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This letter presents a technique that enables very fine tunability of the frequency of ring oscillators (ROs). Multiple ROs with different numbers of tunable elements were designed and fabricated in a 65-nm CMOS technology. A tunable element consists of two inverters under different local layout effects (LLEs) and a multiplexer. LLEs impact the transient response of inverters deterministically and allow to establish a fine tunable mechanism even in the presence of large process variation. The entire RO is digital and its layout is standard-cell compatible. We demonstrate the tunability of multistage ROs with post-silicon measurements of oscillation frequencies in the range of 80–900 MHz and tuning steps of 90 kHz. [ABSTRACT FROM AUTHOR]

Fault classification is crucial in fault mitigation to maintain selectivity in tripping only the faulted phase or zone in power system networks. However, inverter-interfaced renewable energy sources' unique fault current profile poses challenges to classifiers designed for conventional systems, which are inadequate in the presence of renewable energy resources such as inverter-interfaced photovoltaic (PV) or wind turbine systems in the grid. The inverters have internal protection schemes that trip during unbalanced conditions; however, in grids with high penetration of renewable energy, the inverter must ride through the fault and let relays protect the system. Moreover, the different control strategies for inverters can make the fault current small enough to be unreliable to use as a parameter in fault classifications. This study proposes a reliable fault classification method that can accurately identify faults in power systems with high penetration of renewable energy sources. This paper discusses a machine learning (ML)-based classifier using phase current and voltage magnitude to classify faults. The performance of the proposed classifier is validated against different fault scenarios in power systems like the IEEE 9-bus system. The classifier discussed in this paper achieved a satisfactory accuracy of 99.78% with voltage measurements for test conditions within three-quarters of a cycle. The classifier can be used for any three-phase system to provide correct faulted phase information to other protection components. The same methodology is extended to identify evolving faults, achieving an accuracy of 99.6% in determining the evolving fault type. Thus, the proposed ML-based classifier provides a reliable and accurate method for fault classification in power systems with high penetration of renewable energy sources. [ABSTRACT FROM AUTHOR]

The increasing demand for integrating renewable energy sources necessitates inverter topologies with boosting capabilities. Using inverters with boosting capability and a low number of components to integrate renewable energy sources can reduce costs. This study describes a three‐phase multilevel inverter based on extendable switching capacitors. The use of voltage‐doubling modules permits the development of the inverter's capability. By increasing the number of doubling modules, the number of output voltage levels and boost factor are increased. Furthermore, the study introduces and implements a line voltage‐based pulse width modulation approach developed for the proposed inverter. The operation of the proposed multilevel inverter, along with the pulse width modulation scheme, common mode voltage, and power loss analysis are thoroughly discussed. Additionally, a comparative analysis is provided; highlighting the advantage of reducing the number of power switches in the proposed three‐phase inverter compared to other existing topologies. Finally, a laboratory prototype is developed, operating at a 4 kHz switching frequency and with a 120 V DC‐link voltage. The experimental results corroborate the efficiency and performance of the proposed multilevel inverter, thereby validating its practical applicability. [ABSTRACT FROM AUTHOR]

Single‐component ambipolar polymers are highly desirable for organic electrochemical transistors (OECTs) and integration into complementary logic circuits with reduced process complexity. However, they often suffer from imbalanced p‐type and n‐type characteristics and/or stability issues. Herein, a novel single‐component ambipolar polymer, namely, gIDT–BBT is reported based on indacenodithiophene (IDT) as the electron donor, benzobisthiadiazole (BBT) as the electron acceptor and oligo ethylene glycol (OEG) as the side chain. Benefitting from the extended backbone planarity and rigidity of IDT, pronounced electron‐withdrawing capability of BBT, favored ionic transport from OEG together with vertical OECT device structure, a nearly balanced ambipolar OECT performance is achieved for gIDT–BBT, revealing a high transconductance of 155.05 ± 1.58/27.28 ± 0.92 mS, a high current on/off ratio >106 and an excellent operational stability under both p‐type and n‐type operation conditions. With gIDT–BBT in hand, furthermore, vertically stacked complementary inverters are successfully fabricated to show a maximum voltage gain of 28 V V−1 (VIN = 0.9 V) and stable operation over 1000 switching cycles, and then used for efficient electrooculogram recording. This work provides a new approach for the development of ambipolar single‐component organic mixed ionic–electronic conductors and establishes a foundation for the manufacture of high‐performance ambipolar OECTs and associated complementary circuits. [ABSTRACT FROM AUTHOR]

Summary: Multilevel inverters are known as essential converters in renewable sources. First, in this paper, a new submodule is presented, and based on it, a new sub‐multilevel inverter is presented. The proposed sub‐multilevel inverter consists of several unidirectional and bidirectional switches and DC voltage sources. Then, the generalized topology, developed in two modular and cascaded modes, is presented to increase production levels. The proposed submodules are connected in series in the modular topology, increasing production levels. The proposed topology to produce the maximum output levels has the minimum number of IGBTs, drivers, DC voltage sources, etc. Mathematical analyses for conduction and switching losses are provided, and mathematical analyses for the number of devices and voltage across the switches are also presented. In addition to the mathematical analysis of losses, the simulation results are also presented. A general comparison of proposed topology components is presented to demonstrate their advantages. This comparison shows that the proposed topology has the minimum number of power electronic devices. In this paper, nearest level modulation is used to control the proposed topology. The simulation and experimental results of the proposed sub‐multilevel verify the performance of the proposed topology. [ABSTRACT FROM AUTHOR]

