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Bipolar gradual resistive switching was investigated in ITO/InGaZnO/ITO resistive switching devices. Controlled intrinsic oxygen vacancy formation inside the switching layer enabled the establishment of a stable multilevel memory state, allowing for RESET voltage control and non-degradable data endurance. The ITO/InGaZnO interface governs the migration of oxygen ions and redox reactions within the switching layer. Voltage–stress-induced electron trapping and oxygen vacancy formation were observed before conductive filament electroforming. This device mimicked biological synapses, demonstrating short- and long-term potentiation and depression through electrical pulse sequences. Modulation of post-synaptic currents and pulse frequency-dependent short-term potentiation were successfully emulated in the InGaZnO-based artificial synapse. The ITO/InGaZnO/ITO memristor exhibited spike–amplitude-dependent plasticity, spike–rate-dependent plasticity, and potentiation–depression synaptic learning with low energy consumption, making it a promising candidate for large-scale integration. [ABSTRACT FROM AUTHOR]

Reliability and packing density concerns are the two major shortcomings of spin transfer torque and spin orbit torque based magnetic memory, respectively. Voltage controlled magnetic anisotropy (VCMA) becomes energy efficient and fast, showing transcendence for the writing mechanism in the magnetic tunnel junction. Deterministic switching cannot be achieved by VCMA alone in the out of plane nanomagnet. It requires an external in-plane magnetic field, but the use of an external field is inconvenient for on-chip applications. We exploit stress and exchange bias provided by an antiferromagnetic material to mitigate the external magnetic field requisite. We perform macro-spin simulations using the Landau–Lifshitz–Gilbert equation at room temperature. We use the VCMA effect cum stress effect to investigate field free switching performance, and this improves the write error rate (WER) to 5 × 10 − 5 against WER of 0.1 with the VCMA effect alone. We studied the effects of applied voltage (amplitude and pulse width), exchange bias field, and VCMA coefficient on the switching performance in detail. This proposed two-terminal device can be helpful in achieving high cell density to implement nonvolatile magnetic memory. [ABSTRACT FROM AUTHOR]

In this paper, a single-phase five-level active neutral-point-clamped with coupled inductors (ANPC-CI) rectifier topology is studied to meet the needs of efficient and reliable power electronic converters. A sliding mode model predictive power control method is proposed to achieve high-efficiency energy conversion, precise voltage control, and low harmonic distortion. By analyzing the working states, establishing a mathematical model and introducing the theory of instantaneous power, the outer loop sliding mode power control and the inner loop model predictive power control algorithms are designed. When compared with traditional PI-DPC algorithm, this algorithm avoids the tedious setting of parameters, reduces input power fluctuations, and improves the system dynamic response speed. The superiority of the sliding mode model predictive power control is verified by simulation and experimental results. [ABSTRACT FROM AUTHOR]

This manuscript investigates the transformative shift in electricity generation and distribution towards distributed power networks, particularly microgrids, amid escalating energy demand and environmental concerns. Emphasizing a pioneering technoeconomic conservation voltage reduction–based demand response approach, the study integrates conservation voltage reduction as a controllable demand response method within distributed power networks, highlighting the developed droop control method for effective regulation. Conservation voltage reduction, a no‐cost procedure for minimizing loss, is applied to reduce voltage during peak periods to conserve power, decrease active and reactive power losses through precise load modeling, and enhance consumption efficiency. The most significant challenge of this project is the simultaneous use of conservation voltage reduction with the uncertainties of distributed generation sources, resulting to reduce losses and ultimately lower operating costs, a topic not previously studied in existing literature. The contributions include introducing a novel approach based on droop control to manage resources and presenting a detailed control strategy tailored to distributed power networks for improving voltage stability with minimal costs. Importantly, the proposed method demonstrates superior accuracy, achieving up to an 18% improvement over existing methods. This research contributes to comprehensive solutions for optimizing energy consumption, enhancing grid stability, and adapting to the evolving distributed power systems landscape. [ABSTRACT FROM AUTHOR]

ABSTRACT The unidirectional multilevel rectifier has immense potential in high‐power medium‐voltage industrial applications. This paper proposes a multiobjective control method based on the combination of optimal‐vector‐pair modulated model predictive control (OVP‐M2PC) and a phase‐shifted modulation strategy for a unidirectional five‐level rectifier. This strategy takes both of the inductor current tracking and capacitor voltage balancing as the control objectives. First, an optimal vector pair is determined based on the AC‐side current variation rate, and then, through combining the calculated action duration of OVP with carrier phase‐shifted modulation, inductor current tracking is achieved. Second, capacitor voltage balancing control is carried out by compensating for the duty cycles which also decouples the input current tracking and output capacitor voltage balance control. Compared with traditional FCS‐MPC, under the proposed control strategy, complex cost function calculation and weighting factor tuning are not required, which much reduced computational burden. Multiobjective control is achieved with better performance in both steady‐state and dynamic conditions. The superiority of the proposed strategy over traditional FCS‐MPC are validated through simulations and hardware experiments. [ABSTRACT FROM AUTHOR]

Dielectric elastomers (DE), renowned for their lightweight, rapid response, high energy density, and efficient conversion, have garnered significant attention in the realm of avian flight bionics. However, a lack of understanding of the mechanical principles underlying flapping wing biomimetics has hindered accurate simulations of actual bird flight postures. To address this, a stiffness-variable DE-based wing (DEW) has been designed, inspired by the characteristics of seagulls, to mimic the wing deformations across different bird flight phases. The evolution of the DEW’s deformation is modeled based on the differential equation describing the bending curve of a DE cantilever beam. By applying different voltage cycles, three continuous avian flight postures have been replicated: takeoff, cruising, and hovering. The simulation results demonstrate that the stiffness-variable DEW effectively mimics the wing deformations observed in birds during different flight postures, closely resembling real-world flight conditions. This study has the potential to serve as an important reference for exploring changes in bird flight behavior, thereby advancing the application of DE materials in the field of soft robotics. [ABSTRACT FROM AUTHOR]

