10.7.2 Application
The most common application of the PAPGAPC (27) function is to provide tripping at the
remote end of lines with passive load or with weak end infeed. The function must be
included in the terminal at the weak infeed end of the feeder.
Permissive communication schemes can basically operate only when the protection at the
remote end of a feeder can detect the fault. The detection requires a minimum of fault
current, normally >20% of Ir.
The fault current can be low due to absence of generated power or low short circuit current
of the source. The fault current can initially be too low due to the fault current distribution.
In this case, the fault current increases when the breaker opens at the strong line end and
a sequential tripping is achieved.
The detection of the fault by an independent tripping zone 1 is then required.
To avoid sequential tripping as described or when zone 1 is not available, the protection
terminal must be provided with this application function.
10.7.3 Setting guidelines
The parameters for PAPGAPC (27) application function are set via the local HMI or
Protection and Control Manager PCM600.
Operation: The function can be set Enabled/Disabled.
GlobalBaseSel: Used to select a GBASVAL function for reference of base values,
primary current (IBase), primary voltage (VBase) and primary power (SBase).
VPhSel<: Faulted phase voltage in % of quadrature phase – phase voltage divided by sqrt
(3). Setting this value to 100% is equivalent to disabling the voltage operation.
Tau: Time constant for reference voltage.
FastOperation: Enabling of fast fault clearing.
t3Ph: Time delay for three phase operation.
Pickup_N: Residual current detection in % of IBase.
ResCurrCheck: Enabling of residual current check for delayed operation at single phase
faults.
Del1PhOp: Enabling of delayed single phase operation.
t1Ph: Time delay for single phase operation.
1MRK 506 369-UUS - Section 10
Voltage protection
Line distance protection REL670 2.2 ANSI 591
Application manual
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