Power Transmission Method Research Articles

Characterization of LIPUS Parameters Suitable for Hip Bone Fracture.

To investigate the effects of ultrasound treatment on the healing of hip bone fractures using frequencies of 0.5 MHz and 1.5 MHz with constant intensity (30 mW/cm2) at the fractured site. For the ex vivo experiments, acoustic attenuations of 0.5 MHz and 1.5 MHz ultrasound were measured and compared using different thicknesses of human cadaver and porcine tissues in a hydrophone system. For the in vivo experiments, 20 hip-fractured rabbits were divided into four groups, namely: control, 1.5 MHz with unchangeable intensity (positive control), 0.5 MHz with changeable intensity, and 1.5 MHz with changeable intensity. For the 0.5 and 1.5 MHz groups with changeable intensity, a constant intensity of 30 mW/cm2 at the fracture site was achieved using a compensation method for power transmission with reference to the acoustic attenuation. The effective intensity measured using a hydrophone was substantially reduced to 6.16 mW/cm2 from 30 mW/cm2 in the positive control device after propagating soft tissues with a thickness of 5.0 cm, with an attenuation of approximately 6.0 dB. Meanwhile, for the 0.5 and 1.5 MHz groups, the ultrasound intensity was consistently controlled at 30 mW/cm2 after passing through tissues with different thicknesses using the compensation method. In the in vivo study using a newly established hip fracture rabbit model, the best results in bone histomorphometry, mechanical properties, and histological evaluation were consistently found in the 0.5 MHz group, while the 1.5 MHz group exhibited relatively better bone healing than the positive control group. The results suggest a LIPUS frequency of 0.5 MHz together with the consistent intensity of 30 mW/cm2 at the fracture site for more effective treatment of hip bone fractures.

Study of the features of angular stabilization of spacecraft with flexible struc-tural elements with the use mobile control methods

The development of space power engineering is one of the well-known lines in rocket and space science and innovative technologies which attracts the attention of many scientists and researchers. Engineering solutions in space-based solar power plant design and wireless space-to-Earth and satellite-to-satellite power transmission and power spacecraft control methods have been substantiated theoretically to sufficient depth. However, despite this, there is a need to improve methods for and approaches to the development of an optimal design methodology for power spacecraft. A way to improve existing approaches to the development of space-based solar power plants and power satellites may be the use of mobile control methods in the development of an attitude and orbit control system. Such methods allow one to reduce power consumption for control operations. The goal of this paper is to study the features of mobile control and construct a methodology for the development of solar power satellites’ attitude and orbit control system (AOCS) using mobile control algorithms. The paper considers the features of mobile control algorithm synthesis for the attitude control and stabilization of solar power spacecraft (solar power plants and power satellites). Power spacecraft control tasks are classified, and the expediency of using mobile control methods is justified. An analysis is made for the stability problem that arises in controlling power spacecraft with flexible elements. The paper presents methodological recommendations on determining the AOCS design parameters for space-based solar power plants and power spacecraft for wireless satellite-to-satellite power transmission. This methodology may be used in power satellite development.

Summary of Wireless Charging Technology for Electric Vehicles

The rapid popularity of electric vehicles has promoted the rapid development of wireless charging technology. This paper reviews the current research progress and application status of wireless charging technology for electric vehicles. Inductive coupling, magnetic resonance coupling and non-directional radiofrequency radiation, three main wireless power transmission methods, including their principles and advantages, are introduced. In addition, the practical application of the technique, such as near field application and far field application, is also discussed. Finally, the development direction of wireless charging technology for electric vehicles in the future is looked forward, including the key technical paths of optimizing system design, improving energy transmission efficiency and reducing system cost. In summary, this paper aims to provide comprehensive theoretical support and practical guidance for the research and practice of wireless charging technology for electric vehicles.