Commercial off‐the‐shelf (OTS) photovoltaic systems coupled with battery energy storage units (PV‐BES) are typically designed to increase household self‐consumption, neglecting their potential for voltage regulation in low voltage distribution networks (LVDNs). This work proposes an enhanced sensitivity‐based combined (ESC) control method for voltage regulation, using BES control as level 1 and reactive power compensation as level 2. A centralized controller manages charging/discharging intervals, while local inverters handle real‐time power rates and reactive power, ensuring effective LVDN voltage regulation. The BES set points are obtained concerning the measured local bus voltage and according to enhanced sensitivity coefficients. The enhancement algorithm ensures that the full capacity of BES is utilized and that there is adequate capacity during charging and discharging time intervals. The proposed method, tested on 8‐bus and 116‐bus LV test feeders, outperforms OTS and an adaptive decentralized (AD) control method by completely preventing overvoltage issues, minimizing various changes in the direction of BES power, and reducing voltage deviation without significantly affecting consumers' grid dependency. [ABSTRACT FROM AUTHOR]

Aiming to improve the voltage distribution and realize the proportional sharing of active and reactive power in the distribution network (DN), this article proposes a distributed optimal control strategy based on the grouping cooperation mechanism of the distributed generation (DG). The proposed strategy integrates the local information of the DG and the global information of the DN. Considering the high resistance/reactance ratio of DN, distributed optimization control strategies for node voltage control and active power management are developed with the consensus variable of active utilization rate. And distributed strategy for reactive power management is proposed with a consensus variable of reactive utilization rate. The convergence of the distributed control system for each group is proved. The validity and robustness of the proposed strategy are verified by several simulations in the IEEE 33‐bus system. [ABSTRACT FROM AUTHOR]

The point of common coupling (PCC) voltage feedforward control strategy can effectively reduce the startup inrush current and improve the anti‐interference ability of the LCL‐type converters, which is widely used in the renewable energy converters control field. With the high penetration of the new energy, the increase of grid impedance leads to the weakening of the grid. Under weak grid conditions, the PCC voltage feedforward control strategy will generate an additional feedback loop of grid‐side current, which has a great impact on the stability of the system. In this paper, the damping characteristic of the PCC voltage feedforward control strategy and the effect on the open loop characteristic of the system have been deeply analyzed. An improved PCC voltage feedforward control strategy based on a proportional plus band‐pass filter is proposed, which can effectively improve the phase margin and achieve active damping under weak grid conditions, therefore, the robustness of the converters can be effectively improved. A three‐phase LCL‐type AC/DC converter platform is built and comparative experiments are carried out to verify the effectiveness of the proposed algorithm. The experimental results are consistent with the theoretical analysis. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In this paper, a modular resonant inverter is proposed for high frequency industrial heating applications. To maintain a uniform heating profile, the inverter is operated in constant power mode. A hybrid voltage and frequency control is proposed. Voltage control is used for active power tracking while frequency control is used to minimise circulating current due to reactive power and to achieve soft switching for the inverter switches. Analytical and test results are shown to verify the proposed approach. [ABSTRACT FROM AUTHOR]

ABSTRACT In low‐voltage applications using low‐Q LC filters, alias‐free capacitor voltage acquisition can be achieved, but synchronous capacitor voltage sampling under high‐Q filters used in high‐voltage applications in grid‐forming converters causes some degree of distortion and results in degradation of the power supply quality. And the inherent 1.5 sampling periods that delay in this approach limit the control bandwidth, reduce the stability region, and result in an inadequate time domain response. Despite these shortcomings, this approach is widely accepted in practice. The conclusion of this paper is that shifting the capacitor voltage sampling instant to 2 µs before the pulse width modulation (PWM) reference voltage update results in almost the same distortion as synchronous sampling. However, it can improve the dynamic performance of the system. A distortion‐acceptable univariate feedback voltage dual‐loop active damping control topology with much reduced computational delay is proposed, which is based on an internal active damping loop using a discrete lead compensator and a proportional resonance controller in the external voltage loop. [ABSTRACT FROM AUTHOR]

ABSTRACT The objective of this submission is to provide flexible reactive power regulation of a photovoltaic (PV)‐driven grid‐connected inverter. Here, inverter is realized as a synchronverter by employing frequency regulation using well‐established swing equation. However, reactive power regulation is accomplished by employing combined AC–DC voltage control in addition to traditional synchronverter control for ensuring smooth tracking of reactive power. Thus, the PV‐driven voltage source converter (VSC) will be injecting available active power as per the prevailing irradiation, temperature, and operator defined reactive power by employing proposed control. The performance of suggested control is evaluated and compared against existing control by considering realistic operational scenarios through a case study. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) are rapidly replacing fossil-fuel-powered vehicles, creating a need for a fast-charging infrastructure that is crucial for their widespread adoption. This research addresses this challenge by improving the control of dual active bridge converters, a popular choice for high-power EV charging stations. A critical issue in EV battery charging is the smooth transition between charging stages (constant current and constant voltage) which can disrupt converter performance. This work proposes a novel feedforward control method using a combination of droop-based techniques combined with a sophisticated linear active disturbance rejection control system applied to a single-phase shift-modulated dual active bridge. This combination ensures a seamless transition between charging stages and enhances the robustness of the system against fluctuations in both input voltage and load. Numerical simulations using MATLAB/Simulink R2024a demonstrated that this approach not only enables smooth charging but also reduces the peak input converter current, allowing for the use of lower-rated components in the converter design. This translates to potentially lower costs for building these essential charging stations and faster adoption of EVs. [ABSTRACT FROM AUTHOR]

