Power Routing Research Articles

Power Routing: Active Asset Management in Power Electronics Systems

This article proposes a power routing approach for active asset management in power-electronic-based power systems. The proposed approach aims to expand the lifecycle of power converters as the key assets of modern energy systems. Moreover, it takes into account the operational costs of converter-based generation units in order to obtain economic dispatch in the system. As a result, the useful lifetime of converters is enhanced, thus improving the overall reliability of the system with respect to the operational costs of the generations. A numerical case study on a dc distribution system is presented to illustrate the effectiveness of the proposed approach.

Power and meaning within patriarchal societies: Thinking within, against and beyond the system

The See Me Before the PD Group (SMBPD) are a coproduction group of Experts by Experience and Experts by Profession in Northern Ireland, who came together through seeking or providing treatment for suicidal distress and chronic self-harm. The purpose of the group is to promote a positive image of people labelled as having ‘personality disorder’. Coproduction work and engaging with community activists is a powerful route to addressing social inequalities and enhancing our knowledge base and approaches.

Design of a Multiloop Control Structure for Load-Disturbance Attenuation and Power-Mismatch Mitigation in Isolated Multiport Power Converters

This article proposes a multiloop control structure for isolated multiport power converters (IMPCs), which includes a multiloop load-disturbance attenuation controller (MLDAC) and also an improved multiloop power-mismatch mitigation controller (MPMMC). The inherent capability of the IMPC to use a common magnetic link (CML) instead of multiple magnetic links offers an attractive solution to design a compact multimodule-based IMPC. With the proposed MLDAC, the IMPC can regulate the system voltage for any load disturbance without requiring any feedforward output current sensor. Moreover, the proposed MPMMC effectively mitigates leakage parameter mismatch and strictly balances the power routing in the multiple ports of the IMPC. The proposed MLDAC and MPMMC are decoupled with an improved decoupling mechanism. Additionally, this article develops a control law to indicate a safe operating area of the MPMMC. The strict voltage regulation of the IMPC under random load disturbance facilitates plug-n-play connectivity and supply of power to pulsed power loads. Moreover, eliminating the power-mismatch issues in the CML ensures equal thermal stresses and duty-life cycles of the solid-state switching devices. The performance of the proposed MLDAC is tested and compared with existing disturbance attenuation techniques. The simulation and the experimental results substantiate the superiority of the proposed MLDAC and MPMMC.

Resilient outage recovery of a distribution system: co-optimizing mobile power sources with network structure

Outage recovery is important for reducing the economic cost and improving the reliability of a distribution system (DS) in extreme weather and with equipment faults. Previous studies have separately considered network reconfiguration (NR) and dispatching mobile power sources (MPS) to restore the outage load. However, NR cannot deal with the scenario of an electrical island, while dispatching MPS results in a long power outage. In this paper, a resilient outage recovery method based on co-optimizing MPS and NR is proposed, where the DS and traffic network (TN) are considered simultaneously. In the DS, the switch action cost and power losses are minimized, and the access points of MPSs are changed by carrying out the NR process. In the TN, an MPS dispatching model with the objective of minimizing power outage time, routing and power generation cost is developed to optimize the MPSs’ schedule. A solution algorithm based on iteration and relaxation methods is proposed to simplify the solving process and obtain the optimal recovery strategy. Finally, numerical case studies on the IEEE 33 and 119-bus systems validate the proposed resilient outage recovery method. It is shown that the access point of MPS can be changed by NR to decrease the power outage time and dispatching cost of MPS. The results also show that the system operation cost can be reduced by considering power losses in the objective function.

Heterointerface-triggered electronic structure reformation: Pd/CuO nano-olives motivate nitrite electroreduction to ammonia

Electrochemical nitrite reduction reaction (NO2−RR) to synthesize NH3 is a green and sustainable technology. Herein, we report porous-rich Pd/CuO nano-olives (Pd/CuO NOs) with heterointerfaces for efficient NO2−RR. The porous structure of Pd/CuO NOs provides abundant channels for molecular permeation and increases the accessible active sites between the reactant and the catalyst. More importantly, the Pd/CuO heterointerfaces spontaneously establish a built-in electric field in the interfacial region, which favorably adjusts the electronic structure of Pd and Cu sites and optimizes the adsorption of NO2− and reaction intermediates. Benefiting from structural advantages and interfacial engineering, the Pd/CuO NOs exhibit excellent NO2−RR performance (NH3 yield rate: 906.4 μg h−1 mg−1cat., NH3 Faradaic efficiency: 91.8%, NH3 selectivity: 94.9%) at − 1.5 V. This work provides a powerful route for fabricating porous-rich heterostructures with local charge polarization and provides a promising strategy for design of efficient catalysts for various electrocatalytic and electrosynthesis applications, beyond NO2−RR.

