Power Efficiency Research Articles

A hybrid energy harvesting approach for transmission lines based on triboelectric nanogenerator and micro thermoelectric generator

To effectively detect faults in transmission lines, monitoring the operating status of these lines is imperative. However, providing power to monitoring devices for transmission line status presents a significant challenge. In this research, a hybrid energy harvesting approach based on micro thermoelectric generator (MTEG) and triboelectric nanogenerator (TENG) is proposed, and a theoretical model for MTEG-TENG hybrid energy harvesting is established. This study develops an integrated energy harvesting prototype, which incorporates oscillating-TENG (O-TENGs), MTEGs, and a power management control unit. This prototype not only harvests energy from the vibrations of transmission lines but also converts the lines thermal energy into electricity. The Experiment results show that the maximum open-circuit voltages of O-TENG and MTEG reach 80.3 V and 1.094 V, respectively. Compared to a single MTEG energy harvesting device, the prototype of the MTEG-TENG hybrid energy harvesting device demonstrates a 5.36% improvement in energy harvesting and battery charging performance. Consequently, this approach achieves self-powered monitoring with excellent stability and lower manufacturing costs. It provides an efficient and durable power approach for transmission line status monitoring devices.

A comparative study on ReLU Implementation using TMDFETs

In this study, we compare the implementation of the rectified linear (ReLU) activation function using transition metal dichalcogenide field-effect transistors (TMDFETs) and metal-oxide-semiconductor FETs (MOSFETs). Five TMDs - MoS 2, MoSe 2, MoTe 2, WS 2, WSe 2 along with three variants (low-power, high-performance, and multi-gate) of the MOSFETs are simulated. Three ReLU circuits utilizing these FETs are employed for the comparison. The power consumption, speed, and accuracy of the ReLU implementation are measured and compared for each circuit and each FET. Our simulation results show that the MOSFETs consume much less power than the TMDFETs and deliver more accurate ReLU functionality. However, the TMDFETs are much faster than the MOSFETs. Among the TMDFETs, the WS 2 FET stands out, as it has higher accuracy, consumes the least power and its power consumption is comparable to the MOSFETs. Additionally, WS 2 is faster compared to MOSFETs, resulting in a trade-off between power efficiency and speed. This makes WS 2 an attractive option for implementing the ReLU activation function.

Design and simulation of a new QCA-based low-power universal gate

Quantum-dot Cellular Automata (QCA) is recognized in electronics for its low power consumption and high-density capabilities, emerging as a potential substitute for CMOS technology. GDI (Gate Diffusion Input) technology is featured as an innovative approach for enhancing power efficiency and spatial optimization in digital circuits. This study introduces an advanced four-input Improved Gate Diffusion Input (IGDI) design specifically for QCA technology as a universal gate. A key feature of the proposed 10-cell block is the absence of cross-wiring, which significantly enhances the circuit’s operational efficiency. Its universal cell nature allows for the carrying out of various logical gates by merely altering input values, without necessitating any structural redesign. The proposed design showcases notable advancements over prior models, including a reduced cell count by 17%, a 29% decrease in total energy usage, and a 44% reduction in average energy loss. This innovative IGDI design efficiently executes 21 combinational and various sequential functions. Simulations in 18 nm technology, accompanied by energy consumption analyses, demonstrate this design’s superior performance compared to existing models in key areas such as multiplexers, comparators, and memory circuits, alongside a significant reduction in cell count.

A Novel CNFET SRAM-Based Compute-In-Memory for BNN Considering Chirality and Nanotubes

