CHAPTER 7: PROTECTION CONTROL ELEMENTS
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL 383
Figure 321: Recloser curve initialization
NOTE:
The multiplier and adder settings affect the curve portion of the characteristic and not the
MRT and HCT settings. The HCT settings override the MRT settings for multiples of pickup
greater than the HCT ratio.
Composite recloser curve example
A composite curve can be created from the GE_111 standard with MRT = 200 ms and HCT
initially disabled and then enabled at eight times pickup with an operating time of 30 ms.
At approximately four times pickup, the curve operating time is equal to the MRT and from
then onwards the operating time remains at 200 ms (see figure).
Figure 322: Composite recloser curve with HCT disabled
With the HCT feature enabled, the operating time reduces to 30 ms for pickup multiples
exceeding eight times pickup.
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