Toshiba GR200 Series Instruction Manual page 501

Scheme for synchronism
2.35.3
VCHK has a measuring function, which checks the difference between a running voltage and
an incoming voltage. The measuring function checks phase angles, voltages, and frequencies.
The VCHK1 determines the synchronism based on the presence of voltage on both Bus-bar and
Line, as shown in Figure 2.35-4(a). The VCHK2 also determines the synchronism based on the
presence of voltage on both Line2 and Line, as shown in Figure 2.35-4(b).
S = SYN1-Angle
s
1
VCHK-OVB or
VCHK-OVL
a. SYN1
Figure 2.35-4 SYN1 and SYN2 characteristics
This function performs three checks: (1) checking voltage difference, (2) checking
frequency difference, and (3) checking phase difference. The following variables represent
algebraic expression used in these checking:
V B =
V L1 =
V L2 =
ΔV1 =
ΔV2 =
fV B =
fV L =
fV L2 =
f =
Δf1 =
Δf2 =
θ1=
θ2 =
SYN1-dV =
SYN2-dV =
VCHK-OVB = voltage setting for Bus-bar [VCHK-OVB]
VCHK-OVL = voltage setting for Line [VCHK-OVL]
VCHK-OVL2 = voltage setting for Line2 [VCHK-OVL2]
V L
V B
V1
Bus-bar voltage
Line voltage
Line2 voltage
Voltage difference between Bus-bar and Line
Voltage difference between Line2 and Line
frequency of V B
frequency of V L
frequency of V L2
slip cycle
frequency difference between Bus-bar and Line
frequency difference between Line2 and Line1
phase difference between V B and V L
phase difference between V L2 and V L
Voltage difference setting [SYN1-dV]
another voltage difference setting [SYN2-dV]
- 478 -
S = SYN2-Angle
s
2
VCHK-OVL2 or
VCHK-OVL
b. SYN2
6F2S1914 (0.49)
V L
V L2
V2
GRL200 (Soft 033 & 037)