As AI models grow in complexity to enhance accuracy, supporting hardware encounters challenges such as heightened power consumption and diminished processing speed due to high throughput demands. Compute-in-memory (CIM) technology emerges as a promising solution. Furthermore, carbon nanotube field-effect transistors (CNFETs) show significant potential in bolstering CIM technology. Despite advancements in silicon semiconductor technology, CNFETs pose as formidable competitors, offering advantages in reliability, performance, and power efficiency. This is particularly pertinent given the ongoing challenges posed by the reduction in silicon feature size. We proposed an ultra-low-power architecture leveraging CNFETs for Binary Neural Networks (BNNs), featuring an advanced state-of-the-art 8T SRAM bit cell and CNFET model to optimize performance in intricate AI computations. Through meticulous optimization, we fine-tune the CNFET model by adjusting tube counts and chiral vectors, as well as optimizing transistor ratios for SRAM transistors and nanotube diameters. SPICE simulation in 32 nm CNFET technology facilitates the determination of optimal transistor ratios and chiral vectors across various nanotube diameters under a 0.9 V supply voltage. Comparative analysis with conventional FinFET-based CIM structures underscores the superior performance of our CNFET SRAM-based CIM design, boasting a 99% reduction in power consumption and a 91.2% decrease in delay compared to state-of-the-art designs.

DC Power Boosting Circuit for Freestanding‐Sliding Triboelectric Nanogenerators with High Intrinsic Impedance and Multi‐Harmonic Output

AbstractThis study presents a freestanding sliding triboelectric nanogenerator (FS‐TENG) designed for low‐frequency motions (below 2 Hz). However, for practical applications, an efficient power management strategy is required to handle the harmonic outputs of the FS‐TENG. The high‐frequency signal is not sustainable for powering low‐power electronic applications. To address the issue, a novel direct current power supply circuit (DPS) is proposed that utilizes a double charge circuit (DCC) and a comb filtering circuit (CFC) to efficiently harness harmonic sources from the FS‐TENG. The direct power supply (DPS) outperforms traditional converters by reducing the impedance of the FS‐TENG and collecting the target harmonic sources, which facilitates a continuous power supply to the load. The results demonstrate that the DPS is capable of providing a continuous DC voltage of 2.2 V to a 10 MΩ load with minimal ripple (0.039%) at a low operating frequency of 0.625 Hz. Additionally, the practical application of a self‐powered temperature sensor is demonstrated to highlight the potential of FS‐TENG and DPS for low‐frequency energy harvesting solutions in real‐world scenarios.

Advances in 2D Materials Based Gas Sensors for Industrial Machine Olfactory Applications.

The escalating development and improvement of gas sensing ability in industrial equipment, or "machine olfactory", propels the evolution of gas sensors toward enhanced sensitivity, selectivity, stability, power efficiency, cost-effectiveness, and longevity. Two-dimensional (2D) materials, distinguished by their atomic-thin profile, expansive specific surface area, remarkable mechanical strength, and surface tunability, hold significant potential for addressing the intricate challenges in gas sensing. However, a comprehensive review of 2D materials-based gas sensors for specific industrial applications is absent. This review delves into the recent advances in this field and highlights the potential applications in industrial machine olfaction. The main content encompasses industrial scenario characteristics, fundamental classification, enhancement methods, underlying mechanisms, and diverse gas sensing applications. Additionally, the challenges associated with transitioning 2D material gas sensors from laboratory development to industrialization and commercialization are addressed, and future-looking viewpoints on the evolution of next-generation intelligent gas sensory systems in the industrial sector are prospected.

Modeling the electroluminescence of atomic wires from quantum dynamics simulations.

Static and time-dependent quantum-mechanical approaches have been employed in the literature to characterize the physics of light-emitting molecules and nanostructures. However, the electromagnetic emission induced by an input current has remained beyond the realm of molecular simulations. This is the challenge addressed here with the help of an equation of motion for the density matrix coupled to a photon bath based on a Redfield formulation. This equation is evolved within the framework of the driven-Liouville von Neumann approach, which incorporates open boundaries by introducing an applied bias and a circulating current. The dissipated electromagnetic power can be computed in this context from the time derivative of the energy. This scheme is applied in combination with a self-consistent tight-binding Hamiltonian to investigate the effects of bias and molecular size on the electroluminescence of metallic and semiconducting chains. For the latter, a complex interplay between bias and molecular length is observed: there is an optimal number of atoms that maximizes the emitted power at high voltages but not at low ones. This unanticipated behavior can be understood in terms of the band bending produced along the semiconducting chain, a phenomenon that is captured by the self-consistency of the method. A simple analytical model is proposed that explains the main features revealed by the simulations. The methodology, applied here at a self-consistent tight-binding level but extendable to more sophisticated Hamiltonians such as density functional tight binding and time dependent density functional theory, promises to be helpful for quantifying the power and quantum efficiency of nanoscale electroluminescent devices.

