Time And Current Grading For IDMT Relay Setting

The View Relay Settings option allows viewing of the time­current characteristic curve set tings, trip mode, and frequency for the selected fault interrupter..

In case of OCR coordination problem the relay characteristic, described by(1.6),is nonlinear in nature because of which the objective function, the operating

The desired accuracy level of the nonlinear time-current characteristic curve prediction of each overcurrent protective relay can best be obtained from the practical

Phase Over-Current relay on the Delta side may operate as a back up for Star side Ground faults. But, this will take long time and if system is resistance earthed , it may

Figure 13-54: SEL-387 Slope-2 Differential Formulas 346 Figure 13-55: Percentage Differential Protection Dual Slope Characteristic Curve in Amps 347 Figure 13-56: Using Graphs

where the constants A, B and p are used to select the relay characteristic curve, M I is the ratio between the fault current seen by the relay and the relay pickup current and

External fault Unbalanced loading stress Unbalanced loading stress Over load/negative phase Over load/negative phase sequence relay, Backup sequence relay, Backup Impedance/

 To investigate the significance of protection techniques in electric power system via emphasis lies upon distance relay MHO type characteristic principles and