This paper describes active battery balancing based on a bidirectional buck converter, a flyback converter, and battery cells by using the proposed chain-loop comparison strategy. The role of the bidirectional buck converter is to charge/discharge the battery pack. During the charging period, the converter is in buck mode, and its output is controlled by constant current/voltage; during the discharging period, the converter is in boost mode, and its output is controlled by constant voltage. The role of the flyback converter is voltage equalization of the battery pack, and its output is controlled by constant current. A chain-loop comparison strategy is used to control battery voltage equalization. In this work, three equalization modes, namely, charging balance, discharging balance, and static balance, were considered. The voltage difference between the maximum and minimum is 0.007 V after a balancing time of 19.75 min, 0.005 V after a balancing time of 24 min, and 0.007 V after a balancing time of 20 min for charging balance, discharging balance, and static balance, respectively. [ABSTRACT FROM AUTHOR]

Coordinated voltage control enables the active management of voltage levels throughout electricity distribution networks by leveraging the voltage support capabilities of existing grid-connected PV inverters. The efficient management of power flows and precise voltage regulation through coordinated voltage control schemes facilitate the increased adoption of rooftop PV systems and enhance the hosting capacity of electricity distribution networks. The research work presented in this paper proposes a coordinated voltage control scheme and evaluates the enhanced hosting capacity utilizing a deep reinforcement learning-based approach. A comparative analysis of the proposed algorithm is presented, and the performance is benchmarked against existing local voltage control schemes. The proposed coordinated voltage control scheme in this paper is evaluated using simulations on a real-world low-voltage electricity distribution network. The evaluation involves quasi-static time series power flow simulations for assessing performance. Furthermore, a discussion is presented that reflects on the strengths and limitations of the proposed scheme based on the results observed from the case study. [ABSTRACT FROM AUTHOR]

This paper focuses on the distributed generation (DG) controller of a PV-based microgrid. An independent DG controller (IDGC) is designed for PV applications to improve Maximum-Power Point Tracking (MPPT). The Extreme-Learning Machine (ELM)-based MPPT method exactly estimates the controller's reference input, such as the voltage and current at the MPP. Feedback controls employ linear PI schemes or nonlinear, intricate techniques. Here, the converter controller is an IDGC that is improved by directly measuring the converter duty cycle and PWM index in a single DG PV-based MG. It introduces a fast-learning Extreme-Learning Machine (ELM) using the Moore–Penrose pseudo-inverse technique and online sequential ridge methods for robust control reference (CR) estimation. This approach ensures the stability of the microgrid during PV uncertainties and various operational conditions. The internal DG control approach improves the stability of the microgrid during a three-phase fault at the load bus, partial shading, irradiance changes, islanding operations, and load changes. The model is designed and simulated on the MATLAB/SIMULINK platform, and some of the results are validated on a hardware-in-the-loop (HIL) platform. [ABSTRACT FROM AUTHOR]

The step-down DC/DC converter is characterized by the parametric uncertainty of its model and its high sensitivity to external disturbances identified by variations in the input voltage, load and output reference voltage. To overcome these limitations, this paper proposes the experimental evaluation of a new adaptive synergetic control law based on the M5P model tree for efficient output voltage control of the step-down type DC/DC converter. A combination of the synergetic technique, the fuzzy logic theory and the machine learning has been used for the first time to develop this advanced control law. The synergetic strategy is exploited to overcome the chattering problem arising from the use of the sliding mode approach which has been applied in previous research. Furthermore, the novel machine learning M5P tree-based approximator was designed and applied to approximate the unknown and imprecise dynamics of the studied converter. The learning data comes from the smart approximator, which is based on fuzzy logic, with the aim of extracting its own advantages and offering them to the new tree-based approximator M5P. This action will make it possible to improve the operation of the fuzzy approximator, which has already been studied in some research. Finally, the developed control strategy was successfully evaluated in the laboratory using the dSPACE 1104 board and compared with the fuzzy adaptive synergetic approach under different conditions of load variations and imposed references. The practical results show that the proposed tree adaptive synergetic approach is competitive with the fuzzy adaptive strategy in terms of ease of practical implementation, fast control execution and better output voltage regulation quality. [ABSTRACT FROM AUTHOR]

The increasing energy demand in information technologies requires novel low‐power procedures to store and process data. Magnetic materials, central to these technologies, are usually controlled through magnetic fields or spin‐polarized currents that are prone to the Joule heating effect. Magneto‐ionics is a unique energy‐efficient strategy to control magnetism that can induce large non‐volatile modulation of magnetization, coercivity and other properties through voltage‐driven ionic motion. Recent studies have shown promising magneto‐ionic effects using nitrogen ions. However, either liquid electrolytes or prior annealing procedures are necessary to induce the desired N‐ion motion. In this work, magneto‐ionic effects are voltage‐triggered at room temperature in solid state systems of CoxMn1‐xN films, without the need of thermal annealing. Upon gating, a rearrangement of nitrogen ions in the layers is observed, leading to changes in the co‐existing ferromagnetic and antiferromagnetic phases, which result in substantial increase of magnetization at room temperature and modulation of the exchange bias effect at low temperatures. A detailed correlation between the structural and magnetic evolution of the system upon voltage actuation is provided. The obtained results offer promising new avenues for the utilization of nitride compounds in energy‐efficient spintronic and other memory devices. [ABSTRACT FROM AUTHOR]

With the rapid development of 5G base station construction, significant energy storage is installed to ensure stable communication. However, these storage resources often remain idle, leading to inefficiency. To enhance the utilization of base station energy storage (BSES), this paper proposes a co-regulation method for distribution network (DN) voltage control, enabling BSES participation in grid interactions. In this paper, firstly, an energy consumption prediction model based on long and short-term memory neural network (LSTM) is established to accurately predict the daily load changes of base stations. Secondly, a BSES aggregation model is constructed by using the power feasible domain maximal inner approximation method and Minkowski summation to evaluate the charging and discharging potential and adjustable capacity of BSES clusters. Subsequently, a BSES demand assessment and optimal scheduling model for low voltage regulation in DN is developed. This model optimizes the charging and discharging strategies of BSES to alleviate low voltage problems in DN. Finally, the simulation results effectively verify the feasibility of the proposed optimal scheduling method of BSES for voltage regulation in DN. [ABSTRACT FROM AUTHOR]

