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Article
Publication date: 30 September 2014

Michael J. Armstrong and Christine A.H. Ross

This article is aims to inform aircraft propulsion system designers of the implications which fundamental power distribution design assumptions have on the effectiveness…

Abstract

Purpose

This article is aims to inform aircraft propulsion system designers of the implications which fundamental power distribution design assumptions have on the effectiveness and viability of turboelectric distributed propulsion (TeDP) systems. Improvements and challenges associated with selecting alternating or direct current for normal- and superconducting distribution systems are presented. Additionally, for superconducting systems, the benefits of bi-polar DC distribution are discussed, as well as the implications of operating voltage on the mass and efficiency of TeDP grid components.

Design/methodology/approach

The approach to this paper selects several high-level fundamental configuration decisions, which must be made, and it qualitatively discusses potential implications of these decisions.

Findings

Near term TeDP architectures which employ conventionally conducting systems may benefit from alternating current (AC) distribution concepts to eliminate the mass and losses associated with power conversion. Farther term TeDP concepts which employ superconducting technologies may benefit from direct current (DC) distribution to reduce the cryocooling requirements stemming from AC conduction losses. Selecting the operating voltage for superconducting concepts requires a divergence from the present day criteria employed with terrestrial superconducting transmission systems.

Practical implications

The criteria presented in the paper will assist in the early conceptual architecting of TeDP systems.

Originality/value

The governing principles behind the configuration of multi-MW airborne electrical microgrid systems are presently immature. This paper represents a unique look and the motivating principles behind fundamental electrical configuration decisions in the context of TeDP.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 86 no. 6
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 17 March 2020

Akanksha Mishra, Nagesh Kumar G.V. and Sravana Kumar Bali

There is a worldwide need to amplify the usage of renewable energy in the manufacture of electrical energy. Thus, the integrated energy systems (IESs) have become a major…

Abstract

Purpose

There is a worldwide need to amplify the usage of renewable energy in the manufacture of electrical energy. Thus, the integrated energy systems (IESs) have become a major part of today’s power systems. Wind and solar energies are intermittent power sources and may lead to voltage and power flow instabilities. The purpose of this paper is to use the interline power flow controller (IPFC) for limiting the overloading of the transmission lines and improving the voltage stability of the IES.

Design/methodology/approach

This paper deals with an integrated system consisting of wind and solar energies and conventional systems. An appropriate position for the IPFC in the IES is proposed based on the disparity line utilization factor. The IPFC is then tuned for decreasing the loss of power and lessening the voltage deviation using the grey wolf algorithm.

Findings

The method is implemented on a modified IEEE 30-bus system. Results from the study show that the mega volt ampere (MVA) loading of the overloaded lines is reduced for the IES. Also, the voltage stability and the voltage profile of the system are improved to a major extent. The real and reactive power loss of the system is also brought down.

Originality/value

The use of renewable energy sources is a need of the present world to overcome environmental problems. This research focuses on the use of flexible AC transmission system (FACTS) devices with renewable sources incorporated in the power system. Very limited research has been done in this field. The IPFC, which is one of the most advanced FACTS device, is used for the study.

Details

World Journal of Engineering, vol. 17 no. 2
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 4 January 2011

Piotr Biczel and Marcin Koniak

The purpose of this paper is to present the simulation method of power plants and storage system capacity design.

Abstract

Purpose

The purpose of this paper is to present the simulation method of power plants and storage system capacity design.

Design/methodology/approach

Owing to solar irradiation, wind speed and water flow are highly and randomly changeable, time variation of the signals needs to be taken into consideration as well as some features of the power plants and storage system. A Matlab/Simulink model of the given system – DC microgrid has been developed. The model allows simulation of a few years static simulations of the power balance. Hence, it can be used to size the plants.

Findings

An effective method of the power system design has been developed. It allows sizing the plants taking into consideration resources and load profiles, year changes in profiles and future development of the system. The storage system can be optimized to avoid high power unbalance and power cost increasing.

Research limitations/implications

The model describes only static power behaviour of the modelled power system. It does not allow simulating local voltage changes and dynamic properties of the plants and storage.

Practical implications

This technique helps to size the plants and, first of all, storage system taking into consideration several technical and economical issues.

Originality/value

The method gives opportunity to design a storage system's capacity and power and optimize them. The authors have not found similar methods in the literature.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 9 January 2007

M.A. El‐Kady, B.A. Alaskar, A.M. Shaalan and B.M. Al‐Shammri

The purpose of this paper is to present a practical method for computing contingency‐based reliability and quality indices in power systems and to answer questions related…

Abstract

Purpose

The purpose of this paper is to present a practical method for computing contingency‐based reliability and quality indices in power systems and to answer questions related to how much the system is reliable, how robust it is in surviving random contingencies, how much it is costing to maintain appropriate system security and reliability levels and, finally, to what extent the desired balance is maintained between generation facilities, transmission capabilities and consumer demand levels in various zones of the electric power system.

