ROCOF Protection Configuration
ROCOF protection can be made available by making UOF protection available.
This can be done in WSOS on the Feature Selection page.
> >
Or on the operator interface.
Once UOF has been made available, ROCOF can be configured in WSOS on the same page in the Protection Group settings.
Figure 176
ROCOF Definite Time Protection
settings
ROCOF can also be configured on the operator interface.
ROCOF can be configured using the settings described in the following table:
Table 62 ROCOF Protection settings
|
Setting |
Description |
|---|---|
|
ROCOF Trip |
Must be On in the active protection group for ROCOF to cause a protection trip. |
|
Setting Rate |
The minimum ROCOF (df/dt) in Hertz per second that will cause ROCOF to pick up and start the protection timing. |
|
Definite Time |
The time ROCOF must be in the pickup state before a protection trip will occur. |
|
Reset Time |
The time it takes the protection timing to reset if the measured df/dt falls below the Setting Rate when a pickup is active. |
|
Direction |
Determines whether the element will react to just rising of falling frequency conditions or both. |
|
Frequency Block |
Can be helps to prevent ROCOF protection tripping unless the measured frequency is outside of normal limits. Make sure that the Under Frequency Normal at setting is lower than the Over Frequency Normal At setting for ROCOF Blocking to operate correctly. |