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Article
Publication date: 23 October 2015

Prabhat Chandra Ghosh, Pradip K Sadhu, Debabrata Roy and Soumya Das

This paper investigates the selection of semiconductor switches used in contactless power transfer (CPT) system. In the present paper a single phase high frequency full…

Abstract

This paper investigates the selection of semiconductor switches used in contactless power transfer (CPT) system. In the present paper a single phase high frequency full bridge inverter using different semiconductor switches like IGBT, MPOSFET and GTO has been considered. Harmonic injection in input current of the inverter for different semiconductor switches has been analyzed using PSIM software. The THD of input current of the inverter for the particular switching device has been determined by using Fourier Transforms. It has been observed that THD in case of the IGBT is minimised.

Details

World Journal of Engineering, vol. 12 no. 5
Type: Research Article
ISSN: 1708-5284

Keywords

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Article
Publication date: 3 July 2017

Yusmarnita Yusop, Mohd. Shakir Md. Saat, Siti Huzaimah Husin, Sing Kiong Nguang and Imran Hindustan

This paper aims to present a new wireless power transfer technique using capacitive coupling. The capacitive power transfer (CPT) system has been introduced as an…

Abstract

Purpose

This paper aims to present a new wireless power transfer technique using capacitive coupling. The capacitive power transfer (CPT) system has been introduced as an attractive alternative to the traditional inductive coupling method. The CPT offers benefits such as simple topology, fewer components, better electromagnetic interference (EMI) performance and robustness to surrounding metallic elements.

Design/methodology/approach

A class-E inverter together with and without inductor capacitor (LC) matching circuit has been utilised in this work because of its ability to perform the DC-to-AC inversion efficiently with significant reduction in switching losses. The validity of the proposed concept has been verified by conducting a laboratory experiment of the CPT system.

Findings

The performances for both systems are analysed and evaluated. A 9.7 W output power is generated through a combined interface [printed circuit board (PCB) plate] capacitance of 2.82 nF at an operating frequency of 1 MHz, with 97 per cent efficiency for 0.25 mm coupling gap distance.

Originality value

An efficient CPT system with class-E LC matching topology is proposed in this paper. With this topology, the zero-voltage switching can be achieved even if the load is different by properly designing the LC matching transformation circuit.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 4
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 2 November 2015

Julian Veitengruber, Frank Rinderknecht and Horst E. Friedrich

The purpose of this paper is to devote the optimal substitution of slip rings through an inductive power transfer system for field winding supply of generators or motors…

Abstract

Purpose

The purpose of this paper is to devote the optimal substitution of slip rings through an inductive power transfer system for field winding supply of generators or motors with a wound rotor. By a rotational pot-core transformer approach, the rotor-side energizing of the excitation windings can be provided isolated and free of wear.

Design/methodology/approach

For design purpose, an analytical model of the inductive link and the compensation network elements is shown. Based on a pot-core transformer approach, possible types of compensation networks regarding motor-specific constraints were carried out and compared among themselves by parameter studies. The analytical parts of the model were subsequently validated with measured data of an appropriate core and accompanying FEM calculations. On the basis of an experimental prototype system, the approach has been tested both stationary and transient.

Findings

The publication exemplifies how a brushless excitation system for generators and motors can be inexpensively designed and implemented.

Originality/value

This paper systematically presents a comprehensive analytical approach for brushless excitation systems as well as a prototypical system. Compensation network elements regarding motor-specific constraints were carried out and compared among themselves by parameter studies.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 6
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 7 January 2019

Monir Sadat Hosseini, Hamid Javadi and Sadegh Vaez-Zadeh

This paper aims to investigate analytical electromagnetic fields and thrust ripples representation of linear flux-switching motors with simple modulated secondary referred…

Abstract

Purpose

This paper aims to investigate analytical electromagnetic fields and thrust ripples representation of linear flux-switching motors with simple modulated secondary referred as segmented secondary linear flux-switching motor (SSLFSM).

