How to predict 10 yr corona damage to PEEK
How to predict 10 yr corona damage to PEEK
(OP)
We're considering developing a new connector design using a copper rod with .375-24 UNF thread, screwed into a PEEK insulator. The connector will be 5kv rated and the maximum conductor temp will be 300F. We're concerned about corona between the copper and PEEK in the threaded area, but we don't know how to predict precisely what effect this will have over a 10 year life. We can try things like rounding the thread tips, or using teflon tape or sealant to reduce the air gap, but we still would'nt know if that's good enough to last 10 years at 5kv. Any advice?






RE: How to predict 10 yr corona damage to PEEK
Unless you can get the insulator vendor to commit, it seems like testing would be the only reasonable approach.
RE: How to predict 10 yr corona damage to PEEK
RE: How to predict 10 yr corona damage to PEEK
RE: How to predict 10 yr corona damage to PEEK
An insulation containing any organic material (paper, all kind of plastic) will not last on the long run if there is partial discharge.
Partial discharge will destroy any of these material generating carbon and/or acids.
RE: How to predict 10 yr corona damage to PEEK
Following is for AC 60 hertz.
At 5kv, usually either you have corona or you don't have corona.
It is unlikely that the connector would be able to withstand corona at 60 hertz for 10 years.
The connector should be tested for corona at the worst case of voltage, temperature and altitude. (Highest voltage + safety factor, highest temperature, and highest altitude)
I have had excellent results testing transformers for corona using:
Corona free high voltage source (0 to 10kv)
Low cost oscilloscope (If test setup is not correct, oscilloscope can be damaged)
Circuit per MIL-PRF-27F(This is fairly simple and low cost)
RE: How to predict 10 yr corona damage to PEEK
Reference:
C.L. Wadhwa, "Electrical Power Systems," John Wiley & Sons, 1991,
Chapter 6 Corona, pages 135 ...