Metering Function; Control Function - Toshiba GRE110 Instruction Manual

3.5 Metering Function

The GRE110 performs continuous measurement of the analogue input quantities. The
measurement data shown below is renewed every second and displayed on the LCD of the relay
front panel or on the local or remote PC.
- Magnitude of phase current (I a , I b , I c )
- Magnitude of zero sequence current (I e , I se )
- Magnitude of zero phase voltage (V e )
- Magnitude of positive and negative sequence currents (I
- The ratio of negative to positive sequence current (I
- Percentage of thermal capacity (THM)
- Maximum phase current (I a max, I b max, I c max)
- Maximum zero sequence current (I e max, I se max)
- Maximum zero phase voltage (V e max)
- Maximum negative sequence currents (I
- Maximum ratio of negative to positive sequence current (I
The above system quantities are displayed in values on the primary side or on the secondary side as
determined by a setting. To display accurate values, it is necessary to set the CT ratio as well. For
the setting method, see "Setting the metering" in 4.2.6.6 and "Setting the parameter" in 4.2.6.7. In
the case of the maximum value displays above, the measured quantity is averaged over a rolling 15
minute time window, and the maximum recorded average value is shown on the display screen.
The zero sequence current I e in the model 420 is calculated from the three phase input currents and
the calculated I e (I 0 ) is displayed. The I e in other settings and models is displayed the current fed
from CT.
The zero phase voltage V e input is for model 820 and 821. On model 820 and 821, the B phase
cuurent I b is calculated from A phase current I a and C phase current I c .

3.6 Control Function

The relay is provided with the following control functions:
• CB control
• Interlocking
• Change of CB control hierarchy
The CB control function operates the CB by using the open command key ○ or close command
key ｜ on the front panel of the relay, a BI command from remote state or by using the
communication function.
The interlock function blocks the CB close command using the control lock signal of the BI
command.The change of CB control hierarchy changes the CB control state to Local or Remote.
The Local mode is controled at the front panel of the relay (see chapter 4.2.7). The Remote mode is
controlled by BI command or by a communication function of Modbus (see Appendix M) or IEC
61850 (see Appendix P).
, I
1
/I )
2 1
max)
2
 78 
6 F 2 T 0 1 7 2
)
2
max)
21