MiCOM Alstom P543-P546 is a range of transmission-class protection relays providing high-speed current differential unit protection. They are designed for all overhead line and cable applications, interfacing readily with the longitudinal (end-end) communications channel between line terminals. The interface options support direct fibre optic, or multiplexed digital links.
The P543 to P546 offer resident subcycle distance protection, to complement the powerful suite of main and backup protection. Full scheme, five-zone distance protection is adopted from the class-leading MiCOMho Alstom P443.
The P543 to P546 becomes the standard in all HV, EHV and UHV line protection applications, duplicated where dual redundant main protection is demanded. Set any combination of differential, distance, overcurrent and reclosing, depending on the site needs. One universal relay type instead of two or more discrete models means reduced spares holding, less training, and lower cost.
The MiCOM Alstom P544 & P546 are suitable for the complex installation and feeders controlled by two circuit breakers such as breaker-and-a-half configurations.
- Comprehensive line protection: differential, subcycle distance and directional earth fault (DEF)
- Application fields: all lines and cables long or short. Most appropriate for HV, EHV and UHV
- Suitable for use with differential communications channels of balanced and unequal (eg SDH/SONET) transmit and recieive path delays
- Full suite of monitoring, control and recording capabilities plus fault locator, autoreclose and check synchronism
Key customer benefits:
- A universal relay that reduces spare holding - apply as a current differential relay, a distance relay, or both!
- Neutral differential boosts sensitivity of tripping for resistive earth faults, even for lines with heavy load-flow
- Transient biasing reduces CT knee point dimensioning by typically 25% compared to historical applications
- Differential protection adaptable to all different substation topologies: e.g. in-zone transformers and unequal line end CT ratios
- Comprehensive communication options including IEC 61850 and redundant Ethernet ports
- Fast subcycle distance protection with 5 quadrilateral or mho zones and setting free power swing detection
- InterMiCOM64 at 56/64 kbit/s for direct fibre or MUX links
- Compatible with 2Mbit/s teleprotection equipment using P591
Overall differentiation factors:
- Current transformer supervision operates with or without voltage inputs, fast enough to prevent any spurious tripping, and raise the alarm
- True subcycle distance protection - transmission class security and dependability
- Unparallelled speed, security and selectivity
- P543 Line-Differential with Optional Subcycle Distance IED
- P544 Line-Differential & Distance IED for 2 Breakers per End
- P545 Line-Differential with Optional Subcycle Distance IED
- P546 Management of dual breaker autoreclose logic schemes with synchrocheck for both breakers