Optimization of battery/ultra‐capacitor hybrid energy storage system for frequency response support in low‐inertia microgrid

AbstractModern power system networks are under statutory obligations to integrate renewable energy sources (RES). The primary reason is to meet ever‐increasing energy demand and also to curtail environmental pollution by greenhouse gases. However, the higher penetration of RES has the tendency of reducing inertia of overall power system network. Consequently, frequency stability is affected and deviates beyond allowable permissible limits leading to power blackouts, load shedding, and even total system failure. To address the issues associated with reduced inertia, an optimal control of hybrid energy storage system (HESS) has been proposed. HESS is basically a combination of battery and ultracapacitor, where ultracapacitor addresses rapidly varying power component by mimicking inertia while the battery compensates long‐term power variations. Thus, the HESS is effectively controlled to compensate the loss of inertia by regulating its energy flow. For the purpose of improved efficiency and better power management of the HESS, an improvised particle swarm optimization (MPSO)‐based virtual inertia control design has been proposed. The proposed MPSO is utilized to tune the gains of bidirectional dc–dc converter in such a way that improves frequency nadir with faster response to transient disturbances. This proposed method is simulated in MATLAB and its merits are validated in real time using hardware in loop. On analysing of the results, it can be observed that frequency nadir is improved by 48.96% with significant reduction in rate of change of frequency in comparison to conventional particle swarm optimization.

Second-Order Sliding-Mode Control Applied to Microgrids: DC & AC Buck Converters Powering Constant Power Loads

Microgrids are designed to connect different types of AC and DC loads, which require robust power controllers to achieve an efficient power transfer. However, the effects of both AC and DC disturbances in the same type of controller make achieving stability a design challenge, especially in coupled systems where disturbances affect both the upstream and downstream in the microgrid. This paper presents an analysis of a second-order sliding-mode control (SOSMC) applied to a microgrid with direct-current (DC) and alternating-current (AC) power converters. The aim is to simulate the second-order sliding-mode control with buck converters that feed constant DC–DC and DC–AC power loads. The controller was tested in consideration of a unique sliding surface facing external disturbances, such as variations in the frequency of AC converters, sudden changes in upstream voltages, and constant power loads (CPL). The influence of the gain values (K) on the controller was also analyzed. The results show that the controller is robust regarding its sensitivity to external disturbances and steady-state error. However, the importance of the constant “K” in the model states that there exist K-limit values where if “K” is too low, a slowdown is presented, and the response against disturbances can be critical, and if is too high, an overshoot is presented in the output voltage.

Design and Analysis of High Performance FinFET-Based Linear Feedback Shift Register for Cryptography Applications

Nowadays, all the elements of our surrounding is occupied by electronics. Electronics occupies major role on our day today life. Electronics device integration on a single chip enhances performance in terms of speed, low-power circuits, and area. Integration of VLSI provides better scalability and reliability. This research paper focused on the implementation of Linear feedback shift registers (LFSR) using FinFET techniques at the layout level for various applications, including cryptography. FinFETs are highlighted as a replacement for CMOS technology, offering advantages such as improved performance in terms of speed, low-power circuits, and area. Linear feedback shift registers are commonly used in digital systems and cryptography for generating pseudo-random sequences. The use of FinFET technology in the layout level suggests an interest in exploring advanced semiconductor technologies to enhance the performance of these circuits. The paper appears to cover different design methods of LFSRs, which could include aspects like circuit optimization, power efficiency, and reliability. The integration of electronics on a single chip, particularly with FinFET technology, is noted for its potential to provide better scalability and reliability. The first architecture is created using bulk CMOS techniques; whereas the second is constructed using two fin FinFET LFSRs. Using the Microwind designing tool, the third technique is developed with a 3-fin FinFET LFSR. It provides a solution for a novel FinFET architecture that implements LFSR. When comparing CMOS and FinFET circuit designs for LFSR, the latter achieves superior performance in terms of area and power efficiency. An analysis is conducted on the design techniques and performance of CMOS LFSR, 2 fin FinFET based LFSR, and 3 fin FinFET. According to the experimental findings, the CMOS-based LFSR uses 1.243 mW of power; the FinFET-based LFSR uses 90.47 μW, and the two fin FinFET LFRS uses 0.254 mW.

