Energy Flow Control Research Articles

Real-Time Structural Dynamics at the 3D/2D Perovskite Interface in CsPbBr3/PEA2PbBr4 Nano-heterostructures.

Three-dimensional (3D) and two-dimensional (2D) perovskite hybrid systems, known for their exceptional optoelectronic properties and stability, are revolutionizing optoelectronic materials research. However, fundamental physics of the 3D/2D interfaces and their dynamics remain poorly understood. We use fluorescence microspectroscopy to study the photoluminescence (PL) properties of 3D/2D nano-heterostructures of CsPbBr3/PEA2PbBr4 formed by postgrowth self-assembly. The in situ PL spectra uncover the presence of new structural phases, quasi-2D PEA2Csn-1PbnBr3n+1 layers of varying n, at the 3D/2D interface and demonstrate their reversible restructuring under light excitation at room temperature. The restructuring is a result of layer-by-layer cation diffusion at the epitaxial interfaces, manifested as reversible spectral shifts occurring on a time scale of seconds. Such dynamics ultimately leads to optimized distribution of the quasi-2D phases in the system for efficient energy transfer from the 2D to the 3D phases. Our findings provide new insights into controlling energy flow in 3D/2D perovskites for next-generation optoelectronic devices.

Emerging Advances in Lanthanide Photon Avalanche Nanophotonics.

Photon avalanche (PA) upconversion in lanthanide nanosystems represents a groundbreaking discovery, demonstrating an optical nonlinearity exceeding 50. This remarkable sensitivity to even the slightest light perturbations unlocks new possibilities for ultrasensitive biosensing, super-resolution imaging, and a range of other applications. This review delves into the fundamental mechanisms underlying PA and the approaches for controlling energy flow within these nanomaterials. We present innovative design strategies for optimizing optical dynamics tailored to specific applications. Furthermore, we critically assess the advantages and limitations of PA technology across diverse applications. In addition, we explore future directions, highlighting the key challenges and proposing pathways for further research. By enhancing the understanding of PA phenomena and encouraging interdisciplinary collaboration, this review seeks to foster ongoing innovation at the convergence of nanophotonics and materials science, pushing the boundaries of current capabilities in photonics research.

Robust control based on type-2 fuzzy logic for permanent magnet synchronous motor (PMSM)

This paper introduces a novel control technique utilizing the orientation of stator flux based on type 2 fuzzy controllers to control the mechanical power generated by a permanent magnet synchronous motor and addressing parametric variation challenges to enhance robust performance against external fluctuations. The Permanent Magnet Synchronous Motors driven by stator variables via two converters relies on these components to interface with the electrical network in distinct manners. The network-side converter facilitates continuous bus control and enhances power factor, while the motor-side converter enables precise control and optimization of energy flow during motor operation. The paper outlines the motor and converter models, followed by the development of control commands to regulate mechanical power (speed, torque) for optimal efficiency and production quality and we will then present a comparative study between the developed controls to highlight the best performing and most robust of each, . Numerical simulations demonstrate the effectiveness of implementing type 2 fuzzy logic control in achieving these objectives.

Agrochemical control of gene expression using evolved split RNA polymerase. II.

Agrochemical inducible gene expression system provides cost-effective and orthogonal control of energy and information flow in bacterial cells. However, the previous version of Mandipropamid inducible gene expression system (Mandi-T7) became constitutively active at room temperature. We moved the split site of the eRNAP from position LYS179 to position ILE109. This new eRNAP showed proximity dependence at 23 °C, but not at 37 °C. We built Mandi-T7-v2 system based on the new eRNAP and it worked in both Escherichia coli and Agrobacterium tumefaciens. We also induced GFP expression in Agrobacterium cells in a semi-in vivo system. The modified eRNAP when combined with the leucine zipper-based dimerization system, behaved as a cold inducible gene expression system. Our new system provides a means to broaden the application of agrochemicals for both research and agricultural application. Portions of this text were previously published as part of a preprint (https://www.biorxiv.org/content/10.1101/2024.04.02.587689v1).

