Inductive Contactless Power Transfer Research Articles

An Attended-Free, All-in-One-Go, Automatic Analysis Assistant Software for E-liked Shape Contactless Inductive Power Transfer Device

This paper presents automatic software for E-liked shaped contactless inductive power transfer (CIPT) device study and design that provides attended-free, multiple-case auto-generating and auto-deploying analysis in one go. It provides visualized and listed results in a design space or for optimizing solutions. To satisfy the demand for static and dynamic charging devices, the software provides specific cores, such as EE-, EI-, IE-, and II-shaped, with or without legs as optional core structures. The software contains three main parts: a user-friendly interface, analytic approaches providing grid analysis that represent the general performance in a designated parameter range, and optimal analysis for multi-objective optimization using a genetic algorithm (GA). The post-analysis processor converts the analysis results to easy-to-read outputs. Users can customize various parameters, such as core type, structural size, circuit configuration, materials, and analysis setting. Automatic functions, such as resistance and compensation calculation, are available for the convenience of the user. By applying one approach, or by combining them in a specific order, the software achieves designs that satisfy the user’s demands within the user-provided range. The software is built in Python and collaborates with a finite element method (FEM) solver, which is JMAG in this paper. Some examples are given to demonstrate the performance of the software.

Design and Analysis of a Multi-Input Multi-Output System for High Power Based on Improved Magnetic Coupling Structure

Conventional inductive contactless power transfer (ICPT) systems have only one energy transmission path, which makes it challenging to meet the power transmission requirements of high-power and reliability. This study proposes a novel multiple-input multiple-output (MIMO) ICPT system. The three-dimensional finite element analysis tool COMSOL is utilised to study various magnetic coupling structures, analyse the influence of cross-coupling between coils on the same side, design the circuit based on this, propose a parameter configuration method for resonance compensation, and, finally, build an experimental platform with small magnetic coupling structures for single-input single-output systems (SISO) and MIMO systems. The results indicate that the co-directional connection of the coils of the E-shaped and UE-shaped magnetic coupling structures has a strengthening effect on the secondary side coupling. The magnetic coupling structure of the E-shaped iron core exhibits the best transmission performance. The transmission power of the MIMO system with the E-shaped magnetic coupling structure as the core device is significantly improved. In addition, the output power is unchanged after a secondary side fault, which verifies the accuracy of the proposed method.

A novel contactless, feedbackless and sensorless power delivery link to electromagnetic levitation melting system residing in sealed compartment

The paper presents practical considerations and guidelines for designing an improved-efficiency contactless inductive power transfer link, delivering DC power in step-down mode to an electromagnetic levitation melting system residing in a sealed compartment. The proposed arrangement employs none-series compensated inductive power transfer link operating at the so-called “load-independent-voltage-output” frequency, allowing feedback-less and sensor-less design. However, the output voltage of a system operating at such frequency remains influenced by the load to some extent, residing within a certain range with boundary values (minimum and maximum) corresponding to maximum (rated) and minimum load, respectively. Consequently, the proposed contactless power delivery system is first analyzed using both first harmonic approximation (frequency-domain) based approach and differential equations (time-domain) based method to obtain corresponding output voltage bounds. Then, coil-to-coil efficiency and optimal load matching factor are determined. Comparison with both typically utilized symmetrical series-series and recently proposed series-none compensation topologies reveals the superiority of none-series compensation topology in terms of coil-to-coil efficiency for the whole range of coupling coefficients. Simulations and experiments of 400 V, 1 kW none-to-series compensated inductive wireless power transfer link, delivering contactless energy to a 250 V electromagnetic levitation melting system, demonstrate excellent matching and accurately validate the presented analysis.

Design of an ICPT system for battery charging applied to underwater docking systems

High power consumption limits the endurance of autonomous underwater vehicles (AUVs). It’s necessary to build a docking station to recover and recharge AUVs underwater. Inductive coupling is a commonly used method for contactless power transmission, which demonstrates superiorities in an underwater environment. In this study, a pair of coaxial and coreless coil structure is proposed for battery charging of the AUV. The performance of an inductive contactless power transfer (ICPT) system in SP topology is analyzed considering the loss of eddy-current in sea water, switching elements and diode-bridge. An appropriate frequency is selected to realize a maximum system efficiency. In the laboratory experiment, the selected topology demonstrates stable properties and realizes a maximum charging power of approximately 300W. The efficiency of the ICPT system varies from 75% to 91% with a total efficiency of 63–77% during the entire charging period.

Evaluation of Inductive Contactless Power Transfer Outlet with Coaxial Coreless Transformer

SUMMARYA contactless outlet for dc distribution systems is proposed. It uses an inductive contactless power transfer circuit with a series/parallel compensation circuit to prevent voltage fluctuation. However, the output voltage of the circuit rises in light load conditions. In this paper, the main circuit and control method for reducing the rise in output voltage and a method of estimating the output voltage are presented. The proposed circuit and methods were verified and evaluated experimentally using feedback control.

