International Journal of Electrical and Electronics Engineering

1-16

Authors: Oti Robinson Chibu

The objective of every electrical power producer is to meet its customers’ supply demands at a reasonable cost. Therefore plants and equipment in these stations must have availability, reliability and predictability life-cycle cost (LCC). Due to maintenance problems and poor supportive systems, Nigeria electric power generating stations are not able to meet their customers’ requirements; these are the major causes of customers’ dissatisfaction in power supply requirements. Often it is traced back to expected failures leading to unexpected losses and costs. However, with proper consideration of reliability, availability, maintainability, and supportability (RAMS) in maintenance systems decision policies, the number of failures can be reduced and their consequences minimized. Based on experiences of the industrialized countries, an approach for integration of RAMS and risks analysis in maintenance system can be developed as a guide for appropriate maintenance policies. This paper discusses the importance of failure mode effect analysis (FMEA). Failure mode effect criticality analysis (FMECA), LCC analysis, use of feedback information, supportive systems risk analysis, with the integration of various information sources to facilitate easy RAMS implementation in maintenance decision policies. This approach is suggested for implementation in Afam electric power station for the maintenance decision policies as a management control to reduce risk and uncontain costs.

31-44

Authors: Oti Robinson Chibu

The need for improved performance of the huge investment in industrial plant particularly electrical generating machinery in recent times necessitates the application of condition monitoring techniques in its maintenance. This can provide early warning of potential failure with the opportunity of organizing avoidance strategies to minimize lost in time and unexpected costs. This may greatly improve generation and production efficiency. This paper presents a methodology, which is useful in preventive maintenance (PM) and predictive maintenance (PDM) when applied to Afam Thermal Power Station in the Rivers State of Nigeria. This has lead to some proactive approach to maintenance because the action is triggered by the unscheduled event of equipment failure. With this kind of maintenance policy, the maintenance cost is high due to equipment operating under crises condition, secondary drainages and penalty associated with cost production. It shows a paradigm shift of knowing when things are starting to fail and how to prevent failure. Hence two failure perspectives are in focus-functionally and component failures. The functional perspective expresses what the component does, the component perspective shows how it deteriorates.

1-20

Authors: Omkar Rajesh Kachare

Gyroboard is a single wheeled self-balancing skateboard. It will be used as a mode of commutation with actionfilled experience. It is similar to a snowboard, surfboard, skateboard, and Marty McFly’s hoverboard all rolled into one

1-8

Authors: Duong Hung Bui, Manh Cuong Nguyen, Thi Hong Nguyen & Xuan Tho Dang

In fact, many problems with imbalanced data mean that the number of elements of a class is much larger than the number of elements of the remaining classes. This is the major reason for the declining performance of data classification. In addition, we found that in a number of imbalance datasets have many features redundant, unnecessary, not important to predict. Some reports have indicated if removing these features, it will increase the accuracy in imbalance data classification. Therefore, this paper studies, data balancing methods and reduces the number of attributes to improve the efficiency of data classification. Since then, we have developed a new method to reduce the number of feature and elements in the imbalance data classification. We experimented on some sets of biological data taken from the UCI like leukemia, colon-cancer and breast-p. These results show that our new method being more accurate classifiers with the G-mean measure compared with the method using original data. In addition, we use t-test evaluation indicated a method that the results have statistical significance with the p-value on the smaller datasets 0.05.

9-20

Authors: Rinamani Sarmah Bordoloi, Dhritikesh Chakrabarty & Manash Pratim Kasyap

Confidence intervals (of 95%, 99% & 99.73% degrees of confidence) have been determined for each of annual maximum & annual minimum of ambient air temperature at Dhubri. The determination is based on the data from 1969 onwards collected from the Regional Meteorological Centre at Tezpur. This paper describes the method of determination of them and the numerical findings on them.

1-16

Authors: Sunny K Darji, Jigar K Parmar & Gajendra R Patel

Solar energy is the major source of power. Renewable energy sources such as wind-turbine and photovoltaic power generators may make the power grid unstable due to their output fluctuations. Battery energy storage systems (BESSs) are being considered as a countermeasure for this issue. This study presents a battery storage system (BSS) based on a cascaded H-bridge inverter applied to a medium-voltage grid. The BSS is composed of eight equal series connected H-bridge converters, without bulky transformers, for connection to a distribution grid. The BSS is able to keep working even with a failure of one of its converters. Inverters of PV system based distributed generation (DG) are subjected to wide changes in the inverter input voltage, thus demanding a buck-boost operation of inverters. Further the inverter size, weight, and cost are is increased. It is designed transformer less inverter that can be operated over a wide dDCc input voltage range, making it suitable for distributed generation applications.

31-42

Authors: Chaudhari Sachin & Kaumil B. Shah

The work focuses on the photovoltaic array fed water pumping system utilizing induction motor with the model developed in PSIM. The solar panels to absorb and convert sunlight into electricity. Maximum Power Point Tracking (MPPT) is a technique used to maximize output Power from the PV and finally, a 3- phase induction motor is driven by through it. The pPhotovoltaic array is used to run an induction motor that drives the centrifugal pump. The PV array connected to induction motor where MPPT technique (p & o) and (Inc.) plays an important role that is developed in PSIM and the outputs are observed. The PV system cost for maximizinge the output of a PV system, continuously tracking the maximum power point (MPP) is necessary.

1-8

Authors: Rekha Murthy & Amulya H.G

The propitious crystal oscillator is considered as utmost important in a high speed application, since it can dispense the clock reference for the entire clock distribution system. In the proposed paper, a circuit principle is presented to realize an extremely fast ECL to CMOS logic conversion, where the possibility of generating clock frequency of 25MHz is obtained instead of a crystal oscillator. SPICE is found as a mixed use circuit analyzer that simulates electronic circuits and can perform various analysis on electronic circuits. By employing PSPICE, the analysis of the circuit has been proffered in this paper. Also, this paper describes about the significance of crystal oscillator which can be designed using emergent technology described for high speed application.