Bidirectional Control Research Articles

Enhancing online health consultations through fuzzy logic-integrated attribute-based encryption system

Online health consultations are becoming more popular as a result of technological improvements. Patients routinely look for information about medical disorders online, which could jeopardize the privacy of medical records and increase the workload of healthcare professionals. Nonetheless, academics continue to be extremely concerned about issues related to the quality characteristics that relate to the current architectural models, such as energy consumption, latency, resource utilization, scalability, and packet loss. This method, however, also results in a significant strain being placed on medical experts who must sort through vast amounts of medical records to extract certain information. This paper presents a novel ciphertext policy attribute-based encryption method coupled with fuzzy logic to overcome these issues. This solution uses a hybrid structure of IPFS and blockchain to store data and enables complex bidirectional access control. Before being added to IPFS, medical records are encrypted. To ensure data integrity, related IPFS hash indexes are then added to the blockchain. Utilizing attribute-based technology, users’ data is encrypted to give them fine-grained bidirectional access control. A thorough security analysis proves the system’s resilience, especially when faced with chosen plaintext assaults inside the random oracle model. Tests for this study were conducted using 10–50 attribute sets. This paper’s technique solely makes use of a hash operation. All things considered; the study demonstrates that the proposed design is more efficient than earlier schemes. Thus, from the comparison study above, it can be concluded that the system presented in this work is more efficient. Results from simulations provide additional support for the suggested methodology by highlighting the improved computing efficiency of users as compared to baseline conventional systems. This study demonstrates how technological advancement and healthcare requirements can coexist harmoniously, paving the way for secure and effective online medical consultations that are powered by fuzzy logic.

Photoswitchable Cascades for Allosteric and Bidirectional Control over Covalent Bonds and Assemblies.

Studies of complex systems and emerging properties to mimic biosystems are at the forefront of chemical research. Dynamic multistep cascades, especially those exhibiting allosteric regulation, are challenging. Herein, we demonstrate a versatile platform of photoswitchable covalent cascades toward remote and bidirectional control of reversible covalent bonds and ensuing assemblies. The relay of a photochromic switch, keto-enol equilibrium, and ring-chain equilibrium allows light-mediated reversible allosteric structural changes. The accompanying distinct reactivity further enables photoswitchable dynamic covalent bonding and release of substrates bidirectionally through alternating two wavelengths of light, essentially realizing light-mediated signaling cycles. The downfall of energy by covalent bond formation/scission upon photochemical reactions offers the driving force for the controlled direction of the cascade. To show the molecular diversity, photoswitchable on-demand assembly/disassembly of covalent polymers, including structurally reconfigurable polymers, was realized. This work achieves photoswitchable allosteric regulation of covalent architectures within dynamic multistep cascades, which has rarely been reported before. The results resemble allosteric control within biological signaling networks and should set the stage for many endeavors, such as dynamic assemblies, molecular motors, responsive polymers, and intelligent materials.

Fabrication and Development of Solar Powered Cart

Electric vehicles (EVs) are becoming increasingly popular due to their eco-friendliness and low operational costs. However, the use of fossil fuels to generate electricity to charge these EVs undermines their sustainability goals. Combining solar energy with EV charging can create a sustainable and clean transportation system, which can reduce our dependency on non-renewable energy sources. The overall objective of the project is to develop and fabricate an optimized, efficient solar powered electric cart charging with bi-directional smart inverter control that can be used on campus in transporting and carrying Stationery loads. Subsystems such as the frame, drive train, power, suspension, Brakes and Steering that are modeled and analyzed through quantitative methods are purchased and fabricated. The cart is fabricated as per its design for 250kg load carrying capacity, acceleration of 1.2 m/s2 and maximum achievable speed of 15km/h with a power rating of about 1.5kW. Secondary support software such as Excel, and solar analyzing software were used to assist in the planning of the various subsystems as well as data collection and assortment. The proposed model provides the IOT-based smart solar energy consumption analysis and control model by using solar photovoltaic micro grid. The proposed IOT design must meet product and process requirements. Key Words: Power optimization, golf cart, solar transport, Photovoltaic, Solar-powered, Emission Analysis, Environmental. Solar power.

