Volume 13, number 1, 2019. Print version and published papers:
Emmanuel Asuming FRIMPONG, Elvis TWUMASI, Department of Electrical and Electronic Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana, firstname.lastname@example.org, email@example.com
Keywords: energy conservation, energy efficiency, energy wastage
Abstract: Awareness of demand-side management practices among staff of educational institutions is critical for energy savings. This paper presents the results of a survey to determine the extent to which staff of the Kwame Nkrumah University of Science and Technology are aware of measures for energy efficiency and also assess their preparedness to support efforts towards reducing energy wastage. Questionnaires were administered to Senior members, Senior staff and Junior staff of the institution. The questionnaires were designed to collect data on their level of energy efficiency awareness in the use of refrigerators, airconditioners, light bulbs and electronic devices. The extent to which staff are engaged in energy saving activities and their preparedness to get involved in energy saving activities were also determined. The analysis of the collected data was done using the Statistical Package for Social Sciences (SPSS) software. Analysis of responses received show that more than seventy-seven percent of staff are ignorant of the fact that keeping refrigerators close to walls resulted in energy wastage. About fifty-seven percent of them are aware of the fact that when airconditioners are not cleaned regularly, much energy is wasted. Almost eighty-five percent of staff indicated awareness of the fact that keeping electronic devices on standby for long periods could be a source of significant energy wastage. Over eighty-three percent of staff indicated that they had been switching light bulbs off when there is adequate illumination from the sun so as to conserve energy. About thirty-six percent of staff are already engaged in at least one form of energy conservation. Lastly, over 94% of them expressed willingness to take part in energy saving activities.
Francis EFFAH1, Philip OKYERE1, Patrick WHEELER2, Alan WATSON2 , Jon CLARE2, 1 Kwame Nkrumah University of Scince and Technology, Kumasi, Ghana, 2University of Nottingham, Nottingham, UK, firstname.lastname@example.org
Keywords: buck-boost, single-stage, neutral point clamped, space vector modulation
Abstract: An optimized space vector modulation technique for controlling a quasi Z-source NPC inverter for solar photovoltaic application is presented in this paper. The presented algorithm optimizes the number of switching transitions over a switching cycle by modifying the placement of the shoot-through states in some of the sub-triangles of the space vector diagram of a conventional neutral point clamped inverter. This approach leads to a reduction in the total losses of the quasi Z-source inverter by reducing the switching losses. The presented concepts are expected to be cheaper than existing methods because a reduction in losses will lead to the use of smaller and cheaper heat sinks in practical implementation. In this paper, the effectiveness of the proposed optimized space vector modulation technique has been demonstrated through simulations in SABER®.
Nabil TALBI1 , Abderrezak METATLA1 , Toufik SEBBAGH1 , NadirBOUTASSETA2, Mohamed HASSAN2, 1Department of Mechanical Engineering, Faculty of Technology, Université 20 août 1955 Skikda BP 26 Road of El hadaiek, Skikda, Algeria, 2Research Center in Industrial Technologies CRTI, P.O.Box 64, Cheraga, Algeria, n.talbi@ univ-skikda.dz, a.metatla@ univ-skikda.dz, t.sebbagh@ univ-skikda.dz, email@example.com, firstname.lastname@example.org Research Center in Industrial Technologies CRTI, P.O.Box 64, Cheraga, Algeria, n.talbi@ univ-skikda.dz, a.metatla@ univ-skikda.dz, t.sebbagh@ univ-skikda.dz, email@example.com, firstname.lastname@example.org
Keywords: fault diagnosis, ANFIS, parameter extraction, induction motor, fault classification
Abstract: In this paper, we developed a robust technique for fault classification in the induction motor, which was used by the Adaptive Network Reference Information System (ANFIS). A robustness and precision test of the proposed method was performed on a small database. To speed up the response and minimize the calculation time, the most sensitive indicators have been used to ensure the learning of the classifier. The database used was carried out at the University of Case Western, this database has two modes of healthy operation and with rolling defects located side coupling. The objective of the technique used in this paper is to extract the indicators and to test them to select the most sensitive to the apparition of defects. The obtained results show the effectiveness and sensitivity of the proposed approach to identify the nature of the defect even at the birth stage.
Amina GABOUR, Samia BENZAHIOUL, Abbderrezak METATLA, Toufik SEBBAGH, LGMM Laboratory, Université 20 Aout 1955 – Skikda, Algeria, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org
Keywords: multi-source system, optimization, control, GA
Abstract:The aim of this paper is to design the sizing and optimization of multi-source system PV/Diesel/Battery, whereat the power management algorithm is applied to feed load in Algeria where the GA method is used to find the best configuration of the system and for sizing purpose of the components, based on the minimum total cost of the system (STC) subject to renewable energy fraction (FR).Thus, the results show the impact of RF on the STC in addition to the choice of the best configuration and the most adequate one.
Francis Boafo EFFAH1, Philip OKYERE1, Mubarak Sani ELLIS1, Patrick WHEELER2, Alan WATSON2,Jon CLARE2, Joseph OJO3, 1Kwame Nkrumah University of Science and Technology, Kumasi, Ghana, 2University of Nottingham, UK, 3Tennessee Technological University Cookeville, USA. email@example.com
Keywords: series Z-source, cascaded Z-source, partial shoot-through, virtual space vector modulation
Abstract: In previous articles, the concept of series Z-source network has been extended to conventional indirect matrix converter to raise the voltage gain to unity and beyond. In this paper, this idea is modified and applied to a three-level indirect matrix converter. Two series Z-source networks are placed on the virtual dc-link between a rectifier and a neutral point clamped inverter on the positive and negative dc rails. Partial shoot-through states are used for voltage boosting. The series Z-source capacitor voltages and starting current stresses are reduced. A virtual space vector PWM method has been developed to ensure voltage boost ability of the converter. Simulation results from SABER are used to demonstrate the superiority of the proposed converter over the existing topology.
Mihaela ȘTEȚ, Technical University of Cluj-Napoca, Romania, Mihaela.Stet@cunbm.utcluj.ro
Keywords: regulations, electromagnetic exposure, standards, radiofrequency
Abstract: Identification of risks and potential effects of exposure to electromagnetic fields has aroused the interest of researchers in various fields to reduce or even eliminate them. However, the problems they raise, also, determined the need to regulate the exposure limits, thus establishing a series of regulations at the level of different states, of some national and international standards. The paper presents a comparative analysis of several national and international regulations regarding the exposure limits for the general public and for different working environments.