Freq Rate 1 Min Frequency; Freq Rate 1 Max Frequency; Frequency Rate Of Change Scheme Logic - GE T60 Instruction Manual

5.7 CONTROL ELEMENTS
• FREQ RATE 1 MIN FREQUENCY: This setting defines minimum frequency level required for operation of the element.
The setting may be used to effectively block the feature based on frequency. For example, if the intent is to monitor an
increasing trend but only if the frequency is already above certain level, this setting should be set to the required fre-
quency level.
• FREQ RATE 1 MAX FREQUENCY: This setting defines maximum frequency level required for operation of the ele-
ment. The setting may be used to effectively block the feature based on frequency. For example, if the intent is to mon-
itor a decreasing trend but only if the frequency is already below certain level (such as for load shedding), this setting
5
should be set to the required frequency level.
If the signal source assigned to the frequency rate of change element is only set to auxiliary VT, then the minimum
voltage supervision is 3 V.
NOTE
SETTINGS
FREQ RATE 1 FUNCTION:
Enabled = 1
FREQ RATE 1 BLOCK:
Off
SETTING
FREQ RATE 1 SOURCE:
Pos seq voltage (V_1)
Pos seq current (I_1)
Frequency (F)
5-282
SETTING
FREQ RATE 1 OV SUPV
PICKUP:
RUN
| V_1 | > PICKUP
SETTING
FREQ RATE 1 OC SUPV
PICKUP:
RUN
| I_1 | >PICKUP
SETTINGS
FREQ RATE 1 MIN
FREQUENCY:
FREQ RATE 1 MAX
FREQUENCY:
RUN
F > MIN & F < MAX
RUN
Calculate df/dt
Figure 5–143: FREQUENCY RATE OF CHANGE SCHEME LOGIC
T60 Transformer Protection System
SETTINGS
FREQ RATE 1 PICKUP
SETTINGS
DELAY:
FREQ RATE 1 TREND:
FREQ RATE 1 RESET
DELAY:
FREQ RATE 1 PICKUP:
t
RUN PKP
df/dt > PICKUP
5 SETTINGS
FLEXLOGIC OPERANDS
FREQ RATE 1 OP
t
RST FREQ RATE 1 DPO
FREQ RATE 1 PKP
832023A2.CDR
GE Multilin