The findings of this work may also help in problems arising in ocean engineering.

Hydrogen energy storage systems are becoming increasingly accepted owing to their environmental friendliness. The efficiency and performance of these systems largely depend on the attributes of their power electronic interface systems. Among the promising solutions is a multiport-isolated DC-DC converter with characteristics of reduced component count, fewer conversion stages, and galvanic isolation. However, this system presents a challenge due to its inherent cross-coupling effect, complicating precise control. To address this, linear active disturbance rejection control (LADRC) is a viable option, leveraging dynamic/disturbance properties observed by linear extended state observers. LADRC serves as a decoupling controller, mitigating the cross-coupling effect. However, LADRC has several gains, and selecting them can be a difficult task, often requiring manual tuning. To streamline this process, this paper proposes utilising particle swarm optimisation to determine the optimum gains of LADRC. By employing this approach, the implementation of LADRC is facilitated with reduced design efforts while ensuring effective decoupling control within the system. Simulations are conducted to validate the performance of the optimised gain LADRC.

The integration of multiterminal hybrid HVDC grids connecting LCC- and VSC-based networks faces several technical challenges such as DC fault isolation, ensuring multi-vendor interoperability, managing high DC voltage levels, and facilitating high-speed power reversal without interruptions. The two-stage DC-DC converter emerges as a key solution to address these challenges. By implementing the modular multilevel converter (MMC) structure, the converter's basic topology includes half-bridge sub-modules on the VSC side and full-bridge sub-modules on the LCC side. However, while this topology has been discussed in the literature, its connection to an LCC-based network with controlled current magnitude lacks detailed analysis regarding operational challenges, control strategies under various scenarios, and design considerations. This paper fills this gap by providing comprehensive mathematical analysis, design insights, and control strategies for the modular DC-DC converter to regulate DC voltage on the LCC-HVDC side. Additionally, the proposed control scheme minimizes the interfacing inductor between the two bridges, ensuring uninterrupted power flow during reversal and effective handling of DC faults. Validation through Control-Hardware-in-the-Loop testing across diverse operational and fault scenarios, along with a comparative analysis of different converters, further strengthens the findings.© 2017 Elsevier Inc. All rights reserved.

The rapid growth in HVDC grids is becoming inevitable for long-distance power transmission. Therefore, the idea of interconnection between the point-to-point links becomes essential. However, these point-to-point connections face several challenges such as the requirement of DC fault blocking capability, interfacing of different grounding schemes, offering multi-vendor interoperability, and difficulty to achieve high DC voltage stepping. DC-DC converters are considered the optimum solution to tackle these challenges in DC grids interconnection. In this paper, a new hybrid modular DC-DC converter is proposed that achieves a low number of semiconductors, low losses, and cost in comparison to other DC-DC converters due to the utilization of thyristors. The new DC-DC converter consists of two hybrid MMC bridges connected through an isolating transformer. Each MMC bridge is comprised of half bridge submodules and bidirectional thyristors. Detailed mathematical analysis, design, and control are illustrated. A comparison is carried out between different topologies in terms of semiconductor count, power loss, and cost. Also, both simulation model and experimental test rig are built to validate the proposed hybrid modular DC-DC converter under different scenarios. Finally, another variant of the hybrid-thyristor based converter (version two) is proposed for multiport DC-Hub application to achieve DC fault blocking without turning off all connected bridges.

Solid polymer electrolytes containing methylcellulose:dextran (MC-DEX), ammonium hexafluorophosphate (NH4PF6), and glycerol have been prepared via the solution cast method. Various techniques have been used to characterize the prepared electrolyte samples. Fourier transform infrared spectroscopy (FTIR) analysis revealed the interaction between polymers and electrolyte components. According to the electrical impedance spectroscopy (EIS), the highest conducting plasticized system achieves a conductivity of 6.71 × 10-4 S cm−1 at ambient temperature. The mobility, number density, and diffusion coefficient of ions were measured using both FTIR and EIS methods, and it was found that their values rise as the amount of glycerol increases. Polarization due to ion migration is responsible for the high value of dielectric parameters. According to transference number measurement (TNM), the transport ion (tion) is 0.92, verifying that the ions are the primary charge carriers. The electrochemical stability window of the maximum conducting plasticized system is 1.58 V, based on linear sweep voltammetry (LSV) analysis. The electrical double-layer capacitor (EDLC) device is fabricated using the highest conducting plasticized system. The cyclic voltammetry (CV) curve is roughly rectangular in shape and with no presence of Faradaic peaks with its specific capacitance of 32.69F/g at 10 mV/s.

In this paper, the generalized (3+1)-dimensional nonlinear wave equation in fluid with gas bubbles is studied in soliton theory and produced by taking the Hirota bilinear operators. The first- to third rogue wave solutions through numerous rogue wave strategy by Maple typical estimations are recovered. The made conditions for the analyticity and positively of the gotten arrangements can be effectively accomplished by utilizing the specific determinations of the included values. The most merits of this plot are to recoup the Hirota bilinear models and their generalized equivalences. Also, the rational tan (Π (ξ)) technique on the generalized nonlinear wave equation is examined. The perturbed solution of the generalized nonlinear wave equation through the way of Modulational stability is studied. Finally, the graphical reenactments of the precise arrangements are portrayed. By selecting suitable values for the parameters involved in the solutions, 3D graphs, 2D contour graphs and line graphs are presented to provide graphical demonstration of the results. The reported results will be helpful to design new and better optical devices. The findings of this work may also help in problems arising in ocean engineering. [ABSTRACT FROM AUTHOR]