ABB REG650 Technical Manual page 283

1MRK 502 043-UUS B
Technical Manual
×
0.18 TD
=
=
t
op
2
æ ö
M
-
ç 1 ÷
è ø
PUV Hz
ANSIEQUATION2298 V2 EN
where:
M the relative excitation
Pickup1 Operate level of over-excitation function at no load in % of (/f
TD is time multiplier for inverse time functions, see figure 127.
The relative excitation M is calculated using
æ ö
V
measured
ç ÷
è ø
f
=
measured
=
M
æ ö
VBase
ç ÷
è ø
f
rated
ANSIEQUATION2404 V1 EN
Inverse delays as per figure 127, can be modified (limited) by a special definite delay
setting t_MinTripDelay, see figure 126.
delay in s
t_MaxTrip
Delay
under -
inverse delay law
excitation
overexcitation
0
M=Pickup1
Pickup1
ANSI99001067 V2 EN
Figure 126: Restrictions imposed on inverse delays by
A definite maximum time of 1800 seconds can be used to limit the operate time at low
degrees of overexcitation of Pickup1. Inverse delays longer than 1800 seconds will not
×
0.18 TD
2
overexcitation
equation87
V f
measured rated
×
VBase f
measured
t_MinTripDelay
M – Pickup1
Overexcitation M-Pickup1
max
M
Excitation M
max
E (only if f = fn = const)
E
max
ANSI99001067-2-
Voltage protection
)
rated
en.vsd
Section 9
(Equation 86)
(Equation 87)
277