Analyses of subsequent faults

RENEWED INTEREST IN resonant neutral grounding¹ makes it important to have available methods for predicting accurately voltages and currents under abnormal system conditions. A-c network analyzer methods utilizing symmetrical component and 3-phase principles are used for the analysis of subsequent faults on power systems, often called simultaneous faults. Included are systems so grounded that a single line-to-ground fault is not a short circuit. Faults are imposed on two sections of line at x and y, see Figure 1. This selection is general and does not place any restrictions on the location of the chosen line sections which, for example, may be portions of radial feeders at opposite ends of a general network. They may be portions of lines connecting two general networks in any manner, or may be simpler and more familiar configurations.