Down conductor protection.

[Prot123]

In your experience what is the best protection for high impedance/ down conductor fault.

 

[Mbrooke]

If all your loads are delta connected and the substation neutral is solidly or resistance earthed then a low ground pickup will do well.

If MGN, I'm guessing this:

https://cdn.selinc.com/assets/Liter...lyers/Arc-Sense_PF00160.pdf?v=20161031-073656

https://cdn.selinc.com/assets/Liter...pedance_DH_20060914_Web.pdf?v=20151001-084811

 

[RRaghunath]

SEF protection with CBCT proved to be reliable in many installations in PDO.

Rompicherla Raghunath

 

[Prot123]

Thanks guys. SEL's arc sense looks quite robust. Currently examining SEL, ABB(patent technology using frequency) and GE( negative sequence).
Without a core balance CT the SEF protection seems to miss out on quite a number of occasions.

 

[HamburgerHelper]

Your ground fault current will be really low so setting a ground pickup is not attractive and will be load dependent. You can set a zero sequence/ positive sequence current ratio pickup to detect an open phase without being so dependent on load.

There is a PSRC paper on open phase detection that was put together in response to the Byron Nuclear Power Plant getting taken down on open phase. This isn't it but it is something that was put out awhile ago.

http://www.pes-psrc.org/kb/published/reports/High_Impedance_Fault_Detection_Technology.pdf

At the T&AM Conference 3 years ago, a Californian utility working in conjunction I believe with Quanta was developed a method of detecting a method of determining a line was falling and to trip out the line before it could touch the ground using traveling wave. This was an effort to try to reduce fires caused by falling conductors.

Found the paper:

https://cdn.selinc.com/assets/Liter...alling_KG_20160215_Web3.pdf?v=20170706-140455

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