Design/methodology/approach

SSLFSMs are applicable to transportation systems like Maglev due to their simple and consequently low-cost secondary structures and high force density. However, they have high thrust ripples that deteriorate a smooth motion in rail transportation systems. Therefore, derivation of accurate analytical models for thrust ripples minimization of the motor is essential, which is absent in the literature. In this paper, a two-dimensional analytical model is developed for this motor. The model is based on transfer relations and Fourier theory used for solving a two-dimensional boundary value problem. Certain model regions are determined by considering actual machine structure and observing specific rules. Analytical solution of Maxwell and Poison equations are then obtained in the regions.

Finding

Using the presented modeling method, the airgap electromagnetic field distribution and developed thrust of the motor are calculated for different positions of the motor as well as its thrust ripples. They are verified by the results obtained from finite element method. Also, the analytical results are compared with the presented experimental results.

Originality/value

This paper has analytically presented the airgap electromagnetic field distribution, thrust and thrust ripples of the SSLFSMs. This modeling is essential in thrust ripples minimization of the motor.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 38 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 2 March 2015

Emanuel G. Marques and André M.S. Mendes

Inductive power transfer (IPT) is a hands free user charging system, which allows the transfer of energy over a large air gap without physical contact. The purpose of this…

Abstract

Purpose

Inductive power transfer (IPT) is a hands free user charging system, which allows the transfer of energy over a large air gap without physical contact. The purpose of this paper is to evaluate two magnetic coupling structures and its applicability to EVs charging systems.

Design/methodology/approach

A brief introduction of IPT systems is initially presented, with the characterization of the chosen resonant topologies, series uncompensated (SU) and series parallel (SP). The magnetic coupling structures (MCSs) are then investigated and the principal characteristics required for EVs applications are outlined. The circular and the DD magnetic coupling structures are chosen due to its inherent advantages and a description of both physical and electrical most important aspects are made. Finally, different simulation and experimental results are analyzed and discussed for both magnetic structures.

Findings

The SU topology is suitable for applications with low voltages sources at the cost of a more attuned control. The DD pad allows a higher power transfer when compared with the circular pad, with better efficiency for the same working conditions. The DD pad is more tolerant to misalignment in the axis y while the circular pad is independent of the misalignment direction. Both modeled pads can transfer at least 5 kW without saturating the core.

Originality/value

This paper analyzes and compares the power transfer capability, misalignment tolerance and core saturation levels of the selected pads.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 6 November 2017

Jingsong Li, Lixiang Wang, Qingxin Yang, Shanming Wang, Yongjian Li, Changgeng Zhang and Baojun Qu

Due to existence of skin effect under rotational excitation, especially to high-frequency motors and power transformers run at the frequency of hundreds or even thousands…

Abstract

Purpose

Due to existence of skin effect under rotational excitation, especially to high-frequency motors and power transformers run at the frequency of hundreds or even thousands of hertz, core losses will increase significantly, which may cause local overheating damage, and the efficiency and longevity will be decreased. The purpose of this paper is to accurately calculate the rotational anomalous loss in electrical steel sheets.

Design/methodology/approach

The influence of skin effect to rotational anomalous loss coefficient is described in detail. Based on the rotational core losses calculation approach, the transformed coefficient and parameters of rotational anomalous loss are determined in accordance with experimental data obtained by using 3D magnetic properties testing system. Then, a variable loss coefficient calculation model of rotational anomalous loss is built. Meanwhile, a separation of the total 2D elliptical rotation experimental core losses is worked out.

Findings

The two methods are analysed and compared qualitatively. It should be noted that the novel calculation model can be more effectively presented anomalous loss features. Moreover, quantitative comparisons between 2D elliptical rotation and alternating core losses have achieved beneficial conclusions.

Originality/value

Transformed rotational anomalous loss coefficient and parameters of electrical steel sheets considering skin effect are determined. Based on that, a novel calculation model evaluating 2D elliptical rotation anomalous loss is presented and verified based on the experimental measurement and the separation of the total 2D elliptical rotation core losses. The 2D elliptical rotation core losses separation method and quantitative comparison with alternating excitation are helpful to engineering application.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 6
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 7 January 2019

John Compter

This paper aims to present new analytical expressions for the mutual inductance and forces between non-coaxial co-planar circular thin-wall air coils.

Abstract

Purpose

This paper aims to present new analytical expressions for the mutual inductance and forces between non-coaxial co-planar circular thin-wall air coils.

