Application - ABB RELION 670 SERIES Applications Manual

Line distance protection

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1MRK 506 369-UUS -

Line distance protection REL670 2.2 ANSI

Application manual

Application

Zero sequence symmetrical components are present in all abnormal conditions involving

ground. They have a considerably high value during ground faults.

Zero sequence overvoltage protection (LCZSPTOV, 59N) is a definite time stage

comparator function. The Zero sequence input voltage from the SMAI block is connected

as input to the function through a group connection V3P in PCM600. This voltage is

compared against the preset value and a pickup signal will be set high if the input zero

sequence voltage is more than the preset value 3V0PU. Trip signal will be set high after

a time delay setting of t3V0. BLOCK input will block the complete function. BLKTR will

block the trip output . Zero sequence voltage will be available as service value output as

Setting guidelines

GlobalBaseSel: Selects the global base value group used by the function to define IBase,

VBase and SBase as applicable.

The IED is fed from a normal voltage transformer group where the residual voltage is

created from the phase to ground voltages within the protection software or the residual

voltage is fed from a broken delta-connected VT-group. The setting of analogue inputs

always gives 3U0. Therefore set:

EQUATION2268-ANSI V1 EN

3V0PU: Level of high zero sequence voltage detection given in % of VBase. This setting

should be based on fault calculations to find the zero sequence voltage in case of a fault at

the most remote point where the direct trip scheme shall be active. The zero sequence

voltages shall be calculated for different types of ground faults (single phase to ground and

phase to phase to ground short circuits) at different switching states in the network.

t3V0: Time delay for trip in case of high zero sequence voltage detection. The trip function

can be used as stand alone ground fault protection with a long time delay. The choice of

time delay is depending on the application of the protection as well as network topology.

Negative sequence overcurrent protection LCNSPTOC (46)

Scheme communication

(Equation 535)