Photovoltaic power generation and energy storage technology are current hotspots in the clean energy industry. As a core piece of equipment, an inverter is subjected to higher demands for its voltage regulation range and output performance. A differential boost inverter features a boosting function not found in traditional inverters, effectively widening the input voltage range, with characteristics of a single-stage structure and simple modulation. However, the differential boost inverter faces the issue of high common-mode voltage. Considering that the magnitude of the common-mode voltage changes with different modulation methods, a novel modulation strategy with a flexible common-mode voltage is proposed, which can effectively suppress the common-mode voltage under the same gain without affecting the output power quality. This article first introduces the topology, working principle, and traditional modulation methods of the differential boost inverter. Then, the new modulation strategy is defined, and the gain equation is derived. The new modulation method's applicable scenarios are discussed and compared to other modulation methods based on the gain curve, concluding that the new method has advantages in terms of common-mode voltage amplitude and power quality under low boost gain. Finally, the effectiveness of the proposed method is verified through simulation and experiments. [ABSTRACT FROM AUTHOR]

This paper presents a single-phase Full-Bridge (FB) inverter with a hybrid commutation technique designed to reduce the harmonic distortion caused by the loss of the controller capability around the zero-crossing point in the unipolar commutation region. The hybrid modulation changes from unipolar to bipolar commutation under the loss of the reference control, improving the robustness and efficiency of the method. The commutation technique improves the switching performance and reduces the switching losses. Simulation models are developed in MATLAB/Simulink R2023b to evaluate their performance under different operating conditions. The results show that the proposed commutation technique can achieve high efficiency, low total harmonic distortion (THD), and fast dynamic response. The experimental implementation of sliding mode control (SMC) implemented in an STM32 microcontroller confirms that the hybrid commutation technique can reduce the THD by 0.96 percentage points for local (off-grid) loads and up to 2.45 in an industrial grid-tie network, compared with unipolar commutation. These findings highlight the potential of the proposed modulation technique for applications like solar panels and offer crucial insights for ongoing research and development in this field. [ABSTRACT FROM AUTHOR]

A Rectangular core–shell (RCS), employed to three fins vertically stacked with gate oxide stack junctionless nanosheet, along with doping and gate/dielectric engineering, is explored. This paper proposes an N-type three fins vertically stacked with gate oxide stack junctionless nanosheet with opposite core doping in the channel referred to as RCS. The simulation results show that three fins vertically stacked with gate oxide stack with RCS junctionless nano-sheet exhibit reduced Ioff is 6.913E-21, increased Ion is 2.408E-07, Ion/Ioff ratio is 0.418×106, DIBL is 6.9mV and SS is 60.65 mV/dec, respectively. Furthermore, the P-type of three fins vertically stacked with gate oxide stack junctionless nanosheet and combined -type and P-type three fins vertically stacked with gate oxide stack junctionless nano-sheet were stimulated to construct the inverter circuit. The Voltage Transfer Characteristics (VTC) of three fins vertically stacked with gate oxide stack junctionless nano-sheet with RCS have HfO2 as the gate-oxide based inverter has been notably improved compared to SiO2, al2O3 as a gate oxide and conventional three fins vertically stacked with gate oxide stack junctionless nano-sheet inverter. [ABSTRACT FROM AUTHOR]

For applications involving the implantation of organic thin‐film transistors (OTFTs) in flexible environments, maintaining uniform device performance and ultrathin profiles with excellent mechanical stability is crucial for dynamic deformable conditions. This study presents high‐performance, mechanically flexible ultrathin OTFTs with a thickness under 5 µm, designed to be scalable for utilization in large areas. The OTFTs utilized an organosilicon polymer dielectric layer synthesized via initiated chemical vapor deposition combined with the crystalline organic semiconductor 2‐Decyl‐7‐phenyl[1]benzothieno[3,2‐b][1]benzothiophene (Ph‐BTBT‐10). Compared with conventional organic transistors, the OTFTs exhibited exceptional features, such as a charge carrier mobility of up to 7 cm2 V−1 s−1 and a near‐zero threshold voltage. Their performance is showcased across 900 devices on a 10 cm × 10 cm substrate to ensure uniformity and scalability. Additionally, the OTFTs demonstrate remarkable resilience to mechanical deformation, with a 97.4% mobility retention rate under a 20% tensile compression. After 1000 cycles of repeated deformation stress, they maintain a robust 94.6% performance level compared with the initial state. In summary, the ultrathin flexible OTFTs exhibit exceptional resilience to mechanical deformation, extended air exposure, uniformity in large arrays, and high mobility. This makes them promising for diverse applications, such as in vivo organ monitoring and skin displays. [ABSTRACT FROM AUTHOR]

The main contribution of this paper is to present a simple algorithm that theoretically and numerically assesses the switching angles of an inverter operated with the SPWM technique. This technique is the most widely used for eliminating harmonics in DC-AC converters for powering motors, renewable energy applications, household appliances, etc. Unlike conventional implementations of the SPWM technique based on the analog or digital comparison of a sinusoidal signal with a triangular signal, this paper mathematically performs this comparison. It proposes a simple solution to solve the transcendental equations arising from the mathematical analysis numerically. The technique is validated by calculating the total harmonic distortion (THD) of the generated signal theoretically and numerically, and the results indicate that the calculated angles produce the same distribution of harmonics calculated analytically and numerically. The algorithm is limited to single-phase inverters with unipolar SPWM. [ABSTRACT FROM AUTHOR]

With the rapid development of global energy transformation and new power system, ensuring the stability of distributed energy grid connections is the key to maintaining the reliable operation of the whole power system. This paper constructs detailed impedance models of grid-following (GFL) and grid-forming (GFM) inverters using a harmonic linearization method and thoroughly investigates the mechanisms of resonance when inverters are connected to the grid, as well as the impact of model parameters on the stability of the grid system. This paper also briefly analyzes the scenario where distributed energy and electric vehicles are integrated into the grid simultaneously, demonstrating that grid system stability can be ensured in complex grid situations through reasonable parameter design. Lastly, the accuracy of the proposed impedance models and analysis is verified through MATLAB/Simulink simulations. [ABSTRACT FROM AUTHOR]

This paper presents the experimental results of nMOS quantum dot gate field-effect transistor (QDG-FET) based four-state inverter fabricated and tested with Si/SiO2 and Ge/GeO2 quantum dots. The site-specific self-assembly of SiOx-cladded Si and GeOx-cladded Ge quantum dot layers in the gate region implements both the driver and load FETs in enhancement nMOS inverters. A four-state inverter will allow the reduction of FET count in logic block in microprocessors. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny 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.)

