Home Page News Search Contact Us Language Bar فارسی English
 
 
 
Protection Riddle No.20 - Single phase earth fault
Author : GUEST
 
#1
Wed, November 12, 2008 - 10:57
When a phase is grounded, the voltage across this phase will become zero. The other two phasors will remain the same as in a healthy system and add to give the residual voltage.

In healthy condition:

VR=VA1+VA2+VA0

VY=a2VA1+a VA2+VA0

VB=a VA1+a2VA2+VA0

VA0 =0 (residual voltage)

In faulty condition:

V'R=0

V'Y=VY+VA0

V'B=VB+VA0

VA0>0


 
Author : Hamid - From: IRAN
 
Submit Your Answer

 
 
Change Language :