Improving Performance of Solar Array Fed BLDC Drive Using Firefly Algorithm Based High Gain Converter

The improved transient response of PID controller for improved Luo converter supplied Brushless DC (BLDC) motor using solar energy source is extensively investigated. The BLDC drive uses a hybrid PV system and battery-based power generation as a power source to assure continuous power supply to pump water regardless of solar insolation. The PV system serves as the main energy source, and the battery providing as a backup source that discharged its power only during inclement weather or at night if the photovoltaic panel is insufficient to operate the centrifugal pump. The solar panel feeds power into the battery, whenever water to the field is not required, thus there is no need for an extra power source to charge the batteries. The high output voltage gain DC-DC converter does not make any discomfit to the system performance in regards to irradiance variation, switching loss, or power loss by converter or motor side respectively. Moreover, current sensor, voltage sensor, and control circuits are completed excluded which enhance performance and the cost of the system get reduced effectively. A bidirectional charging control allows a bi-directional converter to alter the battery operation mode automatically. The overall system performance is validated using simulation and experimental setup.

High-Speed Controller to Enhance Responsiveness and Stability of Dynamic Characteristics for DC–DC Converter

In general, the DC load is electrically sensitive to the input voltage and current compared to the AC load. As the demand for digital systems that require DC power increases rapidly, the importance of stable DC power supply methods is increasing. Various elements such as renewable energy and load are configured in the power grid that supplies DC, and they are connected in various forms and power patterns. These elements have different starting and operating characteristics, which can be disadvantageous to the design of controllers for power converters to maintain a stable bus voltage in the DC power grid. Therefore, in a DC power system, an energy storage system with active bi-directional power control technology that can minimize transient conditions, such as overshoot, which can occur when a load is connected or power accelerates rapidly, is significantly important. This paper proposes a novel power control method capable of compensating for the instability of the DC bus voltage owing to the transient state in the DC power supply system. This method minimizes overshoot and ensures fast responsiveness and system stability by calculating the flux linkage of an inductor in a bi-directional DC/DC converter and applying an excitation voltage without pulse-width modulation (PWM) switching. The performance and validity of the proposed transient high-speed controller (THSC) were verified through simulations and experiments.

Research on MLD Modeling and Predictive Control of Magnetically Coupled Resonant Bidirectional WPT System

The recent studies on magnetically coupled resonant bidirectional wireless power transfer (MCR-BWPT) systems disregard the challenges posed by nonlinearity, discrete switching action, and hybrid properties within the system. This research focuses on the D-LCL resonant compensation topology MCR-BWPT system. The switch tube’s switching state dictates the division of various working modes and the determination of the switching conditions between them. The coupling relationship between the continuous dynamic characteristics of the system and discrete events and the constrained conditions of the system are derived. The Hybrid System Description Language (HYSDEL) is used to build the Mixed Logic Dynamic (MLD) model of the system. The MLD model is employed as the prediction model, and the hybrid model predictive controller of the MCR-BWPT system is constructed according to the quadratic performance index. Finally, to verify the accuracy of the MLD model and the feasibility of the control strategy, the simulation model of the MLD model is established in MATLAB/Simulink. The study’s findings show that, in terms of response time at system startup and power fluctuation suppression, the approach put forward in this research performs better than both the conventional bilateral dual-phase-shift control strategy and the PQ-based bilateral power control strategy. The MCR-BWPT system can operate more steadily now that PQ’s bidirectional power control technique is in place. The system’s forward and reverse transmission efficiency is increased by 0.29% and 0.32% compared to the conventional bilateral dual-phase-shift control approach; the increases are 0.28% and 0.09%, each compared to the bilateral power control strategy based on PQ.

Enhanced energy balancing and optimal load curtailment strategy for DC microgrid integration in hybrid AC/DC distribution networks

AbstractUnleashing the potential of distributed renewable energy sources (RESs), intelligent and autonomous microgrids are becoming pivotal in attaining net‐zero carbon emission goals. Hybrid AC/DC microgrids rise as cutting‐edge microgrid topologies, capitalising on the best of both AC and DC systems. However, the integration of intermittent renewables and uncertainties in loading poses stability challenges. Advanced bidirectional converter controls provide efficient power exchange, but in extreme contingencies, a resilient supervisory control framework (load management/load curtailment approach) is inevitable to withstand/avoid unplanned renewable disruptions/blackouts. Moreover, the operational paradigm shift towards achieving net‐zero emissions, isolated operation of RESs, and conventional load shedding methods are anticipated to encounter substantial challenges, necessitating the development of alternative strategies. In order to improve the stability of hybrid microgrid systems in islanding scenarios, this research presents an energy balancing and load curtailment strategy. The proposed method aims at optimising resource utilisation, prioritising essential loads, and executing an optimal load curtailment strategy (if required), thereby augmenting the stability of systems. Unlike a meta‐heuristic or exhaustive search, which depends on 2n − 1 possible combinations and become unworkable as load numbers increase, the suggested methodology is based on a mathematically modelled load restriction method. By including load criticality, this strategy effectively prevents blackouts even with an increasing number of loads, providing a significantly more useful and practical solution. Additionally, the proposed charging algorithm ensures that the energy storage system imports energy from the grid during off‐peak hours and maximises power generation from the DC subgrid. The efficacy of the proposed strategy is validated using a modified IEEE‐33 bus system as a test case for a hybrid AC/DC microgrid. Simulation results demonstrate the effectiveness of the MILP‐based load curtailment approach in maintaining system stability and preventing blackouts during unforeseen events.

