Wasiu A. Ahmed Int. Journal of Engineering Research and Applications www.ijera.com ISSN : 2248-9622, Vol. 4, Issue 7( Version 3), July 2014, pp.208-217 www.ijera.com 208|Page Reliability Analysis of a 3-Machine Power Station Using State Space Approach WasiuAkande Ahmed*, Olalekan Ogunbiyi** *(African Regional Centre for Space Science and Technology Education-English, OAU Campus, Ile Ife, Nigeria) ** (Department of Electrical and Computer Engineering, Kwara State University, Malete, Nigeria) ABSTRACT With the advent of high-integrity fault-tolerant systems, the ability to account for repairs of partially failed (but still operational) systems become increasingly important. This paper presents a systemic method of determining the reliability of a 3-machine electric power station, taking into consideration the failure rates and repair rates of the individual component (machine) that make up the system. A state-space transition process for a 3-machine with 2 3 states was developed and consequently, steady state equations were generated based on Markov mathematical modeling of the power station. Important reliability components were deduced from this analysis. This research simulation was achieved with codes written in Excel ® -VBA programming environment. System reliability using state space approach proofs to be a viable and efficient technique of reliability prediction as it is able to predict the state of the system under consideration. For the purpose of neatness and easy entry of data, Graphic User Interface (GUI) was designed. Keywords-Failure Probability, Markov model, Reliability, Repair Rate and State Space I. Introduction Energy is required for every aspect of socio- economic of modern life. It plays a vital role in the economic, social and political development of a nation [1]. It is also considered as one of the most important resources of any country. It is well known that high rate of industrial growth of any country is a function of the amount of energy available in that country and the extent to which this energy is utilized. Nigeria as a country is reach in energy resources as the country is blessed with considerable fossil fuel-based energy reserves in the form of crude oil, natural gas, and coal. In addition, it has large undeveloped amount of renewable energy resources including solar, wind and biogas [2]. Presently there are newly built independent power plant and many are under construction. Integration of these power plants into the national grid may not result into technical challenges but the reliability of each power plant will definitely be. Prediction of the failure probability of the power station systems will aid maintenance and stability of the power station. The power industry faces many problems, with one of the highest priority issues being reliability [3]. Providing reliable power delivery has always been an essential requirement in the design and maintenance of the power generation system [4]. Nevertheless, a useful technique is developed using Markov models of the generators. The assumptions of constant failure rate (Ȝ) and repair rate (µ) are desirable in order to avoid extensive mathematical complications. One of the most important features of any Markov model is that the transition probability from state i to state j depends only on states i and j and is completely independent of all earlier states [5],[6],[7],[8],[9],[10]. Markov modeling is suitable to determine the system condition and the repair intervals needed to achieve a desired level of safety. Taking a look at power supply as the prime mover of technological and social development of any nation, the reliability analysis of electric power station is a necessity. A complete generator comes with its own reliability indices and when such generators are connected in parallel, the reliability analysis of the whole power station is obtainable. A state space method of determining the reliability of a 3-machine electric power station was carried out, taking into consideration the failure rates and repair rates of the individual component (machine) that make up the system. A state-space transition process for a 3-machine with 2 3 states was developed and consequently, steady state equations were generated. Markov mathematical modeling of the power station will result into 2 3 by 2 3 transition matrix. Three machines were chosen for this research purpose, nevertheless the simulation be extended to more machines. The research was simulated using Excel ® -Visual Basic Application tools to generate the number of states, binary codes, steady state equations and then the state transition intensity matrix. Therefore, evaluating the reliability of power generating system RESEARCH ARTICLE OPEN ACCESS