Time Delay - ABB RES670 Technical Manual

1MRK 511 408-UUS A
9.1.7.2
Phasor measurement unit RES670 2.2 ANSI
Technical manual

Time delay

The time delay for the two steps can be either definite time delay (DT) or inverse time
undervoltage (TUV). For the inverse time delay three different modes are available:
• inverse curve A
• inverse curve B
• customer programmable inverse curve
The type A curve is described as:
TD
=
t
< -
Vpickup V
<
Vpickup
ANSIEQUATION1431 V1 EN-US
where:
Vpickup Set value for step 1 and step 2
<
V Measured voltage
The type B curve is described as:
×
TD 480
=
t
æ
Vpickup < -V
× -
ç
32 0.5
è
<
Vpickup
EQUATION1608 V1 EN-US
The customer programmable curve can be created as:
é
ê
×
TD A
ê
=
t
ê
æ
< -
Vpickup V
ê × -
B C
ç
è
ë Vpickup
EQUATION1609 V1 EN-US
When the denominator in the expression is equal to zero the time delay will be infinity.
There will be an undesired discontinuity. Therefore a tuning parameter CrvSatn is set
to compensate for this phenomenon. In the voltage interval Vpickup< down to
+
0.055
2.0
ö
÷
ø
ù
ú
ú
+
D
ú
P
ö
ú
÷
ø
û
Section 9
Voltage protection
M15326-10 v11
(Equation 50)
(Equation 51)
(Equation 52)
277