We have one gas turbine generator in droop mode when it connected to a public grid.

Sometimes grid main breaker's auxiliary relay contact open by malfunctioning. Then, turbine control system change the mode from droop mode to isochronous mode.

We forced the main breaker status contact variable so that control system will never change the mode to isochronous mode.

If public grid shut downed, is it possible running in droop mode ?
In my opinion, the turbine has no reference frequency to follow, so turbine and generator will be tripped.

Is it possible only one generator running in droop mode in island?

Thank you.

 

We have one gas turbine generator in droop mode when it connected to a public grid.

Sometimes grid main breaker's auxiliary relay contact open by malfunctioning. Then, turbine control system change the mode from droop mode to isochronous mode.

We forced the main breaker status contact variable so that control system will never change the mode to isochronous mode.

If public grid shut downed, is it possible running in droop mode ?
In my opinion, the turbine has no reference frequency to follow, so turbine and generator will be tripped.

Is it possible only one generator running in droop mode in island?

Thank you.

Isochronous mode is basically 0% droop with a return to frequency setpoint.

It is possible to run in droop on a island. Some ships do just that for various reasons. However, someone will need to return frequency to the desired setpoint after load changes occur. A large deviation from frequency setpoint can cause protective relays to trip the devices they protect.

I once worked at a facility that had 2 vintage 1939 Worthington diesel generators. The old Woodward mechanical governors only provided droop operation. As the operator, I was responsible for observing and correcting frequency.

 

jackson has a couple of different sites and scenarios. One with one GT and one with two GTs....

 

CSA,

I have grown tired of settling the control room difference of opinion for those the did not really know the facts to begin with.

I have in the past sworn that I will not reply to first time posters. I made a bonehead move again. I am on the posting wagon for a while.

 

I wasn't writing specifically to you, Curious_One; I was kind of just saying this poster is ... unusual. By which I really meant new. And I was really trying to get him to be more specific. Your answer was spot on; nothing wrong with it. And, there is the English language thing to try to understand.

I tried to post the URL to the other thread, for the original poster, mostly. But, it came out very strange and I couldn't get it to work correctly (or, as I thought it should work--maybe the poster can't click on the link he pasted in his reply.?.?.?).

Anyway, everyone has to learn some time. I had three years of university and five electrical and electronics courses and I could NEVER understand VArs, or Droop Speed Control. The VArs were finally explained to me by a retired power plant operator who had 35 years in the control room, and had to do an apprenticeship. His explanation was so simple and relatable, I've never forgotten it. Droop, on the other hand, took me decades to work out. For myself. (Have a look at the wikipedia "definition" of Droop these days--what a friggin' mess!)

It's one of those things that is really very simple, but is quite magical, especially considering they didn't have digital systems in the early days of AC power generation--only flyball governors. And, it' still in use today--because it works, and it works very well. Even though most of us who use cannot explain it to other people so they can understand it. And, most of the textbooks and references I have seen are only right if there is one synchronous generator powering a load and it is running in Droop Speed Control governor mode and NO ONE GIVES A DAMN ABOUT FREQUENCY!!! They just say, "The speed decreases as the load increases." And, speed and frequency are directly related. And, an AC system is supposed to provide power at a (relatively) constant frequency (in most parts of the world).

I wish I was talented enough to write an app (not necessarily for smarter-than-me-phones) that someone could use to "simulate" an island power system to see how it works. Watch multiple load displays/meters and change the load on the island and different generators. They could choose the number of generators. They could try putting a second unit in Isoch.... They could change the load on the Droop machine(s). They could try changing load on the Isoch machines (changing the prime mover speed reference). It could be pretty cool. But, I'm not that talented, and right now I have too much on my plate and my calendar. It's been a rough peak season, and I don't think the fall/winter outage season is going to be any better.

Don't give up, mate! Never let the ... others get you down! And, remember--we all had to start somewhere.