Contactless Power Transmission Research Articles

Analysis on Transmission Characteristics of Dynamic Magnetic Coupling Mechanism of Racetrack Coil with Deflection Angles

In dynamic magnetically coupled contactless power transmission, the fluctuation of mutual inductance is caused by the relative motion between transmission and receiving coils, which affects the stability of power transmission. In order to reduce the fluctuation characteristics of power transmission, the mutual inductance calculation model of transmission mechanism including a racetrack coil with deflection angle is established by using Neumann formula, and the influence of different deflection angle and layout on mutual inductance fluctuation characteristics is analyse and compare. Then the power transmission system with LCC-S compensation for the transmission mechanism is established. The transmission characteristics of the racetrack coil with deflection angle are studied. The results show that reasonable design of the deflection angle can reduce the fluctuation of the mutual inductance and the power output in dynamic transmission. The fluctuation of power output can also be reduced by changing the distance between transmission coils and the length of straight side of receiving coils.

Визначення проєктних параметрів системи керування енергетичних космі-чних апаратів для безконтактного живлення космічної індустріальної платформи

The study of the features of near-Earth space industrialization is a promising line in space science. The scientific development of this line is rather deep, and it is carried out both at a theoretical conceptual level and at an experimental level by trying various technological processes onboard the International Space Station. One of the lines of this concept is the study of the features of designing a power system for a space industrial platform. The power system is of the distributed type, which provides for the combined use of power generation modules onboard the space industrial platform itself and an orbital constellation of power spacecraft. In its turn, the use of power spacecraft with contactless electric power transmission to a space industrial platform is intended for highly power-intensive technological processes. In view of the aforesaid, the goal of this paper is to study the features of controlling the power spacecraft of the distributed power supply system of a space industrial platform in such a way as to provide the synchronization of their operating modes with the operation sequence of the space industrial platform. A power spacecraft’s angular motion controllers are synthesized for a solar battery charging mode, a receiving spacecraft aperture pointing mode, and a waiting mode. Methodological recommendations are given on synthesizing the operation schedules of the power spacecraft of the distributed power supply system in such a way as to provide their synchronization with the operation schedules of the space industrial platform. The design parameters to be chosen in designing spacecraft for contactless power transmission to a space industrial platform are identified.

FEM-based optimal design and testing of synchronous magnetic coupling for aerospace Starter/Generator applications

Improvements in high energy density rare-earth permanent magnets make it innovative to develop magnetic couplings for Starter/Generator applications in the light of more electric aircraft to ensure magnetically insulated contactless power transmission between decoupled shafts for safe operation. Although there are essential studies on magnetic couplings in the literature, especially those for aerospace Starter/Generator structures are rarely encountered. However, methodologies considering system constraints and examining design parameters of couplings are in demand. In response to such a need, this paper proposes the novel design of highly reliable synchronous radial magnetic couplings with torque requirements of 6 and 12 N·m to isolate Starter/Generator and piston engine shafts in model aircraft. The preliminary volume is obtained analytically. Simulations are executed by optimetric approaches in Ansys Maxwell 2D. Optimisation techniques are compared in Maxwell 3D to get the final shape. The retaining sleeve of 0.5 mm is suggested. Loss of synchronisation in the event of the piston shaft failure or exceeding the maximum torque of the coupling is also examined. The torque fluctuation at load changes is 0.1%. Performance tests are conducted on the direct dynamic test bench. Absolute error margin is 37% for the Virtual Work method, 13% for 2D FEM and 6% for 3D FEM. The coupling efficiency is 93.8% at the maximum operating speed and the critical angle, and 96.9% at the minimum torque angle and the minimum operating speed.

Comparing different configurations for rotary transformer of wound-rotor resolvers

Wound-Rotor resolvers are the oldest and the most widely used resolvers. They are two-phase synchronous generators with high frequency AC excitation. Rotary Transformers (RTs) are used to supply the rotating excitation winding of the resolver. Although RTs offer the benefits of contactless power transmission, harmonic contents of the secondary voltage, phase shift error between the primary and the secondary voltages, and high leakage flux are the main challenges in their usage along with resolvers. Therefore, in this paper, different configurations are examined for RT’s ferromagnetic core to overcome the mentioned problems. All the simulations are done using 3-D time variant finite element method (TVFEM) and the best configuration is chosen for experimental prototyping and measurements. Close agreement between the simulation and the experimental test results approves the performed analysis.

