Previous in Forum: Surge Protection Circuit   Next in Forum: Synchronous Generator In Isolated Mode Basics
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
6 comments
Rating: Comments: Nested
visaseller
Associate

Join Date: Dec 2009
Location: Kota Kinabalu, Malaysia
Posts: 39

Generator Droop

01/04/2012 10:09 AM

hi guys, I have problem with my generators.. whenever I parallel them the load KW start hunying and became unstable. I planning to increase the droop setting in woodward 3201D from 3% to 5%. I already contact woodward and they told me to stay with 3% but caterpillar technician advices me to increase it to 5%, what the pro and con 3% and 5% droop?
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Good Answers:

These comments received enough positive votes to make them "good answers".
2
SolarEagle
Guru

Join Date: Mar 2007
Location: by the beach in Florida
Posts: 33392
Good Answers: 1817
#1

Re: Generator Droop

01/04/2012 12:34 PM

The Caterpillar technician should know best....

"

NGC requirements

for units in frequency regulation mode

include being equipped with a fast-acting proportional

speed governor operating with an

overall speed droop of 3-5%. With this control,

a gas turbine will provide a load increase that is

proportional to the size of the grid frequency

change. For example, a turbine operating with

five percent droop would pick up 20% load in

response to a .5 Hz (1%) grid frequency drop.

The rate at which the turbine picks up load in

response to an under-frequency condition is

determined by the gas turbine design and the

response of the fuel and compressor airflow control

systems, but would typically yield a less than

ten-second turbine response to a step change in

grid frequency. Any maintenance factor associated

with this operation depends on the magnitude

of the load change that occurs. A turbine

dispatched at 50% load that responded to a 2%

frequency drop would have parts life and maintenance

impact on the hot gas path as well as the

rotor structure. More typically, however, turbines

are dispatched at closer to rated load

where maintenance factor effects may be less

severe. The NGC requires 10% plant output in

10 seconds in response to a .5Hz (1%) under

frequency condition. In a combined cycle installation

where the gas turbine alone must pick up

the transient loading, a load change of 15% in

10 seconds would be required to meet that

requirement. Maintenance factor effects related

to this would be minimal for the hot gas path

but would impact the rotor maintenance factor."

http://www.accttech.com/LibFiles/ger3620j.pdf

__________________
 All living things seek to control their own destiny....this is the purpose of life
Register to Reply Good Answer (Score 2)
No more Good Answers.
visaseller
Associate

Join Date: Dec 2009
Location: Kota Kinabalu, Malaysia
Posts: 39
#2
In reply to #1

Re: Generator Droop

01/04/2012 6:49 PM

I'm using diesel engine not steam turbine generator, is these note applicable to diesel generator.
Register to Reply
IRSHAD
Power-User

Join Date: Nov 2008
Posts: 121
Good Answers: 4
#3

Re: Generator Droop

01/05/2012 9:09 AM

Higher droops are suitable to meet peak load. Two engines running in parallel in isolated mode should have same droop otherwise the one with higher droop will share more load. you can increase the droop to 5%. this will increase the stability. but before that, pl check compensation adjustment. higher compensation will also result in hunting. additionally , check the control signal emanating from the proximity probe over the flywheel and if required adjust the gap/ correct looseness of control cables to the governor.
Register to Reply
visaseller
Associate

Join Date: Dec 2009
Location: Kota Kinabalu, Malaysia
Posts: 39
#4

Re: Generator Droop

01/05/2012 9:26 AM

I already increased droop to 5% and all 4 generators successfully parallel. looks like caterpillar technicians really know theirs products very well... anyway these is what I found inside woodward manual regarding compensation... Adjust for Stable Operation If prime mover operation is stable, go to the "Speed Setting Adjustment" procedure. If the prime mover is hunting at a rapid rate, slowly decrease the GAIN until performance is stable. If the prime mover is hunting at a slow rate, increase the RESET until the prime mover stabilizes. If increasing the RESET does not stabilize the prime mover, it also may be necessary to either:   Slowly decrease the GAIN or Slowly decrease the GAIN and increase the ACTUATOR COMPENSATION. For the PID adjustment see Chapter 5, Alternative Dynamic Adjustments
Register to Reply
Andy Germany
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#5

Re: Generator Droop

01/05/2012 9:49 AM

Interesting blog.

Just as an aside, in the RN we used a 45% droop with AVR...(don't try it here!) What a difference between then and now!!!

__________________
 "What others say about you reveals more about them, than it does you." Anon.
Register to Reply
nitin revankar
Active Contributor

Join Date: Jul 2011
Location: Bangalore state Karnataka country india
Posts: 11
#6

Re: Generator Droop

01/05/2012 11:27 AM

before setting droop first check two DG seperately by giving load. Note down reading No load and full load reading Engine speed, voltage, engine droop,voltage droop and then match both the reading.then adjust as per your requirement. synchronising and load balancing will be perfect. with this you will find which DG is having problem.simple

__________________
 nitin
Register to Reply
Register to Reply
Have a Different Question?
6 comments

Good Answers:

These comments received enough positive votes to make them "good answers".
Copy to Clipboard

Users who posted comments:

Andy Germany (1); IRSHAD (1); nitin revankar (1); SolarEagle (1); visaseller (2)

Previous in Forum: Surge Protection Circuit   Next in Forum: Synchronous Generator In Isolated Mode Basics

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Electrical Engineering:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (96 right now)
Show Members
Advertisement