Relays: L-PRO Transmission Line Protection

Powerlines Feature Article:

Protection of a 230 kV Line Using Both Conventional & Optical CT Inputs at Arizona Public Service

Arizona Public Service (APS) has installed a 3-phase 230 kV NXVCT & an L-PRO Line Protection Relay at Deer Valley Substation in Phoenix. APS was initially attracted to the NXVCT due to safety advantages (no oil or SF6 gas). This installation tests the performance of the NXVCT for protection applications, by using the unique ability of the L-PRO to accept & operate on both optical signals & conventional signals. The NXVCT & the L-PRO both performed correctly during an actual severe fault event.

Expanded I/O: L-PRO Line Protection Relay

The L-PRO provides comprehensive distance based transmission line protection, fault oscillography, dynamic swing recording & event logging with one integrated technology.

    Protection
    Four zones of Phase & Ground distance functions & communications based schemes. Shapeable mho characteristics are available for Phase elements while the Ground elements have shapeable Mho or Quadrilateral characteristics available.

    Protection functions include IEEE devices, 21P, 21N, 25C, 27, 50BF, 50LS, 50/51/67, 50N/51N/67, 46/50/51/67, 59, 60, 68, 79, 81, Dead Line Pickup & Weak Infeed.

    1.0 to 1.3 cycle operation at 80% reach, ideal for transmission line applications.

    Ring bus capability allows breaker failure & individual breaker operation analysis.

    Four shot recloser with line/dead bus control & syc check

    CCVT compensation

    ProLogic - 12control logic statements.

    Integrated breaker failure protection for ring bus applications. Application Note (PDF, 98Kb)

    8 setting groups with setting group logic

    Optional expanded I/O, up to 20 external inputs & 21 outputs

    Recording, Monitoring & Metering
    High quality recording - fault recording (96 samples/cycle), trend & event logging (1 ms resolution).

    Fault location - information provided by event log access or analog input point for SCADA

    Breaker monitoring

    Metering functions for each input connection

    Substation Automation - Ethernet Ready
    Direct-connect DNP3 & Modbus SCADA communication protocols

    3 communication RS-232 ports

    IRIG-B time stamping & sample synchronization

    30 virtual inputs for local & remote control

    Easy To Use
    User-friendly relay setting & record analysis software (Windows? 9x/ME/NT/2000)

    Intuitive ASCII-terminal interface provides full local or remote access.

    Technical Papers

Bus Relay
Feeder Relay
Transmission Line Relay
Transformer Relay