Power Transmission Technology Research Articles

鉄道車両への大容量非接触給電技術

鉄道車両への大容量非接触給電技術

Application of robotics in gastrointestinal endoscopy: A review.

Multiple robotic flexible endoscope platforms have been developed based on cross specialty collaboration between engineers and medical doctors. However, significant number of these platforms have been developed for the natural orifice transluminal endoscopic surgery paradigm. Increasing amount of evidence suggest the focus of development should be placed on advanced endolumenal procedures such as endoscopic submucosal dissection instead. A thorough literature analysis was performed to assess the current status of robotic flexible endoscopic platforms designed for advanced endolumenal procedures. Current efforts are mainly focused on robotic locomotion and robotic instrument control. In the future, advances in actuation and servoing technology, optical analysis, augmented reality and wireless power transmission technology will no doubt further advance the field of robotic endoscopy. Globally, health systems have become increasingly budget conscious; widespread acceptance of robotic endoscopy will depend on careful design to ensure its delivery of a cost effective service.

Simulation of a coplanar microstrip dipole rectenna

Design of rectenna, a key component in wireless power supply, is important for efficient wireless power transmission technology. However, its simulation of rectenna is not so easy because it consists of a microstrip antenna and a rectification circuit, which requires different simulation regimes. In this paper, a coplanar dipole rectenna is simulated by bridging its antenna simulation and rectification circuit simulation. The antenna simulation result is used for the rectification circuit simulation. The simulation results are verified by fabricating and testing the dipole rectenna. Detailed simulation scheme and its experimental verification are explained.

OPTIMIZATION ON WIRELESS POWER TRANSFER

Today, the limit of wireless devices lays in the way they powered. There has been a renewed focus on wireless power transmission technology due to its wide range of application in charging electronic devices such as mobile, MP3 player and household robots without a cord. Imagine a device that doesn't need a charger or even a battery, which instead gets power wirelessly over the air. To make such a device possible the transfer distance of currently known system have to be increased. The wireless power transfer can be optimized base on Friis equation. The Friis transmission equation is developed from principle of optical radiometry and scalar diffraction. Friis equation will gives the amount of power an antenna received under ideal conditions from another antenna.

Control Strategy of MMC-HVDC under Unbalanced Grid Voltage Conditions

High voltage direct current transmission based on modular multilevel converter (MMC-HVDC) is one of the most promising power transmission technologies. In this study, the mathematical characteristics of MMC-HVDC are analyzed in a synchronous rotational reference frame. A hybrid current vector controller based on proportional integer plus resonant is used to uniformly control the DC and double-base frequency AC currents under unbalanced grid voltage conditions. A corresponding voltage dependent current order limiter is then designed to solve the overcurrent problems that may occur. Moreover, the circulating current sequence components are thoroughly examined and controlled using a developed circulating current suppressor. Simulation results verify the correctness and effectiveness of the proposed control schemes.

A portable wireless power transmission system for video capsule endoscopes.

Wireless power transmission (WPT) technology can solve the energy shortage problem of the video capsule endoscope (VCE) powered by button batteries, but the fixed platform limited its clinical application. This paper presents a portable WPT system for VCE. Besides portability, power transfer efficiency and stability are considered as the main indexes of optimization design of the system, which consists of the transmitting coil structure, portable control box, operating frequency, magnetic core and winding of receiving coil. Upon the above principles, the correlation parameters are measured, compared and chosen. Finally, through experiments on the platform, the methods are tested and evaluated. In the gastrointestinal tract of small pig, the VCE is supplied with sufficient energy by the WPT system, and the energy conversion efficiency is 2.8%. The video obtained is clear with a resolution of 320×240 and a frame rate of 30 frames per second. The experiments verify the feasibility of design scheme, and further improvement direction is discussed.

A new synchronous generator based wind energy conversion system feeding an isolated load through variable frequency transformer

This paper aims to explore the possibility of synchronous generator (SG) based wind energy generation system feeding an isolated load using a latest power transmission technology i.e. variable frequency transformer (VFT). The proposed configuration does not employ any power electronics based interface as in conventional SG based stand-alone wind energy conversion systems (SWECS). For analysis, the simulation models of proposed configuration as well as conventional configuration have been developed under MATLAB-Simulink environment. A series of studies on power fed from the SG to the different loads at various SG input speeds has been carried out with the developed models. Further to analyze the effectiveness of the proposed method; the efficiency, total harmonic distortion (THD) of output voltage and THD of output current of the proposed method have been compared with those of the conventional method. From obtained results, it is observed that the proposed method is simple and does not produce harmonics. Moreover to validate the proposed scheme, an experimental analysis has been carried out. Further, the cost analysis of both systems has also been carried out. From the cost analysis, it is observed that the proposed system is cheaper than the conventional system.

