(c) A three-phase, 500-MVA, 345 kV A: 500 kV Y transformers protected by a differential relay with tap settings. Available tap settings are 5:5, 5:5.5,5:6.6, 5:7.3, 5:8, 5:9, and 5:10.

Select suitable CT ratios and relay tap settings and determine the percentage mismatch for the selected relay tap settings.CT ratios should be selected from 50:5, 100:5, 150:5, 200:5, 250:5, 300:5,400:5, 450:5, 500:5, 600:5, 800:5, 900:5, 1000:5.