GE MiCOM P40 User Manual

3 DISTANCE MEASURING ZONES OPERATING PRINCIPLES
All distance zone characteristics in this product are constructed with one or more comparators. The comparators
are used to construct either Mho, or Quadrilateral characteristics. This section outlines the principles behind the
construction of the characteristics in order to provide an understanding of how best to set them.
The following table details signal definitions used to construct the measuring zone characteristics.
Name Description
I
Current
I
Current used by the Distance protection measuring element
I
M
Residual current of parallel line (mutual current)
I
N
Neutral Current (derived)
I
ph
Faulted phase current (for example IA for A-N fault)
j
The complex operator
k
M
Mutual compensation co-efficient
k
ZN
Residual compensation co-efficient
p
Distance polarizing factor. A percentage of the memory voltage polarizing signal that is added to the self-
polarizing voltage signal to dictate the level of Mho expansion and help establish a directional decision.
R
Resistance
R
Forward Resistance Reach
R’
Reverse Resistance Reach
S
A voltage vector value comprising one or more voltage components
S
1
A voltage vector input to a comparator
S
2
A second voltage vector input to a comparator
V
Voltage
V
Voltage used by the Distance protection measuring element
V/I
Impedance measured by the Distance protection element
V
mem
Voltage memory signal used for polarization
V
ph
Faulted phase voltage (for example VA for A-N fault)
V
ph
/I
ph
Loop impedance measurement
V
S
Source voltage
X
Reactance
Z
Impedance Reach setting
Z’
Reverse Impedance Reach setting
Z
1
Positive sequence impedance
Z
LP
Loop impedance
Z
replica
Forward replica reach in the loop impedance plane = Z(1+kZN.IN/Iph+kZM.IM/Iph)
Z’
replica
Reverse replica reach in the loop impedance plane = Z’(1+kZN.IN/Iph+kZM.IM/Iph)
Z
S
Source impedance
σ
An angle (in degrees) usually associated with the tilt of a reactive line on a Quadrilateral characteristic
Ðσ
A vectorial operator that rotates a vector quantity by an angle of σº (alternative representation e
jσ
)
Chapter 7 - Distance Protection P446SV
110 P446SV-TM-EN-1

GE MiCOM P40 Specifications

General

Brand	GE
Model	MiCOM P40
Category	Relays
Language	English