With the rapid development of 5G base station construction, significant energy storage is installed to ensure stable communication. However, these storage resources often remain idle, leading to inefficiency. To enhance the utilization of base station energy storage (BSES), this paper proposes a co-regulation method for distribution network (DN) voltage control, enabling BSES participation in grid interactions. In this paper, firstly, an energy consumption prediction model based on long and short-term memory neural network (LSTM) is established to accurately predict the daily load changes of base stations. Secondly, a BSES aggregation model is constructed by using the power feasible domain maximal inner approximation method and Minkowski summation to evaluate the charging and discharging potential and adjustable capacity of BSES clusters. Subsequently, a BSES demand assessment and optimal scheduling model for low voltage regulation in DN is developed. This model optimizes the charging and discharging strategies of BSES to alleviate low voltage problems in DN. Finally, the simulation results effectively verify the feasibility of the proposed optimal scheduling method of BSES for voltage regulation in DN. [ABSTRACT FROM AUTHOR]

In this paper, a method for determining line drop compensator (LDC) parameters for step voltage regulators and on‐load tap changers is proposed to avoid voltage violations in distribution systems with voltage fluctuations due to photovoltaic (PV) generation and electric vehicle (EV) charging. Distribution system operators need to effectively solve voltage problems caused by the widespread installation of distributed energy resources with the existing voltage regulators to construct an efficient and rational infrastructure. Our focus was on improving the method for determining the LDC parameters for the existing voltage regulators based on LDC control. A mechanism to dynamically change the LDC parameters depending on the situations in the distribution system was developed by using a mixture of experts, one of the machine learning techniques, and real‐time voltage and power flow information from information technology switches. The power flow calculations were performed using a distribution system model constructed based on the topology, loads, and generation characteristics of an actual distribution system in the Hokuriku region. The effectiveness of the proposed method was evaluated in terms of its improved effect on PV and EV hosting capacity, as well as the impact on the frequency of tap operations of voltage regulators. © 2024 The Author(s). IEEJ Transactions on Electrical and Electronic Engineering published by Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

ABSTRACT The multiple‐input and multiple‐output (MIMO) DC–DC converters offer various advantages such as improved efficiency and reduced component count. However, the preference of these converters over other types of converters is dependent on the specific application and requirements. Various types of boost‐derived MIMO DC–DC converters are discussed in the literature. However, these converters are either nonisolated or isolated types. In the paper, a MIMO‐based cascaded boost hybrid interlink converter (CBHIC) has been proposed. The proposed converter includes four DC–DC boost converters that are supplied power by two input DC sources. The boosted DC output of these converters can be used independently or in a cascaded manner depending upon the requirement of the load. Further, the cascaded action of these four boost converters leads to the production of two high‐frequency AC outputs. By using bridge rectifiers and high‐frequency transformers, high‐frequency AC voltages are converted into DC. Therefore, two isolated DC output voltages can be achieved using CBHIC. The complementary operation of the cascaded boost converters results in reduction of source current ripples. The design, operating modes, and performance evaluation of the proposed CBHIC have been included in the paper. To validate the efficacy of the proposed CBHIC, a lab prototype of 400 W is prepared. The rms value of high‐frequency AC output voltage at each is isolated port is 141 V. The CBHIC exhibits an efficiency of 94.3 at 400 W. The operation of the converter during voltage control mode is further explored and its dynamic response is studies with the help of experimental results. The obtained simulation and experimental results validate the effectiveness of the proposed converter. [ABSTRACT FROM AUTHOR]

Summary: Virtual synchronous generators (VSGs) are comprised of an outer power loop and inner cascaded control loops. The dynamic performance of the output interface is severely degraded when microgrid loads exhibit variability and nonlinearity. Therefore, robustness against load disturbances must be possessed by any voltage control scheme. In this paper, a proportional resonance‐linear active disturbance rejection control (PR‐LADRC) scheme based on an improved linear extended state observer (ILESO) is proposed for VSG voltage control. In comparison with the traditional linear extended state observer (LESO), the differential state variable of the output voltage is utilized to increase the observation bandwidth; consequently, the proposed ILESO can effectively overcome the disadvantage of phase lag when tracking disturbances. Additionally, a proportional resonance controller is incorporated into the LESO feedforward channel to suppress voltage harmonics. The proposed scheme enhances the disturbance observation bandwidth compared to traditional strategies, resulting in a substantial improvement in both the disturbance observation capability of LADRC and the harmonic suppression ability of the VSG system. Theoretical analysis and simulations are conducted to validate the effectiveness of the proposed PR‐LADRC approach. [ABSTRACT FROM AUTHOR]

This paper presents the effect of dead time on active power transfer of the dual active bridge (DAB) and a novel mitigation technique for the same. The whole power range is categorized into five zones based on the switching instant link current direction and the modified active power expressions with effect of dead time are derived for each zone. The novel compensation method for dead time improves the performance of any general optimized techniques for DAB with extended phase shift. Firstly, the link current values at different switching instants are estimated using the mathematical expressions obtained using a linear piece-wise method. Secondly, the values are used for compensation logic formulation in the whole power range. The compensation process is applied to two different configurations, open loop (circulating mode) and close loop (voltage control mode). The mid-power zone is compensated using a constant phase shift modification and the low power zone is compensated using a PI controller based phase shift modification. Finally, the effectiveness of the proposed compensation technique is verified through MATLAB Simulink model and 1.2 kW experimental prototype. [ABSTRACT FROM AUTHOR]

