Toshiba GR-200 Series Instruction Manual page 233

change; the signal is reset when the frequency comes back from the active
rage.
RCD characteristics
(ii)
Setting [FRQ-RCD]: Figure 2.19-9 exemplifies 'Loss of synchronism'. The
frequency (f0) changes rapidly at 0.5 sec. and 1.5 sec. When the [FRQ-RCD] has
20 Hz/s setting, the 'FRQ-RC' signal will be generated, because the Δf/Δt is larger
or more than the setting.
Frequency(Hz)
f0 + 0.5
Nominal (f0)
f0 – 0.5
f0 – 1.0
f0 – 1.5
f0 – 2.0
f0 – 2.5
0
Figure 2.19-9 Frequency change due for Loss of synchronism
Setting [FRQ-RCD-UF]: Figure 2.19-10 exemplifies FRQ-RC signal is generated
when the frequency (f0) is smaller or less than f0–0.5Hz. Thus, FRQ-trip will be
forbidden during the generation of FRQ-RC signal. When the frequency comes
back to the normal, FRQ-trip will be permitted.
Frequency(Hz)
f0 + 0.5
Nominal (f0)
f0 – 0.5
f0 – 1.0
f0 – 1.5
f0 – 2.0
f0 – 2.5
0
Figure 2.19-10 RCD-AR under-frequency setting
Rising(Δf/Δt=20Hz/s)
0.2 0.4 0.6 0.8
[FRQ-RCD-AR-UF]=-0.5Hz
0.2 0.4 0.6 0.8
- 214 -
Downing(Δf/Δt=20Hz/s)
1.0 1.2 1.4 1.6
1.0 1.2 1.4 1.6
6F2T0200 (0.15)
1.8 2.0
Time (sec)
1.8 2.0
Time (sec)
GRE200 (1,2)