Design/methodology/approach

The expressions are based on an integration method found in the literature, so far used only to describe mutual inductances. It is new to apply this method as a starting point to get the forces between non-coaxial co-planar rings and coils. The approach is further extended to include non-coaxial co-planar thin-wall cylindrical coils.

Findings

This new method enables interaction modelling between coils by solving integrals numerically, covering fully, partially and non-overlapping coils in a single form. The expressions are verified by comparing the results with alternatives methods.

Research limitations/implications

The forces and mutual inductances of non-coaxial co-planar circular coils are obtained with analytical expressions, fitted well for optimization studies. The study is limited to coils in free air.

Practical implications

A typical application is the interaction between coils in a wireless energy transfer system (as applied for battery loading for mobile phones and automotive). The expressions can be used to also predict the forces between two non-coaxial disk or ring magnets as used in magnetic levitation systems.

Originality/value

Maxwell described the coupling between two coaxial co-planar rings, and steadily more and more equations describing the interaction between circular coils became available in the past decades. The target of this study is to obtain compact equations for non-coaxial co-planar circular coils. This is realized with the combination of existing literature and mathematical modelling tools.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 38 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 6 November 2017

Jiali Zhou, Bo Zhang and Dongyuan Qiu

This paper aims to analyze the frequency characteristics of wireless power transfer (WPT) systems with relay resonators in terms of the power delivered to the load and…

Abstract

Purpose

This paper aims to analyze the frequency characteristics of wireless power transfer (WPT) systems with relay resonators in terms of the power delivered to the load and system efficiency. Based on the analytical results, system parameters can be optimized to achieve maximum power transfer and higher system efficiency.

Design/methodology/approach

Based on Kirchhoff’s voltage law equations, WPT systems with relay resonators are described by the coupled linear second-order differential equations. Splitting frequencies are estimated by using the matrix theory. In addition, critical coupling conditions are demonstrated based on discriminant analysis.

Findings

It was found that multi-maximum values exist for the power delivered to the load and total system efficiency owing to multiple eigenfrequencies of the system. Also, frequency conditions of maximum power transfer and system efficiency, as well as their critical coupling conditions, were quantitatively estimated.

Research limitations/implications

During our analytical process, we assume that quality factors of resonators in the system are high and the crossing coupling between resonators is negligible.

Originality/value

In previous works, the exact analysis of frequency characteristics is limited to WPT systems with two resonators. The appealing feature of this work lies in its ability to present a simplified analytical method with negligible approximation errors for WPT systems with relay resonators.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 6
Type: Research Article
ISSN: 0332-1649

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Book part
Publication date: 30 March 2005

Richard Iles

Abstract

Details

Public Transport in Developing Countries
Type: Book
ISBN: 978-0-08-045681-2

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Article
Publication date: 4 November 2019

Zhenmin Wang, Wenyan Fan, Fangxiang Xie and Chunxian Ye

This paper aims to present an 8 kW LLC resonant converter designed for plasma power supply with higher efficiency and lighter structure. It presents how to solve the…

Abstract

Purpose

This paper aims to present an 8 kW LLC resonant converter designed for plasma power supply with higher efficiency and lighter structure. It presents how to solve the problems of large volume and weight, low performance and low efficiency of traditional plasma power supply.

Design/methodology/approach

At present, conventional silicon (Si) power devices’ switching performance is close to the theoretical limit determined by its material properties; the next-generation silicon carbide (SiC) power devices with outstanding advantages can be used to optimal design. This 8 kW LLC resonant converter prototype with silicon carbide (SiC) power devices with a modulated switching frequency ranges from 100  to 400 kHz.

Findings

The experimental results show that the topology, switching loss, rectifier loss, transformer loss and drive circuit of the full-bridge LLC silicon carbide (SiC) plasma power supply can be optimized.

Research limitations/implications

Due to the selected research object (plasma power supply), this study may have limited universality. The authors encourage the study of high frequency resonant converters for other applications such as argon arc welding.

Practical implications

This study provides a practical application for users to improve the quality of plasma welding.

Originality/value

The experimental results show that the full-bridge LLC silicon carbide (SiC) plasma power supply is preferred in operation under conditions of high frequency and high voltage. And its efficiency can reach 98%, making it lighter, more compact and more efficient than previous designs.

Details

Circuit World, vol. 45 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

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