ABB RELION 670 Series Technical Manual page 335

1MRK 502 066-UUS B
7.9 High speed distance protection for series compensated
lines ZMFCPDIS (21)
7.9.1 Identification
Function description
High speed distance protection zone
(zone 1-6)
7.9.2 Functionality
High speed distance protection (ZMFCPDIS, 21) provides sub-cycle, down towards half-cycle,
operate time for basic faults within 60% of the line length and up to around SIR 5. At the same
time, it is specifically designed for extra care during difficult conditions in high voltage
transmission networks, like faults on long heavily loaded lines and faults generating heavily
distorted signals. These faults are handled with utmost security and dependability, although
sometimes with reduced operating speed.
High speed distance protection ZMFCPDIS is fundamentally the same function as ZMFPDIS but
provides more flexibility in zone settings to suit more complex applications, such as series
compensated lines. In operation for series compensated networks, the parameters of the
directional function are altered to handle voltage reversal.
The ZMFCPDIS function is a six-zone full scheme protection with three fault loops for phase-to-
phase faults and three fault loops for phase-to-ground faults for each of the independent zones,
which makes the function suitable in applications with single-phase autoreclosing.
In each measurement zone, ZMFCPDIS function is designed with the flexibility to operate in either
quadrilateral or mho characteristic mode for separate phase-to-earth or phase-to-phase loops.
The zones can operate independently of each other. Zones 3 to 5 in directional (forward or reverse)
or non-directional mode. Zone1 and zone2 are designed to measure in forward direction only,
while one zone (ZRV) is designed to measure in the reverse direction. This makes them suitable,
together with a communication scheme, for protection of power lines and cables in complex
network configurations, such as parallel lines, multi-terminal lines, and so on.
A new built-in adaptive load compensation algorithm prevents overreaching of the distance zones
in the load exporting end during phase-to-ground faults on heavily loaded power lines. It also
reduces underreach in the importing end.
The ZMFCPDIS function block incorporates a phase-selection element and a directional element,
contrary to previous designs in the IED series, where these elements were represented with
separate function blocks.
The operation of the phase-selection element is primarily based on current change criteria, with
significant increased dependability. Naturally, there is also a part operating with continuous
criteria that operates in parallel
Technical manual
IEC 61850 IEC 60617
identification identification
ZMFCPDIS
S00346 V1 EN-US
Impedance protection
GUID-ED71CF5A-1453-4F2F-9C64-3A73C59EA948 v3
GUID-0F03DA72-0687-4762-91CB-EC8E59B86E06 v2
ANSI/IEEE C37.2
device number
21
GUID-C5C1ADD8-50A5-4485-848C-77D2222B56DC v6
Section 7
329