Copyright of Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji is the property of Gazi University 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.)

Voltage-source inverter is a significant part of power supply for various applications. In hard working conditions, the inverter is prone to failure, such as open-circuit (OC) faults, which bring great risk to the safe operation. Therefore, a simple and robust fault diagnosis method for OC faults of voltage-source inverter is proposed. First, the fault principle of OC fault is studied, and a rule of voltage sequence is found that the sequence of positive and negative abnormal voltages is related to the fault position. Then, available line voltages are used as fault diagnosis variables, the fault phase is detected by abnormal values of line voltages, and the fault switch is located according to the fault phase and the rule of voltage sequence. Different from existing OC fault diagnosis methods, the proposed method is immune to phase to phase short-circuit fault, which has not been referred to or discussed in existing literatures yet but can lead to the false diagnosis of OC fault diagnosis methods. Moreover, the proposed method is robust to load variation, switching and fundamental frequencies. The experimental tests are carried out on a dSPACE platform, and the proposed method is verified. [ABSTRACT FROM AUTHOR]

As the penetration of distributed generation (DG) systems in the grid is increasing, the challenge of combining large numbers of DGs in the power systems has to be carefully clarified and managed. The control strategy and management concept of the interconnected systems should be flexible and reliable to handle the various types of DGs. This can be suitably met by microgrids. This paper introduces the microgrid structure and elements and states the main objectives that should be achieved by the microgrid controllers and each DG controller in both operation modes (grid‐connected and island mode). It also presents the challenges of having multiple DG units in a microgrid in terms of accurate power control/sharing, voltage and frequency regulation, power management between DGs, different renewable energy sources integration and deployment, seamless mode transfer, and the modeling issues. The centralized and decentralized control techniques as potential solutions have been discussed and compared by highlighting the advantages and disadvantages of each. Furthermore, the recent control techniques for drooped alternating current microgrids and the main proposed solutions and contributions in the literature have been exposed to finally overcome the droop control limitations and obtain a flexible and smart distributed power system. [ABSTRACT FROM AUTHOR]

An inexact 6-transistor full adder (FA) cell is presented. It is low-power and gives full-swing outputs because of the applied gate diffusion input (GDI) along with the dynamic threshold (DT) techniques. The FA which has three errors is used in a 10-transistor inexact 4:2 compressor based on the stacking circuit idea. The implementation by a 16-nm carbon nanotube field-effect transistor (CNTFET) technology shows a small area of 0.027 and $0.045~\mu \text{m}^{\mathrm{ 2}}$ for the FA and compressor, respectively. A new approximate sum of absolute differences (SADs) block is presented by the FA and compressor. The average power, power-delay-product (PDP), and peak signal-to-noise ratio (PSNR) of the SAD are 6.80 mW, 33.86 nJ, and 42.98 dB, respectively, which confirm its efficiency for bioimages difference detection. [ABSTRACT FROM AUTHOR]

The application of electrochemical cells as a source unit of electrical energy is rapidly growing—used in electric vehicles and other electric mobility devices, as well as in energy supply systems—as energy storage, often together with renewable energy sources. The key element of such systems is the power electronic converter used for DC energy storage and AC grid interfacing. It should be bidirectional to charge and discharge the battery when it is necessary. Two-stage battery interface converters are the most common; their DC-DC stage controls the battery current and adjusts voltage, but the DC-AC stage (inverter or frontend) controls the current in the grid. The use of unfolding inverters in two-stage battery interfaces can have some advantages. In this case, the DC-DC converter produces half-sinewave pulsating voltages and currents, but the unfolding circuit changes the polarity of the voltages and currents and produces no switching losses. Another trend of modern power electronics is the principle of partial power processing. In this case, power electronic converters deal only with a part of the total power; therefore, losses in such converters are reduced. This paper considers combining unfolding frontends with partial power DC-DC converters that enable the further reduction in losses. In this paper, it is shown that such implementation of the partial power conversion principle in semi-DC-AC systems is really possible based on the real-time matching of the voltage of the partial-power DC-DC converter, battery voltage (which depends on its state of charge) and the rectified instantaneous voltage of the AC grid. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Fuzhou University is the property of Journal of Fuzhou University, Editorial Department 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.)

Voltage source inverters are currently gaining popularity in a variety of power system applications, including renewable energy, HVdc, and microgrid. Among all the renewable energy applications, multilevel inverters (MLIs) are the most popular converters for high- and medium-power industries. This article reviews and compares many of the recently developed topologies for renewable energy integration with energy storage systems (ESSs). In addition, a new design of a seven-level inverter is proposed. It utilizes only six power electronic switches in its design of which four have unidirectional voltage-blocking capability and two have bidirectional voltage-blocking capability. Various simulation results of the proposed topology along with the total harmonic distortion (THD) contents of voltage and current are presented in detail under different loading conditions. Afterward, a new factor of comparison is proposed in which component ratings are also considered. Finally, a hardware prototype is built to check the authenticity of the proposed design, and satisfactory results are presented. [ABSTRACT FROM AUTHOR]

