ISA T1000 PLUS - Transformer Differential Relay Testing with D1000 or TD1000 PLUS

DOC. MIE91093 Rev. 1.34 Page 112 of 145
1.15 TRANSFORMER DIFFERENTIAL RELAY TESTING WITH D1000
OR TD1000 PLUS
1.15.1 Introduction
This test is performed taking advantage of the option D1000
or of the model TD1000 PLUS, that allow performing the
following tests of differential relays:
 Characteristic curve test;
 Harmonic restraint.
Before proceeding with the test description, we give some
basic hints on differential transformer protections.
1.15.2 The transformer
 There are many ways for connecting the transformer
primary and secondary windings; they are classified as
vectorial group.
 I
A
is the primary current phase 1
 I
a
is the secondary current phase 1
Depending on the connections of winding 1 and 2 and the
polarity, the vectorial groups are as follows:
 Yy0 – Yy6
 Dy1 – Dy5 – Dy7 – Dy11
 Yd1 – Yd5 – Yd7 – Yd11
 Dd0 – Dd2 – Dd4 – Dd6 – Dd8 – Dd10
CONNECTION DAB
CONNECTION DAC