Experimental Demonstration of Microwave Power Transmission and Wireless Communication Within a Prototype Reusable Spacecraft

In this letter, a wireless sensor network system powered by microwave power transmission (MPT) technology within a prototype reusable spacecraft is proposed and evaluated. The evaluation was based on a 5.8 GHz, 50 W class MPT integrated with a 2.4 GHz band wireless communication system. Experiments to evaluate energy balance under 25 cm line-of-sight conditions and to test multi-sensor operation under non line-of-sight conditions within the prototype spacecraft, called a reusable vehicle test (RVT).

Electric conductivity characteristics of FRP and epoxy insulators for GIS under DC voltage

Now that gas insulated switchgear (GIS) for ac systems is becoming increasingly compact as specifications are rationalized, more consideration of their insulation characteristics for residual dc voltage is required. Furthermore, with dc power transmission technology drawing more and more global attention, clarifying the insulation characteristics of GIS for dc voltage is increasingly important. The insulating portions for which the influence of dc voltage must be taken into consideration are solid insulators, such as insulating spacers. Under dc voltage, since the electric field distribution in an insulator differs from that under ac or impulse voltage and is governed by the resistance characteristics, clarifying its characteristics is crucial to study the GIS dc insulation design. As a solid insulator, focusing on fiber-reinforced plastics (FRP) used for GIS, for example, insulating rods, as well as partially treated epoxy resin; this paper experimentally investigated the bulk and surface electric conductivity under dc voltage, using the electric field, temperature, and other factors as parameters. As a result, the bulk electric conductivity of FRP in an edgewise direction exceeded that in the penetrating direction by one digit. It emerged that the electric conductivity of an insulating material with orientation like FRP varied depending on its direction. It was also found that, despite the fact the bulk and surface conductivity depended on the electric field for both FRP and epoxy resin, the variation width was relatively narrow within the range of the actual GIS operating electric field. The bulk and surface electric conductivity were also temperature-dependent, which meant the variation width was relatively wide. Furthermore, the surface electric conductivity was measured in SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> gas and in the air to investigate the influence of the ambient atmosphere, whereupon it emerged that the electric conductivity was higher in air due to the adherence of moisture. As mentioned above, the electric conductivity of an insulator varies due to various factors, such as the influence of the material orientation, electric field, temperature, and moisture. Consequently, the electric field distribution inside the insulator also changes, meaning these electric conductivity characteristics must be taken into consideration to study the GIS dc insulation characteristics.

Physical base development for mathematical simulation of transmission process

Based on the physics of normal operation of power systems, in the article it is proposed new scientific and methodical approach to determining reactive power transmission systems to the power industry and customers equated to them, which is based on understanding the mains voltage as a potential form of electricity. That is why the generation and consumption of electricity in the same time and give it the properties of mobility and versatility. It is proposed realistic modeling of power, in which the mathematical calculations of the regime based on the physics of the process of power transmission technology. It is emphasized that electric networks at a voltage of 110 kV should be considered counter energy market and to establish a base (wholesale) price of electricity for each of its customers on the basis of the concept of its power from the 110 kV network system with the normative coefficient of reactive power transmission (tgφ Д).

원격 생체 측정 장치를 위한 다중 발신 코일 구동 드라이버 설계

Abstract: Implanted telemetry systems provide the ability to monitor different species of animals while they move within theircages. Species monitored include mice, rats, rabbits, dogs, pigs, primates, sheep, horses, cattle, and others. A miniaturetransmitter implanted in each animal measures one or more parameters. Parameters measured include arterial pressure,intra-pleural pressure, left ventricular pressure, intra-ocular pressure, bladder pressure, ECG, EMG, EEG, EOG, temperature,activity, and other parameters and transmits the data via radio frequency signals to a nearby receiver. Every conventionaldedicated transmitter contains one or more sensors, cpu and battery. Due to the expected life of the battery, the measuring timeis limited. To overcome these problems, electromagnetic inductiv e coupling based wireless power transmission technology usingmultiple transmit coils were proposed, with each coil having a different active area driven by the coil driver. In this research, aparallel resonance based coil driver and serial resonance based coil driver are proposed. From the experiments we see that theparallel coil driver shows better performance under a low impedance and multiple coils configuration. However, the serial coildriver is more efficient for high impedance transmit coils.Keywords: implanted telemetry device, electromagnetic inductive, wireless power transmission technology