Research on Plug-in Hybrid Electric Vehicle (PHEV) Energy Management Strategy with Dynamic Planning Considering Engine Start/Stop

The key to improving the fuel economy of plug-in hybrid electric vehicles (PHEVs) lies in the energy management strategy (EMS). Existing EMS often neglects engine operating conditions, leading to frequent start–stop events, which affect fuel economy and engine lifespan. This paper proposes an Integrated Engine Start–Stop Dynamic Programming (IESS-DP) energy management strategy, aiming to optimize energy consumption. An enhanced rule-based strategy is designed for the engine’s operating conditions, significantly reducing fuel consumption during idling through engine start–stop control. Furthermore, the IESS-DP energy management strategy is designed. This strategy comprehensively considers engine start–stop control states and introduces weighting coefficients to balance fuel consumption and engine start–stop costs. Precise control of energy flow is achieved through a global optimization framework to improve fuel economy. Simulation results show that under the World Light Vehicle Test Cycle (WLTC), the IESS-DP EMS achieves a fuel consumption of 3.36 L/100 km. This represents a reduction of 6.15% compared to the traditional DP strategy and 5.35% compared to the deep reinforcement learning-based EMS combined with engine start–stop (DDRL/SS) strategy. Additionally, the number of engine start–stop events is reduced by 43% compared to the DP strategy and 16% compared to the DDRL/SS strategy.

Application and Optimization of Multi-Factor Authentication and Biometric Technology in Power Grid Energy Network Access Control

With the sudden development in electronic and network technology, the power grid has emerged in several evolved nations and other areas with faster development. Energy storage can enhance the stability, resiliency and efficiency of the electric smart grid. The power grid transfers energy via bidirectional control of energy and information flow. In the power grid, a smart meter is an important component that is deployed on the user side to determine the consumption of energy regularly. However, the data about the usage of electricity leads to the leakage of the private information of the user, which threatens the privacy of the user. The attackers can change the in-transit message induce wrong information and sometimes cause disastrous action. Hence, it is important to assure data security and privacy of users by conducting authentication in power grid communication. An optimization technique named Puzzle Optimization Algorithm (POA) is designed for the efficient privacy-preserving aggregation approach with multi-factor authentication and a biometric scheme. Also, optimal key-based Elliptic Curve Cryptography (ECC) is used to encrypt the sensitive data that are securely stored. Authentication offers high security and texture analysis. In the registration phase, the privacy information of the person with their biometrics is the important feature point of the individual unique identification. Additionally, the designed approach is compared with other existing optimizations to analyse the functionality of the implemented technique. The simulation outcome defined that the suggested technique enhances user privacy and information security than other standard approaches.

Real-Time Simulation System for Small Scale Regional Integrated Energy Systems

Regional Integrated Energy Systems (RIESs) integrate wide spectrum of energy sources and storage with optimized energy management and further pollution reduction. This paper presents a real-time simulation system for RIESs powered by multiple digital signal processors (DSPs) with different means of data exchange. The RIES encompasses the DC microgrid (DMG), the district heat network (DHN), and the natural gas network (NGN). To realize multi-energy flow simulation, averaged switch models are investigated for different types of device-level units in the DMG, and the unified energy path method is used to build circuit-dual models of the DHN and NGN. A hierarchical island strategy (HIS) and a multi-energy dispatch strategy (MEDS) are proposed to enhance the energy flow control and operating efficiency. The two-layer HIS can adjust the operating status of device-level units in real time to achieve bus voltage stability in the DMG; MEDS uses energy conversion devices to decouple multi-energy flows and adopts the decomposed flow method to calculate the flow results for each network. The real-time simulation hardware platform is built, and both electricity-led and thermal-led experiments are carried out to verify the accuracy of models and the effectiveness of the proposed strategy. The proposed system with an energy management strategy aims to provide substantial theoretical and practical contributions to the control and simulation of RIESs, thus supporting the advancement of integrated energy systems.