RETRACTED: A design of wet-mateable connector aiming for contactless power transfer and optical communication

At present, contact watertight connectors are commonly utilized for the connection between underwater electromechanical equipment and the seabed observation network. Such conventional watertight connectors are inevitably likely to be irreversibly worn when plugging and unplugging, besides complicated sealing structures and limited service life. This paper designs a Wet-Mateable connector aiming for Contactless Power Transfer and Optical Communication (PTOC-WMC), which is based on technology of Contactless Power Transmission (CLPT) and optical communication. Docking structure of the sockets and plugs are designed, facilitating Remotely Operated Vehicle (ROV) to operate. A prototype of the PTOC-WMC was established. The experimental results show that the connector designed can achieve 200W power transmission, with a maximum power transmission efficiency of 94%. The communication bandwidth reaches 18MHz. The PTOC-WMC can assist the rapid and safe deployment and operation of seabed observation network.

Research on non-contact wet mateable connector for optical communication and power transmission

At present, contact watertight connectors are commonly utilized for the connection between underwater electromechanical equipment and the seabed observation network. Such traditional watertight connectors are easy to be irreversibly worn when plugging and unplugging, however, they have complicated sealing structures and limited service life. This paper designs a Non-contact Wet Mateable connector for Optical Communication and Power Transmission (OCPT-NWMC), which is based on technology of Contactless Power Transmission (CLPT) and optical communication. Docking structure of the sockets and plugs are designed, facilitating Remotely Operated Vehicle (ROV) to operate. A prototype of the OCPT-NWMC was established. The experimental results show that the connector designed can achieve 200W power transmission, with a maximum power transmission efficiency of 94%. The communication bandwidth reaches 18MHz. The OCPT-NWMC can assist the rapid and safe deployment and operation of seabed observation network.

A method to improve multi-node power transmission efficiency of inductively coupled mooring cable.

The inductively coupled mooring cable is an important tool for monitoring the ocean hydrological data. The mooring cable is an open-loop structure that uses a section of seawater as the transmission medium. The power transmission efficiency of this structure is very low due to the large power loss of the seawater medium, and it is rarely studied. In this paper, a contactless power transmission circuit with seawater loss is analyzed, and the theoretical model of multi-node power transmission of the inductively coupled mooring system is established. In this model, the improvement of the output power and transmission efficiency is only related to the frequency selection and the properties of the magnetic core itself, such as the magnetic core material. Moreover, the optimal scheme is selected according to the output power requirements. The experimental results show that when the input current (Irms) is 2A, the output power of a single node is 12W, the total output power is 120W, and the total transmission efficiency reaches 50%.

Research of contactless power transmission in rotating EDM system

Research of contactless power transmission in rotating EDM system

Current Status of Contactless Power Transmission Technology

Current Status of Contactless Power Transmission Technology

MODELLING OF LOSSLESS AND CONTACTLESS POWER TRANSFORMER USING IMPROVED PARTICLE SWARM OPTIMIZATION ALGORITHM

The contactless power transmission is applicable recently for various real time applications like electric vehicle charging, in space travelling, and other distribution systems. The transformer winding has magnetic coupling with each phases; it analyze the primary and secondary winding for core structure of transformer. The conventional Loosely coupled transformer with mixed winding and electromagnetic shielding for contactless power transmission method used various traditional Genetic algorithm and Particle Swarm Optimization algorithms for power loss reduction. This increases the transmission time and it reduces the efficiency. In proposed methodology, the optimal model of contactless power transformer approach uses improved particle swarm optimization algorithm for reducing the power loss in grid connected PV module. The maximum power of solar panel is tracked by using MPPT algorithm and it is fed with the switching controller for reducing the overlap. Here in the IPSO, the frequency dependent scale selection algorithm selects the fitness frequency for optimizing the swarm particle positions to reduce the losses. From this, the impedance matching approach is used for eliminating the frequency scale splitting because it may cause over-coupled signal and the fixed mutual inductance also helps to transfer maximum power. This proposed approach improves the result of power transfer efficiency. Various analytical calculations, numerical simulations and experimental results are taken to address the loss diminution in contactless power transfer approach with better efficiency of power transmission than other existing approaches. Overall the proposed design model is done by MATLAB 2018a/Simulink. Keywords: Contactless power transfer: Frequency dependent; improved particle swarm optimization; optimal frequency scale selection; swarm position updates; PV module; MPPT; Charging station

Implementation algorithm and mathematical model of contactless power transmission for powering an electric vehicle

The work is devoted to methods for increasing the energy efficiency of photovoltaic modules. Various algorithms for determining the maximum power points and their application to obtain the maximum possible efficiency when using solar panels are considered. The principles of the operation of algorithms are described, their advantages and disadvantages are indicated. Their comparison was carried out according to the main significant parameters. The most suitable algorithm for application at a weather station has been selected.