Optimal Design of High-Power Density Medium-Voltage Direct Current Bipolar Power Cables for Lunar Power Transmission

Power systems on the lunar surface require power lines of varying lengths and capacities to connect generation, storage, and load facilities. These lines must be designed to perform efficiently in the harsh lunar environment, considering factors such as weight, volume, safety, cost-effectiveness, and reliability. Traditional power transmission methods face challenges in this environment due to temperature fluctuations, micrometeoroid impacts, and ionizing radiation. Underground deployment, although generally safer, faces challenges due to low soil thermal conductivity. At a depth of 30 cm, the lunar temperature of −23.15 °C can be advantageous for managing waste heat. This study presents a novel approach, developed using COMSOL Multiphysics, for designing bipolar MVDC cables for lunar subsurface power transmission. Kapton® MT+ is chosen as the insulating material for its exceptional properties, including high thermal conductivity and superior dielectric strength. The cables are designed for voltages of ±10 kV and ±5 kV and capacities of 200 kW (low power), 1 MW (medium power), and 2 MW (high power). Our findings indicate that aluminum conductors offer superior performance compared to copper at medium and high power levels. Additionally, elevated voltage levels (±10 kV) enhance cable design and power transfer efficiency. These specially designed cables are well-suited for efficient operation in the challenging lunar environment.

Enhancing a loosely coupled inductive wireless power transfer system for LED-driven slurry photocatalytic reactors

To improve the irradiation profile in a conventional photocatalytic reactor, an LED-based light emitter energized by the inductive power transmission (IPT) method has been proposed recently. However, technical challenges such as low coupling due to the asymmetrical wireless coupler, dynamic impedance due to multiple receivers and changing magnetic properties in the transmitter core, and ease in upscaling remain to be addressed. This work proposes an IPT system for an LED-based photocatalytic reactor using a toroidal transformer to match the impedance between a modified Helmholtz transmitter coil and a class-E inverter. A finite element magnetic field simulation and analytical calculation of the induced voltage are used to assess the field uniformity inside the coil. The mutual inductance at selected locations within the coil volume and the power transfer efficiency (PTE) are evaluated. The proposed system requires less than 2 W to generate a uniform magnetic field inside a 10.6 L acrylic cylinder with an induced voltage of 13.9 ± 0.95 Vrms along the cylinder’s central axis. The proposed wireless coupler achieves a coupling coefficient of 0.013–0.034 and a PTE of 23.7%, outperforming similar systems with asymmetrical coupler design while offering a versatile solution for integrating IPT technology into wastewater treatment.

Smart line planning method for power transmission based on D3QN‐PER algorithm

AbstractThe planning of power transmission line projects encompasses vast and complex geographical terrains. To address the complexity of transmission line planning and achieve lower line costs, this study proposes a novel intelligent line planning method. For the first time, it combines the Dueling Double Deep Q Network (D3QN) with the prioritized experience replay (PER) mechanism. First, correlate the reward function with metrics such as line length, number of corner points, and geographical environmental data, which are pertinent to the construction costs of power transmission line. Second, the D3QN algorithm is formulated by integrating Double DQN and Dueling DQN. The network's input information is divided into two components during training, aligning with the characteristics of power transmission line planning projects. Finally, the convergence efficiency of the algorithm is improved by using the PER mechanism for the problem of cost difference due to the different number of corner points in the planning path. In order to test the feasibility of the algorithm, we conducted experiments using real maps. Compared with the traditional ant colony optimization (ACO) algorithm, the D3QN‐PER deep reinforcement learning algorithm reduces the line length by more than 4% and the number of corner points by more than 60%.

Predicting the Performance and Adaptation of Artificial Elbow Due to Effective Forces using Deep Learning

Measuring power transmission in organs poses a significant challenge for researchers in the field, with various methods being explored, including the use of artificial intelligence algorithms. This study focused on developing a new neural network model to predict force transmission and performance in an artificial elbow. Rather than evaluating natural joints, the study simulated a prosthetic model using medical software. Empirical data was collected using MIMICS software to estimate power properties and transmission methods, which were then used to train a neural network in MATLAB. The neural network demonstrated strong performance, particularly with the use of CNN architecture. The model's accuracy was validated by comparing results with experimental data from Anatomy and Physiology Comparison software, showing that the neural network provided precise results.

