Pulse Ramping

Overview

Pulse Ramping determines magnitude, phase, and frequency thresholds by pulse ramping definitions. It enables quick, accurate and thorough determination of pick-up values of multifunctional relays and allows testing a protection element pick-up value without disabling associated functions. Pulse Ramping also avoids high continuous testing current for electromechanical relays with high instantaneous settings. Solutions for Protection Systems with IEC 61850 and Protection Relay Testing are provided, and documentation includes the CM Line Catalog (4 MB). Used for pick-up testing of multifunctional relays with overlapping elements; overcurrent relays with multiple elements; generator and motor protection; and rate of change relays (including df/dt). Application example Overcurrent: when overcurrent protection is realized with two stages—a standard stage with a longer tripping time and a high set stage with a very short trip time—a test of the pick-up value of the high set stage can be done by setting the pulse length shorter than the standard stage tripping time so pulse ramps do not force a trip of this stage.