Basler Electric GENERATOR PROTECTION SYSTEM BE1-GPS100

Protection, and general-purpose logic timers. Setting Groups and Virtual Control Switches make up the

control functions. The following paragraphs describe each protection and control function.

Overcurrent Protection

Phase and one neutral instantaneous overcurrent elements (50TP and 50TN) with settable time delays

provide inadvertent energization protection when properly supervised by voltage and/or frequency

elements (381. 159. 127).

One phase time-overcurrent element can be voltage restrained (51/27R) or voltage controlled (51/27C) to

provide system backup overcurrent protection (51P).

Two neutral inverse time-overcurrent elements provide ground overcurrent protection and/or generator

step-up (GSU) transformer ground backup protection (51TN and 151TN).

Each neutral 50/51 element can be assigned to monitor either the three-phase residual (IN

) or the optional

independent ground input (IG

).

One inverse time, negative sequence overcurrent element provides generator unbalance overload

protection (46).

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 the IEEE C37.112 document 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. Each time current characteristic can be set for integrating or

instantaneous reset.

Digital signal processing filters out unwanted harmonic components while providing fast overcurrent

response with limited transient overreach and over-travel.

Voltage Protection

One volts per hertz protective element provides overexcitation protection for a generator and/or GSU

transformer (24).

Two phase overvoltage and two phase undervoltage element provides over/undervoltage protection (27P,

127P, 59P, and 159P). Phase overvoltage protection can be set for one of three, two of three, or three of

three logic. When a four-wire voltage transformer connection is used, overvoltage protection can be set

for either phase-to-phase voltage or phase-to-neutral voltage.

Two auxiliary overvoltage and two auxiliary undervoltage elements provide over/undervoltage protection

(27X, 127X, 59X, and 159X). Auxiliary voltage protection elements can be set to individually monitor the

auxiliary voltage fundamental, third harmonic, or phase 3V0 voltages. Complete stator ground fault