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Cat Dealer
hbutt

droop CT (phase allocation)

Yesterday, i visited a site, with about 10 gensets in parallel (manual synchronizing with synch lamps modules & CB controlled by pushbuttons). Customer complain was that they can't synchronize the gensets (C18 with R448, no R731). During my visit i observed that only 4 gensets could be synchronized at a time not more than that. On my further inspection, i found out that the Droop CT was on phase V instead on Phase U (schematics recommend to follow the standard position i.e. phase U). After we swapped the CTs all gensets were synchronized.

 

I can't sit back with just following the schematics. If anyone can anyone explain me the reason, WHY PHASE U  & WHY NOT PHASE V or W ?

 

Kind regards

 

Hassan Butt

Cat Dealer

Re: droop CT (phase allocation)

on analog voltage regulators with single phase sensing, the droop CT must be on the phase that is not sensed so that with unity PF loads its output is 90 degrees out of phase with the voltage sensing. This way, the voltage generated across the CT burden can simply be added to the sensed voltage to create the desired droop.

Contributor
arain1984

Re: droop CT (phase allocation)

please all trubles electrical side forward
New member
vishaladwani

Re: droop CT (phase allocation)

Dear Sir,

 

        I am fresh to the electrical industry so i want to know how droop CT is used to share kvar when the the engine is facing inductive load and why it is not required in island operation of D.G.

A part from this the synchronizing controller maintain the voltage to 415V even after Droop CT drops it to certain extend  what is the meaning of droping the voltage .

How is the load sharing actually takes place in D.G how controller can divide 50% load on each D.G ?

 

 

Trusted Contributor
mikel

Re: droop CT (phase allocation)

For a good primer on how voltage regulation and droop works,

 

http://www.basler.com/downloads/VR_parallel.pdf

 

The Basler site has a technical downloads section with a number of very good papers on excitation and protection, a great place to start if you really want to understand how this all works.

 

Woodward also has some very good general publications on load and VAR control on their publications website.

 

Mike L.

New member
vishaladwani

Re: droop CT (phase allocation)

Thanks mike it was very much help full actually we are in manufacturing of Synchronizing panels so at that the time of commissioning i think one should strictly aware of these thinks if i face some difficulty in understanding i will ask question thanks

 

 

 

 

Regards

Adwani Vishal

New member
vishaladwani

Re: droop CT (phase allocation)

Dear Sir,

 

 

We have to synchronize grid with our turbine so is their any fault calculation formula and what are the other things we should keep in mind while synchroonizing  grid and turbine 

 

 

 

Regards

Adwani Vishal