**7.3 Reliability evaluation**

The database thus created allows moving on to the operations of estimation and graphical representation of the reliability of the system or of the studied component, based on data from historical events until that date presented in Figures 17, 18, 19, 20 (Dulau et al., 2007), (Dulau et al., 2010).

The numerical values associated data are saved in specific files of Matlab environment, respectively matrix or vectors.

All vectors are initialized and any subsequent call will add new data to existing ones and will save the new content.

#### Fig. 17. RCM interface

108 Electrical Generation and Distribution Systems and Power Quality Disturbances

Example: by selecting an OEL 20 KV, from the user interface, we obtain the technical and economical parameters of the OEL in a window. Further on, one is required to select the type of interruption to complete the database, corresponding to corrective maintenance or

For each of the two possible directions, one must access the database for OEL and/or OEL component and fill in with technical and economic data corresponding to the type of

Fig. 16. Interface for the database with the history of incidents and their update

The database thus created allows moving on to the operations of estimation and graphical representation of the reliability of the system or of the studied component, based on data from historical events until that date presented in Figures 17, 18, 19, 20 (Dulau et al., 2007),

The numerical values associated data are saved in specific files of Matlab environment,

All vectors are initialized and any subsequent call will add new data to existing ones and

**7.2 Database of the events** 

preventive maintenance, presented in the Figure 15.

Fig. 15. User interface for line 1 OEL 20 kV

interruption, presented in the Figure 16.

**7.3 Reliability evaluation** 

respectively matrix or vectors.

will save the new content.

(Dulau et al., 2010).


Fig. 18. Interface of the time histograms

Fig. 19. Interface distribution of the operation times and repair times

Fig. 20. Interface for the reliability and nonreliability functions

Reliability Centered Maintenance Optimization of Electric Distribution Systems 111

components; the optimal interval between actions; the optimum degree of safety in

The results are summarized by an integrated software for the maintenance management, to manage the database regarding the history of events, as well as the RCM design and analysis. We consider the models presented can be developed in the following research directions: failure rate λ was considered constant throughout the PMA, although in reality it changes value after every action; the time between two successive renewals was considered constant, although it may be placed in the model, as a new variable to be optimized; in evaluation of costs did not take into account the influence of inflation, which could influence the results; last but not least, the lack of real databases, on technical and maintenance events,

The excellent collaboration that my colleagues and I have with the InTech editors was an experience and an honor for the professional manner in which they coordinated the

Anders, G., Bertling, L., & Li, W. (2007). *Tutorial book on Asset Management – Maintenance and* 

Baron, T., Isaia-Maniu, A., & Tővissi, L. (1988). *Quality and Reliability*, Vol. 1, Technical

Blaga, P. (2002). *Statistics with Matlab*. "Babes-Bolyai" University, Cluj University Press,

Catuneanu, V.M., & Popentiu, F. (1998). *Optimization of Systems Reliability*, Romanian Academy Publisher House, ISBN 973-27-0057-2, Bucharest, Romania Catuneanu, V.M., & Mihalache, A. (1983). *Theoretical Fundamentals of Reliability*, Romanian

Dickey, J.M. (1991). The renewal function for an alternating renewal process, wich has a

Dub, V. (2008). *System Reliability*, Didactic and Pedagogic Publisher, ISBN 978-973-30-2371-5,

Dulau, M., Dub, V., Sarchiz, D., & Georgescu, O. (2007). Informatic system for preventive

Dulau, M., Sarchiz, D., & Bucur, D. (2010). Expert system for Maintenance Actions in

Weibull failure distribution and a constant repair time, In: *Reliability Engineering &* 

maintenance actions in electric systems, In: *Proceedings of the 3rd International symposium on modeling, simulation and system's identification SIMSIS 13,* September 21-22, 2007, "Dunarea de Jos" University of Galati, ISBN 978-973-88413-0-7, pp.203-

Transmission and Distribution Networks, In: *Proceedings of the 3rd International* 

http://eeweb01.ee.kth.se/upload/publications/reports/2007/IRE-EE-

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electricity supply; the optimal management of financial resources for RCM.

and their costs in relation to the components of the OEL.

"Petru Maior" University of Targu Mures, Romania

Stockholm, Sweden, Available from

ISBN 973-610-096-0, Cluj-Napoca, Romania

Academy Publisher House, Bucharest, Romania

*System Safety*. Vol. 31, Issue 3, 1991, pp.321-343

208, Galati University Press, ISSN 1843-5130

Publisher, Bucharest, Romania

**9. Acknowledgment** 

Dorin Sarchiz

**10. References** 

accomplishment of this book.

ETK\_2007\_004.pdf

Bucharest, Romania
