TY - JOUR AU - Mokaddis, G. S. AU - EL-Sherbeny, M. Salah AU - Al-Esayeh, Entesar PY - 2010 TI - Compare Between Two-Unit Cold Standby and Warm Standby Outdoor Electric Power Systems in Changing Weather JF - Journal of Mathematics and Statistics VL - 6 IS - 1 DO - 10.3844/jmssp.2010.17.22 UR - https://thescipub.com/abstract/jmssp.2010.17.22 AB - Problem statement: This study presents the reliability analysis of two mathematical models representing electric power systems operating in fluctuating outdoor weather (i.e., normal and stormy weather) and compared between two models. Approach: Model I deals the reliability analysis of a single-server two-unit cold standby, Model II deals the reliability analysis of a single-server two-unit warm standby, for two systems with two different modes (normal, total failure). System failure occurs when both the units fail totally. Results: The failure rate and failed repair rate of a unit are constants. Laplace transforms of the various state probabilities have been derived and then reliability is obtained by the inversion process. Conclusion/Recommendations: Mean Time To Failure (MTTF) are derived. The failure times of operating/spare units and repair time of failed units are exponential distributed. Certain important results are compared between two systems.