An Incorporated Power and Data Synchronous Transmission Method for SRG Integrated Wind Power Generation Systems

Reliable communication places important roles in renewable generation for operating status monitoring, fault alarming, cooperative control and so on. For existing power and data synchronous transmission strategies applied to switched reluctance generator (SRG) systems, the communication rate is limited by very low power switching frequencies. Hence, in this paper, a new PDST strategy is proposed and implemented in an SRG integrated wind generation system by incorporating power and data composite modulation method with signal injection method. For lower signal band, the data is modulated together with power by regulating the lower power switch of each phase in a fixed interval with given frequency, and for the higher signal band, the data in form of voltage ripple is injected into the bus by a coupling circuit. Therefore, specific voltage ripples with different given frequencies can be embedded into the power line for carrying signals, and the frequency band of signal bus can be well exploited. On signal receiver end, the voltage ripples are sampled and analyzed by fast Fourier transform method for demodulating the transmitted data. The feasibility of the proposed incorporated data transmission method is verified by experimental testing.

A decoupled power and data simultaneous transmission method in laser wireless power transfer system

A decoupled power and data simultaneous transmission method in laser wireless power transfer system

Machine Learning Based Foreign Object Detection in Wireless Power Transfer Systems

As power electronics continue to drive advancement in electronic devices by managing the system's energy flow, it is advantageous to examine all areas of energy transfer. Wireless power transfer is one section seeing increased adoption in consumer, industrial, and healthcare applications. This consequently increases the concern for safety, reliability, and efficiency. Power transmission to any unintended load is a primary safety issue in high-power wireless power transfer applications, such as unmanned aircraft systems. Foreign object detection is utilized to selectively transmit power to only the intended target to mitigate this issue. This paper seeks to demonstrate a novel alternative method of using machine learning and artificial intelligence techniques for performing foreign object detection solely on the transmitter portion of the system by only monitoring the TX coil current. This method is first evaluated in SPICE simulation software. Then by transitioning to a closed-loop hardware-based testbed designed to be deployed in unmanned aircraft systems. During the test process for the novel FOD method, the aggregate detection accuracy achieved was 83%, including worst-case misalignment conditions with the RX coil. When the outlying worst-case conditions are excluded, the detection accuracy improves to 97%. To measure the FOD effectiveness in preventing temperature rise in a metallic object, the metallic object was placed at the peak power draw location on the transmitter coil. When the metallic object is left at this location for extended periods, the novel FOD method lowers the maximum temperature reached by 86.8°C when compared to no FOD being active. The primary advantage to this novel method is the simplistic hardware additions, which only require minimal alterations to a WPTS without any FOD implemented. Along with this, implementing this foreign object detection method in the transmitter would mitigate the need for a direct communication link between the receiver and transmitter. As a result, the entire system complexity would decrease, thus increasing the UAS power density while maintaining a safe, effective, and reliable wireless power transmission method.

Comprehensive Evaluation Model and Methodology for Offshore Wind Farm Collection and Transmission Systems

With the gradual development of offshore wind farms toward large-scale and long-distance trends, economically efficient methods for correcting and transmitting offshore wind energy have garnered increasing attention. The rational and effective evaluation of offshore wind power collection and transmission methods has become an urgent issue. To address this, a comprehensive evaluation model for collection and transmission systems, considering factors such as network losses, lifecycle costs, and reliability, was established. This proposed model was applied to multiple sets of typical collection and transmission scenarios, utilizing an improved TOPSIS comprehensive evaluation method based on dynamic combination weighting to achieve the comprehensive optimization of collection and transmission schemes. Case studies have validated the feasibility of the comprehensive evaluation model. The results indicate that with an increase in offshore distance, the AC/DC collection and transmission system is superior to the all-AC collection and transmission system, and the all-DC collection system exhibits potential cost advantages.