A quadratic converter is now a days being investigated for high boost topologies. This paper presents the quadratic converter-based single-phase grid-connected system. For this system, the DC side control loop is regulated using a symmetrical shoot-through (SST)-based PWM. AC side current controller is implemented by the variation of modulation index in a nearly decoupled manner. The advantage of the suggested system is in terms of several controls particularly for input variations and load changes which are most beneficial in the case of grid application. The experimental results are presented to support the simulation results. The simulation results are achieved using MATLAB/SIMULINK. [ABSTRACT FROM AUTHOR]

1ϕ Z/quasi-Z source (ZSI/qZSI) inverters are nowadays increasingly used in a variety of power applications like renewable energy. During the rectification process of AC to DC side, the low-frequency ripples (2ω) are present in the DC side inductor current, capacitor voltage and also in DC-link voltage. These low-frequency ripples are the double line frequency power ripples that occur at two times the fundamental frequency i.e. at 100 Hz. In the case of renewable energy applications such as PV and fuel cells, these ripples are most hazardous. Due to current and voltage (2ω) ripples, the extraction of power from PV/fuel cell reduces. It also decreases its lifetime. These low-frequency ripples also increase the output current and voltage distortion. Ultimately it affects the performance of a system and degrades its power quality. Passive power decoupling techniques are used to eliminate/reduce low-frequency power ripples (2ω). The primary contribution of this article is to show a comprehensive overview of the passive power decoupling technique for the second harmonic (2ω) power elimination over two decades. This article also provides a proposed modified control strategy that achieves the elimination/reduction of (2ω) ripple in inductor current and capacitor voltage at the lowest values of qZS inductor and capacitor. The simulation and experimental results are also obtained for the proposed model. [ABSTRACT FROM AUTHOR]

This paper conducts a comprehensive analysis of offshore wind-photovoltaic hybrid systems, presenting autonomous components tailored for maritime applications. Focusing on the critical role of these systems in supplying electricity to regions with limited infrastructure, particularly maritime zones, the study explores economic advantages over traditional power line installations, emphasizing remote areas. Key components, including battery storage, autonomy, battery selection (with a spotlight on lead-acid batteries), charge controllers, inverters, and the integration of Automatic Identification System (A.I.S.) for maritime safety, are discussed. The article concludes by underscoring the significance of power supply buoys for ship safety and efficient refueling near hybrid systems. [ABSTRACT FROM AUTHOR]

Non-destructive and reversible modulations of polarity and carrier concentration in transistors are essential for complementary devices. The fabricated multi-gated WSe2 devices obtain dynamic electrostatic field induced electrically configurable functions and demonstrate as diode with high rectification ratio of 4.1 × 105, as well as n- and p-type inverter with voltage gain of 19.9 and 12.1, respectively. Benefiting from the continuous band alignment induced modulation of channel underneath the dual gates, the devices exhibit high-performance photodetection in wide spectral range. The devices yield high photo-responsivity (5.16 A W-1) and large 'light/'dark ratio (1 × 105). Besides, the local gate fields accelerate the separation of photo-induced carriers, leading to fast response without persistent current. This strategy takes the advantage of the simplified design and continues to deliver integrated circuits with high density. The superior electrical and photodetection characteristics exhibit great potency in the domain of future optoelectronics. [ABSTRACT FROM AUTHOR]

The classical problem of islanding detection in distributed generation falls into the commonly used categories known as passive, active, and hybrid techniques. These approaches vary in terms of their accuracy, security, and dependability. Detecting islanding in modern inverter-based distribution systems is of the utmost importance to ensuring the protection of equipment, ensuring the safety of workers, and preventing operational and cascaded faults when the system is specially subjected to renewable integration. This research paper presents a technical comparison of the aforementioned techniques, discussing their detection rate, Non-Detection Zone (NDZ), distinct topologies, and their effectiveness in integration for low-frequency grids. The review offers a thorough analysis comparing the key attributes found in the current literature while also highlighting the forthcoming needs for advanced management, optimization, and control technologies. These technologies are crucial to effectively tackling the difficulties that arise from integrating renewable energy sources into established grid systems. [ABSTRACT FROM AUTHOR]

Research indicates that phase-to-ground short-circuits in a frequency converter can subject the rectifier diode and IGBT to excessive voltage and current, potentially causing damage if the component selection margin during hardware design is insufficient. In order to solve the above problems, this paper studies the design of the LCL filter and ground short circuit problem of the hundred-kilowatt inverter. Firstly, an analytical method for calculating the DC bus capacitance and reactor of the inverter is proposed. The interaction between the DC bus capacitance and the reactor parameters and performance is considered in the implementation process. The parameters of the DC bus capacitor and reactor are given. Secondly, the one-to-ground short circuit of the inverter is studied, and the energy flow mode and mathematical expression of the double boost circuit, considering the influence of the leakage inductance of the power transformer, are given. Based on the above analysis, a method for determining the rectifier diode and IGBT, considering the one-to-ground short circuit of the inverter, is proposed. Finally, a one-hundred-kilowatt inverter is developed, and the corresponding experiments are carried out. The feasibility of the proposed scheme is verified by simulation and experiment. [ABSTRACT FROM AUTHOR]

The growth of renewables in the energy sector, e.g., in public low-voltage networks, leads to an increasing share of installed power electronic devices, e.g., inverters for photovoltaic applications. To rely on these devices, suitable analyses have to be performed. This includes studies of the device stability in the harmonic frequency range, i.e., above 50 Hz up to 2 kHz. State-of-the-art time-domain studies for harmonic stability analyses require detailed knowledge about the inverter design. Black-box studies must identify the inverter characteristics in the laboratory, which can differ depending on specific operating points, i.e., specific operating powers. This study analyzes the operating-point dependency of inverters on the critical inductance values of the network impedance, e.g., the inductances at which the inverter is expected to become unstable. Measurements are performed for three operating powers of an unknown, commercially available single-phase inverter to validate the critical inductances. Two further commercially available inverters and four simulative implementations are analyzed as well with regard to the critical inductance and the critical frequency. The results demonstrate the importance of considering a representative range of operating powers of the inverter for the small-signal stability analysis. [ABSTRACT FROM AUTHOR]