Bidirectional Power Control Strategy for On-Board Charger Based on Single-Stage Three-Phase Converter

To solve the problems of large switching losses and the need for large-capacity electrolytic capacitances in three-phase DC/AC on-board chargers for vehicle-to-grid (V2G) applications, this paper proposes a single-stage bidirectional high-frequency isolated converter that eliminates the need for large-capacity capacitances. Combined with the proposed modulation scheme, it can theoretically reduce the switching loss by about two-thirds with the three-phase converter compared with the conventional modulation scheme, improving the converter’s operating efficiency and power density. Firstly, based on the characteristics of the proposed topology, a hybrid modulation scheme is proposed, which combines a phase-shift modulation scheme based on double modulation waves and a sawtooth carrier with a 1/3 modulation scheme, and the theoretical feasibility of the hybrid modulation scheme is verified using a mathematical modeling equation. Secondly, this paper provides a detailed analysis of the four operating modes of the two full-bridge circuits and the commutation process of the three-phase converter within 1/6 of the fundamental frequency cycle (P1 modulation interval). Then, the control strategy is given for the constant-current and constant-voltage charging and constant-current discharging for electric vehicle batteries. Finally, simulation results verify the correctness of the proposed topology and modulation scheme in vehicle–grid interaction.

Bidirectional energy‐controlled piezoelectric shunt damping technology and its vibration attenuation performance

AbstractPiezoelectric material‐based semi‐active vibration control systems may effectively suppress vibration amplitude without any external power supply, or even harvest electrical energy. This bidirectional electrical energy control phenomenon is theoretically introduced and validated in this paper. A flyback transformer‐based switching piezoelectric shunt circuit that can extract energy from or inject energy into piezoelectric elements is proposed. The analytical expressions of the controlled energy and the corresponding vibration attenuation are therefore derived for a classical electromechanical cantilever beam. Theoretical predictions validated by the experimental results show that the structure vibration attenuation can be tuned from −5 to −25 dB under the given electrical quality factor of the circuit and figure of merit of the electromechanical structure, and the consumed power is in the range of −13 to 25 mW, which is a good theoretical basis for the development of self‐sensing, self‐adapting, and self‐powered piezoelectric vibration control systems.

A hybrid approach for PV based grid tied intelligent controlled water pump system

SummaryThis article proposes a hybrid POA‐RBFNN approach for PV (photovoltaic) based grid tied intelligent controlled water pump system. The proposed method is the hybrid wrapper of Pelican Optimization Algorithm (POA) and Radial Basis Function Neural Network (RBFNN) and later it is termed as POA‐RBFNN method. On the basis of bidirectional power grids, this research presents bidirectional power flow control for PV systems. The water pump is driven through a three‐phase synchronous reluctance motor (RSM). A novel Cuk integrated Landsman converter can operate at low duty cycles to provide larger DC voltages with negligible switching losses is used. In addition, to enhance the pumping system reliability, solar panels and electric pumps can be used to their maximum potential. Despite fluctuating weather conditions, the system supplies nominal displacement all over the day and surplus energy to the grid. Furthermore, if one of the sources fails, the pump performance is unaffected. Switching losses are minimized since the Voltage Source Inverter (VSI) operates at a fundamental frequency. In all operational modes, this control delivers unique grid‐side power quality and unity power factor functioning. Here, the performance of the proposed hybrid system is implemented in the MATLAB and is compared with several existing methods.

