ABB 615 series Technical Manual page 348

Section 4
Protection functions
342
If the Allow Non Dir setting is "False", the directional operation (forward, reverse) is not
allowed when the measured polarizing or operating quantities are invalid, that is, their
magnitude is below the set minimum values. The minimum values can be defined with the
settings Min trip current and Min trip voltage. In case of low magnitudes, the
FAULT_DIR and DIRECTION outputs are set to 0 = unknown, except when the Allow
non dir setting is "True". In that case, the function is allowed to operate in the directional
mode as non-directional, since the directional information is invalid.
Iosin(φ) and Iocos(φ) criteria
A more modern approach to directional protection is the active or reactive current
measurement. The operating characteristic of the directional operation depends on the
grounding principle of the network. The I
network, measuring the reactive component of the fault current caused by the ground
capacitance. The I cos(φ) characteristics is used in a compensated network, measuring the
0
active component of the fault current.
The operation criteria Iosin(φ) and Iocos(φ) are selected with the Operation mode setting
using the values "IoSin" or "IoCos" respectively.
The angle correction setting can be used to improve selectivity. The setting decreases the
operation sector. The correction can only be used with the Iosin(φ) or Iocos(φ) criterion.
The RCA_CTL input is used to change the IG characteristic:
Table 352: Relay characteristic angle control in the IoSin and IoCos operation criteria
Operation mode:
IoSin
IoCos
When the Iosin(φ) or Iocos(φ) criterion is used, the component indicates a forward- or
reverse-type fault through the FAULT_DIR and DIRECTION outputs, in which 1 equals
a forward fault and 2 equals a reverse fault. Directional operation is not allowed (the Allow
non dir setting is "False") when the measured polarizing or operating quantities are not
valid, that is, when their magnitude is below the set minimum values. The minimum
values can be defined with the Min trip current and Min trip voltage settings. In case of
low magnitude, the FAULT_DIR and DIRECTION outputs are set to 0 = unknown,
except when the Allow non dir setting is "True". In that case, the function is allowed to
operate in the directional mode as non-directional, since the directional information is
invalid.
sin(φ) characteristics is used in an isolated
0
RCA_CTL = "False"
Actual operation criterion: Iosin(φ)
Actual operation criterion:
Iocos(φ)
1MAC059074-MB A
RCA_CTL = "True"
Actual operation criterion:
Iocos(φ)
Actual operation criterion: Iosin(φ)
615 series ANSI
Technical Manual