Protection and control functions, Setting groups, Differential protection – Basler Electric BE1-CDS240 General Information User Manual

Page 5: Overcurrent protection, Voltage protection, Frequency protection, Protection and control functions -3

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Each output is programmable using BESTlogic (assign any virtual output to any physical output

relay) and can be given a user meaningful name for the variable and for each state (open and

closed) for use in reporting functions.

Output logic can be overridden to open, close or pulse each output contact for testing, or control

purposes.

Protection and Control Functions
Setting Groups

Four (4) settings groups allow adaptive relaying to be implemented to optimize the relay settings

for various operating conditions.

Automatic and external logic can be employed to select the active setting group.

Differential Protection

Three-phase percentage restrained differential protection with harmonic restraint: 87. Protection

can be set to monitor two, three, or four windings. Unused inputs can be used for overcurrent

protection.

Two restricted earth fault ground differential protection elements with independent ground (IG)

input (and C-phase, IG2, of Current Circuit 4): 87ND and 187ND.

Tap compensation for the differential protection can be automatically calculated by the relay

based upon user settings of CT ratio, MVA and kV base values.

Ground differential between calculated residual of any winding and the phase C current input of a

fourth and unused winding (IG2).

Each winding can be independently set for a phase relationship (relative to winding 1) of 0 to 360

degrees in steps of 30 degrees.

Each winding can be set for IEC standard transformer connections.

Overcurrent Protection

Instantaneous overcurrent with settable time delay for each operating quantity (A, B, C, N (using

IN or IG) and Q. Eight (8) sets Phase, Five (5) sets Neutral, Four (4) sets Negative-Sequence.

Each function is individually assignable to any of the current input circuits. Functions are: 50TP,

150TP, 250TP, 350TP, 450TP, 550TP, 650TP, 750TP, 50TN, 150TN, 250TN, 350TN, 450TN,

50TQ, 150TQ, 250TQ, and 350TQ.

Inverse time overcurrent functions with integrating or instantaneous reset. Four (4) for Phase, five

(5) for Neutral, and four (4) for Negative-Sequence. Each function is individually assignable to

any of the current input circuits. Functions are 51TP, 151TP, 251TP, 351TP, 51TN, 151TN,

251TN, 351TN, 451TN, 51TQ, 151TQ, 251TQ, and 351TQ.

Time overcurrent functions employ a dynamic integrating timing algorithm covering a range from

pickup to 40 times pickup with selectable instantaneous or integrated reset characteristics.

Time overcurrent curves conform to IEEE PC37.112 and include seven curves similar to

Westinghouse/ABB CO curves, five curves similar to GE IAC curves, four IEC curves, a fixed

time curve, and a user programmable curve.

Digital signal processing filters out unwanted harmonic components while providing fast

overcurrent response with limited transient overreach and overtravel.

Voltage Protection

Voltage control or restraint for 51P (51V protection)

One (1) volts per hertz protective element (24) provides overexcitation protection for a generator

and/or transformer.

Two phase (2) undervoltage elements, 27P and 127P, provide phase undervoltage protection.

Two phase (2) overvoltage elements, 59 and 159, provide phase overvoltage protection.

One (1) negative-sequence overvoltage element (47) provides protection for phase unbalance or

a reverse system phase-sequence.

One (1) zero sequence overvoltage element (59X) provides protection for ground faults on

ungrounded systems using calculated 3VO.

Frequency Protection

Six (6) over/underfrequency protection elements are provided: 81, 181, 281, 381, 481, and 581.

9365200990 Rev M

BE1-CDS240 General Information

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