MiCOMho Alstom P443, P445 and P446

MiCOMho Alstom P443, P445 and P446: High Performance Distance Protection
The MiCOM Alstom provides fast, highly selective protection for overhead lines, and the capacity to trip and isolate any faulty circuit.

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

Multiple main protection elements and simplified application
The MiCOMho Alstom 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 Alstom P443, P445 and P446 relay characteristics allow for versatile deployment.

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 MiCOM can be adopted as the standard protection platform.

Breaker control and monitoring application
The MiCOMho Alstom 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.

The MiCOMho Alstom P443 and P445 are suitable for feeders controlled by a single circuit breaker.

  • The logic capabilities of MiCOM products are extremely versatile, for instance managing leader-follower auto-reclosing and check synch schemes in case of 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 & condition monitoring statistics for each pole
  • Trip circuit supervision, control and interlocking schemes can be designed via graphical support software.

Customer 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, fibre or MUX channel
  • Fast CB failure resetting (<3/4 cycle)