ABB Relion 650 Series Technical Manual page 242

Section 7
Voltage protection
Vpickup
EQUATION1606 V1 EN-US
and operation for phase-to-phase voltage under:
Vpickup
EQUATION1991-ANSI V1 EN-US
7.1.7.1 Measurement principle
Depending on the set
phase voltages and compare against set values,
OpMode2 influence the requirements to activate the PICKUP outputs. Either 1 out of 3 , 2 out
and
of 3 , or 3 out of 3 measured voltages have to be lower than the corresponding set point to issue
the corresponding PICKUP signal.
To avoid oscillations of the output PICKUP signal, a hysteresis has been included.
7.1.7.2 Time delay
The time delay for step 1 can be either definite time delay (DT) or inverse time overcurrent (TOV).
Step 2 is always definite time delay (DT). For the inverse time delay two different modes are
available; inverse curve A and inverse curve B.
The type A curve is described as:
=
t
Vpickup
Vpickup
ANSIEQUATION1431 V1 EN-US
The type B curve is described as:
=
t
æ
×
ç 32
è
EQUATION1608 V1 EN-US
The lowest voltage is always used for the inverse time delay integration. The details of the
different inverse time characteristics are shown in section
236
< ×
(%) VBase kV ( )
3
< ×
(%) VBase(kV)
When phase-to-ground voltage measurement is selected the function
automatically introduces division of the base value by the square root of three.
ConnType value, UV2PTUV (27) measures phase-to-ground or phase-to-
TD
< -
V
<
×
TD 480
+
0.055
2.0
ö
Vpickup < -V
-
0.5 ÷
ø
<
Vpickup
© Copyright 2011 ABB Power Grids. All rights reserved
Pickup1 and Pickup2 . The parameters OpMode1
21.3"Inverse time
Line distance protection REL650
1MRK 506 326-UUS B
(Equation 50)
(Equation 51)
M15326-6 v5
M15326-10 v5
(Equation 52)
(Equation 53)
characteristics".
Technical manual