Instantaneous Residual Overcurrent Protection Efpioc; Identification; Application; Setting Guidelines - ABB Relion 650 Series Applications Manual

Section 6
Current protection
[ ]
=
t s
EQUATION1261 V2 EN-US
tPRCrvx , tTRCrvx , tCRCrvx : These parameters are used by the customer to create the inverse
reset time characteristic curve. For more information, refer to
HarmRestrainx : Enables the block of step x from the harmonic restrain function (2nd
harmonic). This function should be used when there is a risk of an unwanted trip caused by
power transformer inrush currents. It can be set to
6.3

Instantaneous residual overcurrent protection EFPIOC

6.3.1

Identification

Function description
Instantaneous residual overcurrent
protection
6.3.2

Application

In many applications, when fault current is limited to a defined value by the object impedance,
an instantaneous earth-fault protection can provide fast and selective tripping.
The Instantaneous residual overcurrent EFPIOC, which can operate in 15 ms (50 Hz nominal
system frequency) for faults characterized by very high currents, is included in the IED.
6.3.3

Setting guidelines

The parameters for the Instantaneous residual overcurrent protection EFPIOC are set via the
local HMI or PCM600.
Some guidelines for the choice of setting parameter for EFPIOC is given.
GlobalBaseSel : Selects the global base value group used by the function to define ( IBase ),
( UBase ) and ( SBase ).
The setting of the function is limited to the operate residual current to the protection (
The basic requirement is to assure selectivity, that is EFPIOC shall not be allowed to operate
for faults at other objects than the protected object (line).
For a normal line in a meshed system single phase-to-earth faults and phase-to-phase-to-earth
faults shall be calculated as shown in figure
protection are calculated. For a fault at the remote line end this fault current is I
74
æ ö
ç ÷
A
ç ÷
+ ×
B IxMult
ç ÷
p
æ ö
i
ç ç ÷ - ÷
C
è è ø ø
in
>
Off / On .
IEC 61850 IEC 60617
identification identification
EFPIOC
IN>>
IEF V1 EN-US
33 and figure 34. The residual currents (3I
1MRK 505 355-UEN A
(Equation 20)
Technical manual .
ANSI/IEEE C37.2
device number
50N
0
. In this
fB
Application manual
IP14508-1 v3
M14887-1 v4
M12699-3 v5
IP14985-1 v1
M12762-44 v2 M12762-4 v4
M12762-6 v7
IN>> ).
) to the