GE Logo
Home Products & Services Industries News/Events About Us Resources Contact Store
category banner
Protection Relays
Line Protection

Home > Grid Automation > Protection Relays > Line Protection > P44 MiCOMho 5th Generation

Related Links
  Interactive Selector Guide - Line Differential
  Interactive Selector Guide - Line Distance
  Spotlight Application
  Typical Applications
  Transmission Principles & Protection
  GSA Schedule
  Legacy Transmission Protection

P44 MiCOMho 5th Generation
Line Distance Protection

The P44, part of the MiCOM P40 Agile 5th Generation family, is a line distance Protection that delivers high performance processing and a graphical HMI as standard and provides up to 9 zones of subcycle distance protection with both mho/quad characteristics and delta directional comparison (incremental) protection.
In addition, distance phase preference tripping logic and transient earth fault detection (TEFD) for Petersen coil earthed and isolated systems. The P44 range of products is ideal for HV, EHV and UHV applications on lines and cables for 1 or 2 breaker applications with patented adaptive auto-reclose functionality.

Key Benefits:

  • Integrated full colour display, for single-line diagram control of the protected bay.
  • True subcycle distance protection with up to 9 fully directional distance zones for transmission class security and dependability
  • Load blinder prevents spurious trips cascading through the network in extreme conditions such as on the verge of a blackout
  • Distance phase preference tripping logic and transient earth fault detection (TEFD) for Petersen coil earthed and isolated systems
  • Unparalleled speed, security and selectivity
  • With fast start up time of less than 10s, resulting in protection, control and communications without the need to wait
  • Full suite of monitoring, control and recording capabilities plus fault locator.
  • Multi-shot autoreclosure with check synchronism - adaptive technology to detect fault arc extinction and accelerate the dead time or drive to lockout for persistent faults
  • Harsh environment coating as standard for all GE’s MiCOM P40 relays protects against corrosive gases such as H2S or SO2
  • No internal batteries in GE-branded models – removes a maintenance item and eases air-freight logistics
  • CyberSentryTM Advanced Security including AAA, Radius, RBAC, and Syslog
  • IEC 61850 9-2LE Process Bus capability with PRP in all models
  • Secure Data vault with 5000 events, 100 Fault records and over 1000s of Oscillography
  • Binary inputs ESI48-4 EB2 compliant
What's New

What's New

MiCOM P40 Agile Explorer


Transmission and distribution systems are essential for the safe, sure routing of power from generation sources to consumers. However, exposed overhead lines transporting power are by nature sometimes vulnerable and prone to fault. In the case of a faulty circuit, the MiCOM range provides speedy protection to trip and isolate it, thereby preventing further damage.

Each relay model contains multiple main protection elements: distance, delta directional incremental protection and directional earth/ground fault unit protection (DEF). This permits simplified application and spares holdings, because the relay can be adopted as the standard protection platform. 

The MiCOMho P44 is suitable for feeders controlled by a single circuit breaker and for complex installations where feeders are controlled by two circuit breakers such as ring bus/mesh corner formations and the breaker-and-a-half configurations. 

Key Benefits

  • Sub-cycle fault clearance from 0.7 to 1 cycle
  • Simple set mode: The relay determines its own settings from protected line data
  • Power swing blocking without the need for setting
  • Integral teleprotection via a MODEM, fiber or MUX channel
  • Fast CB failure resetting (< 3/4 cycle)
  • Phase-preference tripping for cross-country earth faults in Petersen/isolated systems
  • Multi-shot 1/3pole & 3pole autoreclosure with check synchronism - adaptive technology to detect fault arc extinction and accelerate the dead time or drive to lockout for persistent faults.  Improves system stability whilst reducing OPEX.

Main Characteristics:

  • Comprehensive communication options including IEC 61850 Edition 2
  • IEC 61850 redundant Ethernet protocols - RSTP, PRP or HSR
  • IEC 61850 9-2LE redundant PRP Process bus protocol
  • Fast subcycle distance protection with quadrilateral or mho zones and setting free power swing detection
  • InterMiCOM64 for transmitting digital signals (32) through teleprotection communication links
  • CyberSentryTM  Advanced Security including AAA, Radius, RBAC, and Syslog

Functional Block Diagram

Agile P44T Enhanced-diagram

ANSI ® Device Numbers and Functions

Device Number Function
25 Check Synchronizing
27 Pand & Line Undervoltage
37 Undercurrent
46 Negative Sequence Overcurrent
49 Thermal Overload
50 Phase Definite Time Overcurrent
51 Phase Inverse-Time Overcurrent
52 Circuit Breaker Control
59 Phase & Line Overvoltage
67 Directional Phase Overcurrent
68 Power Swing Blocking
78 Out-of-Step Tripping
78DC Delta (Incremental) Protection
79 Autoreclose/Adaptative Autoreclose
Device Number Function
85 InterMiCOM Teleprotection
86 Latching/Lockout Contacts
21BL Load Encroachment/Blinder
21FL Fault Locator
21G Ground Distance
21P Phase Distance
46BC Broken Conductor
50/27 Switch-on to Fault
50BF CB Failure
50N Earth Fault Definite Time Overcurrent
50ST Stub Bus Protection
51N Neutral/Ground IDMT Overcurrent
59N Neutral Voltage Displacement
59R Remote End Overvoltage
Device Number Function
64N Restricted Earth Fault
67N Directional Neutral/Ground Overcurrent
81df/dt Rate of Change Frequency
81O Overfrequency
81U Underfrequency
CTS CT Supervision
PSL Programmable Logic
SEF Sensitive Earth Fault
TEFD Transient Earth Fault Detection
TCS Trip Circuit Supervision
VTS VT Supervision

P44 MiCOMho 5th Generation

P44 MiCOMho Line Distance Protection

Buy Now

MiCOM S1 Agile

Key benefits:

Engineering Tool Suite

S1 Agile is the truly universal PC tool for MiCOM Agile relay, assemble all tools in a palette for simple entry, with intuitive navigation via fewer mouse-clicks. No-longer are separate tools required for redundant Ethernet configuration, phasor measurement unit commissioning, busbar scheme operational dashboards, programmable curve profiles or automatic disturbance record extraction – applications are embedded. MiCOM S1 Agile supports all existing MiCOM, K-Series and Modulex, including a utility for automatic conversion of setting files from previous generations of numerical relays like K-series and MiCOM P20 to the latest P40 Agile models.

To move to the future, with no loss of functionality, no loss of device support, and full compatibility with your installed base and system architecture – request a copy of S1 Agile with the contact form link below.

MiCOM S1 Agile software

Key features in the MiCOM S1 family:

MiCOM S1 Agile software request

To receive the MiCOM S1 Agile, please use our Contact form. This will also ensure that you are kept up-to-date with the latest enhancements, including updates and bug fixes.

Refurbishment Solutions

GE’s latest P44 MiCOMho 5th Generation transmission models offer a perfect functional match to our “mho” family of distance relays, from the heritage installed-base brands GEC Measurements, GEC Alsthom, Alstom and Areva. The subcycle pedigree is maintained, optimised and advanced:

SHNB Micromho and SHPM Quadramho Replacement:

LFZP Optimho and LFZR Replacement:

LFDC Delta Directional Comparison Relay Replacement:

MiCOMho P441/2/3/4/5/6 Relay Replacement:

Pin-Pin Upgrade Methodology: