Line Differential Protection Systems

The MiCOM Agile P541 & P542 series provide high speed current differential unit protection. They are designed for overhead line and cable applications, interfacing readily with the longitudinal (end-end) communications channel between line terminals. The interface options support direct fiber optic or multiplexed digital links.

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Key features:

• Differential protection adaptable to different substation topologies: e.g. 2 or 3 terminal lines/cables, in-zone transformers, 3 pole tripping

• An ideal economy solution for distribution applications

• Small case width eases retrofitting tasks

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Main characteristics:

• Choice of communication protocols (IEC 60870-5-103, Modbus & Courier)

• Time synchronization via RS485, IRIG-B (modulated/unmodulated) or opto inputs

• Harsh environment coating as standard to all MiCOM relay to protect against corrosive gases such as H2S or SO2

• InterMiCOM for transmitting 8 digital signals through teleprotection communication links

• 4 independent setting groups

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Overview

Optimum selectivity is assured, as the scheme measures the currents entering and leaving the protected plant item. Instantaneous tripping results for an internal fault, with stability for any out-of-zone fault. Tripping uses a proven characteristic comparing differential current with through current, for ease of testing. Phase differential elements of this type offer consistent detection of solid and resistive faults, with optimum faulted phase selection, tripping, and indication. 

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Key benefits:

• Phase segregated differential with proven biased characteristic for distribution/sub-transmission networks

• Graphical programmable scheme logic (PSL) eases protection scheme creation, and avoids the need for external logic controllers

• Comprehensive communication options, ideal relay for the step from pilot wire to fiber or multiplexed end-end communications

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Models

MiCOM Agile P541 & P542 Models

P541 Line-Differential Protection IED, in 40TE case

P542 Line-Differential Protection IED with Autoreclose, in 60TE case