The reconfigurable feedback field‐effect transistors (R‐FBFETs) with a double‐gated structure are designed and the logic and memory operations of a logic‐in‐memory (LIM) inverter comprising two R‐FBFETs are investigated. The R‐FBFETs exhibit an extremely low subthreshold swing of ≈1 mV dec−1, a high on/off current ratio of ≈107, and a long retention time of 10 s, owing to a positive feedback loop mechanism. The on‐current ratio of the p‐ to n‐channel modes is 1.03, which indicates a high degree of reconfigurability. The LIM inverter retains the output logic "1" and "0" states for over 50 s under zero‐bias conditions. The symmetric reconfigurable switching and memory operations of the R‐FBFETs enable the LIM inverter to perform logic and memory operations for a long retention time without a power supply. [ABSTRACT FROM AUTHOR]

Organic electrochemical transistors (OECTs) based on Poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) are a benchmark system in organic bioelectronics. In particular, the superior mechanical properties and the ionic‐electronic transduction yield excellent potential for the field of implantable or wearable sensing technology. However, depletion‐mode operation PEDOT:PSS‐based OECTs cause high static power dissipation in electronic circuits, limiting their application in electronic systems. Hence, having control over the threshold voltage is of utmost technological importance. Here, PEDOT:PSS‐based dual‐gate OECTs with solid‐state electrolyte where the threshold voltage is seamlessly adjustable during operation are demonstrated. It is shown that the degree of threshold voltage tuning linearly depends on the gate capacitance, which is a straightforward approach for circuit designers to adjust the threshold voltage only by the device dimensions. The PEDOT:PSS‐based dual‐gate OECTs show excellent device performance and can be pushed to accumulation‐mode operation, resulting in a simplified and relaxed design of complementary inverters. [ABSTRACT FROM AUTHOR]

Semiconducting molybdenum ditelluride (MoTe2) is widely reported owing to its favorable electronic and optoelectronic properties. The effective modulation of its electrical characteristics has garnered growing attention in regard to building high‐performance MoTe2‐based complementary devices. However, the inherent Schottky barrier (SB) in MoTe2‐based devices severely inhibits the charge‐carrier injection efficiency, leading to a high contact resistance between MoTe2 and contact metals. Here, an efficient method is presented for reducing the SB height of field‐effect transistors (FETs) based on MoTe2 by in situ potassium modification. Interestingly, the electrons transported from K continuously change the electrical characteristics of MoTe2 FET from ambipolar to n‐type with an improvement of electron mobility of over one order of magnitude. Meanwhile, the contact resistance of MoTe2 FET is significantly decreased from 11.5 to 0.4 kΩ µm. By regulating the modification region spatially, it is possible to create a complementary inverter with a high gain of ≈32 at VDD = 3 V. This research demonstrates a relatively simple method for optimizing the contact for MoTe2‐based devices and tuning the electrical properties of MoTe2 for future high‐performance complementary electronics. [ABSTRACT FROM AUTHOR]

This article proposes a novel dopingless ternary FET (DLT-FET) composed of the longitudinal metal-source/InAs-channel/InAs-drain structure for compact implementation of the ternary inverter. A single DLT-FET mixes two types of carrier transport mechanisms: 1) according to the concept of charge plasma, the Band-to-Band tunneling (BTBT) can occur at channel/drain interface by metal work function engineering; 2) Schottky Barrier tunneling (SBT) at the source/channel interface. The mechanism of the DLT-FET is verified with the help of TCAD tools. The simulation results revealed that both N/P-type DLT-FETs have a flat drain current characteristic around VG = 0.5VDD, where the VG-independent IBTBT dominates the drain current. The stable third output voltage can be obtained through the voltage dividing, while both the ISBT and IBTBT generate the other voltage levels of 0 V and 1.0VDD. Furthermore, the effects of a series of key device parameters on DLT-FETs and ternary inverter performance are evaluated. The ternary inverter can be implemented by simply replacing two transistors with N/P-type DLT-FETs in a conventional binary inverter and selecting appropriate device parameters for exhibiting comparable transfer characteristics. [ABSTRACT FROM AUTHOR]

Novel circuits designed using carbon nanotube field-effect transistors (CNFETs) are gaining increasing attention because of advantages such as low-power operation, high operating speed, and support of advanced integration technology. In this work, we present a novel arithmetic logic unit (ALU) circuit that is designed entirely using complementary CNFETs. The ALU is intended to process a custom-made algorithm for a near-sensor computing architecture that requires low power and large bit width operation. We completed the ALU design using a large-scale complementary CNFET circuit (number of CNFETs in this circuit is 8160). The total power consumption of the ALU is 218.64 μW, which will satisfy the low-power requirements of the wireless sensor terminal. To verify the behavioral functionality of the circuit, we designed a lightweight binarized neural network and accomplished Modified National Institute of Standards and Technology (MNIST) standard handwritten digit recognition successfully through a register-transfer logic simulation using the proposed circuit and external logic. The accuracy of the algorithm can reach 90.20%. Our research demonstrates the feasibility of employing CNFET circuits in fields that involve the use of complex algorithms, e.g., image classification. The circuits based on the aligned-CNFET model is simulated and compared with MOSFET circuits based on a commercial silicon-based process design kit (PDK). Compared with MOSFET circuits, the aligned-CNFET circuits have an average increase in speed by more than 93% and an order-of-magnitude improvement in the power-delay product (PDP). The ALU and algorithm proposed here are suitable for near-sensor computing architectures for future smart sensors. [ABSTRACT FROM AUTHOR]

