UTXvTR: Differential power transformer protection

UTXvTR is a comprehensive main protection device for Power Transformers with 2, 3 or 4 windings, connected at any winding group and ratios.

It provides effective, fast and reliable Power Transformer CB tripping (one or all the PT sides) due to any detected short circuit. The clou of its reliable operation is precise, yet quick analog value measurements, resulting in fast and accurate current vector finding.

14 Bit A/C converters, two serial interfaces (RS 232 supervision channel and RS 485 using standard IEC 870–5–103 protocol), fibre and/or network protocols – TCP/IP are also provided.

UTXvTR Hardware options

  • UTXvTR2 for two windings transformers
  • UTXvTR3 for three windings transformers
  • UTXvTR4 for four windings transformers

Different options of UTXvTR application

UTXvTR stabilising characteristics

UTXvTR characteristics

  • Multiprocessor – functional, measurement and decision making system, equipped with 3 alternative Setting Groups (Banks)
  • Galvanically insulated (analog and digital) input and output signals
  • PT current differential stage with freely programmable restraint curves
  • Balance current 2nd harmonic detector
  • Balance current 5th harmonic detector
  • Four non-directional phase overcurrent stages (4 x I > T), individually configured and attached to one user selected PT side
  • Freely programmable Substation Circuit Breaker Failure protection function, for each of PT side
  • 74 – Bay failure, or CB tripping/Relay internal trouble: UP, AL, AW signalization
  • 30/74 – Fully programmable digital inputs for signals arriving from external protections
  • 33 – LCD screen, Bay Terminal function, enabling user programming up to 15 switches
  • Each protection stage can be set as signal operating only (operational report)
  • Permanent internal bay element and relay operational status/condition supervision
  • Three-level password protection.
  • Disturbance and Event recording (11; 15; 19 Currents + 16 x digital signals).
  • Analog signal synchro-sampling and externally synchronized internal clock
  • Analog signal/value (I; Id; Ih) measurement, LCD (local) visualization and remote data transfer
  • CB tripping number of operations and protection relay operating hours counters
  • Detailed fault monitoring, for local/remote purposes
  • Graphical (LCD) display; 11- key keypad and 16 LEDs (15 freely programmable)
  • 8 (fully user programmable) internal logic functions, for simple, or sophisticated purposes
  • Firmware SAZ 2000 software for: data visualization, remote operation/control and relay configuration

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