17
Fig 2.15 excitation data
Fig 2.16
Excitation curve interface
(5)Ratio Page
Used for displaying the test results of ratio. Polarity, ratio error, and phase displacement
as shown in fig 2.17.
Fig 2.17
ratio page
III.Appendix
A. Principle Of Low-frequency Test
IEC60044-6 standard (corresponding to the national standard GB16847-1977) claims,
CT test can be done in conditions lower in frequency than the rated, and avoid secondary
windings the risk of failing to allow the terminal voltage. The only requirement is that the
core has the same size on the magnetic flux.
IEC60044-6 standard formula for calculating the magnetic flux given by:
0
0
)]
(
)
(
[
)
(
t
CT
CT
CT
dt
t
I
R
t
U
t
（
A.1
）
