Distance Relay Testing; Introduction - ISA T1000 PLUS User Manual

DOC. MIE91093 Rev. 1.34 Page 87 of 145
1.12 D
ISTANCE RELAY TESTING

1.12.1 Introduction

The test of distance relays is possible only with three T1000
PLUS, taking advantage of the EXTERNAL test start feature.
The test of distance relays can be performed the following
ways:
. With a three phase supply, it is possible to simulate single
phase, phase to phase or three phase faults.
. With single phase supply, single phase or phase to phase
faults can be simulated.
There are two difficulties to perform distance relay testing:
. It is necessary to compute the fault value; from test result, it
is necessary to compute back the corresponding fault
impedance. This task is easy with single phase and three
phase fault; a bit cumbersome with phase to phase faults.
. Currents are in phase with the power supply. This means that
it is necessary to choose the proper T1000 PLUS power supply
connection as a function of the type of power supply (single
phase or three phase), and to compute voltage phase angles
accordingly.
Last, it is necessary to understand very clearly what we mean
when we say "test the setting".
First of all, let us consider a possible characteristic of the
distance relay to be tested, that is designed in the R-X plane.
There are very many different shapes, but the shape does not
affect the testing.