UNBALANCE LOAD, REVERSE POWER IN SYNCHRONIZATION

ControlsGuy25
OP only sent Fault Chart showing kW and PF. Furthermore, there is no mention from anyone, except you, that loads are inductive.
My calc illustrates Gen'r load consists of a large resistive component and a very small inductive component!
BTW, have you noticed that OP no longer participates!
Phil Corso
 
ControlsGuy25
OP only sent Fault Chart showing kW and PF. Furthermore, there is no mention from anyone, except you, that loads are inductive.
My calc illustrates Gen'r load consists of a large resistive component and a very small inductive component!
BTW, have you noticed that OP no longer participates!
Phil Corso
@PhilCorso I noticed that OP is not participate now..
 
Hi ,

We have five 3512B CAT generators with Woodward 2500 synchronizing panels.
Have issue with generator one only(given name 1),So when this 1 gen. is online with any other generators, will be having load sharing issue specially at the time of sudden increase of load. At this time power factor leads to 0.1 and active power goes to negative and sometimes breaker trips because of reverse power. It happens once in a week or twice.
I have tried swapping Woodward 2500 from other generator, speed controller 2301 and also changed the PWM converter but still the results are same.
If need more data to analyze, i will provide it.
Thanks
Did you check the governor actuator and fuel rack mechanism are working fine or not???
I would seriously consider checking it. Stuck fuel racks are not uncommon problem. As you have found that your governor controller is working fine, I would now want to check out in the field.
 
Hi,
Sorry for the late reply, i was little bit busy these days.
As Mr. Udshred advised to check fuel racks , will be the good option at this time and also the CT.
I am attaching one picture of current load sharing, which is running good but if sudden load comes or the total load is very less, it starts giving reverse power.
power factor goes 0.1 and active power in negative.
This set up is on a land oil and gas rig.
I can see load gauge on generator1 fluctuates more than other generators while in synchronization.I CAN NOT UPLOAD THE VIDEO BECAUSE OF THIS WEBSITE RESTRICTIONS.generator1 05012023.jpggenerator1 05012023.jpg
 
Hi,
Sorry for the late reply, i was little bit busy these days.
As Mr. Udshred advised to check fuel racks , will be the good option at this time and also the CT.
I am attaching one picture of current load sharing, which is running good but if sudden load comes or the total load is very less, it starts giving reverse power.
power factor goes 0.1 and active power in negative.
This set up is on a land oil and gas rig.
I can see load gauge on generator1 fluctuates more than other generators while in synchronization.I CAN NOT UPLOAD THE VIDEO BECAUSE OF THIS WEBSITE RESTRICTIONS.View attachment 2618View attachment 2618
Hi

We would need ki,nd of load balance list to understand better the behaviour of this Bus system /Island mode Behaviour
 
JSMHarrish...
The problem is not Electrical! It's Mechanical! In my message #14, I said the gensets are underloaded. I suggest you take a look at the Diesels!
Phil Corso
 
ContolsGuy25...
My opinion is... the Diesel-engine is at fault. Your opinion is... Generator electrics are at fault.
Only one person can resolve it... JSMHarrish.
So, JSM... you are up !
Regards, Phil Corso
 
To all:

A while back I was accused of being "very angry". That term is silly! But, I am disappointed that several men supposedly educated and/or trained in trouble-shooting Gen-set operation don't use the basic terms like, RMS VALUES, PHASORS, POWER properly.

Many have used the terms Volts, Amperes, kW, and Power-Factor. No-one, I repeat no-one has, expressed the term, "power-factor" correctly! It should be expressed in 3 words, Power Factor, "Lag or Lead". Those that have used it, "assume" it's lag!

I'm also disappointed that no-one, I repeat, no-one looked at the Diesel, to confirm or reject, my theory of "underloading"! The point is that effects are VISABLE!

Well, in closing, I wish you all a successful, bright life!
Goodby, Phil Corso
 
JSMarrish...
It's been a while since you brought your paralleled Genset problem to this forum. Hopefully, you have solved it. If not I can still help!
I have produced an Excel program that simulates the situation, and can provide it to this Forum. If are interested contact me at [email protected] !
Regards, Phil Corso
 
JSMHarish...
My program, using your Fault-Chart Data, showed the following:

At time, 16:07, Engine1 started having speed control problems resulting in reduction of output-torque, but without speed-change!

Although Generator1 was synchronized with the others, a decrease in the Engine's output-torque, resulted in lowering of Generator1's output-voltage, which, unfortunately, was not included in the fault-chart! Note the decreasing kW and Amps.

At time, 9:16:13, the Synchronous-Generator transitioned into a Synchronous-Motor, producing output-torque on its shaft linked to the Engine. As time progressed the Sync Mtr's (kW shown in red) output-torque was overcoming that of the Engine's output-torque. The PF value was measured as magnitude, but no indication of direction, i.e., Lag or Lead !

Since the engine's output-torque was being negated by that of the now Sync Mtr, it's fuel-rate dropped. I don't know if it was tripped when the Generator Reverse-Power relay tripped!

Contact me if you want a copy of my program.
Regards, Phil Corso ([email protected], Tel:, 561-289-7688)
 
26 MW triveni steam turbine, generator side coupling shear pins broken suddenly, whenever in synch form with another 16 MW AEG turbine. This happened 09 times since 26 MW installation i.e. 03 years before. What are the reasons of coupling shear pins broken?
 
No answer on what AOA stand for but...
It would be good to open a new thread for this issue..
Also Can you provide more details like shaft arrangement...
Load gear box if applicable
 
I concur--this should be a completely separate thread as it really has little or nothing to do with the original post. And bhilal.bhatti should explain his TLA (Three-Letter Acronym).

That being said, I have seen this once. The shear strength of the coupling bolts was calculated incorrectly--or that's what the steam turbine-generator set packager said (actually, it wasn't probably calculated at all--the packager bought a steam turbine from one manufacturer, a generator from another manufacturer and a coupling from a third supplier). The coupling manufacturer said the bolts are designed to shear primarily based on torque-based calculations (but also includes other electrical phenomenon, PhilCorso) to protect the turbine and the generator from serious damage in the event of pole slippage or similar occurrence. The bolts that were supplied weren't the right bolts for that particular application. (The coupling bolts kept shearing when lightning strikes in the area caused utility breakers to open in an incorrect order and greatly increase the load on the steam turbine-generator at one small biomass plant.) The local utility had to get involved to develop a different breaker tripping scheme than the one which was put in place when the biomass was being built and tied to the utility because the load "throw-on" was definitely going to break even the proper coupling bolts. This problem took over a year-and-a-half to sort out. The PLC being used to control the steam turbine had been improperly programmed and was annunciating a misleading alarm from the AVR. Four sets of coupling bolts were sheared before involving the coupling manufacturer and the STG supplier to solve the problem and obtain the proper bolts for the application and getting the utility to review and revise their protection scheme in the event of a fault or lightning strike near the plant.
 
bilal.bhatti, you haven't provided enough information about when exactly the sheared coupling bolt issue occurs "... whenever in synch form with another 16 MW ... turbine...." Does it happen when synchronizing is occurring? Or after synchronization? EXACTLY WHEN during or after synchronization are the bolts shearing? Because if it's happening during synchronization and not after then there's likely something wrong with the synchronization check circuitry, which is designed to prevent synchronizing out of phase. If it's happening shortly after synchronization it could be that the two turbine governors are both in Isochronous Speed Control when synchronizing or shortly after synchronization somehow they both end up on Isochronous Speed Control mode at the same time and start fighting each other.

The other turbine--is it a steam turbine or a combustion turbine?
 
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