Surface crystallization enhanced upconversion luminescence in NaGdF4:Yb,Er@NaYF4 core/shell nanocrystals

Coating upconversion nanocrystals with an inert shell for removing surface defects is confirmed to be an efficient way for remarkably enhancing upconversion luminescence. However, it is not clear whether surface atomic structures on the outer inert shell affect upconversion luminescence of active cores. Here, we improved the surface crystallinity of NaGdF4:Yb,Er@NaYF4 active-core/inert-shell nanocrystals using ultrasonic oscillation. It was observed that surface crystallization of the inert shell could lead to an obvious enhancement in upconversion luminescence. The improved surface crystallinity has no obvious influence on the electronic transition in upconversion luminescence processes, but decrease the scattering and absorption to excitation and emission photons. This result clearly indicates that surface crystallization of the inert shell is a powerful route for further enhancing upconversion luminescence besides of the concept of core/shell structure.

Optically and Mechanically Engineered Anti‐Reflective Film for Highly Efficient Rigid and Flexible Perovskite Solar Cells

AbstractSticker‐type anti‐reflective (AR) film is a powerful route to achieve the highest efficiency and commercialization of perovskite solar cells (PSCs) by improving the light transition efficiency (LTE). However, conventionally used AR film has high flexural rigidity owing to its limitation of material and thickness, thereby hindering its application to high‐efficiency flexible devices. This paper proposes a sticker‐type ultra‐thin perfluoropolyether (PFPE) AR film (SUPA) made of PFPE (n = 1.34) that is fabricated through a well‐designed two‐step peeling propagation method. The proposed SUPA demonstrates superior properties in terms of LTE (≈98.3%) and film thickness (≈20 µm), exhibiting the best performance among the existing AR films for PSCs. The SUPA‐assisted rigid and flexible PSC guarantees high short‐circuit current density (rigid ≈26.63 mA cm−2, flexible ≈23.05 mA cm−2) and power conversion efficiency (rigid ≈24.31%, flexible ≈20.05%). The SUPA sustains over 97.5% of its initial transmittance under exposure to the light (168 h) and damp heat condition (1000 h), and devices with SUPA show remarkable flexibility maintaining their initial efficiency after 10 000 cycles of a bending test (2 mm radius).

Dynamic control of octahedral rotation in perovskites by defect engineering

Engineering oxygen octahedra rotation patterns in $ABO_3$ perovskites is a powerful route to design functional materials. Here we propose a strategy that exploits point defects that create local electric dipoles and couple to the oxygen sublattice, enabling direct actuation on the rotational degrees of freedom. This approach, which relies on substituting an $A$ site with a smaller ion, paves a way to couple dynamically octahedra rotations to external electric fields. A common antisite defect, $\mathrm{Al_{La}}$ in rhombohedral LaAlO$_3$ is taken as a prototype to validate the idea, with atomistic density functional theory calculations supported with an effective lattice model to simulate the dynamics of switching of the local rotational degrees of freedom to long distances. Our simulations provide an insight of the main parameters that govern the operation of the proposed mechanism, and allow to define guidelines for screening other systems where this approach could be used for tuning the properties of the host material.

Self-Assembled Artificial Nanocilia Actuators.

Self-assembly of nanoparticles (NPs) is a powerful route to constructing higher-order structures. However, the programmed self-assembly of NPs into non-close-packed, 3D, shape-morphing nanocilia arrays remains elusive, whereas dynamically actuated nanometer cilia are universal in living systems. Here, a programmable self-assembly strategy is presented that can direct magnetic NPs into a highly ordered responsive artificial nanocilia actuator with exquisite nanometer 3D structural arrangements. The self-assembled artificial NP cilia can maintain their structural integrity through the interplay of interparticle interactions. Interestingly, the nanocilia can exhibit a field-responsive actuation motion through "rolling and sliding" between assembled NPs rather than bending the entire ciliary beam. It is demonstrated that oleic acid coated over the NPs acts as a lubricating bearing and enables the rolling/sliding-based actuation of the cilia.