Influence of Cell Temperature on Theoretical Properties of InGaP/ InGaAs/Ge Triple-Junction Concentrated Solar Cells

Aims: This study aims to analyze the accuracy of single- and double-diode models in predicting the electrical parameters of InGaP/InGaAs/Ge triple-junction solar cells as described in relevant patents under various operating conditions. Methods: This study obtained and analyzed experimental and theoretical values of the relevant electrical parameters of solar cells through a combination of experimental research and theoretical model calculations. Results: The results indicated that the root mean square error of the short-circuit current decreased from 0.21 at 400 W/m² to 0.11 at 1000 W/m². The temperature of the two precision cut-off points for the open-circuit voltage in the single- and double-diode models increased from 34°C and 64°C at 400 W/m² to 39°C and 72°C at 1000 W/m². Additionally, for peak power and conversion efficiency, the precision cut-off temperatures of the single- and double-diode models were 56°C, 68°C, and 77°C at 400 W/m², 600 W/m², and 800 W/m², respectively. Conclusion: The theoretical values of the short-circuit current exceeded the corresponding experimental values. The single- and double-diode models for open-circuit voltage exhibited two accuracy cut-off points, with the single-diode model demonstrating greater accuracy within this temperature range. Similarly, the peak power and conversion efficiency models for single- and double-diodes have an accuracy cut-off point, with the double-diode model performing better at higher temperatures.

A device to device driven approach towards optimizing energy efficiency for 6G networks

Our study aims to develop more energy-efficient mobile communication systems through the exploration of the 6th generation (6G) technology that is expected to be implemented in 2033. We focus on the impact of device-to-device (D2D) communication on power efficiency, which is a crucial need in this domain. To achieve this, we conducted a pioneering experiment using an in-house testbed and K-means clustering to classify locations as D2D enabled or disabled. Our findings show that there is a dynamic clustering mechanism that enables certain nodes to sustain D2D functionality around temporary base stations, resulting in a remarkable 5% improvement in network lifetime per second. This research not only enhances our understanding of 6G networks but also provides a practical methodology for optimizing energy consumption, which holds significant implications for society in advancing sustainable and efficient communication.

Enhancing power conversion efficiency in five-level multilevel inverters using reduced switch topology

This paper presents extensive research on improving the power conversion efficiency of five-level multilevel inverters (MLIs) by utilizing a reduced switch topology. MLIs have received an abundance of focus because of their ability to generate high-quality output waveforms and have better harmonic outcomes than traditional two-level inverters. The high number of switches in MLIs, on the other hand, can result in increased power losses and lower overall efficiency. In this paper, a novel reduced switch topology for five-level MLIs, which is having five switches is proposed with the aim of minimizing power losses while preserving superior performance due to lesser number of switches. To achieve efficient power conversion, the proposed topology employs advanced pulse width modulation control strategies and optimized switching patterns. The simulation results show that the minimized switch topology improves the power conversion efficiency of the five-level MLI, resulting in lower losses and better overall system performance. The total harmonic distortion (THD) value of the output current has been reduced to 7.12% and the efficiency has been achieved to 96.92%. The findings of this investigation help to advance MLI technology, allowing for more efficient and reliable power conversion in a variety of applications such as renewable energy systems, electric vehicles, and industrial drives.