Hybrid Power Transmission Technology in a Wind Turbine Generation System

The direct-drive hydraulic pump suffers the disadvantages of large displacement and difficulty of manufacture. This paper thus proposes a hybrid power transmission technology that utilizes a single-stage gear transmission and low-speed hydraulic pump. The transmission technology reduces the displacement of the hydraulic pump and retains the torque-stable feature of a hydrostatic transmission. This paper designs the basic structure of a hybrid power transmission system and constructs the system model using the AMESim and MATLAB software. Under the grid-connected circumstance, the variable-speed constant-frequency control algorithm when the wind speed is below the rated value and the pitch control algorithm when the wind speed is above the rated value are simulated and analyzed. A 20-kW prototype has been developed. The simulation and the experimental data demonstrate that a hybrid power transmission meets the demands in various working conditions and stabilizes the torque of a wind turbine generation system.

다중코일방식에 기초한 원격 생체 정보 측정을 위한 무선전력전송 기술

The implanted telemetry system provides the monitoring of species while they move within their cages. Species monitored include mice, rats, rabbits, dogs, pigs, primates, sheep, horses, cattle, and others. A miniature transmitter implanted in each animal measures one or more parameters. Parameters measured include arterial pressure, intra-pleural pressure, left ventricular pressure, intra-ocular pressure, bladder pressure, ECG, EMG, EEG, EOG, temperature, activity, and other parameters and transmits the data via radio frequency signals to a nearby receiver. Every conventional dedicated transmitter contains one or more sensors, cpu and battery. Due to the expected life of battery, the measuring time is limited. To overcome these problems, electromagnetic inductive coupling based wireless power transmission technology using multiple transmit coils were proposed. Each coil having different active area are driven by the coil driver. In this research, parallel resonance based coil driver was proposed. In addition, the device to detect where the receiver is positioned was proposed. From the experiments we show how to determine the driving condition of coil driver.

Modular high-voltage bias generator powered by dual-looped self-adaptive wireless power transmission.

We proposed a modular high-voltage (HV) bias generator powered by a novel transmitter-sharing inductive coupled wireless power transmission technology, aimed to extend the generator's flexibility and configurability. To solve the problems caused through an uncertain number of modules, a dual-looped self-adaptive control method is proposed that is capable of tracking resonance frequency while maintaining a relatively stable induction voltage for each HV module. The method combines a phase-locked loop and a current feedback loop, which ensures an accurate resonance state and a relatively constant boost ratio for each module, simplifying the architecture of the boost stage and improving the total efficiency. The prototype was built and tested. The input voltage drop of each module is less than 14% if the module number varies from 3 to 10; resonance tracking is completed within 60 ms. The efficiency of the coupling structure reaches up to 95%, whereas the total efficiency approaches 73% for a rated output. Furthermore, this technology can be used in various multi-load wireless power supply applications.

Insulation characteristics of GIS epoxy insulators with non-uniform surface resistance under DC voltage

Now that gas-insulated switchgear (GIS) for ac systems are becoming increasingly compact as specifications are rationalized, more consideration of their insulation characteristics for residual dc voltage is required. Furthermore, with dc power transmission technology drawing more and more global attention, clarifying the insulation characteristics of GIS for dc voltage is increasingly important. For GIS insulating epoxy spacer, the present paper experimentally and analytically studied the influence of spacer surface condition on dc withstand voltage performance. In specific terms, initially, an insulating spacer model with an area of non-uniform resistivity present in the surface layer was created and the dc voltage breakdown characteristics were obtained. As a result, it was clarified that the time delay to breakdown increased with lowering the applied voltage, or in other words, even if a low voltage was applied, breakdown may occur after an extended period. Subsequently, using the same non-uniform resistivity model, the change in the electric field distribution over time under dc voltage was investigated through transient electric field analysis. Consequently, it was found that the electric field distribution varied from a capacitive to a resistive field and the maximum electric field was generated in the boundary between the high- and low-resistivity areas. It was further clarified, based on these breakdown characteristics and electric field analytical results, that the presence of an area of nonuniform resistivity on the insulating spacer creepage surface caused electric field concentration over time and breakdown occurred if the electric field in the creepage surface direction exceeded 40 kV/mm or so. Moreover, the breakdown characteristics were investigated where a lightning impulse voltage was superimposed over a dc voltage. Consequently, the creepage breakdown electric field where a dc voltage was applied alone was almost identical to that where the superimposed voltage was applied. It means that the application of the superimposed voltage may potentially allow the insulating spacer withstand voltage performance to be evaluated by a shorter time test for a dc voltage alone or the dc voltage with a superimposed VFTO.

