GE D90 Plus Instruction Manual page 269

Line distance protection system

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CHAPTER 7: PROTECTION

LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL

must be greater than the

Current Cutoff Level

Power System > AC Inputs – Current menu. The following figure explains the usage of the

voltage polarized directional unit of the element.

Figure 220: Negative-sequence directional characteristics

The forward-looking function is designed to be more secure as compared to the reverse-

looking function, and therefore, should be used for the tripping direction. The reverse-

looking function is designed to be faster as compared to the forward-looking function and

should be used for the blocking direction. This allows for better protection coordination.

The above bias should be taken into account when using the negative-sequence

directional overcurrent element to directionalize other protection elements.

Select the Settings > Protection > Elements > Group 1 > Current > Negative Sequence

Directional OC menu item to open the negative-sequence directional overcurrent

configuration window.

GROUPED PROTECTION ELEMENTS

setting value specified in the Protection >