Control Systems & PLC's

Vfd Variable

On-site Vacuum Circulate Transformer Oil Purifier,Oil Purification,Vacuum Injecting Machine

Transformer Oil Treatment

Transformers are important devices therefore increasing the importance oil. Transformer oils are lost quality in time. Consisting of moisture in the oil causes sludge and acid after a short time with a oxidation of air.

 

With ZHONGNENG ZYD transformer oil treatment plant, electrical life are brought equivalent in new transformer oil. Transformer oil treatment process can be eliminate acid, moisture, gas, sediment,fitler particles from the oil with the Hi-vacuum system and improve the quality.It can increase its dielectric strength after treatment.

 

 

Feature:

1) Advanced dehydrating and degassing system that uses large area three-dimensional flash distillation technique to remove harmful composition in the oil such as water, air and gas. 
2) It can be widely used for oil filling for transformers and circuit breakers under vacuum condition. 
3) Precise filtration system,high-quality filter element,multi-stage filtration with gradual precision can help to remove mechanical impurities in the oil. 
4) An advanced fully automatic temperature controlling system,liquid-level controlling system,defoaming controlling system,pressure protecting system and excellent configuration can ensure operation of the equipment with high performance. 
5) Online work,allowing separated operation of manual operators from machine with lamps indicating the condition for operation. 
6) It is humanization design with low noise,deep purification and long time free maintenance to save cost from the running process. 
7) Purifiers are equipped with a chain safety protective system,an interlocking of oil drainage system,vacuum system and heating system,which avoids any possible negative impacts caused by mal-operation.

 

Optional mode:
● The customers' request can be met by adopting PLC intelligent control,touch screen and dynamical display.
● On line water tester is available.
● VFD(Variable Frequency Drive) is available.
● Flow meter with accumulated function is available.
● Extra system of pumping vacuum for transformer is available.
● Available in mobile option,immovable option and trailer.
● Oil purifier can be made in hermetical,canopy-covering,open and frame style.
● Color of the oil purifier can follow customer's favor.

 

 

Please contact us for more details.

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cfbc boiler for drum level control what are the values of ( p,i,d) controller DCS,ie..feed control station MOV?

By changing p,i,d values also we tried but now drum level changes from -25mmwc to +25mmwc,
But it should also be tunned .normally feed control station is by pneumatic valve control but here we use MOV.If there is sudden change in drum level MOV is frequently operated forward / reverse , because of this action motor body gets heat and results in trip.For that to achieve the process requirement @ this condition what is the solution to be done.Feed pump is also by VFD .In dcs Process variables have continuous changes like ( Feed water flow ,Pressure drop across feed water station,feed water pressure).now p value is 77%,i value is 0.33%,d value is 0% @ this condition also there is a small change in drum level ,but same variation in 3 txx readings continuous & results average is -15mmwc to +15 mmwc..
Now we want to know which part / location / area we want to concentrate and solve the issue so that safety of boiler is good.

For your safety, and that of those around you, you really ought to take this to a professional.

It could be unsafe to tune the controller for usual operation without considering the hazards that could come from controller tuning interacting with a process upset.

What your controller is doing is called "ringing" in the older terminology, I guess "oscillation" now. It indicates that your gain is too high for the lag time in your process and controller.
One hazard is that a change in water delivery pressure can in effect change the gain on the system, in terms of how big a change in water flow results from a given change in controller output.
I think you might need to change the MOV to a pneumatic actuator; this is one of the dirty secrets about MOVs that the salesmen don't tell you. If you stay with the MOV, you need to ensure that all failure modes are safe.

For your background information only, see http://en.wikipedia.org/wiki/PID_controller#Loop_tuning
It lists some of the methods, the requirements and advantages/disadvantages.

Variable-frequency drive (VFD) external run