Implementation of energy flow control of underground consumers in an iron ore mine

Implementation of energy flow control of underground consumers in an iron ore mine

Sunlight-Driven Smart Windows with a Wide Temperature Range of Optical Switching Based on Chiral Nematic Liquid Crystals.

Photoresponsive liquid crystals are promising materials for sunlight-driven smart windows, which can automatically change their optical states in response to sunlight and control energy flow between the inside and outside of a building. Herein, liquid-crystalline systems are developed that show a transparent-scattering transition upon irradiation with sunlight in a wide temperature range. Push-pull azobenzenes with axial chirality have been newly developed as photochromic chiral dopants to allow changes in mesostructures of liquid crystals in response to sunlight. To realize optical switching, photochromic and photoinert chiral compounds with opposite handedness of helical twisting are doped in liquid crystals. This liquid crystalline sample with a compensated nematic phase is transparent in its initial state. Upon irradiation with sunlight, this sample transforms to a scattering state due to the formation of helical mesostructures along with photoisomerization of azobenzene moieties and the change in the helical twisting power. After the cease of irradiation, the sample reverts to the transparent state through thermal back isomerization of azobenzene moieties. This system significantly improves the operating temperature range of sunlight-driven smart windows based on liquid crystals: the transparent-scattering transition is observed at 4-42 °C. The present mechanism allows development of autonomous and wireless smart windows adaptable to various environments.

Synergizing Battery-Powered Permanent Magnet Synchronous Motor Control with Integrated Modular Multilevel Converter Systems

This proposed work presents a comprehensive examination of a modular multilevel converter (MMC) combined with a permanent magnet synchronous motor (PMSM) for battery energy management in applications. In order to provide effective energy transfer and dynamic control, the Modular Multilevel Converter serves as a bridge between the battery system and the Permanent Magnet Synchronous Motor drive. By cleverly controlling energy flow and minimizing losses during charging and discharging cycles, the combination of MMC with PMSM seeks to increase energy efficiency and prolong battery life. Since the energy source provides all of the power for the motor, it runs at a constant pace. When the accelerating mode finishes, the energy storage receives just enough power to maintain a steady voltage. The energy storage system utilizes the majority of the renewable power generated by the electric motor when it is in deceleration mode to raise the voltage in the system. During the subsequent acceleration mode, the stored energy might be released the MMC-BESS, which combines a modular multilevel converter with a battery energy storage system, is gaining popularity due to its high adaptability and dependability. This system integrates batteries into a sub module. Sub-modular capacitor voltage fluctuations are caused by the significant reactive power that is generated through the workings of modular multilevel converters. To reduce the fluctuation, large capacitance capacitors is required, which would significantly increase the system's capacity. The proposed approach means to upgrade energy proficiency and execution in electric vehicle applications. By joining the benefits of battery power with the flexibility of MMC frameworks, the arrangement offers upgraded control accuracy, decreased misfortunes, and further developed adaptation to non-critical failure. This combination works with consistent power the executives, guaranteeing ideal use of assets while meeting severe execution prerequisites. Through exhaustive examination and recreation, the adequacy of this incorporated framework is illustrated, displaying propelling the field of electric vehicle impetus and power conversion potential.

Photonic Spin‐Hall Logic Devices Based on Programmable Spoof Plasmonic Metamaterial

AbstractThe entanglement of the momentum of light with its spin at interfaces or inside structured media, known as the photonic spin‐Hall effect, holds great promise for various applications, such as beam splitting, focusing, and polarization detection. However, the photonic spin‐Hall effect remains unexplored in the field of logic operation. In this work, the photonic spin‐Hall effect of spoof surface plasmon polaritons (SSPPs) in programmable metamaterial is demonstrated. Moreover, photonic spin‐Hall logic devices based on programmable spoof plasmonic metamaterial are designed, enabling the control of energy flow through the utilization of both spin and digital coding, with examples including SSPPs logic gates such as the “AND” gate, the “NIMPLY” gate (A AND NOT B), the “OR” gate, and the “NOT” gate. The findings introduce the combination of digital coding metamaterial with the photonic spin Hall effect, which offers a powerful and flexible platform for controlling electromagnetic waves in information processing.

Power management strategy for photovoltaic system with hybrid storage (Batteries/Supercapacitors)

This paper is presented in regard to the interesting continuous interest attributed to photovoltaic energy systems (PESs). To this aim, a study of an isolated photovoltaic system with hybrid storage (HS) is presented. Supercapacitors (SCs) are typically used because of their high specific power density.. Combining batteries and supercapacitors is a solution to maximize their benefits. In this work, the HS is a combinaison of batteries and supercapacitors. The goal of this work is to build a new management algorithm. This aforementioned technique will ensure the control of energy flow between system power sources. Furthermore, it will regulate the charge/discharge cycles of the proposed HS by maintaining their state of charge (SOC) between a desired minimum and maximum values. The proposed method is simple, efficient and it is not computationally heavy. The obtained simulation results are satisfactory and show the interest and effectiveness of the proposed management strategy.

Arbitrary Wireless Energy Distribution within an Epsilon Near‐zero Environment

AbstractEfficient power distribution to multiple receivers with controlled amounts is critical for wireless communication and sensing systems. Previous efforts have attempted to improve power transfer efficiency through strong coupling and parity‐time (PT) symmetry, providing attractive opportunities for flexible energy flow control. In this study, a novel method for achieving arbitrary power distribution is proposed and numerically demonstrated by leveraging the unique properties inside an epsilon near‐zero (ENZ) environment. Specifically, it shows that the power from a single source can be transferred to multiple receivers inside an ENZ medium with negligible loss by modifying optical properties of receivers rather than introducing sophisticated active control modules. Importantly, full power transfer is independent of the size and shape of the ENZ medium, as well as the positions of the receivers and source. A realizable system is further designed with effective zero index at microwave frequencies to confirm the high efficiency of energy transfer. The innovative approach, employing photonic doping for advanced and efficient wireless power transfer, may shed light on the new generation of energy efficient communication/sensing systems with versatile control functionalities.

An Energy Flow Control Algorithm of Regenerative Braking for Trams Based on Pontryagin’s Minimum Principle

Energy savings in electric rail transport are important in order to increase energy efficiency and reduce its carbon footprint. This can be achieved by storing and using the energy generated during regenerative braking. The system described in this paper consists of a supercapacitor energy storage system (SC ESS), a bidirectional DC/DC converter, and an algorithm to control the energy flow. The proper design of the algorithm is critical for maximizing energy savings and stabilizing the power grid, and it affects the lifetime of the SC ESS. This paper presents an energy flow control algorithm based on Pontryagin’s minimum principle that balances maximum energy savings with maximum SC ESS lifetime. The algorithm also performs SC ESS recharging while the rail vehicle stops on inclines to reduce the impact of its next acceleration on the power grid. To validate the algorithm, offline simulations are performed using real tram speed measurements. The results are then verified with a real-time laboratory emulation setup with HIL simulation. The tram and power grid are emulated with LiFePO4 batteries, while the SC ESS is emulated with a supercapacitor. The proposed algorithm controls a three-phase converter that enables energy exchange between the batteries and the supercapacitor. The results show that the proposed algorithm is feasible in real time and that it can be used under real operating conditions.

DESIGN OF CLOSED LOOP MULTIPORT DC DC CONVERTER

In recent years, there has been lots of emphasis put on the development of renewable energy. While considerable improvement on renewable energy has been made, there are some inherent limitations for these renewable energies The Closed-Loop Multiport DC-DC Converter with Adaptive Sliding Mode Control (ASMC) is difficult in power electronics system designed to efficiently manage and control energy flow between multiple energy sources and loads in various applications, including renewable energy integration, electric vehicles, and microgrids. This paper provides an overview of the key features and benefits of this innovative converter system. Multiport DC-DC converters have gained significant attention due to their ability to interface multiple energy sources, such as solar panels and batteries with different voltage levels and power ratings, providing a versatile platform for energy management. The ASMC controller enhances the converter's performance by dynamically adjusting the control parameters based on system conditions and load requirements, thereby improving efficiency and reliability .The ASMC employs a sliding mode control strategy, a robust and adaptable control method, which ensures that the converter operates effectively under various operating conditions, including rapid changes in load and source characteristics. This control technique offers inherent advantages, such as fast transient response and reduced sensitivity to parameter variations, contributing to superior system performance. The ASMC controller optimizes power conversion by minimizing switching losses and ensuring that the converter operates close to its peak efficiency. The controller continuously adapts to changes in input voltage, output voltage, and load conditions, ensuring stable and reliable operation even in dynamic environments. The sliding mode control strategy enables rapid response to sudden load changes, making it suitable for applications with varying power demands. Key Words: DC-DC converter, Sliding-mode control, Battery, Solar PV.

An efficient intelligent energy management strategy based on deep reinforcement learning for hybrid electric flying car

Hybrid electric flying cars hold clear potential to support high mobility and environmentally friendly transportation. For hybrid electric flying cars, overall performance and efficiency highly depend on the coordination of the electrical and fuel systems under ground and air dual-mode. However, the huge differences in the scale and fluctuation characteristics of energy demand between ground driving and air flight modes make the efficient control of energy flow more complex. Thus, designing a power coordinated control strategy for hybrid electric flying cars is a challenging technical problem. This paper proposed a deep reinforcement learning-based energy management strategy (EMS) for a series hybrid electric flying car. A mathematical model of the series hybrid electric flying car driven by the distributed hybrid electric propulsion system (HEPS) which mainly consists of battery packs, twin turboshaft engine and generator sets (TGSs), 16 rotor-motors, and 4 wheel-motors is established. Subsequently, a Double Deep Q Network (DDQN)-based EMS considering ground and air dual driving mode is proposed. A simplified method for the number of control variables is designed to improve exploration efficiency and accelerate the convergence speed. In addition, the frequent engine on/off problem is also taken into account. Finally, DDQN-based and dynamic programming (DP)-based EMSs are applied to investigate the power flow distribution for two completely different hypothetical driving scenarios, namely search and rescue (SAR) scenarios and urban air mobility (UAM) scenarios. The results demonstrate the effectiveness of the DDQN-based EMS and its capacity of reducing the computation time.

Research on Key Technologies and Comprehensive ManagementStrategy of New Energy Hybrid Electric Vehicles

New energy hybrid electric vehicles (HEVs) have emerged as a promising technology for reducing the usage offossil fuels and emissions in the transportation sector. This paper reviews the key technologies and comprehensivemanagement strategy of new energy HEVs. The key technologies of new energy HEVs include battery technology,power technology, and comprehensive management strategy. Battery technology must provide high energy density, longcycle life, and high power density, while power technology must provide high efficiency, low emissions, and smoothpower delivery. The comprehensive management strategy includes energy management control and a battery thermalmanagement system, which optimize the battery’s energy flow and temperature control. The paper discusses the basicprinciples and components of new energy HEVs and examines the developments and research in each technology.The article also explores the challenges and opportunities of new energy HEVs. It concludes that the developmentand adoption of new energy HEVs are essential for achieving a sustainable transportation system and reducing thetransportation sector’s environmental impact.

Global Simulation Model Design of Input-Serial, Output-Parallel Solid-State Transformer for Smart Grid Applications

This paper provides an overview of an early attempt at developing a simulation model on a solid-state transformer (SST) based on input-serial and output-parallel (ISOP) topology. The proposed SST is designed as a base for a smart grid (SG). The paper provides a theoretical review of the power converters under consideration, as well as their control techniques. Further, the paper presents a simulation model of the proposed concept with a PLECS circuit simulator. The proposed simulation model examines bidirectional energy flow control between the medium-voltage AC grid and DC smart grid, while evaluating power flow efficiency and qualitative indicators of the AC grid. After the completion of design verification and electrical properties analysis by the PLECS simulation models, the synthesis offers recommendations on the optimal layout of the proposed SST topology for smart grid application.

In situ works on ecotoxicology in amphibians: current state of the art

Amphibians play a fundamental role in the functioning of ecosystems, mainly in the nutrient cycle, energy flow, and pest control. This group has a massive population decline, with approximately 41% of all species at risk, highlighting pesticide pollution as one of the main threats to the loss of anuran biodiversity. This occurs since amphibians have an epidermis with high permeability and a biphasic life cycle, where they use both the aquatic and terrestrial environments, allowing exposure and making them susceptible to chemical agents released into the environment. This makes amphibians a model group in ecotoxicological studies. However, due to the greater control of experimental conditions, the vast majority of studies are carried out in the laboratory, thus maintaining a gap in knowledge about the effects of pesticides on amphibians in natural environments. Under natural conditions, where environmental variables are not controlled, experiments must relate all the dynamics of the interaction of substances existing in the environment, and their influences on organisms. To evaluate the studies already performed under natural conditions, a bibliographic survey was carried out through a search with the Web of Science and SCOPUS databases, considering articles published in the last twenty years, using the terms 'field experimentation' or 'in situ study', associated with 'tadpole' and 'agrochemical' or 'pesticide', using a descriptive methodology. Twenty-one abstracts were pre-selected, they were further evaluated and the methodologies were checked to ensure only the analysis of experiments conducted in the field conditions. Thus, ten works were selected for the construction of the review. The works selected used native amphibian species, considered generalists, present in the study region, and were carried out in environments intended for agricultural cultivation with control groups in preserved locations. In these works, different methodologies were used, such as intentional spraying of water bodies, quantification of pesticides in the study sites, and verification of changes caused by the environment on tadpoles. The main evaluations were based on the survival and morphological changes of the tadpoles and, in some cases, on cytological and biochemical assays.

Method for efficient excitation of selective vibration modes in pulsed laser photothermal actuation

Photothermal excitation based on thermoelastic mechanisms is widely used in non-destructive testing, precision operations, and driving micro-resonators. The narrow drive bandwidth of the high vibration mode in photothermal excitation limits its application to multi-mode drives. Controlling the laser’s irradiation position is an effective solution. In this study, we build a theoretical model to achieve selective and efficient excitation of different flexural vibration modes of beams with different supports. The model can be extended to other thermal and physical boundaries, which is validated by numerical simulations and experimental results. The results show that higher modes with complex periodic shapes can be efficiently excited by focusing the laser at the peak of the absolute value of the second derivative of the flexural mode while focusing the laser at the inflection point of the mode shape will result in extremely small amplitudes. Our study indicates that the thermal gradient plays a vital role in the oscillation of the beam. The conventional view assumes that the resonance of the photo-thermal excitation beam is caused by the local expansion and contraction of the material, which cannot completely explain the dependence principle of the photothermal vibration on the laser irradiation position. To investigate the mechanism of beam resonance under laser excitation, three excitation modes, unidirectional excitation, bidirectional in-phase excitation, and bidirectional anti-phase excitation, were established, and the conversion process of optical energy to mechanical energy under laser excitation was analyzed. These results provide new options for optimal excitation and multi-mode energy flow control in photothermal driving.