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Article
Publication date: 19 June 2017

Yanhang Zhao, Jingang Wang, Shoupeng Ban, Xueqi Hu and Diancheng Si

The purpose of this paper is to design a current transformer model based on the principle of B-dot. It can reflect the change of transmission line current and meet the…

Abstract

Purpose

The purpose of this paper is to design a current transformer model based on the principle of B-dot. It can reflect the change of transmission line current and meet the requirement of automation and intelligence for current measurement in power system.

Design/methodology/approach

In this paper, a new type of current transformer is designed on the principle of B-dot, which has the structure of the inverse series of planar air core coils and the form of printed circuit board (PCB). With this structure, the current transformers can induce magnetic field quite well. The finite element simulation for the current transformer with n layers structure is conducted in the Maxwell, which help to optimize the design of the current transformer.

Findings

By setting up the experimental platform, the experiment of the current transformer is carried out. The results of the test show that the measurement accuracy can satisfy the requirement of measurement. Besides, the new current transformer has good transient characteristics and can meet the needs of the development of smart grid.

Originality value

The new type of current transformer is based on the principle of B-dot, which is designed with a new type of non-contact PCB hollow coil current transformer. It has no iron core, no ferromagnetic effect and the phenomenon of ferromagnetic resonance. It has great progress in its insulation performance, volume and bandwidth response. In addition, the planar hollow coil of the inverse series structure can make the structure more accurate.

Details

Sensor Review, vol. 37 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 1 April 1995

Terence J. Wieting, Tim D. Andreadis, John M. Kidd, Wayne Quade, Arthur I. Namenson, Louis F. Libello, Christian D. Schleisiger and Chalmers M. Butler

The behaviours of the electric and magnetic fields inside a conducting cylinder with a single axial aperture are not as well understood as is commonly believed. The…

Abstract

The behaviours of the electric and magnetic fields inside a conducting cylinder with a single axial aperture are not as well understood as is commonly believed. The experimental measurements and computer simulations described in this paper comprise a work in progress. The intention of the work is to use the conducting cylinder with a single axial aperture as a standard test object, in order to demonstrate present capabilities in measuring field strengths inside such a test object and to demonstrate the level of agreement attainable with commonly used computer codes. As the following experimental data will show, current free‐field B‐dot sensors cannot be used for measurements inside cavities, as they significantly perturb the fields they are trying to measure. There is indeed a pressing need to develop such nonperturbing sensors for use inside cavities.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 14 no. 4
Type: Research Article
ISSN: 0332-1649

Article
Publication date: 30 August 2013

Jin Jin, Hexi Baoyin and Junfeng Li

The purpose of this paper is to propose an attitude determination and control scheme for a low‐cost Micro‐satellite with defective inertia. Restricted by the payload…

Abstract

Purpose

The purpose of this paper is to propose an attitude determination and control scheme for a low‐cost Micro‐satellite with defective inertia. Restricted by the payload design, the z‐axis inertia of this satellite is larger than the x and y axes, which is unstable for natural attitude dynamics.

Design/methodology/approach

An original operation mode is designed to avoid z axis from long‐time pointing to the sun during damping, which avoids some unexpected damage. In attitude determination design, EKF and UKF algorithms are compared on estimation accuracy, convergence time and computation complexity in attitude estimation design, which is referred to determine the final estimation scheme. A DSP‐based hardware solution is achieved and a semi‐physical testing and simulation system is built.

Findings

Simulation results show the 3‐axis stable mode can be built with the proposed scheme, and the unprotected facet of the satellite can be kept away from long‐time pointing to the sun.

Originality/value

The proposed ADCS scheme can be a reference for the future Micro‐satellite programs which share the similar configuration.

Details

Aircraft Engineering and Aerospace Technology, vol. 85 no. 5
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 11 July 2008

S. Alfonzetti, G. Aiello, E. Dilettoso and N. Salerno

This paper aims to discuss various numerical implementations of the integral equation in the hybrid finite element method‐Dirichlet boundary condition iteration (FEM‐DBCI…

Abstract

Purpose

This paper aims to discuss various numerical implementations of the integral equation in the hybrid finite element method‐Dirichlet boundary condition iteration (FEM‐DBCI) method for the numerical solution of unbounded static and quasi‐static electromagnetic field problems.

