Woodward HighPROtec MCDLV4, Manual, Page: 860 / 1275

Protective Elements
Equivalent circuit at mains failure.
In case of mains failure or auto reclosing the generator suddenly feeds a very high consumer load. The rotor
displacement angle is decreased repeatedly and the voltage vector V1 changes its direction (V1').
Voltage vectors at mains failure.
860 MCDLV4 DOK-HB-MCDLV4-2E
Grid
V´ = I´
1
* j Xd
V
P
V´
1
I
1
Generator Load
V
P
V
1
V´
1
V´ = I´
1
* j Xd