Bi-directional wind-induced vibration control of high-rise buildings using bi-directional rail variable friction pendulum-tuned mass damper

Flexible high-rise buildings are extremely vulnerable to wind, especially when synchronously subjected to alongwind and crosswind forces. In this scenario, acceleration-sensitive targets (such as delicate instruments) are at risk of damage. Moreover, occupant comfort and structural safety may be degraded due to excessive bi-directional vibrations. To resolve this problem, a bi-directional rail variable friction pendulum-tuned mass damper (BRVFP-TMD) is used to achieve optimal bi-directional wind-induced vibration control. The modeling of the BRVFP-TMD for bi-directional high-rise buildings under bi-directional winds was performed. Further, the physical interaction forces of the BRVFP-TMD with a multi-degree-of-freedom structure and the governing equations for the modal structure with the BRVFP-TMD were derived, with experimental results confirming the effectiveness of the linear variable friction force. For the BRVFP-TMD with a lightly damped structure, acceleration optimizations were conducted to obtain closed-form solutions for optimal parameters. However, the deployment position of the tuned mass damper (TMD) was found to degrade the optimal control performance significantly. Therefore, for the convenience of engineers, improved optimal solutions were obtained by considering the actual deployment position of the TMD and the influence of inherent structural damping. The stochastic linearization method was used to evaluate the effect of linear hysteretic damping (HD) with equivalent viscous damping (VD) in the field of random theory. Accordingly, a closed-form expression for the VD ratio was proposed to represent HD. Numerical verifications of a Chinese landmark (Canton Tower) subjected to bi-directional winds were assessed through time history and frequency decomposition analyses. The results verified the effectiveness, correctness, and necessity of the BRVFP-TMD; the improved optimal solutions were also confirmed. Compared with the closed-form solution, which neglects the deployment position of the TMD, and the classic TMD, the improved optimal solutions of the BRVFP-TMD demonstrated superior performance in mitigating both structural displacement and acceleration. The vibration reduction ratios achieved were 44.55% for the displacement at the top of the mast and 46.69% for the acceleration at the top of the main tower.

Power allocation scheme for grid interactive microgrid with hybrid energy storage system using model predictive control

Grid-interactive microgrids have become a promising alternative to traditional centralized power systems as a result of the rising demand for reliable and sustainable energy solutions. DC microgrids (MG) based upon renewable energy sources (RES) are on the rise due to high energy efficiency and compact size than the AC microgrids. Microgrid equipped with hybrid energy storage system is sensible for a reliable and stable power supply to the system. Implementation of a potent control system makes sure of the system stability. A model predictive control (MPC) based control strategy is proposed due to its easy implementation approach and inclusion nonlinear dynamics & constraints of the controlled system. An efficient power allocation scheme is developed in this paper for a grid-interactive photovoltaic microgrid featuring a hybrid energy storage system (HESS). The system-level power allocation scheme (PAS) considers the real-time data of load demands, generation, market energy cost, and energy storage state-of-charge to actively manage the power flow within the microgrid and also with the utility grid. The proposed control scheme uses a sophisticated model predictive current control for the DC/DC bi-directional converters control and model predictive combined power and voltage control is used for bidirectional interlink converter. The proposed control approach provides faster DC bus voltage recovery. The HESS consisting of battery and supercapacitor is used as energy buffers for responding to the fluctuation of power generation and demand for smoothing the PV power. The potency of the proposed controller is verified using MATLAB/Simulink (2021b) environment. Also, the real-time implementation of the proposed approach is carried out using the OPAL-RT OP4510 simulator.

Enhancing Grid-Forming Converters Control in Hybrid AC/DC Microgrids Using Bidirectional Virtual Inertia Support

This paper presents a new grid-forming strategy for hybrid AC/DC microgrids using bidirectional virtual inertia support designed to address weak grid conditions. The stability of hybrid AC/DC microgrids heavily relies on the AC mains frequency and the DC-link voltage, and deviations in these factors can lead to undesirable outcomes such as load curtailments and power system congestions and blackouts. This paper introduces a unique approach that leverages bidirectional virtual inertia support to enhance the stability and reliability of hybrid AC/DC microgrids under weak grid conditions. The proposed strategy employs virtual inertia as a buffer to mitigate rapid changes in DC-link voltage and AC frequency, thereby enhancing system stability margins. This strategy significantly contributes to a more stable and reliable grid operation by reducing voltage and frequency fluctuations. A standard hybrid AC/DC microgrid configuration is used to implement the bidirectional virtual inertia support, where a bidirectional interlinking converter control is adjusted to deliver inertia support to both the AC and DC subgrids. This converter utilizes the DC grid voltage and AC grid frequency as inputs, effectively managing active power balance and implementing auxiliary functions. Extensive simulations are conducted under weak grid conditions and standalone mode to validate the effectiveness of the proposed strategy. The simulation results demonstrate a remarkable improvement in frequency nadir, rate-of-change-of-frequency (RoCoF), and DC bus voltage deviation in the hybrid AC/DC microgrids. The bidirectional virtual inertia support substantially reduces voltage and frequency fluctuations, enhancing the microgrid stability and resilience. There is an improvement of over 45% and 25% in the frequency deviation and voltage deviation, respectively, achieved through implementing the proposed control strategy.

