Protection Engineering Basics and Schemes Protection Engineering | Page 13
current is transformer only in excitation current , which in excess can damage the magnetic coupling of CT or CT .
1.1.3 Errors : There are two types of errors in CT , CT is working for current Transformation , Current is Vector quantity , Errors are typified in terms of Magnitude and Phase angle .
1.1.3.1 Types � Phase Displacement
Error
� Ratio Error Simple vector drawing of Current transformer is shown below
Phase diplacement error is the phase angle difference between primary and secondary current phases due to excitation current . Here it is represented by θ .