HV Transformer Design for Low PD

[VLFit]

Can anyone recommend one or more books for the design of high voltage, oil immersed transformers, particularly the design and processing steps necessary for low pd output.

Thank you.

 

[VLFit]

Please, if anyone reading this can help, it would be greatly appreciated.

 

[waross]

PD, partial discharge?
I suggest doing research on partial discharge.
See what causes PD.
I understand that electrical stress is a factor, similar to corona. (I may be wrong)
Do your research and find the causes, examples and mitigating techniques.
Sorry that I can't be of more direct help, but your own research is always more valuable and will give you much more confidence than a suggestion on the internet.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[Gr8blu]

Basic rules to limit partial discharge (PD):
1) Apply correct insulation (grading tapes) to minimize the step voltage at any point along the conductor
2) Do not overlap phase conductors in close proximity
3) Maintain appropriate clearances between conductors for the applied voltage
4) Since this is an oil-filled transformer, be prepared to monitor the oil for specific chemical indicators on a regular (3 to 6 month) cycle to catch any developing PD in its infancy

Also - have a good idea what you (or at least the transformer owner) considers to be "low PD". Also be aware that there is no applicable standard that defines what is "acceptable" and what is not.

The development of PD is related to several environmental factors (temperature, humidity, altitude, etc.), as well as the voltage. What this means is that as these factors increase (higher temperature/humidity/altitude) the likelihood of PD at a given voltage increases. (This is very similar to corona effect.) In a sea-level (< 1000 m altitude) application, PD may occur at voltages as low as 4160 ... although the more common lower bound is around 10 kV. In comparison, at 1800 m (5900 ft), PD (and corona) inception may occur at 1000 V.

Converting energy to motion for more than half a century

 

[thermionic1]

This one has been around for quite a while and is available.

J & P Transformer Book
13th Edition - September 19, 2007

I would add that in liquid filled transformers the importance of hot oil circulation and then a vacuum / vacuum fill / impregnation.

An interesting video on transformers

https://www.youtube.com/watch?v=sS9Cld9s1uw