Contactless Mechanical Power Transmission Through the High-T c Superconducting Pinning Effect.

Mechanical power transmission (MPT) components are almost indispensable for every engineering equipment with motions. In order to satisfy some rigorous requirements, such as contamination free and zero leakage in the mixing process of biomedical solutions, a contactless MPT mode was proposed in this study based on the high-Tc superconducting flux pinning mechanism. It makes the stirring container with the driven part inside that can be totally isolated from the external environment. The physical principle of superconducting flux pinning effect was discussed firstly to explore a feasible structural scheme, which can completely restrain all the six degrees of freedom (DOFs) by the linkage of magnetic flux lines. Then, a measurement device was established to verify and investigate the proposed contactless MPT mode. The motion can be transferred synchronously from the superconducting driving part to the permanent magnet driven part since they are unified as an integrity through the pinned flux lines. The influence of driving speed, cooling clearance, and magnet arrangement on the transmitted torque was analyzed. The verified contactless MPT mode also has the advantages of self-stability and overload protection, which can avoid the drawbacks of traditional permanent magnetic transmission mode.

Superconducting Coils for Contactless Power Transmission

Scientists develop a coil with superconducting wires that can transmit contactless power with only limited losses.

Magnet-free HV Traction Drives with Contactless Power Transmission

Magnet-free HV Traction Drives with Contactless Power Transmission

CALCULUL CÂMPULUI ELECTRIC ASOCIAT UNUI CUPLOR INDUCTIV DESTINAT TRANSFERULUI DE PUTERE WIRELESS

"Contactless or wireless power transmission has become a widespread disruptive technology. Although known for more than 100 years, it is the result of the unprecedented development of microelectronics and power electronics in recent decades. Numerous technical solutions for near-field energy transmission at different power and frequency levels are currently established: capacitive electric field transmission (CPT), inductive magnetic field transmission (IPT), multi-coil transmission and simultaneous transmission via electric field and magnetic field as a combination of the first two. The materialization of the contactless transmission is achieved in theory and practice through different types of contactless coupling circuits, generically called ""contactless couplers"". The inductive coupler can be considered as an electrical transformer in air or with open magnetic circuit in which the primary (Tx) and the secondary winding (Rx) can occupy different positions from each other depending on the application [1]. It is considered a representative element for WPT (Wireless Power Transfer) systems currently used from transferred powers of several watts to tens or hundreds of kilo-watts. To increase the transfer efficiency, the coupler works at high frequencies, of the order of kHz or MHz and in some cases has planar windings, of different shapes, made of litz wire and usually has magnetic flux concentrators [2]. Any inductive coupler is integrated into a complex transmission system, consisting of many other components [3]. In addition to the electromagnetic calculation widely presented in other works, open magnetic circuit construction produces electric and magnetic scattering fields that have a negative effect on both electrical and electronic equipment in the vicinity and on human health if the exposure exceeds certain thresholds. These thresholds are indicated by international standards and requirements [4-5] achieved by applying the precautionary principle [6] so that they can be reviewed periodically and are not mandatory unless they are taken over in national law. In this paper we analyze by the finite element method, in approximate 2D, the electric field produced by an inductive coupler in various simplified construction variants and calculate certain related quantities of practical importance such as: electric field distribution in the field of calculation, electric field strength in the vicinity of the inductive coupler, equipotential lines, reactive power, equivalent capacities."

Modernization of the cable car in order to take into account the length of the metal cord at the stage of its final production

To achieve accuracy and stability in measuring the length of the metal cord at the stage of its manufacture, it is necessary to modernize the existing rope-twisting equipment. The upgrade introduced a new algorithm for rope-twisting equipment, changed the length accounting system of the steel cord, used the latest equipment and technology. A contactless electric power transmission system and a wireless data transmission system based on an infrared channel have been introduced.The use of the latest technologies and our own innovations allowed us to obtain a completely new type of rope-twisting machine that can produce metal cord according to the requirements of the consumer’s specification.