Design/methodology/approach

The methodology adopted in this paper is based on a combined contingency analysis/reliability evaluation scheme. A three‐component system model is utilized, which can be used effectively for evaluation and sensitivity analysis of reliability and quality in power systems. The model is a reduced (equivalent) system representation that comprises generation, transmission and load components with multi‐state values. The computational scheme presented in the paper integrates both the contingency effect and its probability of occurrence into one routine of analysis while reducing the power system around the region of interest.

Findings

The computational scheme presented in the paper can effectively assess both service reliability and system quality. The practical applications presented demonstrated that lower service reliability levels would jeopardize energy supply continuity and increase the likelihood of additional maintenance and restoration costs due to the resulting higher rate of system outages. Poor system quality levels, on the other hand, imply either deficiency or excess in the overall system capabilities as designed by its planners.

Originality/value

The work of this paper contributes to the solution of the reliability and quality assessment problem in practical power systems. As part of the present work, an advanced computerized scheme for fast composite system reliability and quality assessment was developed and then applied to an equivalent system model of the Saudi electricity system. The results obtained are claimed to have far‐reaching implications on various planning and operation aspects of the power system.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 26 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 10 June 2021

Sinan Keiyinci and Kadir Aydin

The endurance of small unmanned air vehicles (UAVs) is directly associated with the energy density of the propulsion system used. As the batteries commonly used in small…

Abstract

Purpose

The endurance of small unmanned air vehicles (UAVs) is directly associated with the energy density of the propulsion system used. As the batteries commonly used in small UAVs have a relatively low energy density, they are not sufficient for long-term endurance tasks. The purpose of this paper is to offer a solution to increase the endurance of a concept small UAV with combination of different power sources. The design, construction and ground tests of fuel cell-powered hybrid propulsion systems are presented in this paper.

Design/methodology/approach

The power requirements of a concept UAV were calculated according to aerodynamic calculations and then, hybrid propulsion system sources are determined. The hybrid system consists of a 100 W scale proton-exchange membrane (PEM) type fuel cell stack, lithium-polymer battery, solar cells and power management system (PMS). Subsequently, this hybrid power system was integrated with the new design of PMS and then series of ground tests were carried out.

Findings

This experimental study proved that it is theoretically possible to obtain an endurance of around 3 h for concept UAV with the proposed hybrid system.

Practical implications

The research study shows that fuel cell-based hybrid propulsion system with the proposed PMS can be widely used to obtain extended endurance in small UAVs.

Originality/value

A hybrid propulsion system with a novel PMS unit is proposed for small UAVs and the ground tests were implemented.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 5
Type: Research Article
ISSN: 1748-8842

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Book part
Publication date: 16 August 2005

Paul V. Martorana, Adam D. Galinsky and Hayagreeva Rao

When will individuals accept or reject systems that subordinate them, when will they take actions that will challenge these status hierarchies, and when will such…

Abstract

When will individuals accept or reject systems that subordinate them, when will they take actions that will challenge these status hierarchies, and when will such challenges be more intense, overt, and non-normative? Research suggests that individuals often justify and maintain systems that subordinate them, yet we suggest that there are certain boundary conditions that predict when individuals will no longer accept their place in such systems. We propose a model that examines how multiple factors: A sense of power, emotions associated with power, and perceptions of the system's legitimacy and stability – predict when those in low power will act against authority or when they will act to justify and maintain such systems. We also suggest that the level and type of action taken against a hierarchy changes as more of the elements (i.e., sense of power, emotions, perceptions of the status hierarchy) of our model are present. We predict that the actions taken against hierarchies become more overt and non-normative as more of these factors are present.

Details

Status and Groups
Type: Book
ISBN: 978-1-84950-358-7

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Article
Publication date: 4 January 2019

Anna Maria Mazur and Roman Domanski

The presented research is carried out in reaction to the soaring costs of fuel and tight control over environmental issues such as carbon dioxide emissions and noise. The…

Abstract

Purpose

The presented research is carried out in reaction to the soaring costs of fuel and tight control over environmental issues such as carbon dioxide emissions and noise. The purpose of this paper is to study the feasibility of applying the environmental-friendly energy source in an unmanned aerial vehicles (UAVs) propulsion system.

Design/methodology/approach

Currently, the majority of UAVs are still powered by conventional combustion engines. An electric propulsion system is most commonly found in civilian micro and mini UAVs. The UAV classification is reviewed in this study. This paper focuses mainly on application of electric propulsion systems in UAVs. Investigated hybrid energy systems consist of fuel cells, Li-ion batteries, super-capacitors and photovoltaic (PV) modules. Current applications of fuel cell systems in UAVs are also presented.

Findings

The conducted research shows that hybridization allows for better energy management and operation of every energy source onboard the UAV within its limits. The hybrid energy system design should be created to maximize system efficiency without compromising the performance of the aircraft.

Practical implications

The presented study highlights the reduction of the energy consumption, necessary to perform the mission and maximizing of the endurance with simultaneous decrease in emissions and noise level.

