ABB Relion 670 series - Line Application Example

Further description can be found in the technical reference manual.
tPRCrvx, tTRCrvx, tCRCrvx: Parameters for user programmable of inverse reset time
characteristic curve. Further description can be found in the technical reference manual.
9.4.3.6 Line application example
Four step residual overcurrent protection can be used in different ways. Below is
described one application possibility to be used in meshed and effectively grounded
systems.
The protection measures the residual current out on the protected line. The protection
function has a directional function where the polarizing voltage (zero-sequence voltage)
is the polarizing quantity.
The polarizing voltage and current can be internally generated when a three-phase set of
voltage transformers and current transformers are used.
xx05000149_ansi.vsd
67N
ANSI05000149 V1 EN
Figure 266: Connection of polarizing voltage from an open (ANSI-broken) delta
The different steps can be described as follows.
Step 1
This step has directional instantaneous function. The requirement is that overreaching of
the protected line is not allowed.
1MRK 506 369-UUS - Section 9
Current protection
Line distance protection REL670 2.2 ANSI 517
Application manual