Bidirectional interaction between language control and domain-general executive control in unbalanced Chinese-English bilinguals

Recent research has shown that bilinguals outperform monolinguals on tasks requiring non-linguistic executive control skills, thereby generating an interest in the relationship between bilingual language processing and non-linguistic control abilities. Based on this, the present study further examined the bidirectional interaction between language control and non-linguistic control in unbalanced Chinese-English bilinguals. These bilinguals completed a Flanker task in three types of language control contexts (i.e., L1, L2, and Mixed language contexts) in the interleaved word-comprehension-to-Flanker sequence and performed a picture-word matching task in three types of non-linguistic executive control contexts (i.e., color, shape and color-shape mixed contexts) in the interleaved color-shape-switching-to-word-comprehension sequence. The results showed that the Flanker effect in mixed language context was smaller than in single (L1 and L2) context, suggesting language control leads to a better non-linguistic control ability. Additionally, the language switching cost was found smaller in the mixed task context (color/shape switching), indicating that non-linguistic control can enhance the language control ability. Therefore, we conclude that there is a bidirectional interaction between language control and non-linguistic control even in unbalanced bilinguals.

Robust Bidirectional Platoon Control for Mesh Stability of Vehicular Systems With Uncertain Kinematics and Dynamics

Robust Bidirectional Platoon Control for Mesh Stability of Vehicular Systems With Uncertain Kinematics and Dynamics

Bi-directional extensional control of the Berane Basin formation, northern Montenegro

The Berane Basin is a Miocene, northeast-southwest oriented intramountain basin of the Dinarides, overlying the pre-neotectonic basement of the Drina-Ivanjica unit, the East Bosnian-Durmitor unit and the Western Vardar Zone. The structural evolution and the tectonic regimes that controlled the formation of the Berane Basin are not fully understood. In this paper, we conducted field kinematic analysis by applying fault-slip inversion to derive paleostress regimes and study the deformation phases that led to the formation of the Berane Basin. Observed deformation is related to the latest Oligocene-Miocene extension in two directions, perpendicular and parallel to the Dinarides orogen. Such bi-directional extension resulted in a complex fault pattern where, among observed normal, oblique and strike-slip faults, those with oblique-normal slip dominate. The observed faults likely form a system of mutually overprinting half-grabens, mainly driven by orogen-parallel extension associated with the large-scale regional Skadar-Pec Fault, while orogen-perpendicular extension has subordinate effects on the Berane Basin formation.

A Novel Bi-directional Grid Inverter Control Based on Virtual Impedance Using Neural Network for Dynamics Improvement in Microgrids

A Novel Bi-directional Grid Inverter Control Based on Virtual Impedance Using Neural Network for Dynamics Improvement in Microgrids

Assessment of TENS-Evoked Tactile Sensations for Transradial Amputees via EEG Investigation.

Most of current prostheses can offer motor function restoration for limb amputees but usually lack natural and intuitive sensory feedback. Many studies have demonstrated that Transcutaneous Electrical Nerve Stimulation (TENS) is promising in non-invasive sensation evoking for amputees. However, the objective evaluation and mechanism analysis on sensation feedback are still limited. This work utilized multi-channel TENS with diverse stimulus patterns to evoke sensations on four non-disabled subjects and two transradial amputees. Meanwhile, electroencephalogram (EEG) was collected to objectively assess the evoked sensations, where event-related potentials (ERPs), brain electrical activity maps (BEAMs), and functional connectivity (FC) were computed. The results show that various sensations could be successfully evoked for both amputees and non-disabled subjects by customizing stimulus parameters. The ERP confirmed the sensation and revealed the sensory-processing-related components like N100 and P200; the BEAMs confirmed the corresponding regions of somatosensory cortex were activated by stimulation; the FC indicated an increase of interactions between the regions of sensorimotor cortex. This study may shed light on how the brain responds to external stimulation as sensory feedback and serve as a pilot for further bidirectional closed-loop prosthetic control.

Bidirectional Active Equalization Control of Lithium Battery Pack Based on Energy Transfer

Bidirectional Active Equalization Control of Lithium Battery Pack Based on Energy Transfer

A Bidirectional Three-Level Converter Control With Shared Control Circuit and Single-Point Sensing for Flying Capacitor Balance

A Bidirectional Three-Level Converter Control With Shared Control Circuit and Single-Point Sensing for Flying Capacitor Balance