SIPROTEC 7UT612

SIEMENS SIPROTEC 4 SIPROTEC 7UT612 TRANSFORMER DIFFERENTIAL PROTECTION RELAY

The SIPROTEC 7UT612 differential protection numerical relay is used for fast and selective fault clearing of short-circuits in transformers of all voltage levels and also in rotating electric machines like motors and generators, for short lines and busbars. The protection relay can be parameterized for use with three-phase and single-phase transformers. The specific application can be chosen by parameterization.

In this way, an optimal adaption of the relay to the protected object can be achieved. In addition to the differential function, a backup overcurrent protection for 1 winding/star point is integrated into the relay. Optionally, a low or high-impedance restricted earth fault protection, negative sequence protection, and a breaker failure protection can be used. With external temperature monitoring boxes (thermo-boxes) temperatures can be measured and monitored in the relay. Therefore, complete thermal monitoring of a transformer is possible, e.g. hot-spot calculation of the oil temperature.

The relays provide easy-to-use local control and automation functions. The integrated programmable logic (CFC) allows the users to implement their own functions, e.g. for the automation of switchgear (interlocking). User-defined messages can be generated as well.The flexible communication interfaces are open for modem communication architectures with the control system. The protection relay can be parameterized for use with three-phase and single-phase transformers. In addition to this, a thermal replica is integrated for the supervision of the ohmic losses in the plant.

SIPROTEC 7UT612 PROTECTION RELAY FUNCTION OVERVIEW

• Differential protection for two-winding transformers (3-/1-phase)
• Differential protection for motors and generators
• Differential protection for short lines
• Differential protection for busbars up to 7 feeders (phase-segregated or with summation CT)

SIPROTEC 7UT612 PROTECTION RELAY

PROTECTION FUNCTIONS

• Differential protection with phase-segregated measurement
• Sensitive measuring stage for low-fault currents
• Fast tripping for high-fault currents
• Restraint against the inrush of the transformer
• Phase/ground-overcurrent protection
• Overload protection with or without temperature measurement
• Negative-sequence protection
• Breaker failure protection
• Low-or high-impedance restricted earth fault (REF)

CONTROL FUNCTIONS

• Commands for control of c.b. and isolators
• Control via keyboard, binary inputs, DIGSI 4, or SCADA system
• User-defined logic with CFC

MONITORING FUNCTIONS

• Self-supervision of the relay
• Trip circuit supervision
• Oscillographic fault recording
• Permanent differential and restraint current measurement, the extensive scope of operational values

COMMUNICATION INTERFACES

• PC front port for setting with DIGSI 4
• System interface IEC 61850 Ethernet – IEC 60870-5-103 protocol – PROFIBUS-FMS – PROFIBUS-DP – MODBUS – DNP 3.0
• Service interface for DIGSI 4 (modem)/temperature monitoring (thermo-box)
• Time synchronization via IRIG-B/DCF 77

SIPROTEC 4 leads the way in integrating protection, control, measurement, and automation functions in one device. The homogenous system platform, the unique DIGSI 4 engineering program, and extensive experience of more than a million successfully operating devices in the field worldwide – thanks to these unique advantages, SIPROTEC 4 enjoys top recognition among users worldwide. SIPROTEC 4 is the industry standard for digital protection technology today in all fields of application.