Setting Guidelines - ABB REL670 2.2 IEC Applications Manual

1MRK 506 369-UEN B
12.1.3
12.1.3.1
Line distance protection REL670 2.2 IEC
Application manual
The protection against inadvertent energization can be made by a combination of
undervoltage, overvoltage and overcurrent protection functions. The undervoltage
function will, with a delay for example 10 s, detect the situation when the generator
is not connected to the grid (standstill) and activate the overcurrent function. The
overvoltage function will detect the situation when the generator is taken into
operation and will disable the overcurrent function. The overcurrent function will
have a pick-up value about 50% of the rated current of the generator. The trip delay
will be about 50 ms.

Setting guidelines

When inverse time overcurrent characteristic is selected, the
operate time of the stage will be the sum of the inverse time delay
and the set definite time delay. Thus, if only the inverse time delay
is required, it is important to set the definite time delay for that
stage to zero.
The parameters for the general current and voltage protection function (CVGAPC)
are set via the local HMI or Protection and Control Manager (PCM600).
Common base IED values for the primary current (IBase), primary voltage (UBase)
and primary power (SBase) are set in global base values for settings function
GBASVAL.
GlobalBaseSel: Selects the global base value group used by the function to define
IBase, UBase and SBase as applicable.
The overcurrent steps has a IMinx (x=1 or 2 depending on step)
setting to set the minimum operate current. Set IMinx below
StartCurr_OCx for every step to achieve ANSI reset characteristic
according to standard. If IMinx is set above StartCurr_OCx for any
step the ANSI reset works as if current is zero when current drops
below IMinx.
Directional negative sequence overcurrent protection
Directional negative sequence overcurrent protection is typically used as sensitive
earth-fault protection of power lines where incorrect zero sequence polarization
may result from mutual induction between two or more parallel lines. Additionally,
it can be used in applications on underground cables where zero-sequence
impedance depends on the fault current return paths, but the cable negative-
sequence impedance is practically constant. It shall be noted that directional
negative sequence OC element offers protection against all unbalance faults
(phase-to-phase faults as well). Care shall be taken that the minimum pickup of
such protection function shall be set above natural system unbalance level.
Section 12
Multipurpose protection
GUID-F7AA2194-4D1C-4475-8853-C7D064912614 v4
IP15009-1 v2
M13088-237 v4
M13088-3 v5
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