Originality/value

The conducted research studies the feasibility of implementing the environmental-friendly hybrid electric propulsion systems in UAVs that offers high efficiency, reliability, controllability, lack of thermal and noise signature, thus, providing quiet and clean drive with low vibration levels. This paper highlights the main challenges and current research on fuel cell in aviation and draws attention to fuel cell – electric system modeling, hybridization and energy management.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 5
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 4 January 2011

Grzegorz Iwanski

Wind‐diesel sets offered as a reliable hybrid isolated power systems with reduction of fuel consumption, consists of variable speed wind turbines and fixed speed diesel…

Abstract

Purpose

Wind‐diesel sets offered as a reliable hybrid isolated power systems with reduction of fuel consumption, consists of variable speed wind turbines and fixed speed diesel engines. Load and wind energy variations cause, that the load power of the diesel genset is varied in wide range. Fixed speed generation set operates with the best efficiency only in a narrow range of the load, therefore implementation of a load adaptive, adjustable speed genset may additionally reduce fuel consumption.

Design/methodology/approach

Analysis of the system components model, simulation and laboratory tests on a small‐scale model.

Findings

Topology and output voltage control method of four‐wire adjustable speed autonomous wind‐diesel system dedicated for isolated power plants with high wind penetration.

Research limitations/implications

The paper presents only part of the work which has to be done for the complete system. Load and energy management has to be applied in standalone system, as not in each operating point of proposed wind‐diesel system, can rated load be supplied. To fully prove the proposed system and control concept, tests of megawatt range system are advisable. To evaluate the fuel saving, a real wind and load profile in a selected isolated place is needed.

Practical implications

Every adjustable speed generation systems can save fuel. However, proposed topology in main part consists of known and implemented solutions, therefore costs of the new installation will not be increased significantly.

Originality/value

Proposed costs effective topology of adjustable speed wind‐diesel generation system has not been presented by any other authors. Standalone operation of doubly fed induction generator system is rarely reported in the papers.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 21 November 2018

Deepak Kumar, Yajvender Pal Verma and Rintu Khanna

Technological development has not only helped in effective integration of renewable sources but also made it possible for consumers to participate in system operation…

Abstract

Purpose

Technological development has not only helped in effective integration of renewable sources but also made it possible for consumers to participate in system operation. Different market players are coming up in the electricity market, microgrid being one of them. Thus, this paper aims to investigate consumers’ role in the dispatch of a microgrid system that has a hybrid market structure under varied system conditions.

Design/methodology/approach

The mathematical model developed has been solved by the CONOPT solver in the GAMS optimization tool. GAMS-MATLAB interfacing is done to obtain solutions.

Findings

The problem formulated shows the effect of consumers in dispatch and overall operational cost. Consumers’ participation has been proposed through a quadratic cost function. The system operation under pool and bilateral contracts has been investigated. It shows that proper incentives to the consumers can help in reduction and effective management of the demand, carbon emission and overall system operational cost.

Originality/value

This paper considers the hybrid market structure to find the load dispatch in a microgrid system. The participation of consumers in the microgrid system has been implemented considering variations in wind power, solar power and load. The power exchange between the grid and microgrid system has been modeled showing the contribution of the consumers in system operation.

Details

International Journal of Energy Sector Management, vol. 13 no. 2
Type: Research Article
ISSN: 1750-6220

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Article
Publication date: 13 March 2017

Ahmad Sarani Ali Abadi and Saeed Balochian

The purpose of this paper is to address the problem of control in a typical chaotic power system. Chaotic oscillations cannot only extremely endanger the stabilization of…

Abstract

Purpose

The purpose of this paper is to address the problem of control in a typical chaotic power system. Chaotic oscillations cannot only extremely endanger the stabilization of the power system but they can also not be controlled by adding the traditional controllers. So, the sliding mode control based on a fuzzy supervisor can sufficiently ensure perfect tracking and controlling in the presence of uncertainties. Closed-loop stability is proved using the Lyapunov stability theory. The simulation results show the effectiveness of the proposed method in damping chaotic oscillations of the power system, eliminating control signal chattering and also show less control effort in comparison with the methods considered in previous literatures.

Design/methodology/approach

The sliding mode control based on a fuzzy supervisor can sufficiently ensure perfect tracking and controlling in the presence of uncertainties. Closed-loop stability is proved using the Lyapunov stability theory.

Findings

Closed-loop stability is proved using the Lyapunov stability theory. The simulation results show the effectiveness of the proposed method in damping chaotic oscillations of power system, eliminating control signal chattering and also less control effort in comparison with the methods considered in previous literatures.

Originality/value

Main contributions of the paper are as follows: the chaotic behavior of power systems with two uncertainty parameters and tracking reference signal for the control of generator angle and the controller signal are discussed; designing sliding mode control based on a fuzzy supervisor in order to practically implement for the first time; while the generator speed is constant, the proposed controller will enable the power system to go in any desired trajectory for generator angle at first time; stability of the closed-loop sliding mode control based on the fuzzy supervisor system is proved using the Lyapunov stability theory; simulation of the proposed controller shows that the chattering is low control signal.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 10 no. 1
Type: Research Article
ISSN: 1756-378X

Keywords

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