Design/methodology/approach

Three numerical implementations are described and compared from the point of view of accuracy and complexity, by means of two examples regarding simple electrostatic problems.

Findings

The implementation by means of a pair of integration surfaces made of element sides leads to accuracy levels which are much better than that of a single surface (made of element sides) and only a little worse than that of a single surface connecting point in the middle of finite element sides.

Practical implications

The former implementations, however, are simpler since they are practically the same as that of a standard boundary element method integral equation.

Originality/value

The paper constitutes a useful guide to the implementation of the FEM‐DBCI method.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 27 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 5 July 2011

Takaya Inamori, Nobutada Sako and Shinichi Nakasuka

This paper aims to present an attitude determination and control system for a nano‐astrometry satellite which requires precise angular rate control. Focus of the research…

Abstract

Purpose

This paper aims to present an attitude determination and control system for a nano‐astrometry satellite which requires precise angular rate control. Focus of the research is methods to achieve the requirement.

Design/methodology/approach

In order to obtain astrometry data, the satellite attitude should be controlled to an accuracy of 0.05°. Furthermore, attitude spin rate must be controlled to an accuracy of 4×10−7 rad/s during observation. In this paper the following unique ideas to achieve these requirements are introduced: magnetic disturbance compensation and rate estimation using star blurred images.

Findings

This paper presents the feasibility of a high accurate attitude control system in nano‐ and micro‐satellite missions.

Practical implications

This paper presents a possibility of the application of nano‐satellites to remote‐sensing and astronomy mission, which requires accurate attitude control.

Originality/value

Originalities of the paper are the methods to achieve the high accurate attitude control: magnetic disturbance compensation and angular rate estimation using star images.

Details

Aircraft Engineering and Aerospace Technology, vol. 83 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 4 January 2008

Jérôme Lucas, Stéphane Holé and Christophe Bâtis

The purpose of this paper is to introduce a rapid method for calculating capacitive sensor signal variations for any small permittivity or electrode modifications at any…

1127

Abstract

Purpose

The purpose of this paper is to introduce a rapid method for calculating capacitive sensor signal variations for any small permittivity or electrode modifications at any position in space.

Design/methodology/approach

When a capacitive sensor is probing its surrounding, the modification of the permittivity, the displacement or the deformation of one or more electrodes induce a signal variation which depends on the position of the modification. Seeing that modification as a small perturbation and using Gauss identity, it is possible to find integral expressions of the sensor sensitivity map.

Findings

Capacitive sensor sensitivity map expressions depend only on the perturbation to measure, on the electric field before the perturbation, and on a sensitivity field which is the electric field produced by the sensor when the measuring electrode is held to 1 V while the others, except the floating ones, are grounded. The sensitivity field is a kind of Green's function for the capacitive sensor. The knowledge of the electric and sensitivity fields makes it possible to obtain the whole sensor sensitivity map at once without requiring time consuming parametric calculations.

Originality/value

The sensitivity field calculation provides a simple and direct view of the capacitive sensor capabilities. That should improve capacitive sensor design.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 27 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 13 July 2010

Sanjay Jayaram

Recent advances in nano and picosatellite missions and future such missions require three axis attitude control system hardware for attitude control purposes. A simple…

Abstract

Purpose

Recent advances in nano and picosatellite missions and future such missions require three axis attitude control system hardware for attitude control purposes. A simple, cost effective, yet an efficient devise that is used for active attitude control is magnetic torquer coil. The purpose of this paper is to describe the design and fabrication of a template to manufacture magnetic torquer coils of varying sizes and shapes.

Design/methodology/approach

Details about the development of the template design, analysis, and fabrication are discussed. The development status of the system is outlined and the working prototype of the device is described and some preliminary test results are given.

Findings

A fully functional prototype of the template has been developed and testing has been conducted that demonstrated the effectiveness of the device. Magnetic torquer coils of varying sizes were fabricated and tested. A finite element analysis was performed by modeling the characteristics of the fabricated coils to determine thermally induced stresses and deformations during its space operations.

Practical implications

The paper illustrates and demonstrates an effective application of torquer coil template in the satellite fabrication industry. The benefits from the approach are generally applicable to any future university and industry missions using picosatellite technology.

Originality/value

The designed template satisfied all the constraints and requirements. Furthermore, its advantages include scalability, modularity, and its capability to fabricate magnetic torquer coils of varying sizes and shapes.

