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

protection is provided when the auxiliary voltage input is connected to the generator grounding resistor

voltage, the 27X element is set for third harmonic undervoltage, and the 59X is set for the auxiliary

voltage fundamental.

With the auxiliary voltage input connected to the bus, one sync-check function provides synchronism

protection when putting the generator online (25). Sync-check protection checks for phase angle

difference, magnitude difference, frequency difference (slip) and, optionally, if the generator frequency is

greater than the bus frequency.

One negative-sequence overvoltage element provides protection for phase unbalance or a reverse

system phase (47).

Voltage transformer circuit monitoring adds security by detecting problems in the voltage transformer

sensing circuits and preventing misoperations of the 27P, 127P, 47. 59P, 159P, and the 51/27 functions

(60FL).

Directional Power Protection

Two directional power elements provide loss of prime mover protection and/or sequential trip, shutdown

operation (32. 132). Each directional power element can be set individually for forward or reverse power.

The power measurement algorithm is adapted as appropriate for any possible three-phase or single

phase voltage transformer connection. Directional Power is calibrated on a three-phase basis regardless

of the voltage transformer connection used.

Frequency Protection

Four over/underfrequency protection function blocks are provided: 81. 181. 281. and 381. Each function

block can be set for overfrequency or underfrequency operation.

Loss of Excitation

Loss of excitation protection consists of two elements (40Q, 140Q) that use offset sloped var flow

algorithm.

Breaker Failure Protection

One breaker failure protection block (BF) provides programmable breaker failure protection.

General Purpose Logic Timers

Four general-purpose logic timers (62. 162. 262. and 362) with six modes of operation are provided.

Setting Groups

Two setting groups allow adaptive relaying to be implemented to optimize BE1-GPS100 settings for

various operating conditions. Setting group selection can be made via relay logic, 43 auxiliary switches,

and hard-wired inputs.

Virtual Control Switches

BE1-GPS100 virtual control switches include one virtual breaker control switch and four virtual switches.

Trip and close control of a selected breaker can be controlled by the virtual breaker control switch (101).

The virtual breaker control switch is accessed locally from the front panel human machine interface (HMI)

or remotely from the communication ports.

Additional control is provided by the four virtual switches: 43. 143. 243. and 343. These virtual switches

are accessed locally from the front panel HMI or remotely from the communication ports. Virtual switches