Mathematical Modelling of Resonant Electric Power Transmission System

The most significant feature of the power supply to agricultural consumers is the uneven distribution of the electrical load across three phases of the 0.4 kilovolt four-wire power grid and low load density (515 kilowatts per square kilometer) and coverage of large areas. Based on modern requirements for the quality of electricity and reliability of power supply to agricultural consumers, there is a need to modernize existing and create a new generation of rural electric grid. One of the variants of such grid is a resonant power transmission system. (Research purpose) The research object is a physical and mathematical model of a resonant system, taking into account a wide selection of the necessary physical parameters for the transfer function, the research purpose is determining the parameters of the resonant system. (Materials and methods) Used Mathematica version 4.2.0.0. It was established that all physical parameters can be set in accordance with the experiment. (Results and discussion) A new type of electrical systems for electric power transmission with the use of a resonant method of electric power transmission was considered. A mathematical model of a high-frequency line based on a single-wire line with a return through the ground was given. (Conclusions) We investigated the general principle of operation, the main components, and also calculated electrical characteristics, including power, frequency response, efficiency, features of operation, including wireless communication. The calculation results were compared with the existing equipment with a transmission power of up to 8000 watts. It was shown that on the basis of the obtained equations, it is possible to correctly select the parameters of the resonant power transmission line and voltage converters. It was determined that the obtained physical and mathematical model of a resonant single-conductor system, taking into account a wide selection of the necessary physical parameters, makes it possible to understand the operation of a resonant power transmission line and build optimized receiving and transmitting equipment complexes.

Research on Double LCC Compensation Network for Multi-Resonant Point Switching in Underwater Wireless Power Transfer System

This paper introduces a control method suitable for AUVs to transmit underwater radio energy that improves the stability of AUV charging under water based on double LCC compensation. The coupling coefficient decreases with the rise of the coil offset in the underwater wireless power transfer system, such that the power transmission capability is reduced. To solve the above-mentioned problem, a double LCC resonant compensation network impedance characteristic is proposed in this study through the analysis of the double LCC resonant compensation network. To be specific, the wireless power transmission method for multi-resonant point switching of the LCC compensation network is developed. The multiple resonance points of the developed method are not correlated with the load impedance in the double LCC resonance compensation network, and the multiple resonance points are consistent with the power transmission characteristics. Moreover, the appropriate resonance frequency is matched based on different coupling coefficients, and the multi-resonance points are switched to each other to increase the system’s transmission power and transmission efficiency. As revealed by the results of the simulation and experimental studies, the double LCC compensation network with multi-resonance point switching is capable of achieving the output characteristics of constant-voltage/constant-current of the wireless power transfer system, reducing the system current harmonics effectively, and enhancing the power transmission capability and anti-offset capability.

Study on Wireless Power Transfer System for EVs while Driving Using Continuous Repeater Power Transmission Coil

In recent years, the shift to electric vehicles (EVs) has become more prominent in many countries around the world. In line with this trend, research on systems that provide wireless power to running EVs is also underway in many countries. In order to realize this system, it is important to make the infrastructure easy and inexpensive, and one of the most important issues to be solved is to reduce the number of power sources used. We have proposed a repeater coil system as a power transmission method that can be expected to extend the power supply section per power source. In this paper, we discuss the usefulness of a series of repeater coils in a running wireless power transfer system, as well as their coil geometry and power supply characteristics.

Investigation on the Electromagnetic Surface Waves for Single-Wire Power Transmission

Single-wire power transmission (SWPT) is a power transmission method that uses only one wire to realize long-distance transmission of power. For deep insight, the theory of electromagnetic surface waves in this article is applied to reveal the principle of a long-distance large-scale SWPT system. Maxwell's equations under two different media in this system are established, based on them and the boundary conditions on the interface of the media, the propagation law of electromagnetic field energy in the SWPT system is analyzed. A simulation model is built by high frequency simulator structure (HFSS). The distribution law of the Poynting vector in different situations is studied to verify the correctness of the theoretical analysis. Moreover, long-distance transmission experiments are carried in the campus. It is shown that the transmission power can reach 300 W or 135 W when the transmission distance is 100 m or 200 m, respectively.

Online Calibration Study of Non-Contact Current Sensors for Three-Phase Four-Wire Power Cables

Three-phase four-wire power cables are a primary kind of power transmission method in low-voltage distribution networks. This paper addresses the problem that calibration currents are not easily electrified during the transporting of three-phase four-wire power cable measurements, and proposes a method for obtaining the magnetic field strength distribution in the tangential direction around the cable, finally enabling online self-calibration. The simulation and experimental results show that this method can self-calibrate the sensor arrays and reconstruct the phase current waveforms in three-phase four-wire power cables without calibration currents, and this method is not affected by disturbances such as wire diameter, current amplitudes, and high-frequency harmonics. This study reduces the time and equipment costs required to calibrate the sensing module compared to related studies using calibration currents. This research offers the possibility of fusing sensing modules directly with running primary equipment, and the development of hand-held measurement devices.

