Carpathian Journal of Electrical Engineering

7-16

Authors: Emmanuel Asuming FRIMPONG, Elvis TWUMASI

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.

30-44

Authors: Nabil TALBI , Abderrezak METATLA , Toufik SEBBAGH , NadirBOUTASSETA, Mohamed HASSAN

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.

61-76

Authors: Francis Boafo EFFAH, Philip OKYERE, Mubarak Sani ELLIS, Patrick WHEELER, Alan WATSON,Jon CLARE, Joseph OJO

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.