This paper presents hybrid design of a Ternary Inverter (TI) circuit by integrating an Ovonic-Threshold-Switching (OTS) based Phase-Change-Memory (PCM) cell between Complementary-Metal-Oxide-Semiconductor (CMOS) transistors. Volatile OTS behaviour of the PCM structure helps to generate the ternary state. Reliability of the proposed TI design has been demonstrated through the Monte-Carlo simulations in Cadence-Spectre simulator incorporating both Process and Mismatch variability at all corners. The proposed inverter cell consumes 10.44 $\mu$ W power and 1.47 ns delay on UMC-180 nm technology node. Moreover to demonstrate the scaling potential, we have simulated the proposed inverter at various technology nodes i.e 180/90/65/28 nm. At advanced feature sizes, power and delay are improved by significant amount. For benchmarking, we have compared the proposed TI design with various state-of-the-art hybrid structures. Furthermore, to demonstrate potential applications, we designed and simulated ternary universal logic gates i.e NAND/NOR. Benefits of the proposed TI in circuit applications are shown through a Ternary Multiplier (TMUL) arithmetic circuit implementation. Finally, a Ternary-Static-Random-Access-Memory (TSRAM) is proposed with two back-to-back connected CMOS-PCM TIs with three bit storing capability. [ABSTRACT FROM AUTHOR]

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This article deals with a LCC-LCC compensated dynamic wireless power transfer system for electric vehicle charging applications. The presented prototype system allows for a power transfer of about 10 kW at 20 cm coil copper to copper distance. With just one circular pickup coil and a very straightforward control scheme, a new coil arrangement enables a seamless power transfer. Furthermore, the system's design power level is easily adjustable by the size of the the pickup coil. The hardware architecture as well as the software functionality are described in detail. A 20 m test track was built up according to the outlined principle. By measuring the transmitted power, the efficiency and the interference between the primary segments and its effect on the inverter currents are examined. The results show an effective DC to DC efficiency in the range of 91 to 92% and a power fluctuation of approximately 25%. [ABSTRACT FROM AUTHOR]

Two‐dimensional semiconductors are considered as promising candidates in next‐generation nanoelectronics. The polarity regulation, however, has been a great obstacle to their applications. Herein, a strategy to comprehensively modulate the polarity of WSe2 field‐effect transistors (FETs) by combining contact engineering and plasma doping is demonstrated. N‐type and ambipolar WSe2 FETs are obtained by indium (In) and chromium (Cr) contact, respectively. Meanwhile Cr contact and mild oxygen plasma doping are employed simultaneously to realize p‐type WSe2 FET. High on/off ratio of ≈107 has been achieved for both n‐type and p‐type WSe2 FETs. Subsequently, they are connected in series to construct a homogeneous complementary logic inverter and a lateral p–n diode. Anti‐ambipolar transfer characteristics, therefore, are accessed from the inverter. And the forward to backward rectifying ratio reaches 106 for the p–n diode. The proposed strategy paves the way for practical applications of WSe2 FETs in logic circuits and optoelectronics. [ABSTRACT FROM AUTHOR]

In this paper, a grid impedance estimation procedure based on the injection of active and reactive powers through a grid-tied inverter is proposed. The estimation is based on Newton–Raphson algorithm acting on the phasors of the voltages and currents at the point of common coupling between the inverter and the grid. Unlike, similar procedures, based on power injections, the method is implemented in the α β frame, avoiding Park transformations. This is an advantage because dq quantities are prone to be too noisy, or oscillating in unbalance grid conditions or in the presence of voltage harmonics. Moreover, the proposed method allows variations of active and reactive to be imposed simultaneously, differently of methods relying on dq voltages and currents. This feature speeds up the estimation. The voltages and current phasors used to estimate the impedance are determined with the aid of a positive sequence extractor and Fourier algorithm providing the method robustness against unbalance grid conditions and harmonic distortions. Besides the impedance estimation, this paper proposes a technique in which the impedance information is applied to enhance the inverter's control. Here, the impedance value is used with a Routh criterion to assure the system's stability. The propositions are verified with PSIM simulations and with a Hardware-in-the-Loop real-time platform. [ABSTRACT FROM AUTHOR]

This article proposes a bidirectional single-phase dc–ac converter with triple port converter (T-PC) for application of energy storage. This proposed converter provides three ports such as ac port, dc port, and dc bus port to achieve three power interfacing ports. For the direct conversion process, dc port is directly connected to T-PC, and direct power will be exchanged between energy storage device (ESD) and grid when the ESD voltage peak amplitude is lower than the ac voltage. Thus, a dc–dc converter downstream power process gets reduced, and power loss is decreased considerably. Due to multilevel characteristics, switching losses in the T-PC can be reduced. The efficiency of the overall bidirectional dc–ac conversion process can be increased significantly. The circuit model, working principle, and modulation control of T-PC-based bidirectional dc–ac conversion concepts are analyzed. A 1.5-kW test-bench model is developed and its effectiveness is verified to find the merits of suggested conversion. [ABSTRACT FROM AUTHOR]

This article (case study) discusses the influence of household photovoltaic generation on the voltage quality in a three-phase 0.4 kV grid. The research analyzes remotely acquired data from two specially designed three-phase Y-connected power meters to understand the PV system's influence on the grid. The values of the voltages, currents, THD, individual harmonics, power factor, and K-factor are obtained every 200 ms over several months, creating more than 20 GB of data. The loads are typical household electrical appliances and EV portable chargers. The main conclusion after analyzing the measurements is that three-phase PV generation in the presence of household loads can create or increase grid unbalance; important current values into the neutral wire and THD and K-factor increase in some cases. The results also uncovered that without current sensing at the household connection point to the three-phase grid to control the PV inverter, the balanced phase output power of the grid-tied inverter is harmful to the 0.4 kV grid balance. [ABSTRACT FROM AUTHOR]