High-Precision Timing Method of BeiDou-3 System Based on Reinforcement Learning

All aspects of smart grid operation require precise timing technology to improve the timeliness and precision of the network. However, due to the complex and time-varying network environment and the low precision of device timing, the existing timing technology cannot meet the timing precision required by smart grid services. Therefore, according to the multi-armed bandit (MAB) theory and the upper confidence bound (UCB) algorithm, this paper proposes a high-precision timing method for power transmission and distribution park named adaptive timing-aware upper confidence bound (AUCB). The long-term average reward is maximized based on local information and historical decision-making experience. The simulation results show that the proposed high-precision timing method of AUCB in the power transmission and distribution park can effectively improve the device timing precision and realize self-adaptive timing for power system devices.

Application of artificial intelligence image recognition technology based on Faster-R CNN in automatic inspection of power transmission and transformation

In order to effectively improve the work efficiency and real-time performance of an automatic inspection of power transmission and transformation, this paper studies the automatic inspection method of power transmission and transformation based on artificial intelligence image recognition technology. First, we use cameras and unmanned aerial vehicles (UAVs) to obtain image data for power transmission and transformation inspection. Second, through the artificial sample calibration and reconstruction technology, the power transmission, and transformation inspection sample database is constructed. Then, the model is trained using the Faster-R CNN algorithm based on regional relationship features. Finally, the model is further optimized through model release and evaluation to realize intelligent diagnosis in power transmission and transformation detection. This research raises the recognition accuracy of power transmission and transformation inspection, improves the intelligence and efficiency of inspection, and provides good technical support for the construction of intelligent operation inspection.

A review on mechanism and application of functional coatings for overhead transmission lines

Overhead transmission line is the main method of power transmission. Conductors, insulators, and towers are the primary electrical equipment of overhead transmission lines. Due to overhead transmission lines work in the natural environment, problems such as icing, corona discharge, contamination deposition, and corrosion will arise. As a result, some accidents may occur, which cause enormous economic losses. The above problems can be solved by coating functional coatings with superhydrophobic, semiconductive, anti-corrosion, and other characteristics on electrical equipment, which has the advantages of low cost and high efficiency. Therefore, functional coatings have become a research hotspot in the field of external insulation in recent years. In view of the various problems of different electrical equipment in overhead transmission lines, distinctive solutions need to be adopted, so this review classifies the coatings according to the usage scenarios and functions. In each category, first briefly outlines the causes of the electrical equipment problem, then introduces the mechanism of using this type of functional coating to solve the problem, next summarizes the development and application status of this type of coating, after summarizes the limitations of this coating, and finally provides a summary of the key issues in the research of functional coatings and gives an outlook on potential future research directions. This review intends to provide readers with a comprehensive overview of the performance principles and current application status of functional coatings for overhead transmission lines.

The design of a new type coaxial multilayer rotor helicopter vehicle

Today’s small rotor helicopter vehicles mostly use electric motors and batteries as power sources. Most helicopter power configurations are either front powered or rear powered, causing the center of the helicopter to be offset. This kind of offset should be overcome by structural compensation or by adjusting the angle of attack of the blades, but some lift of the angle of attack will be sacrifice at the same time. This paper proposes a new type of electric helicopter powertrain design. The advantage of new type helicopter design is setting the centre of gravity at the centre position of helicopter. The main shaft of the helicopter through the power transmission method of the electric motor built into the internal gear of the star gear, which improves the design of the center offset of the helicopter. That is improved the flight stability of the helicopter. At the same time, in terms of power transmission, the motor power consumed by the primary gear power of the star gear, while the traditional helicopter power transmission method has three or four gear power losses. The new concept of electric motor with star gear structure proposed in this paper can effectively reduce the transmission power loss of the gear. In addition, the distributed power control system proposed in this paper also reduces the possibility of helicopter crash due to motor failure.