Reliability comparison of substation designs

This paper introduces the concept of reliability evaluation of substation d esigns in terms of the cost of lost load. To overcome the problem of dimens ionality, the failure states are merged and a linear-programming approach i s used to determine the LOLE by means of state-enumeration techniques. Wher e the single-line diagram of the substation is not symmetrical, an equivale nt is constructed, thus giving rise to higher and lower values of LOLE, in other words defining an unreliability region. The average value of LOLE, ca lled the mean evaluation of lost load (MELL),can then serve as an input to the economic comparison of alternative substation configurations.