Although field medical microgrids have been widely studied as an important component of future medical power systems, current sharing control in field medical microgrids under false information injection (FDI) attacks has rarely been researched. Based on this, this paper proposes a distributed fuzzy control method for power sharing in field medical microgrids considering communication networks under FDI attacks. First, the field medical microgrid is modeled as a multi-bus DC microgrid system with power coupling. To provide voltage control and initial current equalization, fractional order PI control is applied. In order to reduce the model complexity, the concept of block modeling is employed to transform the model into a linear heterogeneous multi-agent system. Secondly, a fully distributed current sharing fuzzy control strategy is proposed. It can precisely realize current sharing control and reduce the communication bandwidth. Finally, the proposed control strategy is verified by simulation results. [ABSTRACT FROM AUTHOR]

PMUs and micro PMUs are an emerging technology that is gaining increasing importance in the monitoring and control of electric distribution grids. Their ability to provide accurate, real-time information on power quality, along with their ability to quickly detect and isolate any problems on the grid, make them a key tool for increasing grid safety and reliability. In terms of research and development, there is a growing interest in developing more advanced and reliable Micro PMUs that can provide more detailed and accurate information about the grid. In addition, there is a growing focus on integrating Micro PMUs with other grid control and monitoring systems, such as frequency and voltage control systems, to achieve greater efficiency in grid management. In this research, a commercial PMU is tested during transient conditions typical of distribution grids such as load insertion and de-insertion and distributed generation. The system involves simulating a grid in a Simulink environment and transforming digital signals into analog signals to be supplied to the PMU. Some indices such as TVE, ROCOF are then used for performance analysis. [ABSTRACT FROM AUTHOR]

This letter presents a 28 GHz balun‐first low noise amplifier (LNA) featuring a wide dB‐linear variable gain range. The architecture of LNA includes three‐stage cascode amplifiers. An integrated balun at the input stage provides RF ESD protection and converts a single‐ended signal to a differential one (S‐to‐D). A transformer‐based dual‐resonant matching network is designed and analyzed to achieve wideband performance. To realize a continuous dB‐linear variable gain range and consistent input/output matching, gain control is implemented in the second stage using a 5‐bit digital‐to‐analog converter (DAC) for a 32 dB gain range. The DAC can generate a nonlinear analog voltage to control the gate of the common‐gate transistor in the second cascode stage, inversely compensating for the nonlinear gain variations of the cascode amplifier. The LNA is fabricated in 65‐nm CMOS process with a core size of 0.154 mm². Measurement results exhibit a maximum gain of 33.5 dB and a minimum noise figure (NF) of 3.65 dB with a 3‐dB bandwidth of 23–29.5 GHz. The measured variable gain range is approximately 32 dB across 32 different gain states, with a linear gain step of ~1 dB per state and an IP1dB ranging from −6.5 dBm to −35.25 dBm. The power consumption is 35.4–48 mW from a 1.2 V supply voltage. [ABSTRACT FROM AUTHOR]

For maintenance of distributed wind power networks, it remains important to realize intelligent operation scheduling strategies for wind power equipments according to their working status. As a consequence, this paper proposes a deep learning-based optimal scheme for distributed wind power networks. First of all, an adaptive status assessment model is constructed to identify time-varying operation status for unit components. Then, based on the predicted operation risk of unit components, a preventive maintenance decision model is formulated to realize flexible decision-making of maintenance tasks. Finally, a dynamic maintenance task scheduling model based on extreme learning machine (ELM) neural network is designed. The ELM neural network-based scheduling approach is expected to use a historical strategy library to assist in revising realtime voltage control strategy. Also, we conduct some experiments to evaluate the performance of the proposed method through simulation modeling. The obtained results show that real-time voltage control accuracy for wind power networks with an incomplete observation area is improved. [ABSTRACT FROM AUTHOR]

To improve the voltage regulation of asynchronous generators during load switching, a Lyapunov-based control strategy has been proposed to stabilize the generator's voltage by connecting a static synchronous compensator. By constructing a Lyapunov function from the mathematical model, the error tracking problem is transformed into a global asymptotic stability problem of the Lyapunov function at the equilibrium point. The outer loop linearizes the direct current (DC) voltage control process, while the inner loop replaces integral terms with differential terms. The proposed Lyapunov method achieves linearized voltage control with a quadratic outer loop structure and the inner loop differential structure exhibits a shorter transient process, outperforming traditional methods. Simulation and experimental tests were then used, where the latter was a down-scale laboratory prototype experiment. Compared to traditional (voltage-oriented control) VOC, the outer loop (Lyapunov-function-based control) LBC reduces the DC voltage transient processes by approximately 9.4 milliseconds, while the inner loop LBC reduces both alternating current (AC) and DC voltage transient processes by approximately 2.6 ms and 8.7 ms, respectively. [ABSTRACT FROM AUTHOR]

This paper proposes goal-function-based decentralized control of microgrids. In addition to being an instrument for maintaining the grid voltage and frequency stability, each grid-tie inverter generates a current component with the aim of compensating for voltage distortion in the node where it is connected. The designed goal-function does not need to rely on the assumption that a microgrid is dominantly inductive or resistive to derive its control law, as is mostly the case with the droop-based approach. The priorities of the proposed scheme can be adjusted according to user preferences. In addition, the control algorithm is independent of network topology, can be applied in both islanded and non-islanded microgrids, and secure system scalability. The proposed method is verified by detailed simulations. [ABSTRACT FROM AUTHOR]

Flexible user-side resources are of great potential in providing power regulation so as to effectively address the challenges of reverse power flow and overvoltage issues in distribution networks characterized by high photovoltaic (PV) penetration. However, existing distributed algorithms typically implement control signals after the convergence of the algorithms, making it difficult to track frequent and rapid fluctuations in PV power outputs in real time. Given this background, an online-distributed control algorithm for the real-time power regulation of flexible user-side resources is proposed in this paper. The objective of the established control model is to minimize network losses by dynamically adjusting active power outputs of flexible user-side resources and reactive power outputs of PV inverters while respecting branch power flow and voltage magnitude constraints. Furthermore, by deconstructing the centralized problem into a primal–dual one, a distributed control strategy based on the dual ascent method is implemented. With the proposed method, agents can achieve global optimality by exchanging limited information with their neighbors. The simulation results verify the good balance between economic efficiency and voltage control performance of the proposed method. [ABSTRACT FROM AUTHOR]