LCL Resonant Compensation of Movable ICPT Systems with a Multi-load

Compared to LC resonance, LCL resonance has distinct advantages such as a large resonant capability, low voltage and current stresses of the power device, constant voltage or current output characteristics, and fault-tolerance capability. Thus, LCL resonant compensation is employed for a movable Inductive Contactless Power Transfer (ICPT) system with a multi-load in this paper, which achieves constant current output characteristics. Peculiarly, the primary side adopts a much larger compensation inductor than the primary leakage inductor to lower the reactive power, reduce the input current ripple, generate a large current in the primary side, and realize soft-switching. Furthermore, this paper proposes an approximate resonant point for large inductor-ratio LCL resonant compensation through fundamental wave analysis. In addition, the PWM control strategy is used for this system to achieve constant current output characteristics. Finally, an experimental platform is built, whose secondary E-Type coils can ride and move on a primary rail. Simulations and experiments are conducted to verify the effectiveness and accuracy of both the theory and the design method.

同軸円筒形空芯トランスを用いた電磁誘導方式非接触コンセント・プラグの特性評価

A contactless outlet for dc distribution systems was proposed. It uses an inductive contactless power transfer circuit with a Series/Parallel (S/P) compensation circuit to prevent voltage fluctuation. However, the output voltage of the circuit rises in light load conditions. In this paper, the main circuit and control method for reducing the rise in output voltage and a method to estimate the output voltage are presented. The proposed circuit and methods were verified and evaluated experimentally using feedback control.

Effects of Coil Misalignments on theMagnetic Field and Magnetic ForceComponents between Circular Filaments

Wireless transfer of electrical energy between air-cored circular coils can be achieved using contactless inductive power transfer (CIPT) system. Notwithstanding, the aim of designing CIPT systems is not always realized because of coil misalignments between the primary and the secondary coils. Based on this information, the author of this paper analyses the effects of lateral and angular misalignments on the magnetic field and the magnetic force between filamentarycircularcoilswhicharearbitrarilypositionedinspace.Thisinvestigation is achieved based on advanced and relevant models formulated in the literature. Detailed results obtained using SCILAB application software is given.

Design Methodology for High Efficient Inductive Power Transfer Systems With High Coil Positioning Flexibility

With contactless inductive power transfer (IPT), it is possible to transfer electrical energy to stationary or movable consumers without contacts, cables, or slip rings. To reduce the very high development effort of new contactless inductive energy supplies, a new systematic and modular design methodology is presented in the paper. This methodology includes new methods to increase the transfer efficiency and the positioning flexibility of the consumer device and is particularly implemented into a simulation software tool. The positioning tolerance is improved by the optimization of the coil and ferrite geometry. Thereby, the influence of physical and geometrical parameters on the magnetic coupling and on the electrical transfer characteristics is investigated. As a result of the design methodology, a new IPT system for household appliances in the output power range of 1 kW at an overall efficiency of more than 90% and with a high positioning tolerance is presented.

Novel Method for Selective Nonlinear Flux Guide Switching for Contactless Inductive Power Transfer

Efficient inductive power transfer has become an area of increasing scientific interest as it can solve some problems associated with traditional wired or contact power transmission. These include but are not limited to corrosion, mechanical friction, clutter and impracticality in places like underwater and subterranean applications. This wireless energy transfer is made possible by the optimization of electromagnetic induction, circuit frequency resonance all achieved with advanced power electronics. One of the components of this technology is the precise delivery of the incident electromagnetic fields to the precise location to which they are converted to power via induction, without indiscriminate emission of these electromagnetic fields inefficiently into the surrounding areas. This paper presents a method in achieving bounded spatial freedom using flux-guide saturation for flux delivery to one or more secondary coils for contactless inductive power transfer. The experiments demonstrate the principle of using the nonlinearity of a ferrite flux shield in order to “open up” a flux path from the primary to the secondary coil to achieve inductive power transfer.

Design of Integration Tool-Holder System for Ultrasonic Vibration Machining Using Contactless Inductive Power Transfer

Contactless inductive power transfer system with conventional inductive technology was studied and a design method was presented after applying it to ultrasonic vibration machining systems. The compensation techniques are used for piezoelectricity transducer. Nodal plane support of transducer is researched and models of different structures for nodal plane support are got. Influence of rotary precision for different support due to centrifugal force and displacement vibration of nodal plane support to toolholder are analyzed. The system integrated with ultrasonic-vibration toolholder based on contactless inductive power transfer is designed. Power transfer and dynamic tests show that the design procedures and result based on theoretical analysis are comparative.

Modeling and Analyzing an Inductive Contactless Power Transfer System for Artificial Hearts Using the Generalized State Space Averaging Method

Modeling and Analyzing an Inductive Contactless Power Transfer System for Artificial Hearts Using the Generalized State Space Averaging Method