Protection Engineering Basics and Schemes Protection Engineering | Page 206

I short circuit HT = I SCH = MVA SC ∗

I Short circuit LT = I SCL = MVA SC ∗

1000 1.732 ∗ V HT 1000 1.732 ∗ V LT

MVA % Z MVA Short HV LV I FLH I FLL I SCH I SCL 20 12.50 173.01 33 11.5 350 1004 2099.356 8033

Our Choice of CTs is

CT Side

Ratio

Class

HT

400 / 1

X

LT

1200 / 1

X

Our System with CTs is now look like below mention figure

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