Critical Review of Reliability Centred Maintenance (RCM) for Asset Management in Electric Power Distribution System

The purpose of maintenance is to extend equipment lifetime or at least the mean time to the next failure. Maintenance too incurs expenditures that result in very costly consequences when not performed or performed too little, and it may not even be economical to perform it too frequently. Therefore the two costs must be balanced. In the past, this balance had been estimated by extrapolating the experience obtained from existing systems and using the rule - of – thumb methods. Nowadays, the tempo of advanced and softiscated research in that direction has rendered such rule – of – thumb methods obsolete. The literature works describing the reliability centred maintenance methods for managing distribution assets have grown until the papers can now be numbered in thousands. This paper presents critical review of the various existing methods that have been developed by different reseachers and proposes a probabilistic model that will provide a quantitative connection between reliability and maintenance, a link missing in all the heuristic approaches

Development of a research project repository

The advances of technology resulting in the proliferation of mobile devices have changed the way we live and have necessitated the restructuring of the educational system. This can be employed to aid student’s participation in research studies. This study aims at promoting- research in universities amongst students by giving them the opportunity to exercise their scholarly abilities, easy access to research projects carried out by other students, collaboration with other students with similar research inclinations as well as gain visibility before the school management or companies interested in granting scholarships to outstanding works. This project is implemented using JavaScript, HTML and CSS for the front-end; Node.js, a JavaScript framework for the back-end and MongoDB for the database. It is a web application that enables the students to upload their research works, view the research of others and collaborate with peers. This system has a high potential to enhance student participation in universities’ research studies

Modeling Distribution Component Deterioration: An application to Transformer Insulation.

The two most critical components in a typical Power System are the circuit breakers and transformers. Failure of any of these components will result in high cost due to component replacement and associated load loss. Reliability Centred Maintenance (RCM) may reduce this cost in the long run by extending the component lifetime and increasing availability. This will be possible, since the adopted RCM will balance carrying out too much maintenance which will increase maintenance cost or too little maintenance that will result in catastrophic failure and hence increases the cost of maintenance and repair. A Markov model that relates probability of failure to maintenance activity is developed for distribution transformers. This model incorporates various levels of insulation deterioration and minor maintenance state. It was applied to one of the distribution transformers in Abule-Egba Business unit network of Power Holding Company of Nigeria. The result obtained from model simulation agrees with the one obtained from the mathematical analysis of the developed model. With an adjustment in the inspection parameter, this probabilistic deterioration model for a distribution transformer can also be applied to predict the performance of circuit breakers

Reliability Analysis of Circuit Breakerin the Nigerian 330-kV Transmission Network.

This paper is concerned with using the fault analysis to establish the requirements for the proper selection of circuit breaker; A Case Study of Power Holding company of Nigeria (PHCN) 330-kV Transmission Grid System. The work is modelled for Fault Analysis and it is written in a flexible MATLAB programs to accommodate addition or reduction in the Transmission Grid System. It aimed at establishing the Circuit Breaker Capacity at any point in the system. The result is then compared with the existing circuit breaker capacity of PHCN 330-kV system. The short-circuit fault is simulated by combining a solution of algebraic equations describing the changes in the network with a numerical solution of the differential equations. Two MATLAB programs were written and simulated; one for Lord Flow study to know the pre-fault bus voltages based on Gauss-Seidel Method; the other for Short Circuit Studies which made use of Thevenin’s theorem application. The highest Circuit Breaker Capacity established by the result of this study is relatively lower and the investments needed for this are smaller compared with the normal practice with PHCN system. This reveals that PHCN system can be protected with this low capacity circuit breaker with a reduced cost effectiveness and equal sensitivity which is a break-through in terms of Circuit Breaker Capacity in the field of power system protection

On The Cost Implications of Technical Energy Losses on Nigerian 330-kV Transmission Grid System

Base on the author’s result of power line losses obtained for low, medium and high current levels as 146.73MW, 322.24MW and 738.28MW respectively, in his bid to evaluate the power line losses using symmetrical component theory of unbalanced fault, the annual energy (MWH) losses for year 2013 was calculated and validated in this study. The annual technical energy losses due to the low, medium and high power losses were respectively found to be 443.45GWH, 976.895GWH and 2231.230GWHbased on Load Factor and Load Loss Factor amounting to N8.4 billion, N18.6 billion and N42.4 billion respectively. The low power loss (steady-state) result of this work was validated by the result of load-flow obtained using the MATLAB and Power Word Simulator (PWS) while the annual MWH for the high power loss level compares favourably well with the normal practice of utility operator’s monthly energy balance thereby closing the gap between the practical information and the theoretical one

On The Cost Implications of Technical Energy Losses on Nigerian 330-kV Transmission Grid System

Base on the author’s result of power line losses obtained for low, medium and high current levels as 146.73MW, 322.24MW and 738.28MW respectively, in his bid to evaluate the power line losses using symmetrical component theory of unbalanced fault, the annual energy (MWH) losses for year 2013 was calculated and validated in this study. The annual technical energy losses due to the low, medium and high power losses were respectively found to be 443.45GWH, 976.895GWH and 2231.230GWHbased on Load Factor and Load Loss Factor amounting to N8.4 billion, N18.6 billion and N42.4 billion respectively. The low power loss (steady-state) result of this work was validated by the result of load-flow obtained using the MATLAB and Power Word Simulator (PWS) while the annual MWH for the high power loss level compares favourably well with the normal practice of utility operator’s monthly energy balance thereby closing the gap between the practical information and the theoretical one

A Probabilistic modeling of distribution equipment Deterioration; An application to transformer insulation.

In this paper, a probabilistic maintenance model relating probability of failure to maintenance activity had been developed for maintainable distribution components. This model incorporates various levels of insulation deterioration and minor maintenance state. It was applied to a distribution transformers ranging from 300 kVA to 15 MVA in Abule-Egba Business Unit network of Power Holding Company of Nigeria. The result obtained from the application study and model simulation verified the mathematical analysis of the developed model. Although this application illustrates the development of a probabilistic deterioration model for a distribution transformer, it can be applied to predict the performance of other distribution components in the electric power system network

A Markov model for estimating the remaining life of electrical insulation in distribution transformer

In this paper, a Markov maintenance model for predicting the rema1n1ng life of transformer insulation has been developed. It incorporates various stages of insulation deterioration and minor maintenance state. Given that a current state of insulation ageing has been reached, from a diagnostic testing and inspection, this model is capable of computing the predicted average time before insulation failure occurs. The algorithm developed in this model was implemented in a computer program using Matlab. The data required for this program and the numerical example based on the developed algorithm are also discusse

Development of a Programmable Mobile Robot

In the world today, self-driving cars have proven to be a very interesting concept. The concept of self-driving cars was exploded in 2004 during the DARPA Grand Challenge competition where fully autonomous vehicles competed against each other on a desert course. The Stanford University's STANLEY was the winner of this competition. Ever since then there have been Junior by Stanford University, the Google self-driving cars, the European City Mobile Project among others. The necessary kinematic equations and algorithms for this mobile robot are obtained to ensure mobility and maneuverability of the robot. An Arduino-based controller circuit is built to implement the necessary algorithms, and servomotors are used to carry out independent wheel motion of the mobile robot. The obstacles are identified by means of tactile sensors; different shades of light are observed and in turn the zero normalized differential shade is calculated by means of the Phototransistors. The Infrared (IR) Sensors are needed to enable manual remote control escape in difficult terrains all of which make for a programmable mobile robot