Cascaded tripping of power lines due to mal-operation of zone 3 distance relays was one of the main causes of many previous blackouts worldwide. Encroachment of load into the zone 3 characteristics is one of the main cause for the maloperation of the relays. By improving the operation of zone 3 of distance relays it is possible to prevent such mal-operations so that cascaded line tripping can b...

The paper reviews models for inelastic deformation processes preceding earthquake rupture in brittle, natural rock masses. The discussion is organized around three types of failure models: (i) localization bifurcations, whereby a uniform or nearly uniform pattern of deformation gives way to highly localized deformations within a fault zone; (ii) non-homogeneous deformations due to an inclusion-...