Approximate computing (AC) is an emerging technique in arithmetic circuits. In this letter, a new AC-based full adder (FA) circuit is presented with 12 transistors, 150mm]Please confirm or add details for any funding or financial support for the research of this article. -160mm]If you haven’t done so already, please make sure you have submitted a video graphical abstract (GA) for your paper, along with a caption and overlay image. The GA will be displayed on your articles abstract page on IEEE Xplore. Note that captions cannot exceed 1800 characters (including spaces). Overlay images are usually a screenshot of your video that best represents the video. This is for readers who may not have access to video-viewing software. 0.239 $\mu \text{m}^{2}$ of area, and two errors in the outputs. In the proposed FA, the gate diffusion input (GDI) and dynamic-threshold (DT) techniques are applied using the carbon nanotube field-effect transistor (CNTFET) technology. Accuracy metrics, such as normalized mean error distance (NMED) and mean relative error distance (MRED) along with circuitry parameters of power-delay-product (PDP), energy-delay-product (EDP), and power-delay-area-product (PDAP), confirm the efficiency of the proposed FA for complex structures. The proposed FA is embedded in a ripple carry adder (RCA) by various numbers of approximate bits (NABs), and then the accuracy and circuitry parameters are extracted. Compared to the state-of-the-art designs, the high-efficient behavior of the proposed FA is proved when it is used in image processing applications. [ABSTRACT FROM AUTHOR]

A direct speed control strategy based on finite control set model predictive control (FCS–MPC) with a voltage smoother is presented herein. In the proposed concept, a finite set of smoothed voltage vectors characterized by an adjustable amplitude and a movable origin is introduced as voltage candidates in the FCS–MPC scheme. The controller predicts the future current and speed and outputs the optimal smoothed voltage using pulse-width modulation. Owing to this control scheme, an abrupt change in the output voltage, which causes a large current ripple, is avoided without additional computational costs. Simulation and experimental results obtained using a permanent magnet synchronous motor fed by a two-level three-phase inverter show that the proposed method effectively reduces the current ripple while achieving a high dynamic drive compared with the conventional FCS–MPC scheme. [ABSTRACT FROM AUTHOR]

The interface inverters arbitrate the network impedance based on the source characteristics for efficient solar energy harvesting. The wide impedance arbitration capability of the interface inverter defines the wide operational integrity with the ac network. In the weak grid scenario, the uncompensated grid inductance beyond point of common coupling (PCC) offers the negative damping for power oscillations at the PCC tugs the system toward instability. In this article, the negative damping influence due to interactions between the system impedance (filter inductance and grid power injection resistance) and ac network impedance (grid inductance) on the inverter closed-loop controller is characterized by observing the natural phase deviations in real and imaginary axis. Through distinguished system’s natural response, a novel second-order system impedance model is derived, and proposed current controller gain characterization aiming to achieve positive damping to mitigate the PCC’s oscillations. Further tuning of the controller based on the natural response of the derived impedance model accomplishes the enhanced grid injected power quality. The efficacy of the derived system impedance model along with coherence of current controller gain is demonstrated on hardware for enhanced power quality under the stable operating region. [ABSTRACT FROM AUTHOR]

In parallel three-level inverters, to eliminate the undesired internal common-mode (CM) resonance circulating currents (ICMRCCs) and external CM resonance circulating currents (ECMRCCs) introduced by the improved LCL, the inverter-side CM current feedback (ICMCF) control is presented. However, since the switching frequency of the inverters is generally low in high-power applications to reduce power loss, the stability of the ICMCF control will be threatened by the delays of digital controller. In this case, the existing methods are not capable of ICMRCC and ECMRCC suppression any more. To deal with the situation, an improved CM resonance circulating current control method for high-power parallel inverters is proposed. First, the model of ICMCF with control delay is established. Second, the influences of control delay with different sampling modes on the stability of CM current control are investigated. Based on this, the allowable range of control delays and sampling frequency to keep the system stable is analyzed and deduced. Third, the multisampling mode is further extended to CM current control in the parallel inverters. The analysis results show that the stability margin and control bandwidth of the ICMCF control are significantly improved. Finally, the theoretical analysis and proposed control method are verified by simulation and experiment. [ABSTRACT FROM AUTHOR]

In a high-power semiconductor power module where multiple chips are populated in parallel, the thermal imbalance problem arises. In this article, the next-generation standard high-voltage insulated-gate bipolar transistor module for high-speed railcar traction is investigated to characterize the internal thermal imbalance among paralleling chips and evaluate the impact on temperature distribution in field application. The former is accomplished by a new test algorithm with a purposely designed module sample, while the latter is achieved via an advanced electro-thermal simulation from chip level to system level. The experimentally verified thermal network among paralleling chips reveals the multiple reasons for the thermal imbalance. A comparison between the simulation and experimental results regarding the paralleling chips’ power-cycling scenario helps to confirm the effectiveness of the chip model, the thermal network, and the electro-thermal simulation approach. A further electro-thermal simulation shows that the module internal thermal imbalance can lead to significant junction temperature discrepancy among paralleling chips in traction inverter applications, which should be taken into consideration for the long-term reliability assessment. [ABSTRACT FROM AUTHOR]

