Intelligent Electronic Device for Metering, Control and Protection





  • 3 devices in 1: multifunctional power meter, remote terminal unit, relay protection and emergency control terminal.
  • Modular design: unit changeability (including «hot swap»), eased set of spare parts and accessories onsite.
  • Malfunction diagnostic: diagnostic of units, control channels, communication channels, internal links etc.
  • Up-to-date communication capabilities:   

communication protocols IEC 61850,   

IEC 610870-5-101/104, complete device integration.

  • Reliable multiprocessor architecture:

communication processor, input/output processor, algorithm processor.

Relay protection functions:

  • 4-stage overcurrent protection (OCP) against phase-to-phase short circuit with current control in 2 or 3 phases; OCP is used for protection against phase-to-phase short circuit and overload of protected feeders. First and second stage has independent and dependent (inverse, heavy inverse, extra inverse) time-current characteristic. Third and fourth stage have independent time-current characteristic. Device provides implementation of up to 4 independent groups of settings.
  • Busbar protection (BP). BP is used for accelerating of overcurrent protection effect against short circuit on feeders bus. Interfacing of busbar protection is implemented by parallel or cascade scheme.
  • Automatic start of overcurrent protection stages acceleration is triggered by circuit-breaker.
  • Current over-phase and unbalance protection. Current over-phase and unbalance protection is implemented with current correlation control (positive-sequence current, negative-sequence current).
  • Phase-to-earth fault protection by higher harmonics sum.
  • Phase-to-earth fault protection by current of nominal frequency.
  • Built-in test of voltage circuits.

Emergency automatics functions:

  • Breakers control automation function (BCA).
  • Single or double automatic reclosing.
  • Automatic switching over to a reserve source with restoration service functions.
  • Breaker failure protection.

The device provides forming of output signal for related circuit breaker opening in case of protection start and circuit breaker failure.

  • Circuit breaker open/close operations by external commands with multiple switching protection.
  • External protections interface  (ex.: arc protection)
  • Implementation of external signals (ex.:, frequency load shedding, frequency-actuated automatic reclosing, special load shedding automatics, etc).

Emergency events recorder functions:

  • Starting at specified conditions (UA, UB, UC, U1, U2, 3U0, IA, IB, IC, I1, I2, 3I0, f, discrete signals, etc), manual (program).
  • Event logging.

Relay protection and automatics. Additional functions:

  • Rapid and freely programmable logic (less than               5 ms  per 1 iteration).
  • Fast-speed functions for current, voltage and frequency (under pullup/pulldown of characteristic referred to specified tripping points with program defined hysteresis).
  • Remote internal configuration (input/output of protections and automatics, configuration of specified sets of automatics, protection feature selection, etc).
  • Remote input and energy-independent storage  of protection trip points and designed automatics configurations.
  • Hold of outputs in case of device breakage for exception of false firing.

Automation and remote control functions:

  • Measurement of current and voltage values.
  • Digital signal information with timestamp less than 1 ms.
  • Remote control commands.
  • Receiving and data transferring of digital and analog signal statuses by IEC 61850-8-1 (GOOSE).
  • Microprocessor devices integration via RS 422/485, IEC 61850-8-1 (MMS), IEC 60870-5-101/103/104, Modbus, etc.
  • Local data archiving and buffering of event information.
  • Computing of parameters and integral characteristics by current and voltage values.
  • Technical metering.
  • Implementation of algorithms freely programmable logic.
  • Implementation of interlocking function and switchgear management permission.
  • Implementation of prompt circuit breaker disconnection algorithms.
  • Preprocessing of data, buffering and data transmission to SCADA server and/or Station Controller by TCP/IP IEC 61850-8-1 (MMS), МЭК 60870-5-104.
  • Data transmission to control center by IEC 60870-5-104 (using TCP/IP) or IEC 60870-5-101 using RS 422/485)
  • Time synchronization using NTP, SNTP, PTP, NMEA or TSIP protocols with accurate up to ± 0,5 ms.
  • Feeder management by front panel (if available).

Device installation:

  • Device can be installed on the door of switchgear relay box and on assembling panel as well.
  • Plug-in connectors are available either on lateral side or on rear side of the device.
  • Could be equipped by removable front panel.

Connection layout: