Reverse Power Pressure Interlock

[Rodmcm]

We are retrofitting an old AEG turbine/generator with new protection and the old circuits show that the reverse power relay has a hardwired pressure interlock in the short time reverse power trip, the long time trip in unaffected. Can anyone shed light on what this is for?

 

[GTstartup]

Pressure of what?

 

[byrdj]

I would assUme the pressure is a stage pressure, thus representive of turbine mechanical power.

I'm not familar with AEG control phylosipy so I don't know there reasoning.

Could it be there incase some type of generator fault caused a monetary reverse power, with the turbine at power, it would NOT open the breaker.

I Know one company's scheme was to use a combination of valve closed limit switches which indicated steam flow was blocked before arming reverse power breaker trip. I could see a stage pressure being the same.

 

[slavag]

Hi.
"I Know one company's scheme was to use a combination of valve closed limit switches which indicated steam flow was blocked before arming reverse power breaker trip. I could see a stage pressure being the same."
I know one company that used only steam flow/pressure as indication of main valve closed position ( via PLC) w/o limit switch.
For my pinion, in new numerical relay you can use this signal for the reverse power short time block.
Regards.
Slava