Optimal working state tracking method and experiments on inductive contactless power transmission system

To address the problems of traditional frequency tracking, such as falling into a local optimum, oscillation near the optimal point, and contradiction between tracking speed and tracking accuracy, an improved perturb–observe method based on component drift parametric scanning is proposed. An inductive contactless power transmission system with LCC/S third-order compensation topology is employed as the research object. First, the relationships between the output voltage and frequency under component drift parametric scanning are given by theoretical deduction and calculation. Then, a reasonable working frequency band is intercepted, and the improved perturb–observe method (including start, end, step, and anti-death cycle judgement) is used to track the optimal working state adaptively. Finally, the correctness of the proposed theory and method was verified by simulations and physical experiments.

Performance Enhancement of an Ultrasonic Power Transfer System Through a Tightly Coupled Solid Media Using a KLM Model.

Contactless ultrasonic power transmission (UPT) through a metal barrier has become an exciting field of research, as metal barriers prevent the use of electromagnetic wireless power transfer due to Faraday shielding effects. In this paper, we demonstrate power transfer through a metal wall with the use of ultrasonic waves generated from a piezoelectric transducer. Accurate characterization and modeling of the transducer and investigation of the influence of the acoustic properties of the transmitting medium are instrumental for the performance prediction and optimal design of an ultrasonic power link. In this work, we applied the KLM model for the emitting and receiving transducers, with respect to the transmitting medium and model for both the emission and reception function. A practical UPT system was built by mechanically coupling and co-axially aligning two composite transducers on opposite sides of a transmitting medium wall. The optimal transmission performance of the ultrasonic power link through thickness-stretch vibrations of the wall together with two piezoelectric transducers working in TE mode was determined. Eventually, the operating frequency and ohmic loading condition for maximum power transmission were obtained for two different media, aluminium and polyoxymethylene (POM), with contrasting specific acoustic impedances. The results showed that the measured optimal electric loads and operating frequency for maximum power transfer agreed well with the theoretical predictions.

Dynamics of acoustic impedance matching layers in contactless ultrasonic power transfer systems

The acoustic impedance mismatch between transducer materials and medium in ultrasonic power transfer systems narrows the transduction bandwidth and causes losses through the back reflection of progressive pressure waves at the boundary between the transducers and medium. Capturing both resonances and losses due to impedance mismatch of interwoven elements is essential for advancing the development of these systems. We present a unified approach, based on the multiplication of a sequence of transfer matrices, to determine an equivalent acoustic impedance. The analytical model couples the properties of the transmitter and receiver with multiple matching layers and a single classical quarter-wave layer in controlled setups with the objective of minimizing reflections through acoustic impedance mismatch alleviation. Losses due to ultrasonic attenuation in the material layers and medium are also considered. The acoustic field at the receiver location constitutes the input to the coupled electro-elastic equations of the fluid-loaded and electrically-loaded piezoelectric receiver. Experiments are performed to identify the input acoustic pressure from a cylindrical transmitter to a receiver disk operating in the 33-mode of piezoelectricity. The results show significant enhancements in terms of the receiver’s electrical power output when implementing a two-layer matching structure. We present the results showing non-dimensional wave number variations versus characteristic impedance, which can be used to calculate the materials’ thicknesses for acoustically matching ultrasonic power transfer systems to an acoustic medium of interest at any desired resonant frequency while considering any type of glue or epoxy as the bonding layer. The derived physical models facilitate the development of high-fidelity matched systems with enhanced contactless power transmission.

Dual-Slot Power-Pickup Structure for Contactless Strip Inductive Power Track System

In this paper, a dual-slot power pickup suitable for an inductive power track system was developed using contactless power transmission techniques. A new strip-type inductive power track with high magnetic flux density and magnetic field uniformity is proposed. A dual-slot type power-pickup structure with high magnetic flux linkage was designed using equivalent magnetic circuit model analysis to improve the power transmission capacity and transmitting efficiency. To verify the contactless transmission characteristics of the proposed strip-type inductive power track system, a 1.2 m long laboratory-scale inductive power track was constructed. The SPLSC topology was used as the compound resonant circuit of a full-bridge inverter. According to the experimental results, the maximum transmitting efficiency of overall system is 72.52% at an output power of 289.52 W.