Polyhedron Method for Early Short Circuit Detection

The algorithm for detecting the short circuit current in its early stage greatly helps low voltage protection devices to make improvements in current limitation. Based on the analysis the working principle of the early short circuit detection technology, the new method of polyhedron criterion has been proposed. The short circuit current is predicted based on the relationship among the instantaneous values of current, current 1^st derivative and current´s 2nd derivative with respect to time as a combined criterion. And the simulation and experiment results are presented and the results validate its good performance.