Details

Journal of Engineering, Design and Technology, vol. 8 no. 2
Type: Research Article
ISSN: 1726-0531

Keywords

Book part
Publication date: 29 January 2018

Huat Bin (Andy) Ang and Arch G. Woodside

This study applies asymmetric rather than conventional symmetric analysis to advance theory in occupational psychology. The study applies systematic case-based analyses to…

Abstract

This study applies asymmetric rather than conventional symmetric analysis to advance theory in occupational psychology. The study applies systematic case-based analyses to model complex relations among conditions (i.e., configurations of high and low scores for variables) in terms of set memberships of managers. The study uses Boolean algebra to identify configurations (i.e., recipes) reflecting complex conditions sufficient for the occurrence of outcomes of interest (e.g., high versus low financial job stress, job strain, and job satisfaction). The study applies complexity theory tenets to offer a nuanced perspective concerning the occurrence of contrarian cases – for example, in identifying different cases (e.g., managers) with high membership scores in a variable (e.g., core self-evaluation) who have low job satisfaction scores and when different cases with low membership scores in the same variable have high job satisfaction. In a large-scale empirical study of managers (n = 928) in four (contextual) segments of the farm industry in New Zealand, this study tests the fit and predictive validities of set membership configurations for simple and complex antecedent conditions that indicate high/low core self-evaluations, job stress, and high/low job satisfaction. The findings support the conclusion that complexity theory in combination with configural analysis offers useful insights for explaining nuances in the causes and outcomes to high stress as well as low stress among farm managers. Some findings support and some are contrary to symmetric relationship findings (i.e., highly significant correlations that support main effect hypotheses).

Details

Improving the Marriage of Modeling and Theory for Accurate Forecasts of Outcomes
Type: Book
ISBN: 978-1-78635-122-7

Keywords

Book part
Publication date: 6 August 2014

Darren Prokop

This chapter examines the unique regulatory environment that trans-border air carriers work within. Using a U.S. perspective the concept of the bilateral air agreement is…

Abstract

This chapter examines the unique regulatory environment that trans-border air carriers work within. Using a U.S. perspective the concept of the bilateral air agreement is outlined and discussed. These agreements form the basis for how two countries decide to share their airspaces among their air carriers. The trend has been toward more liberal approaches. To explain this trend the concepts of the Freedoms of the Air and Open Skies are discussed. Other liberalization programs are also discussed; specifically, co-terminalization and cabotage. Finally, the air cargo transfer operations at Ted Stevens Anchorage International Airport are used as an example to highlight a rare example of unilateral liberalization on the part of the United States.

Details

The Economics of International Airline Transport
Type: Book
ISBN: 978-1-78350-639-2

Keywords

Article
Publication date: 12 September 2017

Rajesh Kumar Sinha and Atanu Adhikari

This paper aims to investigate the influence of advertised reference price (ARP) and sales price (SP) as anchor points on the latitude of expected price, and subsequently…

1551

Abstract

Purpose

This paper aims to investigate the influence of advertised reference price (ARP) and sales price (SP) as anchor points on the latitude of expected price, and subsequently on purchase intention (PI). The research involves the theoretical lens of selective anchoring mechanism, which allows investigation of the influence of ARP and SP in a situation where price estimation task is a “non-thoughtful processes”.

Design/methodology/approach

On the basis of quasi-experimental design, the study involves intercept survey of 142 shoppers.

Findings

The study finds that due to anchoring effect, the highest and the lowest expected prices shift toward ARP and SP, respectively. Consequently, it influences the latitude of expected price, which in turn influences purchase intention. In addition, the study proposes and tests a method to forecast expansion and contraction of the latitude of expected price.

Research limitations/implications

It suggests a new mechanism to understand the simultaneous influence of ARP and SP, provides a mechanism to understand shifts in price latitude’s end-points and investigates a phenomenon with two externally provided anchors.

Practical implications

The study highlights the role of the latitude of expected price in understanding consumers’ response. Results suggest that a plausible ARP, when joined with an above-expectation SP, can fetch better consumer responses.

Originality/value

The study uniquely investigates a problem with two anchor points and two estimation targets, and proposes a construct of internal price uncertainty (IPU).

Details

European Journal of Marketing, vol. 51 no. 9/10
Type: Research Article
ISSN: 0309-0566

Keywords

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