Ca2+ release from the sarcoplasmic reticulum (SR) plays a central role in excitation-contraction coupling (ECC) in skeletal muscles. However, the mechanism by which activation of the voltage-sensors/dihydropyridine receptors (DHPRs) in the membrane of the transverse tubular system leads to activation of the Ca2+-release channels/ryanodine receptors (RyRs) in the SR is not fully understood. Recent observations showing that a very small Ca2+ leak through RyR1s in mammalian skeletal muscle can markedly raise the background [Ca2+] in the junctional space (JS) above the Ca2+ level in the bulk of the cytosol indicate that there is a diffusional barrier between the JS and the cytosol at large. Here, I use a mathematical model to explore the hypothesis that a sudden rise in Ca2+ leak through DHPR-coupled RyR1s, caused by reduced inhibition at the RyR1 Ca2+/Mg2+ inhibitory I1-sites when the associated DHPRs are activated, is sufficient to enable synchronized responses that trigger a regenerative rise of Ca2+ release that remains under voltage control. In this way, the characteristic response to Ca2+ of RyR channels is key not only for the Ca2+ release mechanism in cardiac muscle and other tissues, but also for the DHPRdependent Ca2+ release in skeletal muscle. [ABSTRACT FROM AUTHOR]

This paper develops a distributed secondary control strategy for direct current (DC) microgrid based on the distributed state estimation under false data injection (FDI) attacks. FDI attacks occurring on sensors, communication links, and control channels are fully considered, and a distributed state estimation–based secondary control is designed to filter out the effects of attack signals introduced in the secondary control. The secondary control is designed based on a consistent Kalman filtering algorithm, which is able to improve the accuracy by introducing corrections to the current predicted values from the previous moment of the neighbors. In addition, the consistency gain matrix is transformed into consistency coefficients to improve the correction speed. The filtered secondary control signal is fed into the primary control for voltage recovery and precise power distribution. A rigorous proof based on Lyapunov's technique shows that the method guarantees the convergence of global voltage regulation under FDI attacks. Simulation results show that the proposed method can achieve voltage recovery and accurate power distribution when the DC microgrid is subjected to FDI attacks. [ABSTRACT FROM AUTHOR]

As photovoltaic energy is clean, renewable, and less noisy, it is increasingly integrated into the grid. This integration aims to overcome energy deficits and get rid of pollution from conventional sources. In this paper, a two-stage configuration of PV energy conversion to a three-phase grid has been studied. The control of this configuration can be divided into two parts, such as DC bus control and AC bus control. The DC bus is controlled by MPPT control. The AC bus is controlled by DC link voltage control, phase-looked loop control, and voltage source inverter control. The contribution in this study aims to improve the quality of energy injected via a new hybrid approach to MPPT control. The proposed control is a combination of robust sliding-mode control and incremental inductance. Unlike conventional hybridization, the proposed control estimates correct the error upon entry of the conductance incremental control. This correction provides an adaptive incremental step for increment conductance control. The proposed control is compared with three other controls under MATLAB/Simulink. Such as incremental conductance, variable step size incremental conductance, and conventional hybrid MPPT incremental inductance-sliding mode control. The simulation results show a remarkable minimization of the ripple phenomenon and the chatter phenomenon. Thus, the quality of the energy injected into the network is improved, such as by reducing the total harmonic distortion of the current and increasing efficiency. [ABSTRACT FROM AUTHOR]

A powerful and efficient program for restoring the electrical distribution system by effectively utilizing the maximum capabilities within the system, including soft open points, distributed generation resources, and network configuration changes, can significantly reduce both the quantity and duration of lost loads caused by permanent faults. In this research study, we address the issue of distribution network restoration with a focus on soft open points (SOPs) and intentional islanding using distributed generations. This problem is formulated as a constrained optimization problem in order to determine the optimal distribution network configuration, quality of intentional islanding through DGs, control function of SOPs, and amount of load shedding. The objective is to minimize lost load while minimizing switching operations and preferably minimal islanding. Given that this problem involves multiple complexities such as combinatorial nature, mixed-integer variables, non-linearity, non-convexity along with numerous variables and constraints; we employ an evolutionary method known as simulated annealing (SA) algorithm to solve it without any simplifications or assumptions about convexity. To enhance efficiency during implementation of SA algorithm, Kruskal’s algorithm is utilized for generating radial solutions which restricts search space to feasible solutions resulting in quicker attainment of high-quality optimal solutions. Finally, the outcomes of implementing the suggested approach on the 69-bus IEEE distribution system are presented and examined. It is demonstrated that by leveraging the potential of soft open points in load transfer control and network voltage regulation, along with utilizing intentional islanding capability provided by distributed generation resources, the restoration capability of the distribution system can be greatly enhanced. [ABSTRACT FROM AUTHOR]

This paper discusses the design and analysis of a three-level LLC (TL-LLC) resonant converter for an electric vehicle (EV) charging application. The proposed two-stage onboard charger comprises an ac-to-dc power factor correction (PFC) stage, followed by the second stage required to provide galvanic isolation and dc-to-dc conversion. The PFC stage uses a bridgeless SEPIC converter with average current control and voltage mode control algorithm for achieving unity power factor (pf) operation with constant DC link voltage. In contrast, the dc/dc stage uses a three-level LLC resonant converter with a frequency control algorithm to control the output voltage. A 1 kW, 360 V output model of the proposed onboard charger is implemented and simulated in PSIM, and the obtained results are investigated and examined in detail. Results obtained from the simulation show a power factor greater than 0.99 with THD less than 5 $$\% $$ % at the input side. For TL-LLC, both zero voltage switching (ZVS) for primary MOSFETs and zero current switching (ZCS) for secondary side rectifier diodes are achieved. [ABSTRACT FROM AUTHOR]

