35
principle, the current output adopts intermittent output.
9
Calculating formula
Choose
the
calculating
formula
that
the
manufacturer provided, in which I1 (IA) for the high side
current, I2 (IB) for the low (middle) side current, K1 for
the balance coefficient of the high side, K2 for the
balance coefficient of low (middle) side. K3 is a constant.
(3) Testing equipment
1
Number of transformer turns: two windings or three windings.
2
Connecting mode
【
Y/Y-12
】：
The program automatically set the phase difference of I1 and I2 to 180
degrees.
【
Y/Δ-1
】：
The program automatically set the phase difference of I1 and I2 to 150
degrees.
【
Y/Δ-11
】：
The program automatically set the phase difference of I1 and I2 to 210
degrees.
For this relay tester, you must manually adjust the phase difference of I1 and I2 to 0
degrees or 180 degrees. Otherwise, an error will occur in the experimental results.
3
Setting equilibrium factor
Three kinds of setting modes are available for selection.
a) Setting balance coefficient directly: According to the setting value of protection
，
set
equilibrium factor directly.
b) Calculating by rated voltage and CT variable ratio:
Take connection of transformer Y/Y/
△
-11 as example, calculating mode of each side’s
equilibrium factor is as follows:
K1=1/1.732=0.577
K2=U2n*CT2/(1.732*U1n*CT1)
K3=U3n*CT3/(U1n*CT1)
Summary of Contents for HT-802
Page 78: ...78...
