Voltage and Reactive Power Hunting Show in My Power Plant.what Reason Behind

As mentioned,if grid connectivity is not there, the inflencing factor for a change in reactive power only would be terminal voltage controller (AVR). With 3 units running in parallel, voltage drop would be dependant on their individual AVR droop settings.

Please confirm that there is no change in load (MW) requirement.

1.Check for individual response & settings of AVR. Normally should be same.

2. Load sharing review is required, as is evident, by data given , unit no:2 acts as master (50.2 hz), and causes the other two to " follow".

3. Response of Controller valves of STGs for similar inputs needs to be checked.

sir,

no change in load,

TG model no.TGP221240/2

AVR TYPE. EX173166/4 both BHEL make.

See thread http://cr4.globalspec.com/thread/73608 This the second time you've asked the question!

Please put some understanding into it. The different frequency reading are impossible as frequency. They indicate phase variation and hunting around a common center value. Your regulator's setting are impossibly tight. Nor do I see any dead band where there is no regulation at all. Relax the settings to more reasonable values. Allow a % or 2 before regulation kicks in. Allow one gen be the first to pick up load. It cannot hunt against itself. Etc, etc.

Relax yourself, relax them. And report back in a few weeks, that most likely all your problems disappeared.