Radial ribs are important supporting parts of umbrella antenna, and its shape is a crucial factor affecting the overall reflector accuracy. Considering the difficulty of in-orbit shape sensing, a fiber-optic shape sensing (FOSS) method for the radial rib is presented in this paper, then on the basis of FOSS a shape active control method for the radial rib driven by Macro-Fiber Composite actuators is proposed. Firstly, combining the deformation characteristics of the radial rib structure, an improved Ko displacement algorithm is proposed for its shape sensing using distributed fiber-optic. Then, establish the shape active control model with the Influence-Coefficient-Matrix method, and propose a closed-loop shape active control method with FOSS as feedback for the radial rib. In this paper, the optimization problem of solving control voltage is established by using the Least-Square method, and Root-Mean-Square error is taken as the convergence condition. Finally, numerical simulation and experiment show that the relative error of the shape sensing with fiber-optic is less than 5%, and the shape accuracy of radial rib after control is improved by more than 90% to reach submillimeter level, which verifies the effectiveness of the radial rib shape active control method based on FOSS. [ABSTRACT FROM AUTHOR]

In this work, a nine level (9-L) asymmetrical switched-capacitor multilevel inverter (ASCMLI) based induction heated (IH) autoclave for sterilization in medical applications is proposed. Due to the several benefits of multilevel inverter such as controlling of voltage magnitude and hence uniformity of heat is maintained at the load side as compared to conventional heating of autoclave. It has two common ground-connected dc voltage sources, which makes it ideal for usage in medical applications. Moreover, the development of a compact autoclave is carried out in this work that has a much reduced running time without sacrificing the quality of its sterilization. Further, the sterilization schedule for conventional and IH autoclave is presented in different temperature and pressure condition. The distributions of magnetic flux density and induced eddy current density in the multilevel inverter based IH autoclave were also exhibited. Finally, the performance of the proposed system are validated by simulation and experimental results obtained from a laboratory prototype setup. [ABSTRACT FROM AUTHOR]

In microgrids, voltage imbalance control is crucial to preserving the required level of power quality. The article presents a tracker design that mitigates the unbalance in the microgrids. The proposed microgrid model includes positive and negative sequences, whereby the positive sequences are controlled, and the negative sequence is treated as an external disturbance (whose effect must be attenuated). The uncertainty in the external disturbance is modelled in the norm-bounded form. The suggested control is based on attracting (driving) the state trajectory into a small region, including the origin (attracting ellipsoid-set). The effect of the negative sequence components is attenuated by minimizing the ellipsoid volume. When the state trajectory enters that region, it will never leave it for the future time (termed invariant-set). Two theorems were formulated for tracker synthesis that follows the desired reference and reduces the negative sequence impact. These theorems are the invariant-set method and the H ∞ approach. The validity of the suggested control is demonstrated via testing the system under various operational unbalanced scenarios, such as unbalances or faults at the load side or in the transmission lines. The simulations show the superiority of the suggested method in terms of accuracy and dynamic response when compared with the H∞. Additionally, a comparison is made between the suggested tracker and Active Disturbance Rejection Control (ADRC). • Microgrid model with positive and negative sequences is presented. • Negative sequence is treated as an uncertain disturbance. • Two developed new theorems handle this disturbance in tracker design. • A positive-sequence tracker using invariant-sets is proposed for efficient disturbance rejection. • Performance is compared to H¥ and ADRC under various operational conditions. [ABSTRACT FROM AUTHOR]

The increasing penetration of distributed energy resources poses new challenges for operating distribution systems, as high penetration levels are causing adverse grid impacts. In this context, active grid regulation, such as the smart inverters functions recommended in IEEE 1547–2018, has become necessary. In this regard, advanced monitoring techniques, such as state estimation, are promising alternatives to enhance the operation of active distribution networks. However, the lack of reliable information is a technical limitation for applying estimation algorithms to distribution circuits. Therefore, knowledge of the control mode of distributed energy resources may be valuable information to enhance the accuracy of the estimates. This paper proposes to include the volt-var smart inverter function in WLS three-phase state estimation via iterative adjustment. The volt-var control variables are introduced as pseudo-measurements in the first stage, and the second one ensures the control and state variables' compliance with the control model. The validation and benefits of the proposed method are presented via simulation results in the IEEE 34-node test feeder. [ABSTRACT FROM AUTHOR]

The AlInGaN/GaN heterojunction epitaxy material with high cutoff frequency and saturated power density has become a very popular candidate for millimeter wave applications in next-generation mobile communication. In this study, an advanced voltage-controllable capacitor based on the AlInGaN/GaN-Si (111) epitaxy was proposed by employing a bi-directional series MIS capacitor structure. The capacitor was fabricated by using a pad area of 40 μm × 40 μm, with a 1 μm distance between the positive and negative electrodes. The test results show that the capacitance is turned on with a saturation capacitance density and a maximum leakage current density of 0.30 fF/μm2 of 0.37 pA/μm2, respectively, for the control voltage from −6.5 V to 6 V. In particular, in the proposed design method, the saturation capacitance required for the practical application can be obtained by simply adjusting the capacitance area. The capacitor showcases characteristics of rapid turn-on and turn-off responses coupled with low loss, underscoring its promising prospects for deployment in RF switching applications. [ABSTRACT FROM AUTHOR]

This research study presents a resilient control scheme for an islanded DC microgrid (DC MG) integrating solar photovoltaic (PV), battery storage (BESS), and piezoelectric (PE) energy harvesting modules. The microgrid (MG) case study represents an energy hub designed to provide electricity for lighting systems in transportation, roads, and other infrastructure. To enhance practicality, the PE is modeled using the real data captured from a traffic simulator. The proposed reinforcement learning (RL) method was tested against four severe and unexpected failure scenarios, including short circuit at the load side, sudden and severe change of load, open circuit, and converter failure. The performance of the controller was quantitatively compared with a conventional PI controller. The results show marginal improvement in one scenario and significant improvement in the other three, suggesting that the proposed scheme is a robust candidate for microgrids with high levels of uncertainty, such as those involving solar and PE harvesters. [ABSTRACT FROM AUTHOR]

