This paper presents a method for evaluating reliability when some error occurs in upstream grid and the microgrid is in island mode. Also, a connection matrix for the linkage between grid components as well as a load prioritization matrix for indicating loads priority along with effects of prioritization on reliability indices is recommended. In addition, a failure effect matrix for a feeder over loads of adjacent feeders is provided. Moreover, an algorithm is used to show how the failure effect matrix is obtained. In present paper, a 4-bus RBTS system with microgrids is studied, the reliability of which is analyzed in 3 modes: (i) No microgrids, (ii) with microgrid in island mode without load prioritization, and (iii) with microgrid in island mode with load prioritization; and failure effects on loads are also examined and, for these 3 modes, reliability indices are calculated, indicating that it is improved in the mode of load prioritization.

One of the methods that are used for increasing accelerator force of projectile in the railgun is the increasing of inductance gradient. Essentially, the inductance gradient is determined by current density in rails and projectile. If we change geometry of the rail, the current density and inductance gradient will be changed. One of the factors that restricts variation domain of rails geometry is the tolerable current of rails. In this paper, we have obtained analytical formulas for the maximum current density and the inductance gradient in terms of rail dimensions using the results that have been obtained by 2-D finite-element method. By these formulas and Lagrange's optimization equations, we determined the optimum dimensions of rail. Tolerable current is bonded for Lagrange's equations.