App-8
IM 253710-01E
Appendix 3 Determination of Delta Computation
Delta Computation Menu, Sampled Data, Symbols Used when Displaying the
Computed Result
The sampled data in the table are substituted into the equations on the next page to
derive the computed results.
Delta
computation
menu
u1–u2
The zero crossing
source signal when the
measurement/
computation period is
set to zero crossing
detection
Notes
u1 – u2
u1 – u2
u1 – u2
u2 – u3
u3 – u1
u3 – u4
—
—
—
Signal used to detect
zero crossing points
on Element 1
Signal used to detect
zero crossing points
on Element 1
Signal used to detect
zero crossing points
on Element 1
Signal used to detect
zero crossing points
on Element 1
Signal used to detect
zero crossing points
on Element 1
Signal used to detect
zero crossing points
on Element 3
∆
Urms1
∆
Umn1
∆
Udc1
∆
Uac1
—
Delta
Star
u1 –
—
∆
Urms1
∆
Umn1
∆
Udc1
∆
Uac1
∆
Urms2
∆
Umn2
∆
Udc2
∆
Uac2
i1–i2
i1 – i2
– i1 – i2
– i3 – i4
i1 + i2 + i3
i1 + i2 + i3
—
—
∆
Urms3
∆
Umn3
∆
Udc3
∆
Uac3
—
3P3W
3V3A
∆
Urms1
∆
Umn1
∆
Udc1
∆
Uac1
∆
Irms1
∆
Imn1
∆
Idc1
∆
Iac1
∆
Irms1
∆
Imn1
∆
Idc1
∆
Iac1
∆
Urms3
∆
Umn3
∆
Udc3
∆
Uac3
∆
Irms3
∆
Imn3
∆
Idc3
∆
Iac3
—
—
—
—
—
Star
Delta
∆
Urms1
∆
Umn1
∆
Udc1
∆
Uac1
∆
Urms2
∆
Umn2
∆
Udc2
∆
Uac2
∆
Irms4
∆
Imn4
∆
Idc4
∆
Iac4
∆
Urms3
∆
Umn3
∆
Udc3
∆
Uac3
∆
Irms4
∆
Imn4
∆
Idc4
∆
Iac4
i1 + i2 + i3 = 0
Assumptions
Assumptions
The centroid of the
delta connection is
computed as the
neutral point of the
star connection.
Sampled Data that are
substituted into the equations
on the next page
u (t)
i (t)
(u1+u2)
3
u2 –
(u1+u2)
3
–
(u1+u2)
3
Symbols used
when displaying
the computed
result
Note
u1, u2, u3, and u4 denote the sampled voltage data of elements 1, 2, 3, and 4, respectively.
i1, i2, i3, and i4 denote the sampled current data of elements 1, 2, 3, and, 4, respectively.