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MiCOMho Agile P443, P445, P446
Distance Protection Systems

The MiCOMho Agile P443, P445 and P446 relays operate with advanced load blinding and disturbance detection techniques, such as power swing blocking, to ensure stability when no tripping is required. Whether protection is required for lines, cables or hybrids of grounded transmission and distribution circuits, the MiCOMho Agile P443, P445 and P446 relay characteristics allow for versatile deployment.

Key features:

  • Extremely versatile logic capabilities, managing leader-follower auto-reclosing and check synch schemes in dual breaker applications
  • Transmission-class circuit breaker failure protection for one or two breakers. The breaker failure protection may be initiated from internal protection within the relay or from external devices
  • Single-pole and 3-pole breaker operation is supported, with independent supervision and condition monitoring statistics for each pole
  • Trip circuit supervision, control and interlocking schemes can be designed via graphical support software
What's New

What's New

Enhanced Ethernet board module with switchable Ethernet redundancy delivered in a single model.

The new board module is supported on P443, P445 and P446 SW 76, 79, 86 and 87.

It supports PRP, HSR and RSTP in one model, allowing a single P40 model to be used in any application requiring redundant Ethernet communications. The new module is designed to handle high density traffic in the IEC 61850-8-1 network, with time latency halved. Larger architecture digital substations can also be supported, with up to 50 nodes now possible in HSR rings.

Key Features & Benefits:

  • Universal IRIG-B – Modulated and demodulated supported in the same model
  • HSR Ring – Extended to 50 node support for larger substation architectures
  • Fast performance, particularly in onerous applications such as where process bus GOOSE is used for tripping purposes


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 Agile range provides speedy protection to trip and isolate it, thereby preventing further damage.

Each relay model contains multiple main protection elements: distance, delta directional comparison 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 Agile P443 and P445 are suitable for feeders controlled by a single circuit breaker. The MiCOMho Agile P446 is suitable 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:

  • P443 and P446: 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 (P443 version 78)


P443 High Performance Distance Protection

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P445 High Performance Distance Protection

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P446 High Performance Distance Protection

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