Page 169 - Practical Power System and Protective Relays Commissioning

Power System Fault Analysis Chapter | 16 169

FIGURE 16.10 Zero-sequence impedance networks of two-winding transformers.
Positive-sequence impedance:
X1 5 subtransient reactance
Negative-sequence impedance:

X 2 5 X 1
Zero-sequence impedance:
Z 0 5 0
Transmission line sequence impedances are described here.
Positive-sequence impedance:
Z 1 can be calculated