Low-power DC-DC converters for smart and environmentally-friendly electric vehicles: design, simulation, and fabrication on a glass substrate

This research focuses on evaluating and comparing different DC-DC converter designs, specifically for low power applications. The study considers inductor-based, switching capacitor, and linear voltage regulator (LVR) DC-DC converters. While there has been critical investigation of DC-DC converters in the literature, there is a gap in assessing their performance based on a comprehensive set of conflicting parameters. Additionally, there is a lack of research on matching the most suitable DC-DC converter with specific low power applications. The chosen application for this study is a DC-DC converter on a glass substrate, specifically for smart glass in electric vehicles. The research presents a complete process that includes design, simulation, layout, fabrication, and measurement. Through simulations, a 4.8 V to 3.3 V buck converter is recommended, demonstrating an almost ideal response time and minimal output ripples. Experimental measurements also confirm a low output ripple of 0.3 %. By addressing this research gap and providing a comprehensive evaluation of DC-DC converters, this study contributes to the development of efficient and reliable power solutions for smart glass applications in electric vehicles.

Wirelessly Powered and Bi-Directional Data Communication System With Adaptive Conversion Chain for Multisite Biomedical Implants Over Single Inductive Link.

A wirelessly powered and data communication system is presented which is implemented as a full system, designed for multisite implanted biomedical applications. The system is capable of receiving wireless power and data communication for each implant separately, using inductive links with different resonance frequencies. To achieve this, dual-band coils are presented in the system. In addition, the system supports bi-directional half-duplex data communication, utilizing amplitude and load shift keying (ASK and LSK) modulation schemes over a single inductive link. The system employs a digitally assisted active rectifier and an automatic resonance tuning system, to improve the power transfer efficiency (PTE) through various coupling coefficients, while minimizing the reverse current and power dissipation. The power control unit enables closed-loop monitoring to prevent high or low power delivery, and it can detect inefficient or excessive wireless power transmission or prevent temperature elevation by limiting the voltage to a safe level. A new structure of self-sampling separated- Vb ASK demodulator is proposed in the paper which is utilized within the data conversion chain, serving both the external and implanted units. The whole system is fabricated using a standard 180-nm 1.8/3.3 V CMOS process with a core area of 0.82 mm[Formula: see text]. The system is tested with coupled multisite inductive links and offers the maximum overall PTE of 31.2%, from the Tx coil to the implant load.

Enhancing energy efficiency in tyre pressure and temperature monitoring systems

This study addresses the pivotal challenge of enhancing power efficiency in tyre pressure and temperature monitoring systems (TPMS) for heavy vehicles and trailers. Employing field-programmable gate arrays (FPGA) and adaptive channel frequency hopping in bluetooth low energy (BLE) communication, the research focuses on mitigating power consumption issues specific to heavy vehicles with multiple tyres. The proposed solution incorporates strategic BLE channel blocking and adaptive frequency hopping on the FPGA platform to alleviate channel congestion and interference, ultimately reducing TPMS power consumption. The FPGA's adaptability tailors frequency hopping strategies to automotive TPMS nuances, optimizing channel selection and minimizing energy-intensive processes. Empirical results showcase a significant reduction in power consumption, with the TPMS operating at 100 MHz during active mode consuming 66 mW, dropping to 11 mW in sleep mode, and reaching 0 mW in hibernate mode for the majority of operational time. This research establishes a practical FPGA-based approach for power optimization in commercial TPMS, promising heightened reliability, safety improvements, and environmental impact reduction in the automotive sector.

Enhancing photovoltaic system maximum power point tracking with fuzzy logic-based perturb and observe method

Photovoltaic systems have emerged as a promising energy resource that caters to the future needs of society, owing to their renewable, inexhaustible, and cost-free nature. The power output of these systems relies on solar cell radiation and temperature. In order to mitigate the dependence on atmospheric conditions and enhance power tracking, a conventional approach has been improved by integrating various methods. To optimize the generation of electricity from solar systems, the maximum power point tracking (MPPT) technique is employed. To overcome limitations such as steady-state voltage oscillations and improve transient response, two traditional MPPT methods, namely fuzzy logic controller (FLC) and perturb and observe (P&O), have been modified. This research paper aims to simulate and validate the step size of the proposed modified P&O and FLC techniques within the MPPT algorithm using MATLAB/Simulink for efficient power tracking in photovoltaic systems.