In islanded ac microgrids, the mismatched impedances of the interfacing feeders between the inverters and the load bus cause poor reactive power sharing when the conventional frequency and voltage droop control technique is employed. Such operation endangers the whole microgrid reliability as it may lead to overloading certain inverters and, consequently, triggering protection relays and causing cascaded failure. Thus, this article proposes an accurate reactive power sharing strategy that considers the mismatched feeder impedances in islanded ac microgrids. It is based on the optimal tuning of the virtual complex impedance for each inverter. The proposed strategy has several advantages. First, it has a physical meaning as it establishes an explicit relationship between the mismatched values of the actual resistive–inductive feeders and the assigned values for the proposed virtual complex impedance to each inverter. Hence, further degradations in the microgrid voltages are prevented. Second, there is no need for prior knowledge about the actual feeder impedances in the design stage as they are estimated online from the available measurements. Finally, the proposed control is reliable and fault-tolerant as it copes with unexpected failures such as failure of (or sudden switching off) some inverters and communication disruptions/delays. It ensures accurate power sharing even under the primary controllers after losing communication links with the secondary controller. The simulation and experimental verification results are presented to validate the performance of the proposed technique. [ABSTRACT FROM AUTHOR]

For the open winding permanent magnet synchronous motor (OW-PMSM) with leg open-circuit faults, a novel zero-sequence current (ZSC) suppression method with asymmetric zero-sequence voltage (ZSV) injection is proposed in this article. To realize the fault-tolerant control (FTC) in leg open-circuit fault conditions, the leg-sharing method is developed, where the output terminal of the faulty leg is connected to that of the remaining equivalent leg. However, the ZSC increases in the FTC mode, which causes severe torque ripple and system performance degradation. If the traditional ZSC suppression method is still adopted, the suppression performance is decreased. Besides, an undesired voltage vector is introduced, resulting in current distortion. To solve these problems, a novel ZSC suppression strategy is put forward. By asymmetrically adjusting the voltage output of the remaining legs, the ZSC of OW-PMSM in FTC mode can be effectively suppressed. Moreover, the proposed strategy is suitable for both the single-leg and double-leg FTC modes, where the ZSC suppression performance is almost the same as that of the traditional method in normal operation mode. Furthermore, experiments are performed on an OW-PMSM to verify the effectiveness of the proposed ZSC suppression scheme. [ABSTRACT FROM AUTHOR]

Multilevel inverters (MLIs) featuring reactive power ability and common ground (CG) have become much popular in transformerless grid-tied photovoltaic applications. A switched-capacitor (SC) based five-level transformerless inverter configuration is thus proposed in this article, which requires only six switches, one diode, three capacitors, and one input dc voltage supply. Notably, only four power switches are operated in high frequency, thus, the switching losses are reduced. Moreover, the presented topology can effectively tackle the leakage current problem using a CG architecture. A multicarrier phase disposition pulsewidth modulation strategy is employed to achieve reactive power regulation and SC voltage self-balancing. To achieve the neutral point voltage balance of the presented five-level inverter, a simple closed-loop voltage-balancing control method is proposed. The operation principles with modulation strategy and voltage self-balancing of SC are discussed in depth. Comparisons between the proposed and the state-of-the-art MLIs are presented in detail. Finally, experimental tests on a single-phase 1.1-kW prototype validate the appropriate performance of the proposed inverter. [ABSTRACT FROM AUTHOR]

Space vector pulsewidth modulation (SVPWM) algorithms for cascaded H-bridge multilevel (CHB ML) inverter usually provide the possibility of using several combinations of active voltage vectors to generate the same output voltage vector. For preselected H-bridges, some of them may generate output voltages opposite to the assumed direction. This results in the change of the dc-link voltages of these H-bridges in the opposite direction to the assumed direction in the ordering algorithm. Consequently, these algorithms are characterized by undue constraints and narrow possibilities of dc-link voltage balancing. In the proposed control algorithm, CHB ML inverter is treated as groups of successively activated three-level inverters; depending on the length of the reference voltage vector. These three-level inverters consist of three H-bridges selected from each phase. The proposed extended selection method enables firm-grip control of the dc-link voltages. For a given direction of phase currents, the possibility of using H-bridges with lowest and highest dc-link voltages is simultaneously analyzed. Additionally, each of the three-level inverters is controlled by one of three proposed alternative modulation methods for which both the attainable output voltage vectors and unbalanced dc-link voltages are predicted. Simulation and experimental results confirm the correctness of the algorithm execution. [ABSTRACT FROM AUTHOR]

This article presents a nonlinear passivity-based control for a grid-connected cascaded H-bridge (CHB) photovoltaic (PV) system. The proposed control system is based on a port-controlled Hamiltonian model extracted from the synchronous reference frame system. Grid current dynamics is included in this model. Compared to existing solutions, the proposed control method has a robust performance and enhances the stability of the CHB-based PV system in the case of disturbances such as unequal irradiance over distinct PV arrays or a sudden sag or swell in the grid voltage. This controller also provides the independent control of each dc-link voltage. Therefore, the individual maximum power point tracking algorithms can be realized in each PV array, and the harvested energy can be maximized. Finally, simulation results and experimental investigations are conducted to verify the effectiveness of the proposed strategy. [ABSTRACT FROM AUTHOR]

This article proposes a three-phase four-wire inverter drive system for an adjustable field interior permanent magnet synchronous motor utilizing magnetic saturation. The magnetic saturation is regarded as a phenomenon of a decrease in permeability depending on an extra magnetic field. In the proposed motor, the number of flux linkage can be controlled by modulating the permeability of magnetic leakage paths in the rotor. However, the proposed adjustable field method requires an additional magnetomotive force (m.m.f.) to control the permeability. Therefore, a zero-sequence current iz fed by the three-phase four-wire inverter is utilized as the additional m.m.f. source. Thereby, the field control can be achieved with a simple three-phase inverter without sacrificing the number of switching devices compared with conventional motor drives. In the article, the control algorithm of the three-phase four-wire inverter is discussed, and its usefulness is verified by comparing the proposed drive system with other methods or systems. [ABSTRACT FROM AUTHOR]