English

In the modern era of science & technology, the transmission of electric power at reduced costs has been a field of great emphasis. As a result, the alternate technology of optical power transmission has been one of the emerging forces in the present times. With hindrances from external electromagnetic fields reduced, more resistance to sparks and network short circuits, lighter than normally used metallic wires and a reduced corrosion level are some of the factors that have made optical power transmission more advantageous and reliable over conventional transmission. This review paper broadly highlights the aspects of transmission through optical fibers and new technologies involved. It gives a brief summary on the powering architectures of optically powered system and the key factors that affect the performance level. Lastly, the prospect of a new developing technology involving micro dispensing and dispensed optical fibers is mentioned. This technology facilitates the direct coupling of fibers and devices.

Distributed Controllers for Multiterminal HVDC Transmission Systems

High-voltage direct current (HVDC) is an increasingly commonly used technology for long-distance electric power transmission, mainly due to its low resistive losses. In this paper, the voltage-droop method is reviewed, and three novel distributed controllers for multiterminal HVDC (MTDC) transmission systems are proposed. Sufficient conditions for when the proposed controllers render the equilibrium of the closed-loop system asymptotically stable are provided. These conditions give insight into a suitable controller architecture, for example, that the communication graph should be identical to the graph of the MTDC system, including edge weights. Since the equilibria of the closed-loop systems are asymptotically stable, it is shown that the voltages asymptotically converge to within predefined bounds. Furthermore, a quadratic cost of the injected current is asymptotically minimized. The proposed controllers are evaluated on a four-bus MTDC system.

1A1-N06 多段式共振器アンテナ構造における磁界共振結合を用いたワイヤレス電力伝送と距離センシングの同時実現

Recently, equipment mounted secondary battery is being spread, and it demands charging with codes or cables. From such a background, technology of wireless power transmission is being paid attention to and application this technology to intelligent space (iSpace) enables ubiquitous power source to realize. There are some types of wireless power transmission. Above all, the method using magnetic resonance coupling is prominent in its characteristics, but in this method, efficiency of transmission changes by a location. So, we suggest simultaneous realization of wireless power transmission and distance sensing. It is sensing distance the high efficiency location previously and realize high efficiency transmission as a whole system. Furthermore, we use the multi-stage resonator for our system which is superior in terms of transmission range.

Prediction Technology of Power Transmission and Transformation Project Cost Based on the Decomposition-Integration

Through the analysis of power transmission and transformation project cost, total cost can be decomposed into construction cost, equipment purchase cost, installation cost, and other costs. This paper proposes a decomposition-integration cost prediction model taking a substation project as an example by fully considering the cost characteristics. In decomposition module, the total cost is decomposed into four expenses. In prediction module, different forecasting models are selected to forecast different expense. In integrated module, choose different integration methods to get the predicting results of total cost. The empirical results show that decomposition-integration prediction algorithm has good effect which can effectively predict the cost of power transmission and transformation project and has practical application and popularization value.

Investigation in Wireless Power Transmission for UAV Charging

This paper proposes application of wireless power transfer for charging of electric-powered Unmanned Air Vehicles (UAV)s. Multi-rotor systems, such as quadrotors, are light-weight and easy to operate. They are available in different sizes and with the wide range of capabilities. The main limitation of electric-powered UAVs is their range and endurance, due the limited battery capacity. Increasing battery system size is not a viable solution as its weight becomes a limiting factor. Supercapacitors are not an option, because of their low energy density. An alternative is to recharge UAV on the job, using wireless energy transfer (WET). WET was originally investigated by Nikola Tesla in the beginning of the 20th century. His patents are now common ground for any power transmission technology research, both wired and wireless. Investigations in resonance-based wireless energy transfer promise efficient wireless power transmission over several meters. This offers an ability to recharge moving vehicles, such as cars, trains and UAVs, wirelessly. For example, this technology can be applied to extend the range of UAVs used for the inspection of power transmission lines and towers. Presented project investigate capabilities and limitations of the wireless power transmission, for particular UAV application, i.e. for the infrastructure inspections.