operating curve type is selected, an immediate reset occurs during
the drop-off situation.
The setting Time multiplier is used for scaling the IDMT operation and reset times.
The setting parameter Minimum operate time defines the minimum desired
operation time for IDMT. The setting is applicable only when the IDMT curves are
used
The Minimum operate time setting should be used with great care
because the operation time is according to the IDMT curve but
always at least the value of the Minimum operate time setting. More
information can be found in the IDMT curves for overcurrent
protection .
Timer calculates the start duration value START_DUR, which indicates the
percentage ratio of the start situation, and the set operating time, which can be
either according to DT or IDMT. The value is available in the monitored data view.
More information can be found in the General function block features .
Blocking logic
There are three operation modes in the blocking functionality. The operation modes
are controlled by the BLOCK input and the global setting Configuration/System/
Blocking mode which selects the blocking mode. The BLOCK input can be
controlled by a binary input, a horizontal communication input or an internal signal
of the IED program. The influence of the BLOCK signal activation is preselected
with the global setting Blocking mode.
The Blocking mode setting has three blocking methods. In the Freeze timers mode,
the operation timer is frozen to the prevailing value. In the Block all mode, the
whole function is blocked and the timers are reset. In the Block OPERATE output
mode, the function operates normally but the OPERATE output is not activated.
4.2.5.5 Application
During an earth fault, HAEFPTOC calculates the maximum current for the current
feeder. The value is sent over an analog GOOSE to other IEDs of the busbar in the
substation. At the configuration level, all the values received over the analog
GOOSE are compared through the MAX function to find the maximum value. The
maximum value is sent back to HAEFPTOC as the I_REF_RES input. The
operation of HAEFPTOC is allowed in case I_REF_RES is lower than the locally
measured harmonics current. If I_REF_RES exceeds the locally measured
harmonics current, the operation of HAEFPTOC is blocked.
1YHT530004D05 D Section 4
Protection functions
615 series 341
Technical Manual
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