Measurement Principle - ABB RES670 Technical Manual

1MRK 511 408-UUS A
9.2.7.1
9.2.7.2
Phasor measurement unit RES670 2.2 ANSI
Technical manual
> ⋅
Vpickup (%) VBase kV (
EQUATION1610 V2 EN-US
and operation for phase-to-phase voltage over:
> ×
Vpickup (%) VBase(kV)
EQUATION1992 V1 EN-US
When phase-to-ground voltage measurement is selected the function
automatically introduces division of the base value by the square root
of three.

Measurement principle

All the three voltages are measured continuously, and compared with the set values,
Pickup1 for Step 1 and Pickup2 for Step 2. The parameters OpMode1 and OpMode2
influence the requirements to activate the PICKUP outputs. Either 1 out of 3, 2 out of 3
or 3 out of 3 measured voltages have to be higher than the corresponding set point to
issue the corresponding PICKUP signal.
To avoid oscillations of the output PICKUP signal, a hysteresis is included.
Time delay
The time delay for the two steps can be either definite time delay (DT) or inverse time
delay (TOV). For the inverse time delay four different modes are available:
• inverse curve A
• inverse curve B
• inverse curve C
• customer programmable inverse curve
The type A curve is described as:
TD
=
t
− >
V Vpickup
>
Vpickup
EQUATION1625 V2 EN-US
) / 3
Section 9
Voltage protection
(Equation 54)
(Equation 55)
M15330-6 v6
M15330-10 v11
(Equation 56)
291