Strategic electromagnetic interferences suppression in boost converters: zero-switch techniques

This article delves into the growing demand for efficient power conversion technologies accompanying the rise in electric vehicle (EV) adoption. Boost converters, essential for increasing the battery pack voltage to propel EV motors, pose a challenge due to the electromagnetic interference (EMI) generated by the high switching frequency of power devices. To address this issue, practitioners employ zero-voltage switching (ZVS) and zero-current switching (ZCS) techniques. In this comparative study, we systematically evaluate the effectiveness of these soft switching techniques in reducing conducted EMI in boost converters designed for EV applications. The results illuminate the potential of both ZVS and ZCS in significantly mitigating EMI emissions when compared to conventional hard-switching methods. Notably, ZVS soft switching emerges as more efficient and effective, particularly under higher loads, while ZCS soft switching excels in reducing EMI at lighter loads. In conclusion, the study asserts that ZVS soft switching presents a more promising solution for curtailing conducted EMI in boost converters for EV applications, particularly in high-load scenarios. However, it underscores the importance of considering specific operational conditions when deciding between the two techniques.

A novel generation design dipole magnet power supply of booster to storage ring transport line in NSRRC

The Taiwan Light Source (TLS) is a synchrotron radiation facility located in Taiwan. The booster ring at TLS injects electrons into the storage ring, which then circulates the electrons to produce synchrotron radiation for various experiments. The Taiwan Light Source (TLS) has been in service for more than 20 years, and some of the power supplies used in the facility are old and hard to maintain repair and the component are phase-out. The upgrade is specifically aimed at replacing the power supply for the BTS (Booster to Storage ring) transmission line with a new machine. During the regular shunt down time, dipole magnet power supply replacements were completed. The main reason for using the Chroma 62075H-30E power supply is commonality, for this machine is widely used in Taiwan Photon Source (TPS), and the output current of the power supply is paralleled to a dipole magnet. Therefore, a total of 17 power supplies are used in this upgrade planned to be executed. This novel generation upgrade design is important because the power supply for the BTS transmission line is critical for the operation of the facility, as it is responsible for maintaining the electron beam at a stable energy level as it is injected from the booster ring into the storage ring. A more reliable and efficient power supply can help improve the stability and quality of the electron beam, leading to better experimental results and more efficient use of the facility. Overall, this novel generation upgrade design is part of the ongoing effort to modernize and improve the infrastructure of the TLS, ensuring that it remains a state-of-the-art research facility for years to come.

Kinematic Modeling and Performance Analysis of a 5-DoF Robot for Welding Applications

Robotic manipulators are critical for industrial automation, boosting productivity, quality, and safety in various production applications. Key factors like the payload, speed, accuracy, and reach define robot performance. Optimizing these factors is crucial for future robot applications across diverse fields. While 6-Degrees-of-Freedom (DoF)-articulated robots are popular due to their diverse applications, this research proposes a novel 5-DoF robot design for industrial automation, featuring a combination of three prismatic and two revolute (2R) joints, and analyzes its workspace. The proposed techno-economically efficient design offers control over the robot manipulator to achieve any reachable position and orientation within its workspace, replacing traditional 6-DoF robots. The kinematic model integrates both parallel and serial manipulator principles, combining a Cartesian mechanism with rotational mechanisms. Simulations demonstrate the end effector’s flexibility for tasks like welding, additive manufacturing, and material inspections, achieving the desired position and orientation. The research encompasses the design of linear and rotational actuators, kinematic modeling, Human–Machine Interface (HMI) development, and welding application integration. The developed robot demonstrates a superior performance and user-friendliness in welding. The experimental work validates the design’s optimized joint trajectories, efficient power usage, singularity avoidance, easy access in application areas, and reduced costs due to fewer actuators.