Toshiba GR-200 Series Instruction Manual page 302

Synchronism check scheme
2.25.2
The VCHK function has a measuring element to check the difference between a running
voltage and an incoming voltage. The measuring element can check phase angles, voltages,
and frequencies. Operation in the synchronism check mode is carried out in the 'B1' zone, as
shown in Table 2.25-1.
The scheme checks the following parameters: (i). voltage difference, (ii). frequency
difference, and (iii). phase difference. The following variables represent the algebraic
expression used to implement the scheme:
V B =
V L =
ΔV =
fV B =
fV L =
f =
Δf =
θ =
SYN-dV =
VCHK-OVB = Pickup voltage set by [VCHK-OVB] for Busbar
VCHK-OVL = Pickup voltage set by [VCHK-OVL] for Line
SYN-Angle = Phase difference between V B and V L , set by [SYN-Angle]
SYN-df =
T_SYN =
Setting Range
SYN-df 0.01–2.00
SYN-dV 0–150

= setting [SYN-Angle]
S

s

Pickup set by [VCHK-OVB] or [VCHK-OVL]
Figure 2.25-3 SYN measuring element
Busbar voltage
Line voltage
Voltage difference between Busbar and Line
Frequency of V B
Frequency of V L
Slip cycle
Frequency difference between Busbar and Line
Phase difference between V B and V L
Voltage difference set by [SYN-dV]
Value of frequency difference between Busbar and Line, set by [SYN-df]
Delay timer for checking synchronism, set by [T_SYN] (in seconds)
Table 2.25-2 VCHK synchronism setting
Units
Setting of difference in frequency between V B and V L
Hz
Setting of difference in voltage between V B and V L
V
- 283 -
V L
V B
V
Comment
6F2T0200 (0.15)
GRE200 (1,2)