SENSITIVITIES OF MULTI AREA RELIABILITY INDEXES WITH RESPECT TO VARIATIONS OF EQUIPMENT FAILURE AND REPAIR RATES - AN ANALYTICAL APPROACH

This paper describes a methodology for calculating the exact sensitivi ty of multi-area reliability indices such as LOLP, EPNS and LOLF with respect to variations in equipment failure and repair rates. The syste m is initially decomposed into ''failure modes'', which are then analy tically integrated to simultaneously produce the reliability indices a nd their sensitivities. The methodology is easy to implement on existi ng reliability evaluation programs and the required additional computa tional effort is modest. The proposed methodology is illustrated in ca se studies with a 5-area and 255-generator Brazilian Southeastern syst em, and the results are discussed. These sensitivities allow ranking e quipments in terms of their effect on system reliability indices, as w ell as estimating the impact of parameter uncertainty on reliability i ndices. (C) 1997 Elsevier Science Ltd.