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Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Multilevel inverters with improved voltage quality are widely used in applications such as motor control and electric vehicles. The four-level active neutral point clamped (4L-ANPC) inverter effectively meets the demands for high power density and low device voltage stress. However, balancing the capacitor voltage and reducing its low-frequency voltage fluctuation are critical challenges that need to be addressed. To address these challenges, this paper proposes a "variable reference + zero-sequence injection" method that requires only three reference voltage signals to determine the injected zero-sequence components. Particularly, the expression of the midpoint current, regarding the modulation index and phase current amplitude, is theoretically derived. This reveals the fundamental connection between the zero-sequence voltage signal and the midpoint current, providing a theoretical foundation for the zero-sequence injection method in four-level inverters. Subsequently, a simulation model and an experimental platform of the 4L-ANPC inverter were developed to compare and analyze the waveforms of the upper and lower capacitor voltages, phase currents, and line voltages under different modulation methods. Additionally, the upper and lower capacitor voltage waveforms were examined for various modulation indices. The results indicate that as the modulation index increases, the low-frequency voltage fluctuation in the upper and lower capacitor voltages also rises. At a modulation index of 0.95, the "variable reference + zero-sequence injection" method effectively suppresses the fluctuation in the upper and lower capacitor voltages to be no more than 1 V. These experimental findings validate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Under the background of high permeability, voltage feedforward control may further weaken the stability of grid-connected inverter (GCI) systems and may cause sub-synchronous oscillation in extreme cases. To solve this problem, this paper firstly considers the influence of the frequency coupling effect and voltage feedforward control, and adopts the harmonic linearization method to construct the L-type GCI sequence admittance model with PI (proportional integral) control and PR (proportional resonant) control, respectively. By comparing the sequence admittance characteristics of the GCI under two control strategies, combined with the sequence admittance model and Nyquist criterion, this paper analyzes the influence of voltage feedforward and control parameters on the stability of the GCI under two control strategies. The results show that the stability of GCI under PR control is slightly better than that under PI control. At the same time, the voltage feedforward control does reduce the stability of the GCI system under the two control strategies. Finally, the accuracy of the theoretical analysis is verified by simulation and experiment. [ABSTRACT FROM AUTHOR]

In DC microgrids, a large-capacity hybrid energy storage system (HESS) is introduced to eliminate variable fluctuations of distributed source powers and load powers. Aiming at improving disturbance immunity and decreasing adjustment time, this paper proposes active disturbance rejection control (ADRC) combined with improved MPC for n + 1 parallel converters of large-capacity hybrid energy storage systems. ADRC is utilized in outer voltage control loops, and improved MPC is employed in inner current control loops of n battery converters. Droop control is adopted to obtain power distribution between n battery converters, and a DC bus voltage compensator is used to compensate voltage deviations and maintain constant DC bus voltage. The low-pass filter (LPF) is adopted to obtain high-frequency power as the reference for the supercapacitor converter, ADRC is also utilized in the outer power control loop, and MPC is employed in the inner current control loop. Compared with traditional observers, the voltage expansion state observer of the proposed ADRC control is independent of the system model and parameters and consequently has strong disturbance immunity, and significantly reduces voltage overshoots during power fluctuations. The MPC-based inner current control loops of n + 1 converters accelerate current response speed and significantly decrease switching losses. Simulation and experimental results indicate that utilizing the proposed control strategies, large-capacity HESS has stronger anti-interference ability, shorter regulation time, smaller switching loss, and simultaneously maintains the stability of the DC bus voltage. [ABSTRACT FROM AUTHOR]

This article proposes a voltage compensation control strategy for the distribution network based on the unified power quality conditioner (UPQC) with battery energy storage systems (BESS) to achieve comprehensive management of the power quality and improve the system dynamic responses. Specifically, aiming at that amplitude and phase jump of the terminal voltage, a capacity configuration compensation scheme is proposed to achieve voltage vector compensation. The series converter is designed to compensate for the amplitude and phase of the load voltage. The parallel converter is designed to realize power compensation and ensure that the grid voltage and current are sinusoidal and in phase. A voltage control approach based on the nonlinear disturbance observer (NDO) is developed for BESS to stabilize the DC bus voltage and improve the anti-interference performance of the current. An NDO is designed to accomplish current disturbance tracking and provide disturbance feedforward compensation. Simulations validate that the proposed approach is effective and feasible. [ABSTRACT FROM AUTHOR]

While the physical principles for regulating localized surface plasmon resonance (LSPR) are well established, dynamically tuning the LSPR in a given material post synthesis remains challenging. Herein, this study demonstrates a strategy for dynamically tuning the LSPR of Au nanostructures by selectively altering the dielectric environment. Au is integrated with an electrochemically gatable oxide, i.e., SrCoOx (SCO), into vertically aligned nanocomposite thin films via a self‐assembly growth mechanism, where Au develops into nanopillars embedded in the SCO matrix. By selectively controlling the tri‐state phase transitions of SCO matrix via varying the bias voltage polarity in ionic liquid gating (ILG), the LSPR behavior of Au nanopillars can be dynamically tuned. Specifically, gating with a negative bias fully suppresses the LSPR, while a positive bias leads to a continuous blueshift of the LSPR wavelength upon increasing the ILG duration. This work not only opens new directions for the dynamic control of LSPR of noble metal nanostructures, but also offers insight to the voltage control of multifunctionalities via structural and physical intercoupling between different phases in self‐assembled nanocomposites. [ABSTRACT FROM AUTHOR]