Toshiba GR 200 Series, Instruction Manual

Page: 402 / 1563

6F2S1915 (0.46)
GRZ200 (Soft 031 & 032)
- 381 -
2.25.3
Scheme for synchronism
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 2.25-4(a). The VCHK2 also determines the synchronism based on the
presence of voltage on both Line2 and Line, as shown in Figure 2.25-4(b).
VCHK-OVB or
VCHK-OVL

1

s
a. SYN1
VB
VL

V1

S = SYN1-Angle
VCHK-OVL2 or
VCHK-OVL

2

s
b. SYN2
VL2
VL

V2

S = SYN2-Angle
Figure 2.25-4 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:
VB = Bus-bar voltage
VL1 = Line voltage
VL2 = Line2 voltage
ΔV1 = Voltage difference between Bus-bar and Line
ΔV2 = Voltage difference between Line2 and Line
fVB = frequency of VB
fVL = frequency of VL
fVL2 = frequency of VL2
f = slip cycle
Δf1 = frequency difference between Bus-bar and Line
Δf2 = frequency difference between Line2 and Line1
θ1= phase difference between VB and VL
θ2 = phase difference between VL2 and VL
SYN1-dV = Voltage difference setting [
SYN1-dV
]
SYN2-dV = another voltage difference setting [
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
]