Loss of excitation, no voltage and no current in startup phase of a generator at full speed no load, what's the root cause of all of this

 

What have you done to troubleshoot the problem? What were the results of the troubleshooting?

When did this problem occur? After a maintenance outage? After a unit emergency shutdown/trip? If so, what was the cause of the trip?

You haven't provided any useful information about the unit at your site. Every generator is not the same as every other generator. We can only presume the unit has a synchronous generator. Does it have a rotating exciter? A brush-less exciter? A static exciter? Does it use field flashing?

What alarms were annunciated on the excitation panel or the turbine control panel that were related to the absence of terminal voltage and field current? It's unlikely that no alarms (Process or Diagnostic) were annunciated to provide some clue to this condition.

Have you checked the power supply to the excitation system?

If the unit uses field flashing during starting, have you checked the field flashing supply breaker to see that it's closed?

 

> Loss of excitation, no voltage and no current in startup phase of a generator at full speed no load

What happens if you re start? Can you manage to get the voltage?

 

>> Loss of excitation, no voltage and nocurrent in startup phase of a generator at full speed no load

> What happens if you re start? Can you manage to get the voltage?

First.. What type of excitation system do you have?
EX200, EX2100? Is it an analog system? Is it a brushless generator or not. According to these question you'll have the answers.

 

>>> Loss of excitation, no voltage and nocurrent in startup phase of a generator at full speed no load

>> What happens if you re start? Can you manage to get the voltage?

> First.. What type of excitation system do you have? EX200, EX2100? Is it an analog system?
> Is it a brushless generator or not. According to these question you'll have the answers.

We have very similar problems like this. It happened many times. Most of the time we managed to get the voltage after second or third attempt. Sometimes our electrical maintenance staff had to do something extra to synchronize the generators.

I don't know the poster has similar problem like us. The best thing to do is to ask questions.

 

It's 13 June 2011, and this thread was originally posted on 11 May 2011. The originator has never responded to any questions or with any additional information.

Any further questions of the original poster, or any speculation on this thread, is probably not a good use of anyone's time since the original poster doesn't seem to feel the need to respond.

 

I agree with CSA. But for those you might have experienced similar problem, i bet its because the field breaker did not operate to close. Its always good to monitor the field voltage and current during start up

 

or your generator could be blown up...yup I've seen it. "couldn't excite the unit"

The stud on the rotor that connects the field windings broke and bounced around and also shorted out stator bars.