Power swing after earth fault in 12 MW industrial generator system

  • Thread starter Thread starter m.s.j
  • Start date Start date
  • Tags Tags
    Power Swing
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
Sign up Log in
1 reply · 3K views
m.s.j
Messages
212
Reaction score
1
An industrial power system includes one gas turbine generator (6KV, 12 MW), a step up transformer (6/20 KV, Dyn11, 20 MVA) and relevant distribution system. The 20 KV side of power transformer is earthed by a low impedance neutral grounding resistor. The rated current of resistor is 250 A for 10 seconds.
According to operator's electrical reports, some times badly power swing occurs in electrical system especially after one sever Earth fault.

What is your opinion? How can we solve this problem?



--------------------------------------
Creative thinking is enjoyable, Then think about your surrounding things and other thought products. http://electrical-riddles.com
 
Engineering news on Phys.org

Discussion

m.s.j said:
An industrial power system includes one gas turbine generator (6KV, 12 MW), a step up transformer (6/20 KV, Dyn11, 20 MVA) and relevant distribution system. The 20 KV side of power transformer is earthed by a low impedance neutral grounding resistor. The rated current of resistor is 250 A for 10 seconds.
According to operator's electrical reports, some times badly power swing occurs in electrical system especially after one sever Earth fault.

What is your opinion? How can we solve this problem?
--------------------------------------
Creative thinking is enjoyable, Then think about your surrounding things and other thought products. http://electrical-riddles.com
First, you don't provide enough information for a real answer. You don't even give us the periods of those swings.

But excessive swings can be caused by:
  • too much series impedance between generator and load
  • exciter dynamics
  • speed governor/primer mover dynamics