Different Voltage Adjustment when Generator in synchrone position

[mrpurba]

Help me all...
we have 4 generator with synchrone position when supply power to the load..
When we would like to increase the voltage from each generator.. we turn the voltage adjustment to clockwise and decrease voltage turn the voltage adjustment(potentiometer) to counterclockwise ....but one generator different from others..if increase the voltage turn voltage adjustment(potentiometer) to counterclockwise and decrease the voltage turn the voltage adjustment to clockwise..

This generator nothing problem in single operation..only in synchrone..

waiting info from goog guy
thanks

 

[crshears]

Need more info...

Are all of the AC generators equipped with [a] both manual field control and automatic voltage regulation, manual excitation control only, or [c] AVR only?

If the machines have both auto and manual voltage control, is the problem present only when the one machine is on auto, only when it's on manual, or what?

It is also unclear as to why this problem would be present with multiple machines in operation but not when one unit is in service by itself...are you saying the excitation on the one 'backward' machine is directly proportional when it's carrying the load alone and only develops a problem of inverse proportionality when a second unit is parallelled to it?

 

[mrpurba]

dear sir

all generator cat 3512 used avr6...generator connected to operator control panel that used load sharing control and synchronizer from woodward..voltage and hz adjustment installed on operator panel..on single operation generator no.1 or no.2.or no.3 or no.4..nothing problem...turn the voltage adjustment to right, increasing the voltage..turn the voltage adjustment to left decreasing the voltage..
if all unit in parallled and carrying the load..generator no.1 have a problem...its different from others...turn the voltage adjustment to right..decrease the voltage and turn the voltage adjustment to left..increasing the voltage..

each generator have load sharing and input load sharing come from 3pcs ct and 3pcs pt from each generator too..output from load sharing used as common line for all generator to detect the load...

1. what happen if generator no.1 different phase from output ct to load sharing???
2. what happen if output potential transformer (pt) different phase that connected to load sharing??

i have try to change input loade sharing (output ct) but still not to solve the problem..

please need some adevise
regards
mrpurba

 

[catserveng]

Depending on the type of load share/control module you have you shouldn't need to adjust voltage while in parallel, if the control is properly setup it will take care of that for you.

Can you be specific about which Woodward control you are using? Like is it a DSLC, DSLC2, EasyGen, etc?

Maybe you can post a picture of two? Your description doesn't seem to make much sense, unless you are using Load Share Modules over CAT electronic engines, an SPM-A type synchronizer, and are doing VAR sharing in either droop or cross current. If you are doing VAR share in cross current then you may have a wire crossed in the droop CT circuit when in parallel. About the only thing I can think of at this point that would give you the results you are describing.

Are you having any problems with the VAR sharing while paralleled?

Regards, Mike L.

 

[redlinej]

TO expand on what catserveng say, what happen with the reactive power\power factor with the gentset in parallel.Secondly the genset voltage have to be adjusted when synchronising so how the genset get to sync with the other set