Hitachi Relion 670 Series Applications Manual page 187

1MRK506375-UEN Rev. N
where:
R
G,I
R
G,C
Z
G
I is described as:
NG

I
NG
Z
IECEQUATION051 V2 EN-US
I R is described as:
Fe G,I
I R
Fe G ,
IECEQUATION052 V2 EN-US
For
Z , R
G G
IECEQUATION053 V2 EN-US
I is described as:
Fe

I
Fe
IECEQUATION054 V2 EN-US
The current flow in case of an external phase to ground fault should not operate the tank protection.
Therefore, start value is set above the absolute value of this current. In other words, the ratio of
ground contact resistance R
regardless of atmospheric conditions.
8.10.4 Setting guidelines
The parameters for transformer tank protection TPPIOC are set via the local HMI or PCM600.
The setting parameters for the transformer tank protection TPPIOC are described below:
Common base IED values for primary current (setting IBase) is set in a Global base values for
settings function GBASVAL setting.
GlobalBaseSel: Selects the global base value group used by the function to define (IBase).
I>>>: Instantaneous peak current start value in % of IBase.
Railway application RER670
Application manual
Leakage resistance of the tank
Ground contact resistance
Neutral grounding impedance
V
NG

R R
G G , C G , I
 
( I I ) R
I NG Fe G , C

R
, I G , C
R
V
G , C
NG
Z R
G G , I
to leakage resistance R
G,C
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should not exceed a certain value
G,I
GUID-916B2550-5C16-47F7-9782-7DD6FABAA0A2 v2
Section 8
Current protection
(Equation 59)
(Equation 60)
(Equation 61)
(Equation 62)
181