Solving Power Swing Problem in Industrial Power Systems | Electrical Riddles

[m.s.j]

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?



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

 

[anorlunda]

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?
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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