GE VERNOVA | CENTRALIZED BUS PROTECTION SYSTEM | MICOM P747
The MiCOM Agile P747 provides complete protection for voltage levels up to extra high voltage busbar configurations with a centralized 3-box architecture. The MiCOM Agile P747 can accommodate up to 4 zones plus check zone and protect up to 18 terminals. The MiCOM Agile P747 Is particularly useful in double busbar with double bus coupler applications and allows a high number of opto inputs, relay outputs, and virtual inputs and outputs to manage the complete substation scheme. The MiCOM Agile P747 also incorporates enhanced circuit breaker failure logic with additional protection functions such as dead zone and overcurrent. In addition, the MiCOM Agile P747 provides a wide range of measurement, monitoring, post fault analysis and self-diagnostic features. Powerful programmable scheme logic, trip circuit supervision, fully customizable menu texts, multi-level password protection, on-line measurements and plant status monitoring are all included. MiCOM Agile P747 employs an innovative external fault detection algorithm to ensure stability when CTs become saturated.
Application
MiCOM Agile P747 centralised numerical busbar protection has been designed to protect a wide range of busbar configurations:- 3-box mode – one P747 per phase. (The units are totally independent and not linked to each other.
The MiCOM Agile P747 can accommodate up to 4 zones plus check zone. Each box (per phase) can manage:
- 4 VTs (1 VT per zone), up to 18 CTs, 18 breakers and 72 isolators
- Up to 40 digital inputs and 128 virtual inputs
- Up to 32 digital outputs and 128 virtual outputs The MiCOM Agile P747 is associated with each CT location, usually one per incomer/ feeder and one or two for each bus coupler/bus section
The P747 acquires the analogue signals from the associated CT and the binary signals from the auxiliary contacts of the circuit-breakers and isolators.
Key Benefits
- Tripping time is independent of substation topology and number of feeders
- User-friendly software tools for scheme monitoring
- Built-in CT saturation proof breaker failure protection
- Harsh environment protection extends the life of the product
- No internal batteries in GE Vernova-branded models – removes a maintenance item and eases air-freight logistics
- Advanced binary inputs comply with the harshest norms for surge withstand, plus the ESI 48-4 EB2 standard. Spurious wiring pickup is eliminated without the use of interposing relays, external resistors or time delays. Battery/wiring faults, switching noise, and induction from long parallel circuits are tolerated without mis-operation
Protection & Control
The primary protection element of the P747 is the phasesegregated biased current differential protection. The techniqueis based on the numerical application of Kirchoff's Law for theselective detection and high-speed isolation of a faulty section ofthe busbar. To ensure the adaptability of the relay to any type ofbusbar configuration, the P747 is built with a universal topologyprocessing algorithm. This algorithm determines the optimaltripping zone based on the current status of the plant isolatorsor/and circuit-breakers.
