Identification - ABB RELION 670 SERIES Applications Manual

Line distance protection

Hide thumbs Also See for RELION 670 SERIES:

Table of Contents

Scheme communication

Identification

Function description

Negative sequence overcurrent

Negative sequence symmetrical components are present in all types of fault condition.

Negative sequence overcurrent protection (LCNSPTOC, 46) is a definite time stage

comparator function. The negative sequence input current from the SMAI block is

connected as input to the function through a group connection I3P in PCM600. This

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

negative sequence current is greater than the preset value Pickup2. Trip signal will be set

high after a time delay setting of tI2. BLOCK input will block the complete function.

BLKTR will block the trip output. Negative sequence current is available as service value

Setting guideline

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

VBase and SBase as applicable.

Pickup2: Level of high negative sequence current detection given in % of IBase. This

setting should be based on fault calculations to find the negative sequence current in case

of a fault at the most remote point where the direct trip scheme shall be active. The

negative sequence current shall be calculated for different types of faults (single phase to

ground, phase to phase to ground and phase to phase short circuits) at different switching

states in the network.

tI2: Time delay for trip in case of high negative sequence current detection. The trip

function can be used as stand alone short circuit protection with a long time delay. The

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

Zero sequence overcurrent protection LCZSPTOC (51N)

identification

Line distance protection REL670 2.2 ANSI

1MRK 506 369-UUS -

ANSI/IEEE C37.2

device number

Application manual