Impedance Protection; Distance Protection Zmfpdis; Identification; Application - ABB RELION 650 Series Applications Manual

1MRK 505 363-UEN A
Section 7
7.1

Distance protection ZMFPDIS

7.1.1

Identification

Function description
Distance protection zone
7.1.2

Application

The distance protection function in the IED is designed to meet basic requirements for
application on transmission and sub-transmission lines (solid earthed systems) although it
can also be used on distribution levels.
Sub-transmission networks are being extended and often become more and more complex,
consisting of a high number of multi-circuit and/or multi terminal lines of very different
lengths. These changes in the network will normally impose more stringent demands on the
fault clearing equipment in order to maintain an unchanged or increased security level of the
power system.
7.1.2.1

System earthing

The type of system earthing plays an important role when designing the protection system.
Some hints with respect to distance protection are highlighted below.
Solidly earthed networks
In solidly earthed systems, the transformer neutrals are connected directly to earth without
any impedance between the transformer neutral and earth.
IEC05000215 V2 EN-US
Figure 53: Solidly earthed network
The earth-fault current is as high or even higher than the short-circuit current. The series
impedances determine the magnitude of the fault current. The shunt admittance has very
limited influence on the earth-fault current. The shunt admittance may, however, have some
marginal influence on the earth-fault current in networks with long transmission lines.
Application manual

Impedance protection

IEC 61850
identification
ZMFPDIS
GUID-CC4F7338-2281-411D-B55A-67BF03F31681 v3
GUID-8ACD3565-C607-4399-89D2-A05657840E6D v3
IEC 60617 ANSI/IEEE C37.2
identification device number
21
S00346 V1 EN-US
GUID-2F952D87-6BEB-4425-B823-DF8511B9E742 v3
GUID-EB5B5594-AA81-4FC5-BBC0-7627A8609A23 v1
GUID-6B0F02F4-18ED-415E-8D48-0A1648F7CE00 v2
Section 7
Impedance protection
IP14961-1 v2
101