Technical pipeline for screening microbial communities as a function of substrate specificity through fluorescent labelling

The study of specific glycan uptake and metabolism is an effective tool in aiding with the continued unravelling of the complexities in the human gut microbiome. To this aim fluorescent labelling of glycans may provide a powerful route towards this target. Here, we successfully used the fluorescent label 2-aminobenzamide (2-AB) to monitor and study microbial degradation of labelled glycans. Both single strain and co-cultured fermentations of microbes from the common human-gut derived Bacteroides genus, are able to grow when supplemented with 2-AB labelled glycans of different monosaccharide composition, degrees of acetylation and polymerization. Utilizing a multifaceted approach that combines chromatography, mass spectrometry, microscopy and flow cytometry techniques, it is possible to better understand the metabolism of labelled glycans in both supernatants and at a single cell level. We envisage this combination of complementary techniques will help further the understanding of substrate specificity and the role it plays within microbial communities.

Open Force Field Evaluator: An Automated, Efficient, and Scalable Framework for the Estimation of Physical Properties from Molecular Simulation.

Developing accurate classical force field representations of molecules is key to realizing the full potential of molecular simulations, both as a powerful route to gaining fundamental insights into a broad spectrum of chemical and biological phenomena and for predicting physicochemical and mechanical properties of substances. The Open Force Field Consortium is an industry-funded open science effort to this end, developing open-source tools for rapidly generating new high-quality small-molecule force fields. An integral aspect of this is the parameterization and assessment of force fields against high-quality, condensed-phase physical property data, curated from open data sources such as the NIST ThermoML Archive, alongside quantum chemical data. The quantity of such experimental data in open data archives alone would require an onerous amount of human and computational resources to both curate and estimate manually, especially when estimations must be obtained for numerous sets of force field parameters. Here, we present an entirely automated, highly scalable framework for evaluating physical properties and their gradients in terms of force field parameters. It is written as a modular and extensible Python framework, which employs an intelligent multiscale estimation approach that allows for the automated estimation of properties from simulation and cached simulation data, and a pluggable API for estimation of new properties. In this study, we demonstrate the utility of the framework by benchmarking the OpenFF 1.0.0 small-molecule force field and GAFF 1.8 and GAFF 2.1 force fields against a test set of binary density and enthalpy of mixing measurements curated using the framework utilities. Further, we demonstrate the framework's utility as part of force field optimization by using it alongside ForceBalance, a framework for systematic force field optimization, to retrain a set of nonbonded van der Waals parameters against a training set of density and enthalpy of vaporization measurements.

Designer Gold‐Framed Palladium Nanocubes for Plasmon‐Enhanced Electrocatalytic Oxidation of Ethanol

Surface plasmon of coinage metal nanostructures has been employed as a powerful route in boosting the performances in heterogenous catalysis. Development of efficient plasmonic nanocatalysts with high catalytic performance and efficient light harvesting properties is of vital importance. Herein, we rationally designed and synthesized a plasmonic nanocatalyst composed of Au-framed Pd nanocubes by an Ag(I)-assisted seed-mediated growth method. In the synthesis, the incorporation of Ag(I) suppresses the reduction of Au on the {100} surface of cubic Pd seeds and leads to the formation of Au nanoframes on the Pd nanocubes. The unique Au-framed Pd nanocubes can integrate the superior electrocatalytic of Pd and the outstanding plasmonic properties of Au. Thus, these nanostructures were employed as plasmonic nanocatalysts for plasmon-enhanced electrocatalytic oxidation of ethanol with improved stability.

Delay-Driven Opportunistic Routing with Multichannel Cooperative Neighbor Discovery for Industry 4.0 Wireless Networks Based on Power and Load Awareness

During data transmission, a decentralised Mobile Ad Hoc Network (MANET) might result in high Energy Consumption (EC) and a short Network Lifetime (NLife). To address these difficulties, an on-demand Power and Load-Aware multipath node-disjoint source routing is presented based on the Enhanced Opportunistic Routing (PLAEOR) protocol. This unique protocol aims at using power, load, and latency to manage routing costs depending on control packet flooding from the destination node. However, the exchange of control packets from the target to all nodes may impact network efficiency. As a result, the PLAEOR is designed with a Multichannel Cooperative Neighbor Discovery (MCND) protocol to locate the nearby cooperative nodes for each node in the routing path during control packet transmission. Furthermore, when the packet rate of CBR is 20 packets/sec, the simulated results show that the PLAEOR-MCND achieves 120 sec of NLife and 20 J of EC than the state-of-the-art protocols.

