To Next Page

To Previous Page

5-246 L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL

GROUPED ELEMENTS CHAPTER 5: SETTINGS

The power swing detect element provides both power swing blocking and out-of-step tripping functions. The element

measures the positive-sequence apparent impedance and traces its locus with respect to either two or three user-

selectable operating characteristic boundaries. Upon detecting appropriate timing relations, the blocking and/or tripping

indications are given through FlexLogic operands. The element incorporates an adaptive disturbance detector. This

function does not trigger on power swings, but is capable of detecting faster disturbances—faults in particular—that can

occur during power swings. Operation of this dedicated disturbance detector is signaled via the POWER SWING 50DD

operand.

The power swing detect element asserts two operands intended for blocking selected protection elements on power

swings: POWER SWING BLOCK is a traditional signal that is safely asserted for the entire duration of the power swing, and

POWER SWING UN/BLOCK is established in the same way, but resets when an extra disturbance is detected during the power

swing. The POWER SWING UN/BLOCK operand can be used for blocking selected protection elements if the intent is to

respond to faults during power swing conditions.

Different protection elements respond differently to power swings. If tripping is required for faults during power swing

conditions, some elements can be blocked permanently (using the POWER SWING BLOCK operand), and others can be

blocked and dynamically unblocked upon fault detection (using the POWER SWING UN/BLOCK operand).



POWER SWING INNER

LIMIT ANGLE: 60°

Range: 40 to 140° in steps of 1



POWER SWING OUTER

RGT BLD: 100.00 Ω