Principle Of Operation; Full Scheme Measurement - ABB Relion 670 Series Technical Reference Manual

Section 6
Impedance protection
6.2.2
6.2.2.1
196
X
Reverse
operation
IEC05000034 V1 EN
Figure 87: Typical quadrilateral distance protection zone with load encroachment
function activated
The independent measurement of impedance for each fault loop together with a
sensitive and reliable built in phase selection makes the function suitable in
applications with single phase auto-reclosing.
Built-in adaptive load compensation algorithm for the quadrilateral function prevents
overreaching of zone1 at load exporting end at phase to ground-faults on heavily
loaded power lines.
The distance protection zones can operate, independent of each other, in directional
(forward or reverse) or non-directional mode. This makes them suitable, together with
different communication schemes, for the protection of power lines and cables in
complex network configurations, such as parallel lines, multi-terminal lines.

Principle of operation

Full scheme measurement

The execution of the different fault loops within the IED are of full scheme type, which
means that ground fault loop for phase-to-ground faults and phase-to-phase faults for
forward and reverse faults are executed in parallel.
Figure 88 presents an outline of the different measuring loops for the basic five,
impedance-measuring zones.
Forward
operation
R
en05000034.vsd
1MRK505222-UUS C
Technical reference manual