Phasor Measurement Unit

Description

A Phasor Measurement Unit (PMU) is a sophisticated sensor that measures synchronized phasors (magnitude and phase angle) of voltage and current on the power grid.

Key features of PMUs include:

• High sampling rates for capturing rapid changes
• Precise GPS time-stamping for synchronized measurements
• Real-time data transmission for immediate analysis

PMUs offer significant benefits for power system management, including:

• Wide-Area Monitoring (WAMS): Providing a real-time overview of the interconnected grid.
• Improved Grid Stability: Detecting and mitigating oscillations that can threaten system integrity.
• Faster Fault Detection and Location: Enabling quicker power restoration after outages.
• Enhanced Situational Awareness: Giving operators the information needed to make proactive and informed decisions.

Applications

PMU PRO - Phasor Measurement Unit

• IEEE C37.118.1-2011, IEEE C37.118.1a-2014 and IEC/IEEE 60255-118-1:2018 P-Class and M-class performance compliance
• Clock synchronization to a UTC time reference using an IRIG-B timecode source or an IEEE 1588 PTPv2 master clock source
• Streaming of phasor data over Ethernet using the IEC 61850-9-2 multicast sampled value (SV) service with IEEE C37.118.2 compliant mapping of synchrophasor data upon IEC 61850-9-2 and IEC 61850-90-5 guidelines
• Expected steady-state total vector error (TVE) at nominal frequency: < 0.05%
• IEEE C37.118.1
  • Compliant 3-phase voltage, current, positive and negative sequence phasor measurements synchronized to a common UTC time reference
  • Synchronous frequency and Rate of Change of Frequency (ROCOF) measurements
• IEEE C37.118.2
  • Commanded client-server UDP and TCP data transmission and spontaneous UDP data transmission over IP protocol
  • Streaming rates up to 200 frames/s @ 50Hz and up to 240 frames/s @ 60Hz
  • Synchrophasor data frames transmit a time stamped set of measurements including phasor estimates, frequency deviation from the nominal power, line frequency or actual frequency, rate of change of frequency.
  • Data frame can be expanded to contain analog data (total active, reactive and apparent power, power factor) and digital input status information (up to 32 inputs).
  • Phasor components can include 3 voltage and 3 current phasors, positive sequence voltage and current phasors, negative sequence voltage and current phasors, or all of them in one frame.
  • Complex phasor values can be sent in a rectangular coordinates format (real and imaginary) or in polar coordinates (magnitude and angle).
  • Phasor and frequency data can be represented in 32-bit IEEE floating-point format or as 16-bit scaled integer numbers. When using the integer format, the data conversion factors are provided in IEEE C37.118.2 configuration frames.
  • The PMU PRO supports CFG-1, CFG-2 and CFG-3 configuration frames.
  • In spontaneous UDP data transmission mode, CFG-2 or CFG-3 configuration frames can be sent spontaneously without an explicit user command. When enabled, a configuration frame is sent periodically every 30 seconds.
• 5 data streaming slots for continuous synchrophasor data streaming via unicast UDP or/and TCP connections

Plug-In Modules

Automation & Control Modules

Auxiliary Power Supply Module

Tech Specs

• Logging, Recording & Programming

  • Programmable controller: up to 32 control setpoints and half-cycle scan time
  • OR, AND, arithmetical functions logic, extensive triggers, programmable thresholds and delays, relay control, event-driven data recording
  • Event recorder for logging internal diagnostic events, power faults and operations of the logic controller and digital I/O
  • 8 data recorders with programmable datasets for data logging on a periodic basis and on any internal or external trigger
  • 32 digital counters for counting internal events and pulses from external sources
  • 16 interval timers with programmable periods from ½ cycle to 24 hours for periodic recording and triggering timed operations

• • Variable Current Inputs

    • 5A
    • 1A

  • Voltage Measurement Inputs

    • Measurement category: CAT III
    • Operating range: up to 277/480V AC + 25%

• I/O

  • Built-in I/O
    • 1 AI (±1 mA; 0-1 mA; 0-20 mA; 4-20 mA)
    • 1 SSR (100mA/250V AC/DC) External power supply 24/48/125/250V DC
    • 1 DI Internally wetted @ 24VDC
  • 4 Relay Outputs - Electromechanical (SPST Form A)
    • 5A/30 VDC
    • 5A/250V AC
    • 100mA/800V DC
  • Combo: 4 Digital Inputs + 2 Relay Outputs
  • 4 Analog Outputs

    Universal (configurable) isolated analog outputs

    • ±1 mA
    • 0-1 mA
    • 0-20 mA
    • 4-20 mA

• Communication Interfaces

  • Two 10/100Base-T IEEE 1588 Ethernet ports
    • Packet forwarding / routing capabilities
    • Connecting to Ethernet through one or two different network switches
    • Daisy chaining multiple devices to a switch using a linear or ring network topology (daisy chaining is not available for PTP-enabled devices)
    • Up to 8 simultaneous TCP connections via Modbus TCP, DNP3, IEC 60870-5-104, IEC 61850 protocols
    • Up to 5 client associations, GOOSE and MSV publishers
  • Up to 5 TCP or/and UDP synchrophasor data streams via C37.118.2 protocol
  • Full speed USB 2.0 type C port for local configuring and monitoring the device via Modbus RTU protocol
  • Modbus TCP notification client
  • Expertpower Client
  • RS-485 serial communication port
    • 2400 - 115200 bps
    • Modbus RTU, DNP3 and IEC 60870-5-101 protocols
    • Using the IRIG-B time synchronization source disables the port

• Display

  • High contrast 1.77” TFT color graphics display with configurable backlight
  • Multi-page displays; time, instrumentation and service data
  • Menu-driven setups
  • Multilanguage support

• Real-Time Clock & Synchronization

  • High-accuracy real-time clock with a lithium backup battery
  • Clock synchronization to a UTC time reference using an IRIG-B timecode source or an IEEE 1588 PTPv2 master clock
  • Daylight saving time shift for local time indication with configurable DST start and end time

• Power Supply

  • Built-in
    • 57.7-277V AC / 48-290V DC
  • Additional options:
    • AUX 88-264V AC / 90-290V DC
    • AUX 9-36V DC

• • Enhanced Meter Security

    • 3 levels Password security for protecting meter setups and accumulated data from unauthorized changes

  • Mounting

    • DIN Rail mount

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