Supercapacitor voltage based power sharing and energy management strategy for hybrid energy storage system

Integrating batteries accomplishes a highly reliable, efficient, and durable photovoltaic (PV) DC microgrid. Supercapacitors (SC) boost the dynamics and battery life even further, and such a combination is known as a hybrid energy storage system (HESS). The control and power splitting between the battery and SC plays a crucial role in the operation of the HESS. The most common power routing method is constant bandwidth low pass filter (LPF), the drawback of which causes slow dynamics of the control loop and significant variation in SC operating voltage leads to ringing in the DC bus voltage. Hence, this work proposes a power management scheme with a variable bandwidth filter for HESS and a power splitting control strategy to eliminate the sluggishness imposed on the battery control loop by LPF. The proposed approach has several advantages over the conventional method, including efficient SC utilization, improved battery life, and better DC bus voltage regulation. The proposed scheme is validated using simulation results. Hardware tests have been carried out to verify the proposed system’s accuracy and viability.

Solvent Vapor Annealing for Controlled Pore Expansion of Block Copolymer-Assembled Inorganic Mesoporous Films.

Mesoporous inorganic thin films are promising materials architectures for a variety of high-value applications, ranging from optical coatings and purification membranes to sensing and energy storage devices. Having precise control over the structural parameters of the porous network is crucial for broadening their applicability. To this end, the use of block copolymers (BCP) as sacrificial structure-directing agents via micelle coassembly is a particularly attractive route, since the resultant pore size is directly related to scaling laws for the radius of gyration of the pore-forming macromolecule. However, tailoring the molecular weight of the BCP via bespoke synthesis is an elaborate process that requires precise control over highly sensitive reactions conditions. Alternative methods have emerged, based on supramolecular assembly or the addition of different swelling agents. Nevertheleses, to date, these present a negative impact on the structural order and pore size dispersity of the final inorganic mesoporous films. In this work, we propose a novel and effective method for control over pore size, porosity, and structural order, which relies on a synergistic combination of BCP selective swelling via solvent vapor annealing (SVA) and locking of the structure by condensation of the inorganic sol–gel precursors. The results obtained in this work for TiO2 establish SVA as a new, straightforward, simple, and powerful route for the fabrication of mesoporous thin-film materials with controllable structural characteristics.

Buried Interconnects for Sub-5 nm SRAM Design

The metal resistance increase due to interconnect pitch scaling was traditionally offset by interconnect length scaling. This is no longer the case for deeply scaled nodes with narrow critical dimensions (CDs) of metals. Static random access memories (SRAMs) route long critical signals such as bitlines and wordlines in lower metal layers of the back-end-of-line (BEOL) and are particularly affected by this metal resistance increase. Buried power rail (BPR) has been proposed in sub-5-nm nodes for routing power and ground lines to improve the performance and density of standard cells and mitigate voltage IR drop issues. We extend the work by exploring the use of buried interconnect for both signal and power routing in SRAMs with minimal process flow changes to the already proposed BPR technology. A high-accuracy 3-D field solver is used for accurate parasitic extraction of SRAM bitcells with buried interconnects. Industry-standard methods are used to evaluate the SRAM macro-level power–performance metrics. We show that the buried interconnects can improve SRAM access time by up to 11%, write time by up to 28%, and dynamic power by 4%, effectively equivalent to one full technology-node gain improvement.

Zeolite-encaged palladium catalysts for heterogeneous Suzuki-Miyaura cross-coupling reactions

Suzuki-Miyaura cross-coupling reaction by homogeneous Pd complex is a powerful route to construct carbon-carbon bond and is now widely applied in the synthesis of functional organic compounds. Heterogeneous Pd catalysts are highly desired as alternatives to homogeneous ones due to their facile reusability and good compatibility. Herein, zeolite-encaged Pd particles, namely Pd@MFI, have been successfully prepared via an in-situ hydrothermal strategy and investigated as promising heterogeneous catalysts for Suzuki-Miyaura cross-coupling reactions. Characterization results demonstrate that high dispersed Pd particles with apparent sizes of 1–2 nm have been encaged in and efficiently stabilized by the matrix of MFI zeolite. The as-prepared Pd@MFI catalysts are active in the Suzuki-Miyaura coupling reaction between bromobenzene and phenylboronic acid, and the presence of basic sites adjacent to Pd sites are crucial to achieving high catalytic activity via effective cooperation. Pd@K-ZSM-5 can be optimized for the coupling between bromobenzene and phenylboronic acid and can catalyze the reaction with a low apparent activation energy value of 41.2 kJ/mol. Pd@K-ZSM-5 also shows good stability and can be recycled for at least five times without obvious loss in activity, demonstrating its great potential as a heterogeneous catalyst for Suzuki-Miyaura cross-coupling reactions. Encapsulation of metal species in zeolite matrix offers a big opportunity to the heterogenization of homogeneous metal catalysts for practical chemical transformations.

A Directional Selective Power Routing Protocol for the Internet of Underwater Things

The Internet of Underwater Things (IoUT) has lately gained popularity as a means of facilitating a wide range of underwater applications. In the IoUT, underwater communication is best accomplished by the usage of acoustic waves, whereas the terrestrial communication between the surface sinks and the on-shore control stations is typically achieved using radio waves. As a result, the greatest portion of an IoUT is enabled by the underwater acoustic sensor network (UASN), where the specific issues provided by the use of acoustic waves, the underwater node mobility, and the localization difficulties have yet to be addressed. In this paper, we discuss the challenges faced by the IoUT in terms of the currently proposed routing protocols and propose a Directional Selective Power Routing Protocol (DSPR) to cope with most of these challenges. The proposed protocol (i.e., DSPR) uses the angle of arrival and the sender depth information to find the best direction to the surface sink. In addition, the DSPR uses selective power control to enhance the delivery ratio and ensure connectivity while reducing energy consumption. To testify the performance of the proposed protocol, intensive simulation experiments have been conducted. The simulation results show that the proposed DSPR protocol outperforms two variations of the fixed directional routing (DR) protocol and the variable power depth-based routing (VDBR) protocol in terms of energy consumption and delivery ratio. For instance, the proposed DSPR protocol achieves at least 8 times enhancement in energy consumption compared with VDBR. In addition, DSPR saves around 30% of energy consumption over the DR protocols when the network is mobile. Moreover, the DSPR protocol acquires a delivery ratio above 90% for static/dynamic scenarios in both sparse and dense networks.

Extending lifetime of heterogeneous wireless sensor networks using spider monkey optimization routing protocol

The nodes of wireless sensor networks (WSN) are severely restricted in terms of computing capabilities, limited communications, and limited power supplies, as it is difficult or impossible to replace or recharge the sensor battery. Consequently, the energy of nodes is one of the most important resources to consider when designing of WSNs. So, most of the routing protocols in WSNs are to assure the saving of energy as a significant aim for improvement. Nevertheless, just providing power is not sufficient to extend the lifetime of WSN. Where unbalance energy depletion in WSNs is a challenging issue often leading to splits the network and reduces its lifetime, also retrogression of its performance. This paper, therefore, uses a powerful routing protocol named spider monkey optimization routing protocol (SMORP) to generate an optimal data routing of the pathway for heterogeneous WSNs (HWSNs). SMORP, here, can compute the best way from a sensor to the sink through the cluster head, inside the intra-cluster, and the inter-cluster respectively. For this purpose and the organization of heterogeneous nodes, this paper uses the clustering partition. The simulation results revealed that SMORP significantly improves in terms of data latency reduction, stabilizing depletion of energy, and maximizing the network lifetime for HWSNs.

Pulsed‐Laser‐Deposition Fabricated ZnIn2S4 Photodetectors with Excellent ON/OFF Switching Characteristics toward High‐Temperature‐Resistant Photodetection Applications

AbstractThe extensively explored unary and binary 2D layered materials (2DLMs) based photodetectors suffer from deficiencies of either poor stability, or indistinctive photoswitching, or poor scalability, or low durability to high‐temperature environment. Herein, a two‐step scenario, pulsed laser deposition (PLD) followed by post‐deposition annealing, is developed to produce centimeter‐scale 2D ZnIn2S4 (ZIS) nanofilms. Transport characterizations indicate that the as‐fabricated ZIS photodetectors manifest outstanding photosensitivity with an on/off switching ratio beyond 1000 upon 405 nm illumination. Beyond this, it is revealed that the photoresponse of the ZIS photodetectors increases with increasing channel thickness, where a responsivity of 1.4 A W−1, an external quantum efficiency of 430% and a detectivity of 9.8 × 109 Jones (1 Jones = 1 cm Hz1/2 W–1) are demonstrated with a pulse number of 10 000. In addition, these devices without encapsulation maintain stable within 1900 photoswitching cycles and over a one‐month storage in air. Furthermore, robust photoswitching is demonstrated under an operating temperature up to 150 °C. In summary, all these findings establish that PLD provides a powerful route to produce large‐scale multielement 2DLMs and the PLD‐derived ZIS photodetectors hold grand prospect for photoelectric technologies in specific high‐temperature environments (e.g., the lunar exploration program).